System and method for producing concrete using salt water

Abstract

The invention relates to a system for producing a plurality of brine streams for use in concrete production. The system comprises a selected brine stream production system configured to produce a monovalent brine and a multivalent brine from seawater, and to produce at least one other brine having a different mineral salt concentration than the monovalent brine and the multivalent brine, wherein the monovalent brine and the at least one other brine are used for producing concrete. The invention also relates to a method for producing a plurality of brine streams for use in concrete production, and to a system and method for producing concrete using brine.

Description

Technical Field

[0001] This invention relates to systems and methods for producing various brine streams for use in concrete production. Furthermore, this invention relates to systems and methods for producing concrete using brine, particularly, but not exclusively, the production of 3D-printable concrete using brine produced by seawater desalination plants. Background Technology

[0002] Seawater desalination is a widely used method for producing drinking water in arid regions of the world. This desalination process produces brine as a byproduct, also known as waste brine. This waste brine is typically discharged into aquatic environments, potentially having negative environmental impacts. One environmentally sustainable technology to address this challenge is to convert the waste brine into commercially valuable products, rather than releasing it back into the ocean.

[0003] It is known to use brine, brackish water, or water from desalination plants to mix with cement to form concrete—see, for example, US2023 / 0071790. However, these methods have not yet been commercialized due to several limitations. First, concrete produced by such methods sets very quickly (its viscosity increases rapidly once the brine is mixed with