Brine valorisation system and method for brine mining and mineral recovery

Abstract

The present invention relates to a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream, the brine valorisation system comprising: I. (a) an ultra-high pressure reverse osmosis (UHPRO) system (402) for processing the MVB stream (104a) into a UHPRO retentate and desalinated water; (b) either (I) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate; and (c) a crystallizer system (406) for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and / or II. two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant. Also provided is a system for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution using the brine valorisation system of the invention; as well as methods for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream.

Description

Brine Valorisation System and Method for Brine Mining and Mineral RecoveryTECHNICAL FIELD

[0001] The present disclosure is directed to a brine valorisation system and method for brine mining and mineral recovery. In particular, a system and method for recovering mineral salts, metals and desalinated water from brine generated by seawater desalination plants or other high-salinity solutions.BACKGROUND

[0002] Brine generated from desalination plants and industrial production processes, such as produced water from oil industries, is a concentrated liquid with a higher salinity than seawater. Presently, it is common practice to discharge the brine into natural aquatic or terrestrial habitats, which has a negative impact on their ecosystems and natural environments.

[0003] An environmentally sustainable technology to address this challenge is being actively developed by the water industry with the production of zero liquid discharge (ZLD) technologies. In a ZLD system, mineral salts from the brine are removed in the form of solid crystals and potable water is produced. Such ZLD technologies therefore seek to eliminate the discharge of brine into the aquatic and terrestrial environments.

[0004] Existing ZLD technologies are however highly energy intensive which can mitigate the benefits of the general technology. Furthermore, implementation of such technology has primarily been in small-scale developments, which have resulted from academic research or small-scale technology-based companies with single-unit processes.

[0005] More importantly, existing ZLD technologies are designed to recover a few mineral salts, but they still produce solid waste, which requires disposal. More specifically, existing ZLD technologies produce mixed salt products that have limited or no commercial value. Therefore, in most existing plants that comprise a ZLD system, the crystallized salts are disposed of as solids waste in landfills with relatively high associated costs.

[0006] Presently, there is only one known implementation of a full-scale ZLD-like plant, described in US10947143. This document describes the use of nanofiltration to separate brine into a monovalent and a divalent stream and methods to further concentrate the two brine streams. However, methods for reclaiming mineral salts and elemental metals from the brine streams are not described and therefore this system still suffers from the waste issues described above and many valuable constituents of seawater are not recovered.

[0007] ZLD-like plants, as described for example in the publication mentioned above, currently recover a limited number of mineral salts but they still cannot reclaim many of the other potentially valuable constituents of seawater. As a result, these ZLD-like plants typically generate mixtures of mineral salts that are considered to be waste products which need to be disposed of. Moreover, methods for recovery of individual mineral salts and metals for the production of commercially viable goods are not described for existing ZLD technologies.

[0008] The present disclosure seeks to address at least some of these concerns.SUMMARY OF THE DISCLOSURE

[0009] The present disclosure is directed to a brine valorisation system for recovering at least one mineral salt and / or at least one metai from a monovalent brine (MVB) stream and / or a polyvalent brine stream (PVB) stream. The brine valorisation system may be a ZLD system. Alternatively, it may be possible to combine the brine valorisation system of the disclosure with known systems to form a ZLD system. Typically, a brine valorisation system is considered a ZLD system when “zero liquid discharge” is achieved, such that all products produced have a commercial value and no waste products are produced. The present disclosure is also directed to a system for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution using a brine valorisation system of the disclosure. Further, the present disclosure is directed to a method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream. Additionally, the present disclosure is directed to a method for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution using a brine valorisation system of the disclosure.

[0010] The present disclosure seeks to reclaim mineral salts and metals that are commercially viable from brine produced at desalination plants, using an innovative brine valorisation system (e.g, a zero liquid discharge (ZLD) system). Instead of brine from desalination plants, other high-salinity sources may be used as input, such as produced water (i.e. high-salinity waste water) from the oil industry or geothermal industry (in particular from oil wells), brackish water, high-salinity water from lakes and seas, high-salinity groundwater, mineral water from springs and wells, as well as other natural or human-made high-salinity streams with a total dissolved solid (TDS) / salinity concentration of about 1 ,000 mg / L or more, for example about 2,000 mg / L or more. Typically, suitable high-salinity solutions have a salinity of up to about 300,000 mg / L. Typically, suitable high-salinity solutions have a salinity of from about 1 ,000 mg / L to about 300,000 mg / L. Naturally, it will be understood that the different sources of high-salinity solutions may have different salinities. For example, typically seawater has a salinity in the range of from about 35,000 mg / L to about 44,000 mg / L. Typically, produced water has a salinity in the range of from about 100,000 mg / L to about 300,000 mg / L. Typically, brackish water has a salinity in the range of from about 1 ,000 mg / L to about 4,000 mg / L. It should be understood that where seawater is referenced throughout the disclosure, other high-salinity solutions may be used instead of, or as well as, seawater. The mineral salts and / or metals recovered from the brine can thenbe sold to create a long-term (25 to 30 years) stream of steady revenue that will cover the initial investment into the system within 5 years. This revenue can also be used to defray the cost of production of desalinated water, thereby making the desalination of saline sources both environmentally safe and fiscally sustainable. The system disclosed herein, therefore creates a path for desalination to become the lowest cost method for production of drinking water.

[0011] The present brine valorisation system of an embodiment of the disclosure has embedded synergistic multistage brine mining technologies. Applying the disclosed techniques of the present embodiments to seawater or other high-salinity solutions, for example, produces various commercial grade mineral salts, including sodium chloride, potassium chloride, lithium chloride, rubidium chloride, calcium salts and magnesium salts, as well as elemental metals, such as lithium and magnesium, and desalinated water.

[0012] As mentioned above, existing ZLD-like systems comprise processing elements that cannot recover mineral salts from seawater and as such they generate mixtures of mineral salts from brine, where such mixtures have no commercial value and are therefore considered waste products. These have associated high disposal costs and so, in the long run, existing systems are not environmentally and fiscally sustainable.

[0013] In contrast to existing ZLD systems, the embodiments of the present disclosure comprise multistage processes that have been specifically selected, designed, and sequentially positioned to allow a plurality of different mineral salts and / or metals to be recovered from brine and converted into commercially viable high purity mineral and metal products. Brine valorisation systems and ZLD systems of the present disclosure may therefore be considered to produce industrial grade mineral salts and / or metals of sufficient purity to be sold directly to industry. These products are suitable for use in many industries, including the production of chemicals, food, fertilizers, pharmaceuticals, health supplements, as well as in the oil industry. Different industries require metals and / or mineral salts of different purities. Typically, the food industry requires metals and / or mineral salts with a purity of 96% or greater. Typically, the chemical industry requires metals and / or mineral salts with a purity of 99.6% or greater. Typically, the pharmaceutical industry requires metals and / or mineral salts with a purity of 99.9% or greater. Specific companies within each industry may additionally require the metals and / or mineral salts to have specific impurities and / or to not have specific impurities. The systems and methods of the present disclosure produce mineral salts and / or metals of suitable purity and with suitable impurities for sale without further processing of the products. Additionally, the water recovered from the present system is of low salinity and of sufficiently high quality such that it can be used for both industrial and municipal purposes, such as drinking water, irrigation, cooling water, etc.

[0014] An advantage of the brine valorisation system disclosed herein is that it provides a means to achieve ZLD whilst simultaneously valorising the mineral salts and metals contained in brine, rather than discharging the brine back into the sea. The modular nature of the brine valorisation system of the present embodiments integrates a carefully selected sequence of interrelated cutting-edgemembranes and / or thermal separation units, with concentration and crystallization technologies from multiple sources. Therefore, in some embodiments, the various sub-systems of the brine valorisation system of the disclosure may form a ZLD system (i.e. the brine valorisation system may be a ZLD system). As discussed above, a brine valorisation system is typically considered a ZLD system when all elements of the input are processed to produce commercial outputs, such that no waste products are produced. As such, the brine valorisation system of the disclosure may be considered a ZLD system when the brine valorisation system comprises a system for processing a monovalent brine stream and a polyvalent brine stream. In other embodiments, it may be possible to combine the brine valorisation system of the disclosure, with other known systems to form a ZLD system. Besides environmental and fiscal sustainability, the innovative brine valorisation system of the present embodiments is industrially applicable as it utilises low-cost and low-energy processing to reclaim a plurality of different valuable mineral salts and / or metals from seawater without generating liquid discharges.

[0015] The present disclosure provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream, the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system for processing the MVB stream into a UHPRO retentate and desalinated water;(b) either (i) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate; and(c) a crystallizer system for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and / orII. two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

[0016] In some embodiments, the present disclosure provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and a polyvalent brine (PVB) stream, the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system for processing the MVB stream into a UHPRO retentate and desalinated water;(b) either (i) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate; and(c) a crystallizer system for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; andII. two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

[0017] In some embodiments, the brine valorisation system comprises an OARO system comprising one or more OARO stage for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate. In some such embodiments, the OARO system comprises two or more OARO stages, and wherein each OARO stage further concentrates the UHPRO retentate.

[0018] Each OARO stage within the OARO system may comprise a membrane that maintains a salinity gradient between the two sides of the membrane, such that there is an osmotic draw pressure of from about 140 bars to about 155 bars.

[0019] Each OARO stage within the OARO system may comprise a membrane with a pore size of from about 0.001 micrometres to about 0.01 micrometres.

[0020] In some embodiments, the crystallizer system comprises a thermal crystallizer or a membrane crystallizer for processing the concentrated UHPRO retentate into distilled water, sodium chloride crystals, a sodium chloride brine solution, and a monovalent purge stream.

[0021] In some embodiments, the brine valorisation system further comprises a monovalent minerals and metals recovery (monovalent MMR) system for processing the monovalent purge stream output from the crystallizer system to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride.

[0022] In some embodiments where the brine valorisation system comprises a monovalent MMR system, the monovalent MMR system comprises one or more of:I. a forward osmosis driven membrane crystallizer for extracting potassium chloride;II. an electrodialysis unit for extracting lithium metal and lithium chloride; and ill. an ion exchange system for extracting rubidium chloride.

[0023] In some embodiments, the monovalent MMR system comprises a forward osmosis driven membrane crystallizer for processing the monovalent purge stream to produce potassium chloride and a first permeate.

[0024] The monovalent MMR system may further comprise an electrodialysis unit for processing the first permeate output from the forward osmosis driven membrane crystallizer into lithium metal, lithium chloride and an electrodialysis purge containing the remaining monovalent metals and mineral salts.

[0025] The monovalent MMR system may further comprise an ion exchange system for processing the electrodialysis purge output from the electrodialysis unit to produce rubidium chloride.

[0026] In some embodiments, the two or more mineral clarifiers comprise a first clarifier comprising a calcium clarifier for processing the PVB stream to produce a calcium rich sludge and a low calcium supernatant, and a second clarifier comprising a magnesium clarifier for processing the low calcium supernatant to produce a magnesium rich sludge and a low magnesium supernatant.

[0027] In other embodiments, the two or more mineral clarifiers comprise a first clarifier comprising a magnesium clarifier for processing the PVB stream to produce a magnesium rich sludge and a low magnesium supernatant, and a second clarifier comprising a calcium clarifier for processing the low magnesium supernatant to produce a calcium rich sludge and a low calcium supernatant.

[0028] The brine valorisation system may comprise a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant. The filtration system may be an ultrafiltration system.

[0029] The brine valorisation system may further comprise a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride. In some embodiments, the crystallizer is a membrane crystallizer.

[0030] In some embodiments, the brine valorisation system further comprises an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant.

[0031] In some embodiments, the brine valorisation system further comprises a polyvalent minerals and metals recovery (polyvalent MMR) system for processing:I. the magnesium rich sludge output from the magnesium clarifier; and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0032] In embodiments where the brine valorisation system comprises a polyvalent MMR system, the polyvalent MMR system may comprise one or more of:I. one or more crystallizer for processing the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system to extract one or more of magnesium hydroxide, calcium carbonate, sodium sulphate, calcium sulphate, magnesium sulphate, calcium chloride, magnesium chloride and / or sodium carbonate; andII. a magnesium metal production system for processing the magnesium rich sludge output from the magnesium clarifier to produce magnesium metal.

[0033] The one or more crystallizer in the brine valorisation system, may be a forward osmosis driven membrane crystallizer or a thermal crystallizer. In some embodiments, the one or more crystallizer is a forward osmosis driven membrane crystallizer.

[0034] The present disclosure also provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream, the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system for processing the MVB stream into a UHPRO retentate and desalinated water;(b) either (i) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate;(c) a crystallizer system for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) a monovalent minerals and metals recovery (monovalent MMR) system for processing the monovalent purge stream output from the crystallizer system to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride; and / orII. (a) two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant;(b) a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(I) a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride; and / or(ii) an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and a polyvalent minerals and metals recovery (polyvalent MMR) system for processing:III. the magnesium rich sludge output from the magnesium clarifier; and / orIV. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0035] The present disclosure further provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and a polyvalent brine (PVB) stream, the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system for processing the MVB stream into a UHPRO retentate and desalinated water;(b) either (I) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate;(c) a crystallizer system for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) a monovalent minerals and metals recovery (monovalent MMR) system for processing the monovalent purge stream output from the crystallizer system to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride; andII. (a) two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant;(b) a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove finesolids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(i) a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride; and / or(ii) an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and a polyvalent minerals and metals recovery (polyvalent MMR) system for processing:I. the magnesium rich sludge output from the magnesium clarifier; and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0036] The present disclosure further provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream, the brine valorisation system comprising:(a) an ultra-high pressure reverse osmosis (UHPRO) system for processing the MVB stream into a UHPRO retentate and desalinated water;(b) either (I) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate;(c) a crystallizer system for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) a monovalent minerals and metals recovery (monovalent MMR) system for processing the monovalent purge stream output from the crystallizer system to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride.

[0037] The present disclosure also provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a polyvalent brine (PVB) stream, the brine valorisation system comprising:(a) two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a lowcalcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant;(b) a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c) a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride.

[0038] The present disclosure further provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a polyvalent brine (PVB) stream, the brine valorisation system comprising:(a) two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant;(b) a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c) an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and a polyvalent minerals and metals recovery (polyvalent MMR) system for processing:I. the magnesium rich sludge output from the magnesium clarifier; and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0039] The present disclosure also provides a brine valorisation system for recovering at least one mineral salt and / or at least one metal from a polyvalent brine (PVB) stream, the brine valorisation system comprising:(a) two or more clarifiers for processing the PVB stream, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant;(b) a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and (c)(i) a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride; and / or(ii) an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and a polyvalent minerals and metals recovery (polyvalent MMR) system (416) for processing:I. the magnesium rich sludge output from the magnesium clarifier (410b); and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[8040] Further provided by the disclosure is a system for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution, the system comprising:(i) a desalination plant configured to separate seawater and / or other high salinity solution into a monovalent brine (MVB) stream and a polyvalent brine (PVB) stream; and(ii) a brine valorisation system according to the disclosure.

[0041] In some embodiments of the system, the desalination plant comprises an intake system for pre-treating the seawater and / or other high salinity solution.

[0042] The intake system may be configured to chemically pre-treat the seawater and / or other high salinity solution (e.g. by electrochlorination or chemical chlorination by adding sodium hypochlorite to the seawater and / or other high salinity solution).

[0043] Alternatively, the intake system may be configured to heat treat the seawater and / or other high salinity solution.

[0044] The desalination plant may further comprise a filtration system to remove fine solids and other contaminants from the seawater and / or other high salinity solution.

[0045] In some embodiments, the filtration system comprises an ultrafiltration (UF) system. The UF system may comprise a UF membrane with a pore size in the range of from about 0.01 micrometresto about 0.1 micrometres. The UF system may be configured to remove at least about 90% of fine soiids and other contaminants having a particle size larger than about 5 micrometres.

[0046] In some embodiments, the desalination plant comprises a separation system for separating the seawater or other high salinity solution into a permeate comprising mainly monovalent ions (the monovalent stream, MVS) and a brine containing mainly polyvalent ions (the polyvalent brine stream, PVB stream).

[0047] The separation system may be a nanofiltration (NF) system comprising one or more NF membranes to filter out polyvalent dissolved salts, organic matter, and other contaminants. The one or more NF membranes may have a pore size of from about 0.0005 micrometres to about 0.002 micrometres.

[0048] In some embodiments, the NF system is configured such that at least about 90% of the ions in the MVS are monovalent ions.

[0049] In some embodiments, the NF system is configured such that at least about 90% of the ions in the PVB stream are polyvalent ions.

[0050] The desalination plant may further comprise a seawater reverse osmosis (SWRO) system for processing the MVS into a low salinity water and a monovalent brine (MVB) stream.

[0051] Also provided by the disclosure is a method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream, the method comprising:I. (a) processing the MVB stream in an ultra-high pressure reverse osmosis (UHPRO) system to produce a UHPRO retentate and desalinated water;(b) concentrating the UHPRO retentate in either (I) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate; and(c) processing the concentrated UHPRO retentate in a crystallizer system to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and / orII. processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

[0052] Further provided by the disclosure, is a method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and a polyvalent brine (PVB) stream, the method comprising:I. (a) processing the MVB stream in an ultra-high pressure reverse osmosis (UHPRO) system to produce a UHPRO retentate and desalinated water;(b) concentrating the UHPRO retentate in either (i) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate; and(c) processing the concentrated UHPRO retentate in a crystallizer system to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; andII. processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

[0053] In some embodiments of the method, concentrating the UHPRO retentate comprises concentrating the UHPRO retentate in an OARO system comprising one or more OARO stage through which the UHPRO retentate is passed to produce a concentrated UHPRO retentate.

[0054] Concentrating the UHPRO retentate in an OARO system may comprise passing the UHPRO retentate through two or more OARO stages, and wherein each OARO stage further concentrates the UHPRO retentate. In some such embodiments, each OARO stage comprises passing the UHPRO retentate through an OARO membrane, and wherein the OARO membrane maintains a salinity gradient between the two sides of the membrane, such that there is an osmotic draw pressure of from about 140 bars to about 155 bars.

[0055] Each OARO stage may comprise passing the UHPRO retentate through an OARO membrane with a pore size of from about 0.001 micrometres to about 0.01 micrometres.

[0056] Processing the concentrated UHPRO retentate may comprise processing the concentrated UHPRO retentate in a crystallizer system comprising a thermal crystallizer or a membrane crystallizer, to produce distilled water, sodium chloride crystals, a sodium chloride brine solution, and a monovalent purge stream.

[0057] The method may further comprise processing the monovalent purge stream in a monovalent minerals and metals recovery (monovalent MMR) system to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride;

[0058] In some embodiments, processing the monovalent purge stream in the monovalent MMR system comprises processing the monovalent purge stream in a forward osmosis driven membrane crystallizer to produce potassium chloride and a first permeate.

[0059] Processing the monovalent purge stream in the monovalent MMR system may further comprise processing the first permeate output from the forward osmosis driven membrane crystallizer in an electrodialysis unit to produce lithium metal, lithium chloride and an electrodialysis purge containing the remaining monovalent metals and mineral salts.

[0060] Processing the monovalent purge stream in the monovalent MMR system may further comprise processing the electrodialysis purge output from the electrodialysis unit in an ion exchange system to produce rubidium chloride.

[0061] In some embodiments of the method, processing the PVB brine stream in two or more mineral clarifiers comprises processing the PVB brine stream in a first clarifier comprising a calcium clarifier to produce a calcium rich sludge and a low calcium supernatant and processing the low calcium supernatant in second clarifier comprising a magnesium clarifier to produce a magnesium rich sludge and a low magnesium supernatant.

[0062] In such embodiments, processing the PVB brine stream in a first clarifier comprising a calcium clarifier may comprise adding sodium carbonate to the PVB stream, and wherein the calcium rich sludge comprises a calcium carbonate rich sludge. Processing the low calcium supernatant in a second clarifier comprising a magnesium clarifier may comprise adding sodium hydroxide or ammonium hydroxide to the low calcium supernatant, and wherein the magnesium rich sludge comprises a magnesium hydroxide rich sludge.

[0063] In alternative embodiments of the method, processing the PVB brine stream in two or more mineral clarifiers comprises processing the PVB brine stream in a first clarifier comprising a magnesium clarifier to produce a magnesium rich sludge and a low magnesium supernatant and processing the low magnesium supernatant in a second clarifier comprising a calcium clarifier to produce a calcium rich sludge and a low calcium supernatant.

[0064] In such embodiments, processing the PVB brine stream in a first clarifier comprising a magnesium clarifier may comprise adding sodium hydroxide or ammonium hydroxide to the PVB stream, and wherein the magnesium rich sludge comprises a magnesium hydroxide rich sludge. Processing the low magnesium supernatant in a second clarifier comprising a calcium clarifier may comprise adding sodium carbonate to the low magnesium supernatant, and wherein the calcium rich sludge comprises a calcium carbonate rich sludge.

[0065] In some embodiments, the calcium carbonate concentration in the calcium carbonate rich sludge is in the range of from about 90 wt.% to about 98 wt.%.

[0066] In some embodiments, the magnesium hydroxide concentration in the magnesium hydroxide rich sludge is in the range of from about 90 wt.% to about 98 wt.%.

[0067] In embodiments where the first clarifier comprises a magnesium clarifier and the second clarifier comprises a calcium clarifier, the magnesium hydroxide concentration in the magnesium hydroxide rich sludge may be in the range of from about 95 wt.% to about 98 wt.%.

[0068] In embodiments where the first clarifier comprises a magnesium clarifier and the second clarifier comprises a calcium clarifier, the calcium carbonate concentration in the calcium carbonate rich sludge may be in the range of from about 95 wt.% to about 98 wt.%.

[0069] In some embodiments, the calcium concentration in the low calcium supernatant is less than about 2000mg / L.

[0070] In some embodiments, the magnesium concentration in the low magnesium supernatant is less than about 2000mg / L.

[0071] In some embodiments, the method further comprises processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant. The filtration system may be an ultrafiltration system.

[0072] The method may further comprise processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride. The crystallizer may be a membrane crystallizer.

[0073] In some embodiments, the method further comprises concentrating at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OARO system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant.

[0074] In some embodiments, the method further comprises processing:I. the magnesium rich sludge output from the magnesium clarifier; and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0075] In some such embodiments, processing (I) the magnesium rich sludge and / or (ii) the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant in the polyvalent MMR system comprises one or more of:I. processing the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system in a crystallizer to extract one or more of magnesium hydroxide, calcium carbonate, sodium sulphate, calcium sulphate, magnesium sulphate, calcium chloride, magnesium chloride and / or sodium carbonate; and / orII. processing the magnesium rich sludge output from the magnesium clarifier in a magnesium metal production system to extract magnesium metal.

[0076] The one or more crystallizer may be a forward osmosis driven membrane crystallizer or a thermal crystallizer. In some embodiments, the one or more crystallizer is a forward osmosis driven membrane crystallizer.

[0077] The diluted draw solution output from the polyvalent MMR system may be used as a draw solution in the crystallizer system or the monovalent MMR system.

[0078] The present disclosure further provides a method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and / or a polyvalent brine (PVB) stream, the method comprising:I. (a) processing the MVB stream in an ultra-high pressure reverse osmosis (UHPRO) system to produce a UHPRO retentate and desalinated water;(b) concentrating the UHPRO retentate in either (i) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate; and(c) processing the concentrated UHPRO retentate in a crystallizer system to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) processing the monovalent purge stream in a monovalent minerals and metals recovery (monovalent MMR) system (408) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride; and / orII. (a) processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.(b) processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solidswith a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(i) processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride; and / or(ii) concentrating at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OARO system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and processing:I. the magnesium rich sludge output from the magnesium clarifier; and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0079] The present disclosure further provides a method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and a polyvalent brine (PVB) stream, the method comprising:I, (a) processing the MVB stream in an ultra-high pressure reverse osmosis (UHPRO) system to produce a UHPRO retentate and desalinated water;(b) concentrating the UHPRO retentate in either (I) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate; and(c) processing the concentrated UHPRO retentate in a crystallizer system to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) processing the monovalent purge stream in a monovalent minerals and metals recovery (monovalent MMR) system (408) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride; andII. (a) processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.(b) processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(i) processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride; and / or(ii) concentrating at ieast a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OARO system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and processing:I. the magnesium rich sludge output from the magnesium clarifier; and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0080] The present disclosure further provides a method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream, the method comprising:(a) processing the MVB stream in an ultra-high pressure reverse osmosis (UHPRO) system to produce a UHPRO retentate and desalinated water;(b) concentrating the UHPRO retentate in either (i) an osmotically assisted reverse osmosis (OARO) system comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate;(c) processing the concentrated UHPRO retentate in a crystallizer system to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) processing the monovalent purge stream in a monovalent minerals and metals recovery (monovalent MMR) system (408) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride;.

[0081] The present disclosure further provides a method for recovering at ieast one mineral salt and / or at least one metal from a polyvalent brine (PVB) stream, the method comprising:(a) processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.(b) processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c) processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride.

[0082] The present disclosure further provides a method for recovering at. least one mineral salt and / or at least one metal from a polyvalent, brine (PVB) stream, the method comprising:(a) processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.(b) processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c) concentrating at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OARO system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and processing:I. the magnesium rich sludge output from the magnesium clarifier; and / or the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0083] The present disclosure further provides a method for recovering at least one mineral salt and / or at least one metal from a polyvalent brine (PVB) stream, the method comprising:(a) processing the PVB brine stream in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier and a magnesium clarifier, and wherein the calcium clarifier produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.(b) processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(i) processing (224) at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride; and / or(ii) concentrating at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OARO system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and processing:the magnesium rich sludge output from the magnesium clarifier (410b); and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system (416) to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

[0084] The disclosure further provides a method for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution, the method comprising:(i) processing the seawater and / or other high salinity solution in a desalination plant to separate the seawater and / or other high salinity solution into a monovalent brine (MVB) stream and a polyvalent brine (PVB) stream; and(ii) processing the MVB stream and / or the PVB stream according to the method of the disclosure to recover at least one mineral salt and / or metal.

[0085] In some embodiments of the method, the other high salinity solution has a total dissolved solid / salinity concentration of 2,000 mg / L or greater.

[0086] In some embodiments, processing the seawater and / or other high salinity solution in a desalination plant may comprise pre-treating the seawater and / or other high salinity solution in an intake system.

[0087] Pre-treating the seawater and / or other high salinity solution in the intake system may comprise chemically pre-treating the seawater and / or other high salinity solution (e.g. by electrochlorination or chemical chlorination by adding sodium hypochlorite to the seawater and / or other high salinity solution).

[0088] Alternatively, pre-treating the seawater and / or other high salinity solution in the intake system may comprise heat treating the seawater and / or other high salinity solution.

[0089] Processing the seawater and / or other high salinity solution in a desalination plant may comprise filtering the seawater and / or other high salinity solution in a filtration system to remove fine solids and other contaminants from the seawater and / or other high salinity solution.

[0090] Filtering the seawater and / or other high salinity solution in the filtration system may comprise filtering the seawater and / or other high salinity solution in an ultrafiltration (UF) system.

[0091] Filtering the seawater and / or other high salinity solution in the ultrafiltration (UF) system may comprise passing the seawater and / or other high salinity solution through a UF membrane with a pore size in the range of from about 0.01 micrometres to about 0.1 micrometres.

[0092] In some embodiments, filtering the seawater and / or other high salinity solution in the filtration system and / or the UF system removes at least about 90% of fine solids and other contaminants having a particle size larger than about 5 micrometres.

[0093] In some embodiments, processing the seawater and / or other high salinity solution in a desalination plant comprises separating the seawater and / or other high salinity solution into a permeate comprising mainly monovalent ions (the monovalent stream, MVS) and a brine containing mainly polyvalent ions (the polyvalent brine stream, PVB stream) in a separation system.

[0094] Separating the seawater and / or other high salinity solution into an MVS and a PVB stream may comprise separating the seawater and / or other high salinity solution into an MVS and a PVB stream in a nanofiltration (NF) system comprising one or more NF membranes to filter out polyvalent dissolved salts, organic matter, and other contaminants.

[0095] In some embodiments, separating the seawater and / or other high salinity solution into the MVS and the PVB stream in the nanofiltration (NF) system comprises passing the seawater and / or other high salinity solution through the one or more NF membranes having a pore size of from about 0.0005 micrometres to about 0.002 micrometres.

[0096] In some embodiments, at least about 90% of the ions in the resultant MVS are monovalent ions.

[0097] In some embodiments, at least about 90% of the ions in the resultant PVB stream are polyvalent ions.

[0098] Processing the seawater and / or other high salinity solution in a desalination plant may further comprise processing the MVS into a low salinity water and a monovalent brine (MVB) stream in a seawater reverse osmosis (SWRO) system.

[0099] In some embodiments, a portion of the concentrated UHPRO retentate output from the OARO system may be passed back to the SWRO system to produce the required osmotic pressure gradient needed to concentrate the MVS into the MVB.

[0100] Also provided herein, is the method of the disclosure for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream and a polyvalent brine stream.

[0101] In embodiments of the system according to the disclosure and / or the method according to the disclosure, the at least one mineral salt and / or at least one metal may have a purity of 90% or greater.

[0102] In embodiments of the system according to the disclosure and / or the method according to the disclosure, the at least one mineral salt and / or at least one metal has a purity of 96% or greater.BRIEF DESCRIPTION OF THE DRAWINGS

[0103] Embodiments of the disclosure will now be described, by way of example, with reference to the accompanying drawings, in which:

[0104] Figure 1 is a block diagram overview of a system according to an embodiment of the present disclosure, showing a desalination plant and a zero liquid discharge system for recovering metals and mineral salts from seawater;

[0105] Figure 2 is a flow diagram of a method of recovering metals and mineral salts from seawater according to an embodiment of the present disclosure;

[0106] Figure 3 is an expanded block diagram showing details of a desalination plant according to an embodiment of the present disclosure;

[0107] Figure 4 is an expanded block diagram showing details of a zero liquid discharge system according to an embodiment of the present disclosure;

[0108] Figure 5 is a schematic overview of an example system of the present disclosure, comprising a desalination plant and zero liquid discharge system as shown in Figure 1.DETAILED DESCRIPTION

[0109] Various exemplary embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the disclosure or as a limitation of the scope of the disclosure. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

[0110] The figures are schematic and simplified for clarity, and they merely show details which aid understanding of the disclosure, while other details have been left out.

[0111] Generally, a system 100 according to the disclosure can be considered schematically as shown in Figure 1. Typically, the system 100 comprises a desalination plant 102 coupled to a brine valorisation system (e.g. a ZLD system) 106. Here a desalination plant 102 produces desalinated water and brine 104a / b from seawater or other high-salinity solutions and conveys the brine 104a / b toa brine valorisation system 106. In the embodiment shown in the figures, the brine valorisation system 106 may be used to process a monovalent brine stream 104a and a polyvalent brine stream 104b. As such, the brine valorisation stream 106 shown in the figures may be considered a ZLD system 106. In other embodiments of the disclosure, the brine valorisation system 106 may comprise only a system for processing a monovalent brine stream 104a or only a system for processing a polyvalent brine stream 104b, in which case the brine valorisation system 106 may be a “ZLD-like” system 106 or simply a brine valorisation system 106. The brine produced by the desalination plant 102 is separated, in the desalination plant 102, into a monovalent brine (MVB) stream 104a comprising mainly monovalent ions and a polyvalent brine (PVB) brine stream 104b comprising mainly polyvalent ions. The ZLD system 106 comprises several filtration systems and crystallizers for processing the MVB stream 104a and PVB stream 104b to produce desalinated water and desired metals and mineral salts. Typically, the MVB stream 104a and the PVB stream 104b are processed substantially separately within the ZLD system 106.

[0112] Figure 2 shows a flow diagram of an exemplary method 200 used in the desalination plant 102 and ZLD system 106 to recover (e.g. reclaim) desalinated water, metals and mineral salts from seawater or other high-salinity solutions. The components of the desalination plant 102 and the ZLD system 106 are shown in greater detail in Figures 3 and 4. The overall desalination plant 102, ZLD system 106 and process 200 is now described with reference to Figures 2, 3 and 4.

[0113] Figure 3 shows the desalination plant 102 in more detail. The desalination plant 102 may comprise an intake system 302, an ultrafiltration (UF) system 304, a nanofiltration (NF) system 306, and a seawater reverse osmosis (SWRO) system 308.

[0114] In an embodiment of the present disclosure, the intake system 302 may collect seawater or another high salinity solution and pre-treat it to remove suspended solids, bacteria and / or other contaminants from the seawater that may cause biofouling of one or more system in the desalination plant 102. The pre-treatment may be chemical pre-treatment and / or heat treatment. Chemical pretreatment may comprise chlorination (e.g. electrochiorination or chemical chlorination by adding sodium hypochlorite). Heat treatment involves heating the seawater to a temperature of at least about 50°C (e.g. heating the seawater to a temperature of from about 50°C to about 90°C).

[0115] Depending on the quality of the seawater, it may be subsequently passed to the ultrafiltration (UF) system 304 which removes fine solids and other contaminants larger than the pore size of the membrane. Typically, processing in the UF system 304 is required if the seawater or other high- salinity solution has a turbidity of about 0.2 or greater, for example about 0.3 or greater and / or the silt density index 5 (SDI5, i.e. the silt density index measured after 5 minutes of fluid flow) is about 3 or greater, for example about 4 or greater. Accordingly, processing in the UF system 304 is typically not required if the seawater or other high-salinity solution has a turbidity of about 0.3 or less, for example about 0.2 or less and / or an SDI5 of about 4 or less, for example about 3 or less. If processing in the UF system 304 is required, the pre-treated seawater is passed from the intake system 302 to the UFsystem 304. If processing in the UF system 304 is not required, the pre-treated seawater is passed directly from the intake system 302 to the nanofiltration (NF) system 306.

[0116] The UF system 304 may be any filtration system capable of removing about 90% or more of the fine solids or other contaminants having a particle size (e.g. minimum diameter) of about 5 micrometres or greater. The seawater or other high-salinity solution is passed through at least one membrane. Typically, in the UF system 304 (when present) the pre-treated seawater or other high- salinity solution is passed through one or more UF membranes with a pore size in the range of from about 0.005 micrometres to about 0.1 micrometres (e.g. from about 0.01 micrometres to about 0.1 micrometres). The processed seawater or other high-salinity solution output by the UF system (304) typically has a turbidity of about 0.3 or less, for example about 0.2 or less and / or an SDI5 of about 4 or less, for example about 3 or less.

[0117] The seawater is subsequently passed to the nanofiltration (NF) system 306 and treated using nanofiltration at Step 202. For seawater of sufficiently high quality (turbidity of less than 0.3 NTU and slit density index 5 of less than 3), the seawater may be passed from the intake system 302 directly to the NF system 306. In some embodiments, the seawater or other high-salinity solution may be passed directly to the NF system 306, without being passed through the intake system 302 or UF system 304. However, it is preferred that the seawater or other high-salinity solution is passed via the intake system 302 and, if required, via the UF system 304.

[0118] The NF system 306 separates the seawater at Step 202 into a permeate containing substantially only monovalent ions (monovalent stream, MVS) and a brine containing substantially only polyvalent ions (polyvalent brine stream, PVB) 104b. Typically, at least about 90% of the ions in the MVS stream (and MVB stream 104a) are monovalent ions, for example at least about 95% of the ions in the MVS stream (and MVB stream 104a) are monovalent ions. Typically, at least about 90% of the ions in the PVB stream 104b are polyvalent ions, for example at least about 95% of the ions in the PVB stream 104b are polyvalent ions. To separate the seawater or other high-salinity solution into an MVS and a PVB stream 104b, the NF system 306 comprises one or more NF membranes to filter out polyvalent dissolved salts, organic matter, and other contaminants larger than the NF membrane pore size. Typically, the one or more NF membranes have a pore size in the range of from about 0.0005 micrometres to about 0.002 micrometres (e.g. about 0.001 pm).

[0119] Advantageously, the NF system 306 according to the present disclosure has a high magnesium rejection rate. At least about 85% or greater of the magnesium ions, for example at least about 90% or greater of the magnesium ions, in the input seawater or other high-salinity solution are collected by the one or more NF membranes and consequently end up in the PVB stream 104b.

[0120] In other embodiments, the separation of the seawater into a MVS and a PVB 104b can be achieved by other methods (and consequently in other separation systems). Suitable alternative separation methods include electrodialysis, ion exchange, and capacitive deionisation. However,nanofiltration is the preferred method for separating the MVS and PVB 104b, because of its high selectivity and relatively low cost.

[0121] The MVS from the NF system 306 is subsequently processed by two stages of reverse osmosis membrane separation. The first stage of treatment at Step 204, included in the desalination plant 102, comprises treatment by a conventional seawater reverse osmosis (SWRO) system 308. The SWRO system 308 produces at Step 204, a permeate comprising low-salinity water (having a salt concentration of less than 1000 mg / L of total dissolved solids (TDS)) and a monovalent brine (MVB) 104a.

[0122] The MVB and PVB streams 104a / b are subsequently conveyed to the ZLD system 106. As shown in Figure 3 and Figure 4, the MVB stream 104a and PVB stream 104b are passed to the ZLD system separately and are processed substantially separately in the ZLD system 106.

[0123] The separation of the seawater into monovalent and polyvalent streams is important to reclaiming the mineral salts and metals contained in the seawater with sufficiently high quality to be commercially viable. This is because in other ZLD-like systems, the monovalent stream often contains impurities of polyvalent ions, such as calcium and magnesium. Similarly, monovalent ions contained in a polyvalent stream are usually considered impurities. For example, many commercial products recovered from a polyvalent stream contain sodium, which is considered an impurity and decreases their commercial grade.

[0124] Figure 4 shows a block diagram of a zero-liquid discharge (ZLD) system according to an embodiment of the disclosure in more detail. Specifically, how the ZLD system 106 is connected to the desalination plant 102 described above, and how the monovalent and polyvalent brine streams 104a / b are processed to recover industrial grade metals / mineral salts and desalinated water. As described herein, the brine valorisation system may comprise a system for processing the MVB stream 104a and / or the PVB stream 104b. In some embodiments, the brine valorisation system may be a ZLD system and may comprise a system for processing the MVB stream 104a and the PVB stream 104b (e.g. as shown in Figure 4).

[0125] The ZLD system 106 may comprise an ultra-high pressure reverse osmosis (UHPRO) system 402, an osmotically assisted reverse osmosis (OARO) system 404, two or more mineral clarifiers 410a / b, crystallizers (systems) 406, 414, an ultrafiltration system 412, a monovalent minerals and metals recovery (MMR) system 408 and a polyvalent minerals and metals recovery (MMR) system 416.

[0126] In this embodiment, the MVB 104a from the SWRO system 308 of the desalination plant 102) is conveyed to the UHPRO system 402, which is the second stage of reverse osmosis membrane separation. The UHPRO system 402 concentrates at Step 206 the MVB stream 104a to produce a UHPRO retentate and desalinated water. Typically, the salt concentration in the UHPRO retentate is inthe range of from about 100,000 mg / L to about 140,000 mg / L, for example from about 110,000 mg / L to about 130,000 mg / L.

[0127] In an embodiment of the present disclosure, the UHPRO-treated MVB (UHPRO retentate) may be passed to the osmotically assisted reverse osmosis (OARO) system 404, where it is further concentrated at Step 208 to produce a concentrated UHPRO retentate. Alternatively, the UHPRO- treated MVB may be concentrated in a thermal evaporation unit to the same concentration as in the OARO system 404. However, the OARO system 404 is preferred due to its lower energy consumption as compared to thermal evaporation and therefore lower operational cost.

[0128] Where present, the OARO system 404 comprises one or more OARO stage for concentrating the UHPRO retentate. In some embodiments, the OARO system 404 comprises two or more OARO stages wherein each OARO stage further concentrates the UHPRO retentate. Each OARO stage within the OARO system 404 includes a special type of OARO membrane that maintains a salinity gradient between the two sides of the membrane i.e. the permeate (desalinated water) side and the retentate (brine) side. In addition, this special type of OARO membrane allows additional osmotic draw pressure of 70 to 72 bars to be applied to the standard osmotic pressure of 70 to 83 bars, such that there is a total osmotic draw pressure of from about 140 bars to about 155 bars. To achieve the desired osmotic pressure across the membrane, the permeate from a later OARO stage may be fed back to an earlier OARO stage (e.g. the permeate from a second OARO stage may be fed back to the first OARO stage). Typically, a first OARO membrane (i.e. the OARO membrane of a first OARO stage) has a pore size of from about 0.001 micrometres to about 0.01 micrometres. In embodiments wherein the OARO system 404 comprises two or more OARO stages, each successive OARO stage may comprise an OARO membrane having the same pore size or an increase in pore size. In some embodiments, each successive OARO stage may comprise an OARO membrane having the same pore size (e.g. a pore size of from about 0.001 micrometres to about 0.01 micrometres).

[0129] In some embodiments, the concentrated UHPRO retentate output from the OARO system404 has a concentration of from about 18,000 mg / L to about 30,000 mg / L of TDS (total dissolved solids). In some embodiments, the concentrated UHPRO retentate output from the OARO system 404 has a concentration of about 220 to about 230 ppt (parts per trillion).

[0130] At least a portion of the high-concentration MVB (concentrated UHPRO retentate) output from the OARO system 404 is directed to the crystallizer system 406 where the high-concentration MVB (concentrated UHPRO retentate) output is crystallized at Step 210. In some embodiments, a portion of the concentrated UHPRO retentate may be passed back to the SWRO system 308 in the desalination plant 102 to produce the required osmotic pressure gradient needed to concentrate the MVS into the MVB 104a. The crystallizer system 406 may comprise a thermal crystallizer 406a or a membrane crystallizer 406b. The thermal crystallizer 406a or membrane crystallizer 406b may be a conventional thermal or membrane crystallizer. Where present, the thermal crystallizer 406a may be configured to comprise at least three evaporators, operating on the basis of fractionation evaporation, where each evaporator heats the concentrated UHPRO retentate to a different temperature. Thevapours produced may be processed in a subsequent evaporator, or collated into a monovalent purge stream.

[0131] Typically, the concentrated UHPRO retentate is passed to a crystallizer (e.g. a thermal crystallizer 406a or a membrane crystallizer 406b) within the crystallizer system 406 to produce distilled water, sodium chloride crystals, a sodium-chloride brine solution and a purge (monovalent purge stream) that contains most of the other mineral salts / metals contained in the high-concentration MVB. In some embodiments, the monovalent purge stream may comprise KCI, RbGI and / or LiCI.

[0132] In some embodiments, the distilled water from the crystallizer system 406 is subsequently mixed with the recovered NaCI to be used as a draw solution in the monovalent minerals and metals recovery (MMR) system 408 described below.

[0133] In some embodiments, the distilled water from the crystallizer 406 is mixed with the permeate from the SWRO system 308 of the desalination plant 102 to be used as drinking water or fed back to the intake system 302 of the desalination plant 102, thereby achieving ZLD of the monovalent brine stream 104a.

[0134] The monovalent purge stream from the crystallizer system 406 contains valuable rare metals and mineral salts such as lithium, rubidium, potassium, and others. These metals / mineral salts may be reclaimed in an industrial usable form by further processing the purge stream in the monovalent MMR system 408. In other embodiments, the monovalent purge stream may be disposed of in an evaporation pond.

[0135] In an embodiment comprising a monovalent MMR system 408, potassium chloride may be obtained at Step 212 by use of a forward osmosis driven membrane crystallizer 408a. Lithium metal and lithium chloride may be obtained, at Step 214, by use of an electrodialysis unit 408b. Rubidium chloride may be obtained by use of an ion exchange system 408c at Step 216. In a preferred embodiment, these processes are carried out in series to increase the amount of metals and mineral salts recovered from the same purge stream in the monovalent MMR system 408, as shown in Figure 2. It is noted that the monovalent MMR system 408 is optional and may be used when it is desirable (e.g. cost effective) to obtain rarer metals and / or mineral salts not already recovered by earlier stages in the system.

[0136] The ZLD system 106 may also comprise two or more mineral clarifiers 410a / b, an ultrafiltration system 412, an additional crystallizer 414, and a polyvalent minerals and metals recovery (MMR) system 416, as mentioned above, for processing the PVB stream 104b.

[0137] The polyvalent brine (PVB) stream 104b from the nanofiltration (NF) system 306 in the desalination plant 102 is conveyed to the two or more mineral clarifiers 410a / b. The mineral clarifiers 410a / b process, at Steps 218 and 220, the PVB stream 104b such that each clarifier separates the desired mineral salts (which settle as a mineral sludge) from a supernatant. The supernatants may befurther processed, as described below. The mineral sludges are rich in desired minerals and may be sold as extracted from the clarifiers (with or without minor processing of the mineral sludges).Alternatively, one or both mineral sludges may subsequently be sent for further processing in the polyvalent MMR system 416, for the recovery of further commercially viable polyvalent mineral salts and elemental metals.

[0138] In some embodiments, the two or more mineral clarifiers 410a / b may comprise a calcium clarifier 410a and a magnesium clarifier 410b. The order of the calcium clarifier 410a and magnesium clarifier 410b and / or the compounds added within each clarifier, may affect the products, and purities of the products, produced by the mineral clarifiers 410a / b. In preferred embodiments, the first clarifier comprises a magnesium clarifier 410b and the second clarifier comprises a calcium clarifier 410a.

[0139] For example, in the embodiment shown in Figure 2, the PVB stream 104b is first processed, at Step 218, in the calcium clarifier 410a (the first clarifier) by adding sodium carbonate to produce a low calcium supernatant and a calcium rich sludge (in this case a calcium carbonate rich sludge). Typically, the concentration of calcium carbonate in the calcium carbonate sludge is in the range of from about 90 wt.% to about 98 wt.%, for example from about 90 wt.% to about 95 wt.%. The concentration of calcium in the low calcium supernatant is typically less than 2000 mg / L and preferably less than 1000 mg / L. The low calcium supernatant is then processed, at Step 220, in the magnesium clarifier 410b (the second clarifier) by adding sodium hydroxide or ammonium hydroxide to produce a low magnesium supernatant and a magnesium rich sludge (in this case a magnesium hydroxide rich sludge). Typically, the concentration of magnesium hydroxide in the magnesium hydroxide sludge is in the range of from about 90 wt.% to about 98 wt.%, for example from about 90 wt.% to about 95 wt.%. The concentration of magnesium in the low magnesium supernatant is typically less than 2000 mg / L and preferably less than 1000 mg / L.

[0140] In an alternative embodiment (not shown), the PVB stream 104b is first processed in the magnesium clarifier 41 Ob (the first clarifier) by adding sodium hydroxide or ammonium hydroxide to produce a low magnesium supernatant and a magnesium rich sludge (in this case a magnesium hydroxide rich sludge). Typically, the concentration of magnesium hydroxide in the magnesium hydroxide sludge is in the range of from about 90 wt.% to about 98 wt.%, for example from about 95 wt.% to about 98 wt.%. The concentration of magnesium in the low magnesium supernatant is typically less than 2000 mg / L and preferably less than 1000 mg / L. The low magnesium supernatant is then processed in the calcium clarifier 410a (the second clarifier) by adding sodium carbonate to produce a low calcium supernatant and a calcium rich sludge (in this case a calcium carbonate rich sludge). Typically, the concentration of calcium carbonate in the calcium carbonate sludge is in the range of from about 90 wt.% to about 98 wt.%, for example from about 95 wt.% to about 98 wt.%. The concentration of calcium in the low calcium supernatant is typically less than 2000 mg / L and preferably less than 1000 mg / L.

[0141] For the avoidance of doubt, it is noted that the supernatant output from the second clarifier will be low in magnesium and calcium, regardless of whether the second clarifier comprises amagnesium clarifier 104b or a calcium clarifier 104a, However, for convenience in referring to the outputs of the clarifiers, the supernatant output from the second clarifier has been named according to whether the second clarifier comprises a magnesium clarifier 104b or a calcium clarifier 104a.Therefore, in embodiments where the first clarifier comprises a calcium clarifier 104a, and the second clarifier comprises a magnesium clarifier 104b, the supernatant output from the second clarifier is referred to as a low magnesium supernatant, despite being low in magnesium and low in calcium. Similarly, in embodiments where the first clarifier comprises a magnesium clarifier 104b, and the second clarifier comprises a calcium clarifier 104a, the supernatant output from the second clarifier is referred to as a low calcium supernatant, despite being low in calcium and low in magnesium.

[0142] Regardless of the order of the clarifiers 41 Oa / b, the calcium rich sludge and / or the magnesium rich sludge may be sold as they are extracted from the clarifiers. Alternatively, the calcium rich sludge and / or the magnesium rich sludge may undergo further minor processing (e.g. washed and dried) prior to being sold, in some embodiments, the magnesium rich sludge may be further processed in the polyvalent MMR system 416 to produce magnesium metal.

[0143] The supernatant (e.g. the low magnesium supernatant or the low calcium supernatant) from the second mineral clarifier 41 Oa / b, may be sent to an ultrafiltration (UF) system 412 or a conventional filtration system to remove, at Step 222, any fine solids with a size larger than 5pm, to produce a filtered supernatant (e.g. a filtered low magnesium supernatant or a filtered low calcium supernatant). At least a portion of the filtered supernatant may be subsequently conveyed to a membrane crystallizer 414 for the recovery, at Step 224, of potassium chloride (KCI). In some embodiments, at least a portion of the filtered supernatant may be concentrated by an OARO system (not shown), such as the one described above for concentrating the UHPRO-treated MVB, to produce a concentrated filtered supernatant (e.g. a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant) and then conveyed to the polyvalent MMR system 416.

[0144] As noted above, at least a portion of the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant may be conveyed to the polyvalent MMR system 416 and processed by one or more forward osmosis driven membrane crystallizer 416a and / or one or more thermal crystallizer to recover industrial grade crystals of one or more mineral salts including magnesium hydroxide (Mg(OH)2), magnesium oxide (MgO), calcium carbonate (CaCO3), sodium sulphate (Na2SO4), sodium sulphite (Na2SO3), calcium sulphate (CaSO4), magnesium sulphate (MgSO4), calcium chloride (e.g. CaCl2and / or Ca2Cl3), magnesium chloride (MgCb) and / or sodium carbonate (Na2CO3). In some embodiments, the polyvalent MMR system 416 produces crystals of magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), sodium sulphate (Na2SO4), calcium sulphate (CaSO4), magnesium sulphate (MgSO4), calcium chloride (Ca2Cl3), magnesium chloride (MgCia) and / or sodium carbonate (Na2CO3). It will be understood that in embodiments where more than one different mineral salt is produced by the polyvalent MMR system 416, the polyvalent MMR system 416 will comprise more than one crystallizer (e.g. more than one forward osmosis driven membrane crystallizer 416a and / or thermal crystallizer), since each different mineral salt will beproduced by a different crystallizer. The one or more forward osmosis driven membrane crystallizer 416a may use a sodium chloride draw solution produced using sodium chloride from the MVB 104a, that has a salinity between 200,000 and 300,000 mg / L of TDS, to produce the calcium and magnesium mineral salts mentioned above. The one or more forward osmosis driven membrane crystallizer 416a draws out water from the concentrated filtered supernatant and crystallizes the one or more mineral salts (listed above) on the membrane’s surface. These crystals can then be collected for commercial purposes. This process may additionally produce a diluted draw solution (e.g. a diluted draw solution containing MgCb), comprising the water drawn out from the concentrated filtered supernatant. This diluted draw solution may be used in the crystallizer system 406 or monovalent MMR system 408 for processing the MVB stream 104a discussed above.

[0145] As mentioned above the magnesium rich sludge may be further processed in the polyvalent MMR system 416. As shown in Figure 2, magnesium hydroxide sludge recovered from the magnesium clarifier 410b is processed, at Step 226, by a conventional magnesium metal production system 416b to produce magnesium metal.Example embodiment of ZLD system

[0146] A non-limiting example of the system described in the present disclosure is shown in Figure 5. Specifically, Figure 5 shows the multiple stages of filtration and crystallization used for reclaiming commercially viable metals and mineral salts, as well as desalinated water, from seawater. Optional bypasses and processing stages are shown in dashed lines.

[0147] The intake system 302 includes a plurality of intake chambers and seawater tanks, as well as a chemical storage and feed system for sodium metabisulfite (SMBS). The intake chambers collect seawater and convey it to a seawater tank that is connected to the chemical storage and feed system. In the first seawater tank, sodium hypochlorite is added to the seawater to prevent damage of the chlorine-sensitive membranes of the desalination plant 102 and ZLD system 106. The seawater is subsequently distributed between at least three seawater tanks where it is heated to a maximum of 45°C. The chemically treated seawater is then processed in the ultrafiltration system 304, which includes an UF membrane and a feed tank. The UF system 304 removes suspended solids, bacteria, and other contaminants larger than the pore size of the membrane. In alternative embodiments, the UF system 304 may be any filtration system capable of removing over 90% of fine solids that have particle sizes larger than 5 pm. The UF system 304 pretreats the seawater to achieve turbidity of higher than 0.3 NTU and silt density index 5 (SDI5) of less than 4.

[0148] The pre-treated seawater then enters the nanofiltration (NF) system 306 in order to separate the monovalent and polyvalent mineral salts into two streams. The NF system 306 includes high- magnesium rejection NF membranes that reject 85% or more of magnesium and less than 15% of monovalent mineral / metai ions from the seawater. The NF system 306 thereby separates the seawater into a monovalent stream (MVS) and a polyvalent brine (PVB) stream 104b, by filtering outpolyvalent dissolved salts, organic matter, and other contaminants larger than the NF membrane pore size of 0.001 pm.

[0149] The MVS from the NF system 306 contains 90% to 99% of the monovalent mineral and metal ions of the seawater and is subsequently processed by the two stages of reverse osmosis membrane separation described above. The first stage comprises the SWRO system 308 that includes SWRO membranes and a permeate holding tank, which also acts as a feed tank to the SWRO membranes. The SWRO membranes produce low-salinity water (less than 1000 mg / L of TDS) and a monovalent brine (MVB) stream 104a. The low-salinity water is directed to a ‘Permeate Storage Tank’, where it is stored for various purposes including for use as drinking water and may be ultimately recycled for return to the desalination plant’s intake system 302. The MVB stream 104a is then either conveyed directly to the ultra-high pressure reverse osmosis (UHPRO) system 402 or may be stored in a Monovalent Brine Storage Tank that also feeds the UHPRO system 402.

[0150] The UHPRO system 402 serves two functions:(i) to produce more desalinated water; and(ii) to further concentrate the MVB 104a from 70,000-75,000 mg / L of TDS to 110,000- 130,000 mg / L of TDS.

[0151] The UHPRO-treated MVB is then passed to the OARO system 404, which comprises one to three, or more, OARO stages to further concentrate the UHPRO-treated MVB to a concentration of 18,000 to 30,000 mg / L of TDS. Each stage of the OARO system 404 inciudes a special type of OARO membrane that maintains a saiinity gradient between the two sides of the membrane i.e. the permeate (desalinated water) side and the brine side. In addition to the membrane feed pressure, the OARO membranes also allow an additional osmotic draw pressure of 70 to 72 bars to be applied. The brine concentration after the first OARO stage is 180 parts per trillion (ppt).

[0152] Depending on the desired levels of desalinated water recovery and brine concentration, the MVB from the first OARO stage may be subsequently passed through two more OARO stages. Each additional OARO stage may include a different type of OARO membrane, where each OARO membrane has a different pore size for optimized brine concentration. For example, the first stage membrane can have a pore size of 0.001 pm and a subsequent stage membrane a pore size of 0.002pm. In other embodiments, each OARO stage includes the same OARO membrane, with the same pore size. In order to achieve the target concentration of around 220 to 230 ppt, the type of OARO membrane, and therefore the pore size of the membrane, can be varied.

[0153] The concentrated brine from the OARO system 404 is stored in a ‘Concentrated Brine Storage Tank’. This tank is designed to store the brine at a high concentration that has a total dissolved solids value of 225 ppt or more.

[0154] The concentrated permeate from the first OARO stage may be passed back to the SWRO system 308 to create the osmotic pressure gradient needed for brine concentration. For the same reason, the permeate from the second OARO stage may be fed back to the first OARO stage and similarly the permeate from the third OARO stage may be fed back to the second OARO stage.

[0155] The concentrated MVB stored in the ‘Concentrated Brine Storage Tank’ is directed to a crystallizer system 406 that comprises a membrane crystallizer 406b or a thermal crystallizer 406a (whilst both are shown in Figure 4, only one would be used in practice). As described above, the thermal crystallizer may be configured to comprise at least three evaporators, which operate on the basis of fractionation evaporation (i.e. fractional evaporation) where each evaporator heats the concentrated MVB to a different temperature. The vapours may either be processed in another evaporator or directed to the monovalent MMR system 408.

[0156] The concentrated MVB is processed in the thermal crystallizer 406a or membrane crystallizer 406b, which isolates sodium chloride in the brine solution in order to be crystallized and recovered for commercial purposes. The other mineral salts are evaporated and comprise a purge stream that is further processed as described below.

[0157] The thermal crystallizer 406a or membrane crystallizer 406b further separates a condensate (distilled water) from the NaCI brine, thereby increasing the concentration of the brine and causing the dissolved NaCi to crystallize out of the solution. The NaCi crystals are collected to be used for commercial purposes or used as part of the draw solution in the monovalent MMR system 408. The recovered sodium chloride is in the form of fine crystals with edge lengths in the range of from about 2 to about 5 mm and a salt purity in the range of from about 99.0% to about 99.8%, suitable from about 99.6% to about 99.8%.

[0158] The distilled water from the thermal crystallizer 406a or membrane crystallizer 406b may be mixed with the iow-saiinity water from the SWRO system 308 to be used as drinking water, mixed with the recovered NaCi to be used as a draw solution in the monovalent MMR system 408, or fed back to the intake system 302. Using the distilled water for any of these purposes achieves ZLD of the monovalent stream.

[0159] The purge stream produced by the thermal crystallizer 406a or membrane crystallizer 406b, contains most of the impurities from the concentrated brine fed into the crystallizer system 406. These impurities contain valuable rare metals and mineral salts such as lithium, rubidium, potassium, that may be recovered as described below.

[0160] The purge stream is directed to a purge tank, which feeds the monovalent MMR system 408 that comprises various technologies to reclaim valuable mineral salts and metals, such as lithium metal, potassium chloride and rubidium chloride.

[0161] The first stage of the monovalent MMR system 408 comprises a forward osmosis driven membrane crystallization process to reclaim potassium chloride from the purge stream using sodium chloride as a draw solution. The remaining purge is sequentially processed in an electrodialysis unit 408b to produce lithium metal and lithium chloride. The purge is subsequently processed in an ion exchange system 408c that comprises a highly absorbent rubidium chloride active substance on a resin, to produce rubidium chloride.

[0162] The polyvalent brine (PVB) 104b from the nanofiltration (NF) system 306 is either conveyed to a polyvalent brine tank or to a calcium carbonate (CaCO3) clarifier 410a for softening. Softening is achieved by adding sodium carbonate (Na2CO3) to the PVB 104b, which causes the calcium to settle as calcium carbonate in the sludge. The sludge is sent for further processing and crystallization.

[0163] The softened supernatant (the low calcium supernatant) from the calcium carbonate clarifier 410a has a low calcium content (less than 1000 ml / L) and is subsequently passed to a magnesium hydroxide (Mg(OH)2) clarifier 410b to recover magnesium by precipitation.

[0164] In the magnesium hydroxide clarifier 41 Ob, sodium hydroxide (NaOH), or ammonium hydroxide (NH4OH), is added to the softened supernatant (the low calcium supernatant) causing over 90% of the magnesium to precipitate out of the solution in the form of a magnesium hydroxide (Mg(OH)2) sludge. The magnesium hydroxide sludge is sent to the polyvalent MMR system 416 that in part comprises a magnesium metal production system 416b. The magnesium metal production system 416b comprises a magnesium hydroxide storage tank and a magnesium metal recovery system.

[0165] The low magnesium supernatant from the magnesium hydroxide clarifier 410b is sent to an ultrafiltration (UF) system 412 or a conventional filtration system to remove fine solids with a particle size larger than 5 micrometres, i.e. the pores of the filtration membranes comprised in either the UF system or the conventional filtration system have a diameter of about 5 micrometres. The UF system 412 removes any remaining precipitates from the low magnesium supernatant, and then conveys it to a membrane crystallizer 414 for the recovery of potassium chloride ( KCI). The membrane crystallizer used for the recovery of KCI is of the same type as that used to recover NaCI from the MVB, described above.

[0166] Alternatively, the low magnesium supernatant together with the low calcium supernatant are directed to the polyvalent MMR system 416 to produce crystals of magnesium hydroxide (Mg(OH)2), magnesium oxide (MgO), calcium carbonate (CaCO3), sodium sulphate (Na2SO4), sodium sulphite (Na2SO3), calcium sulphate (CaSO4), magnesium sulphate (MgSO4), calcium chloride (e.g. CaCl2and / or Ca2Cl3), magnesium chloride (MgCl2) and / or sodium carbonate (Na2CO3). In some embodiments, the polyvalent MMR system 416 produces crystals of magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), sodium sulphate (Na2SO4), calcium sulphate (CaSO4),magnesium sulphate (MgSO4), calcium chloride (Ca2Cl3), magnesium chloride (MgCl2) and / or sodium carbonate (Na2CO3),

[0167] The low magnesium supernatant may then be filtered by the UF system 412 and subsequently concentrated by an OARO system, which is configured in the same manner as the OARO system 404 used for the UHPRO-treated MVB, and then conveyed to the polyvalent MMR system 416 for the recovery of the above-mentioned mineral salts.

[0168] The polyvalent MMR system 416 in part comprises one or more forward osmosis driven membrane crystallizer 416a, and / or one or more thermal crystallizer, which is used to crystallize the above-mentioned mineral salts. The one or more forward osmosis driven membrane crystallizer 416a may use the sodium chloride draw solution formed from the MVB 104a, that has a salinity between 200,000 and 300,000 mg / L of TDS, to produce the calcium and magnesium mineral salts mentioned above. The one or more forward osmosis driven membrane crystallizer 416a draws out water from the concentrated low magnesium supernatant and low calcium supernatant and crystallizes the calcium and magnesium mineral salts on the membrane’s surface. These crystals can then be collected for commercial purposes.

[0169] This process additionally produces a diluted draw solution, formed of the water drawn out from the concentrated low magnesium supernatant and the concentrated low calcium supernatant. The diluted draw solution may be an MgCl2draw solution, in which case the water drawn out from the concentrated low magnesium supernatant and the concentrated low calcium supernatant may be combined with MgCl2produced by the polyvalent MMR system 416 to form the diluted draw solution. In some embodiments, the diluted draw solution may be used in the crystallizer system 406 (i.e. the diluted draw solution may be used by the thermal crystallizer 406a or membrane crystallizer 406b). In other embodiments, the diluted draw solution may be used in the monovalent MMR system 408 (e.g. in the forward osmosis driven membrane crystallizers 408a). The water from the diluted draw solution may subsequently be separated as a condensate containing the desalinated water separated from the PVB stream 104b, thereby achieving ZLD of the polyvalent stream.

[0170] Variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these claims cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A brine valorisation system (106) for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream (104a) and / or a polyvalent brine (PVB) stream (104b), the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system (402) for processing the MVB stream (104a) into a UHPRO retentate and desalinated water; (b) either (i) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate; and(c) a crystallizer system (406) for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and / orII. two or more clarifiers for processing the PVB stream (104b), wherein the two or more clarifiers comprise a calcium clarifier (410a) and a magnesium clarifier (410b), and wherein the calcium clarifier (410a) produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier (410b) produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

2. The brine valorisation system (106) according to claim 1 , for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream (104a) and a polyvalent brine (PVB) stream (104b), the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system (402) for processing the MVB stream (104a) into a UHPRO retentate and desalinated water; (b) either (I) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate; and(c) a crystallizer system (406) for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; andII. two or more clarifiers for processing the PVB stream (104b), wherein the two or more clarifiers comprise a calcium clarifier (410a) and a magnesium clarifier (410b), and wherein the calcium clarifier (410a) produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesiumclarifier (410b) produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

3. The brine valorisation system according to claim 1 or 2, wherein the brine valorisation system comprises an OARO system (404) comprising one or more OARO stage for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate.

4. The brine valorisation system according to claim 2 or 3, wherein the OARO system (404) comprises two or more OARO stages, and wherein each OARO stage further concentrates the UHPRO retentate.

5. The brine valorisation system according to claim 3 or 4, wherein each OARO stage within the OARO system (404) comprises a membrane that maintains a salinity gradient between the two sides of the membrane, such that there is an osmotic draw pressure of from about 140 bars to about 155 bars.

6. The brine valorisation system according to any of claims 3 to 5, wherein each OARO stage within the OARO system (404) comprises a membrane with a pore size of from about 0.001 micrometres to about 0.01 micrometres.

7. The brine valorisation system according to any previous ciaim, wherein the crystallizer system (406) comprises a thermal crystallizer (406a) or a membrane crystallizer (406b) for processing the concentrated UHPRO retentate into distilled water, sodium chloride crystals, a sodium chloride brine solution, and a monovalent purge stream.

8. The brine valorisation system according to any previous claim, wherein the brine valorisation system further comprises a monovalent minerals and metals recovery (monovalent MMR) system (408) for processing the monovalent purge stream output from the crystallizer system (406) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride.

9. The brine valorisation system according to claim 8, wherein the monovalent MMR system (408) comprises one or more of:I. a forward osmosis driven membrane crystallizer (408a) for extracting potassium chloride;II. an electrodialysis unit (408b) for extracting lithium metal and lithium chloride; andML an ion exchange system (408c) for extracting rubidium chloride.

10. The brine valorisation system according to claim 8 or 9, wherein the monovalent MMR system (408) comprises a forward osmosis driven membrane crystallizer (408a) for processing the monovalent purge stream to produce potassium chloride and a first permeate.

11. The brine valorisation system according to claim 10, wherein the monovalent MMR system (408) further comprises an electrodialysis unit (408b) for processing the first permeate output from the forward osmosis driven membrane crystallizer (408a) into lithium metal, lithium chloride and an electrodialysis purge containing the remaining monovalent metals and mineral salts.

12. The brine valorisation system according to claim 11 , wherein the monovalent MMR system (408) further comprises an ion exchange system (408c) for processing the electrodialysis purge output from the electrodialysis unit (408b) to produce rubidium chloride.

13. The brine valorisation system according to any preceding claim, wherein the two or more mineral clarifiers comprise a first clarifier comprising a calcium clarifier (410a) for processing the PVB stream (104b) to produce a calcium rich sludge and a low calcium supernatant, and a second clarifier comprising a magnesium clarifier (410b) for processing the low calcium supernatant to produce a magnesium rich sludge and a low magnesium supernatant.

14. The brine valorisation system according to any of claims 1 to 12, wherein the two or more mineral clarifiers comprise a first clarifier comprising a magnesium clarifier (410b) for processing the PVB stream (104b) to produce a magnesium rich sludge and a low magnesium supernatant, and a second clarifier comprising a calcium clarifier (410a) for processing the low magnesium supernatant to produce a calcium rich sludge and a low calcium supernatant.

15. The brine valorisation system according to claim 13 or 14, wherein the brine valorisation system further comprises a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant.

16. The brine valorisation system according to claim 15, wherein the filtration system is an ultrafiltration system (412).

17. The brine valorisation system according to claim 15 or 16, wherein the brine valorisation system further comprises a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride.

18. The brine valorisation system according to claim 17, wherein the crystallizer is a membrane crystallizer (414).

19. The brine valorisation system according to any of claims 15 to 18, wherein the brine valorisation system further comprises an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant.

20. The brine valorisation system according to any of claims 13 to 19, wherein the brine valorisation system further comprises a polyvalent minerals and metals recovery (polyvalent MMR) system (416) for processing:I. the magnesium rich sludge output from the magnesium clarifier (410b); and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

21. The brine valorisation system according to claim 20, wherein the polyvalent MMR system (416) comprises one or more of:I. one or more crystallizer for processing the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system to extract one or more of magnesium hydroxide, calcium carbonate, sodium sulphate, calcium sulphate, magnesium sulphate, calcium chloride, magnesium chloride and / or sodium carbonate; andII. a magnesium metal production system (416b) for processing the magnesium rich sludge output from the magnesium clarifier (410b) to produce magnesium metal.

22. The brine valorisation system according to claim 21 , wherein the one or more crystallizer is a forward osmosis driven membrane crystallizer (416a) and / or a thermal crystallizer.

23. The brine valorisation system according to claim 22, wherein the one or more crystallizer is a forward osmosis driven membrane crystallizer (416a).

24. A brine valorisation system (106) for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream (104a) and / or a polyvalent brine (PVB) stream (104b), the brine valorisation system comprising:I. (a) an ultra-high pressure reverse osmosis (UHPRO) system (402) for processing the MVB stream (104a) into a UHPRO retentate and desalinated water;(b) either (I) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage or (ii) a thermal evaporation unit, for concentrating the UHPRO retentate to produce a concentrated UHPRO retentate;(c) a crystallizer system (406) for processing at least a portion of the concentrated UHPRO retentate to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) a monovalent minerals and metals recovery (monovalent MMR) system (408) for processing the monovalent purge stream output from the crystallizer system (406) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride; and / orII. (a) two or more clarifiers for processing the PVB stream (104b), wherein the two or more clarifiers comprise a calcium clarifier (410a) and a magnesium clarifier (410b), and wherein the calcium clarifier (410a) produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier (410b) produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant;(b) a filtration system for processing at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(i) a crystallizer for processing at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce potassium chloride; and / or(ii) an OARO system to concentrate at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant output from the filtration system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and a polyvalent minerals and metals recovery (polyvalent MMR) system (416) for processing:III. the magnesium rich sludge output from the magnesium clarifier (410b); and / orIV. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

25. A system (100) for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution, the system comprising:(i) a desalination plant (102) configured to separate seawater and / or other high salinity solution into a monovalent brine (MVB) stream (104a) and a polyvalent brine (PVB) stream (104b); and(ii) a brine valorisation system according to any of claims 1 to 24.

26. The system (100) according to claim 25, wherein the desalination plant (102) comprises an intake system (302) for pre-treating the seawater and / or other high salinity solution.

27. The system (100) according to claim 26, wherein the intake system (302) is configured to chemically pre-treat the seawater and / or other high salinity solution (e.g. by electrochlorination or chemical chlorination by adding sodium hypochlorite to the seawater and / or other high salinity solution).

28. The system (100) according to claim 26, wherein the intake system (302) is configured to heat treat the seawater and / or other high salinity solution.

29. The system (100) according to any of claims 25 to 28, wherein the desalination plant (102) comprises a filtration system to remove fine solids and other contaminants from the seawater and / or other high salinity solution.

30. The system (100) according to claim 29, wherein the filtration system comprises an ultrafiltration (UF) system (304).

31. The system (100) according to claim 30, wherein the UF system comprises a UF membrane with a pore size in the range of from about 0.01 micrometres to about 0.1 micrometres.

32. The system (100) according to claim 30 or 31 , wherein the UF system (304) is configured to remove at least about 90% of fine solids and other contaminants having a particle size larger than about 5 micrometres.

33. The system (100) according to any of claims 25 to 32, wherein the desalination plant (102) comprises a separation system for separating the seawater or other high salinity solution into a permeate comprising mainly monovalent ions (the monovalent stream, MVS) and a brine containing mainly polyvalent ions (the polyvalent brine stream, PVB stream) (104b).

34. The system (100) according to claim 33, wherein the separation system is a nanofiltration (NF) system (306) comprising one or more NF membranes to filter out polyvalent dissolved salts, organic matter, and other contaminants.

35. The system (100) according to claim 34, wherein the one or more NF membranes have a pore size of from about 0.0005 micrometres to about 0.002 micrometres.

36. The system (100) according to claim 34 or 35, wherein the NF system (306) is configured such that at least about 90% of the ions in the MVS are monovalent ions.

37. The system (100) according to any of claims 34 to 36, wherein the NF system (306) is configured such that at least about 90% of the ions in the PVB stream (104b) are polyvalent ions.

38. The system (100) according to any of claims 33 to 37, wherein the desalination plant (102) further comprises a seawater reverse osmosis (SWRO) system (308) for processing the MVS into a low salinity water and a monovalent brine (MVB) stream (104a).

39. A method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream (104a) and / or a polyvalent brine (PVB) stream (104b), the method comprising:I. (a) processing (206) the MVB stream (104a) in an ultra-high pressure reverse osmosis (UHPRO) system (402) to produce a UHPRO retentate and desalinated water;(b) concentrating (208) the UHPRO retentate in either (I) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate; and(c) processing (210) the concentrated UHPRO retentate in a crystallizer system (406) to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and / orII. processing the PVB brine stream (104b) in two or more mineral clarifiers, wherein the two or more clarifiers comprise a calcium clarifier (410a) and a magnesium clarifier (410b), and wherein the calcium clarifier (410a) produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier (410b) produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

40. The method according to claim 39 for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream (104a) and a polyvalent brine (PVB) stream (104b), the method comprising:I. (a) processing (206) the MVB stream (104a) in an ultra-high pressure reverse osmosis (UHPRO) system (402) to produce a UHPRO retentate and desalinated water;(b) concentrating (208) the UHPRO retentate in either (i) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate; and(c) processing (210) the concentrated UHPRO retentate in a crystallizer system (406) to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; andII. processing the PVB brine stream (104b) in two or more mineral clarifiers wherein the two or more clarifiers comprise a calcium clarifier (410a) and a magnesium clarifier (410b), and wherein the calcium clarifier (410a) produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier (410b) produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.

41. The method according to claim 39 or 40, wherein concentrating (208) the UHPRO retentate comprises concentrating the UHPRO retentate in an OARO system (404) comprising one or more OARO stage through which the UHPRO retentate is passed to produce a concentrated UHPRO retentate.

42. The method according to any of claims 39 to 41 , wherein concentrating the UHPRO retentate in an OARO system (404) comprises passing the UHPRO retentate through two or more OARO stages, and wherein each OARO stage further concentrates the UHPRO retentate.

43. The method according to claim 41 or 420, wherein each OARO stage comprises passing the UHPRO retentate through an OARO membrane, and wherein the OARO membrane maintains a salinity gradient between the two sides of the membrane, such that there is an osmotic draw pressure of from about 140 bars to about 155 bars.

44. The method according to any of claims 41 to 43, wherein each OARO stage comprises passing the UHPRO retentate through an OARO membrane with a pore size of from about 0.001 micrometres to about 0.01 micrometres.

45. The method according to any of ciaims 39 to 44, wherein processing (210) the concentrated UHPRO retentate comprises processing the concentrated UHPRO retentate in a crystallizer system (406) comprising a thermal crystaiiizer (406a) or a membrane crystaiiizer (406b), to produce distilled water, sodium chloride crystals, a sodium chloride brine solution, and a monovalent purge stream.

46. The method according to any of claims 39 to 45, wherein the method further comprises processing the monovalent purge stream in a monovalent minerals and metals recovery (monovalent MMR) system (408) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride.

47. The method according to claim 46, wherein processing the monovalent purge stream in the monovalent MMR system (408) comprises processing (212) the monovalent purge stream in a forward osmosis driven membrane crystallizer (408a) to produce potassium chloride and a first permeate.

48. The method according to claim 47, wherein processing the monovalent purge stream in the monovalent MMR system (408) further comprises processing (214) the first permeate output from the forward osmosis driven membrane crystaiiizer (408a) in an electrodialysis unit (408b) to produce lithium metal, lithium chloride and an electrodialysis purge containing the remaining monovalent metals and mineral salts.

49. The method according to claim 48, wherein processing the monovalent purge stream in the monovalent MMR (408) system further comprises processing (216) the electrodialysis purge output from the electrodialysis unit (408b) in an ion exchange system (408c) to produce rubidium chloride.

50. The method according to any of claims 39 to 49, wherein processing the PVB brine stream (104b) in two or more mineral clarifiers comprises processing the PVB brine stream (104b) in a first clarifier comprising a calcium clarifier (410a) to produce a calcium rich sludge and a low calcium supernatant and processing the low calcium supernatant in second clarifier comprising a magnesium clarifier (410b) to produce a magnesium rich sludge and a low magnesium supernatant.

51. The method according to claim 50, wherein processing the PVB brine stream (104b) in a first clarifier comprising a calcium clarifier (410a) comprises adding sodium carbonate to the PVB stream (104b), and wherein the calcium rich sludge comprises a calcium carbonate rich sludge.

52. The method according to claim 50 or 51 , wherein processing the low calcium supernatant in a second clarifier comprising a magnesium clarifier (410b) comprises adding sodium hydroxide or ammonium hydroxide to the low calcium supernatant, and wherein the magnesium rich sludge comprises a magnesium hydroxide rich sludge.

53. The method according to any of claims 39 to 49, wherein processing the PVB brine stream (104b) in two or more mineral clarifiers comprises processing the PVB brine stream (104b) in a first clarifier comprising a magnesium clarifier (410b) to produce a magnesium rich sludge and a low magnesium supernatant and processing the low magnesium supernatant in a second clarifier comprising a calcium clarifier (410a) to produce a calcium rich sludge and a low calcium supernatant.

54. The method according to claim 53, wherein processing the PVB brine stream (104b) in a first clarifier comprising a magnesium clarifier (410b) comprises adding sodium hydroxide or ammonium hydroxide to the PVB stream (104b), and wherein the magnesium rich sludge comprises a magnesium hydroxide rich sludge.

55. The method according to claim 53 or 54, wherein processing the low magnesium supernatant in a second clarifier comprising a calcium clarifier (410a) comprises adding sodium carbonate to the low magnesium supernatant, and wherein the calcium rich sludge comprises a calcium carbonate rich sludge.

56. The method according to claim 51 or 55, wherein the calcium carbonate concentration in the calcium carbonate rich sludge is in the range of from about 90 wt.% to about 98 wt.%.

57. The method according to claim 52 or 54, wherein the magnesium hydroxide concentration in the magnesium hydroxide rich sludge is in the range of from about 90 wt.% to about 98 wt.%.

58. The method according to claim 54, wherein the magnesium hydroxide concentration in the magnesium hydroxide rich sludge is in the range of from about 95 wt.% to about 98 wt.%.

59. The method according to claim 55, wherein the calcium carbonate concentration in the calcium carbonate rich sludge is in the range of from about 95 wt.% to about 98 wt.%.

60. The method according to any of claims 39 to 59, wherein the calcium concentration in the low calcium supernatant is less than about 2000mg / L.

61. The method according to any of claims 39 to 60, wherein the magnesium concentration in the low magnesium supernatant is less than about 2000mg / L.

62. The method according to any of claims 50 to 61 , wherein the method further comprises processing (222) at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant.

63. The method according to claim 62, wherein the filtration system is an ultrafiltration system(412).

64. The method according to claim 62 or 63, the method further comprising processing (224) at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride.

65. The method according to claim 64, wherein the crystallizer is a membrane crystallizer (414).

66. The method according to any of claims 62 to 65, wherein the method further comprises concentrating at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OARO system to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant.

67. The method according to any of claims 50 to 66, wherein the method further comprises processing:I. the magnesium rich sludge output from the magnesium clarifier (410b); and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system (416) to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

68. The method according to claim 67, wherein processing (i) the magnesium rich sludge and / or (ii) the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant in the polyvalent MMR system (416) comprises one or more of:I. processing the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system in one or more crystallizer to extract one or more of magnesium hydroxide, calcium carbonate, sodium sulphate, calcium sulphate, magnesium sulphate, calcium chloride, magnesium chloride and / or sodium carbonate; and / orII. processing the magnesium rich sludge output from the magnesium clarifier (410b) in a magnesium metal production system (416b) to extract magnesium metal.

69. The method according to claim 68, wherein the one or more crystallizer is a forward osmosis driven membrane crystallizer (416a) or a thermal crystallizer.

70. The method according to claim 69, wherein the one or more crystallizer is a forward osmosis driven membrane crystallizer (416a).

71. The method according to any of claims 67 to 70, wherein the diluted draw solution output from the polyvalent MMR system is used as a draw solution in the crystallizer system (406) or the monovalent MMR system (408).

72. The method according to any of claims 45 to 71 , wherein the sodium chloride brine solution output from the crystallizer system (406) is used as a draw solution in the monovalent MMR system (408).

73. A method for recovering at least one mineral salt and / or at least one metal from a monovalent brine (MVB) stream (104a) and / or a polyvalent brine (PVB) stream (104b), the method comprising:I. (a) processing (206) the MVB stream (104a) in an ultra-high pressure reverse osmosis (UHPRO) system (402) to produce a UHPRO retentate and desalinated water;(b) concentrating (208) the UHPRO retentate in either (i) an osmotically assisted reverse osmosis (OARO) system (404) comprising one or more OARO stage, or (ii) a thermal evaporation unit, to produce a concentrated UHPRO retentate;(c) processing (210) the concentrated UHPRO retentate in a crystallizer system (406) to produce distilled water, a monovalent purge stream and a mineral salt, wherein the mineral salt comprises sodium chloride crystals; and(d) processing the monovalent purge stream in a monovalent minerals and metals recovery (monovalent MMR) system (408) to produce one or more mineral salts and / or metals selected from potassium chloride, lithium metal, lithium chloride and / or rubidium chloride; and / orII. (a) processing the PVB brine stream (104b) in two or more mineral clarifiers wherein the two or more clarifiers comprise a calcium clarifier (410a) and a magnesium clarifier (410b), and wherein the calcium clarifier (410a) produces a calcium rich sludge comprising a calcium salt and / or metal, and a low calcium supernatant, and the magnesium clarifier (410b) produces a magnesium rich sludge comprising a magnesium salt and / or metal, and a low magnesium supernatant.(b) processing (222) at least a portion of the low magnesium supernatant or low calcium supernatant output from the second clarifier in a filtration system to remove fine solids with a size larger than about 5 micrometres, and to produce a filtered low magnesium supernatant or a filtered low calcium supernatant; and(c)(i) processing (224) at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant in a crystallizer to extract potassium chloride; and / or(H) concentrating at least a portion of the filtered low magnesium supernatant or the filtered low calcium supernatant, output from the filtration system, in an OAROsystem to produce a concentrated filtered low magnesium supernatant or a concentrated filtered low calcium supernatant; and processing:I. the magnesium rich sludge output from the magnesium clarifier (410b); and / orII. the concentrated filtered low magnesium supernatant or the concentrated filtered low calcium supernatant output from the OARO system; in a polyvalent minerals and metals recovery (polyvalent MMR) system (416) to produce one or more polyvalent metals or mineral salts and a diluted draw solution.

74. A method for recovering at least one mineral salt and / or at least one metal from seawater and / or another high salinity solution, the method comprising:(i) processing the seawater and / or other high salinity solution in a desalination plant (102) to separate the seawater and / or other high salinity solution into a monovalent brine (MVB) stream (104a) and a polyvalent brine (PVB) stream (104b); and processing the MVB stream (104a) and / or the PVB stream (104b) according to the method of any of claims 39 to 73 to recover at least one mineral salt and / or metal.

75. The method according to any of claims 39 to 74, wherein the other high salinity solution has a total dissolved solid / salinity concentration of 2,000 mg / L or greater.

76. The method according to claim 74 or 75, wherein processing the seawater and / or other high salinity solution in a desalination plant (102) comprises pre-treating the seawater and / or other high salinity solution in an intake system (302).

77. The method according to claim 76, wherein pre-treating the seawater and / or other high salinity solution in the intake system (302) comprises chemically pre-treating the seawater and / or other high salinity solution (e.g. by electrochlorination or chemical chlorination by adding sodium hypochlorite to the seawater and / or other high salinity solution).

78. The method according to claim 76, wherein pre-treating the seawater and / or other high salinity solution in the intake system (302) comprises heat treating the seawater and / or other high salinity solution.

79. The method according to any of claims 74 to 78, wherein processing the seawater and / or other high salinity solution in a desalination plant (102) comprises filtering the seawater and / or other high salinity solution in a filtration system to remove fine solids and other contaminants from the seawater and / or other high salinity solution.

80. The method according to claim 79, wherein filtering the seawater and / or other high salinity solution in the filtration system comprises filtering the seawater and / or other high salinity solution in an ultrafiltration (UF) system (304).

81. The method according to claim 80, wherein filtering the seawater and / or other high salinity solution in the ultrafiltration (UF) system (304) comprises passing the seawater and / or other high salinity solution through a UF membrane with a pore size in the range of from about 0.01 micrometres to about 0.1 micrometres.

82. The method according to any of claims 79 to 81 , wherein filtering the seawater and / or other high salinity solution in the filtration system and / or the UF system (304) removes at least about 90% of fine solids and other contaminants having a particle size larger than about 5 micrometres.

83. The method according to any of claims 74 to 82, wherein processing the seawater and / or other high salinity solution in a desalination plant (102) comprises separating the seawater and / or other high salinity solution into a permeate comprising mainly monovalent ions (the monovalent stream, MVS) and a brine containing mainly polyvalent ions (the polyvalent brine stream, PVB stream) (104b) in a separation system.

84. The method according to claim 83, wherein separating the seawater and / or other high salinity solution into an MVS and a PVB stream comprises separating the seawater and / or other high salinity solution into an MVS and a PVB stream in a nanofiltration (NF) system (306) comprising one or more NF membranes to filter out polyvalent dissolved salts, organic matter, and other contaminants.

85. The method according to claim 84, wherein separating the seawater and / or other high salinity solution into the MVS and the PVB stream in the nanofiltration (NF) system (306) comprises passing the seawater and / or other high salinity solution through the one or more NF membranes having a pore size of from about 0.0005 micrometres to about 0.002 micrometres.

86. The method according to claim 84 or 85, wherein at least about 90% of the ions in the resultant MVS are monovalent ions.

87. The method according to any of claims 84 to 86, wherein at least about 90% of the ions in the resultant PVB stream (104b) are polyvalent ions.

88. The method according to any of claims 84 to 87, wherein processing the seawater and / or other high salinity solution in a desalination plant (102) further comprises processing the MVS into a low salinity water and a monovalent brine (MVB) stream (104a) in a seawater reverse osmosis (SWRO) system (308).

89. The method according to claim 88, wherein a portion of the concentrated UHPRO retentate output from the OARO system (404) is passed back to the SWRO system (308) to produce the required osmotic pressure gradient needed to concentrate the MVS into the MVB (104a).

90. The system according to any of claims 1 to 38 or the method according to any of claims 39 to 89, wherein the at least one mineral salt and / or at least one metal has a purity of 90% or greater.

91. The system according to any of claims 1 to 38 or the method according to any of claims 39 to 89, wherein the at least one mineral salt and / or at least one metal has a purity of 96% or greater.

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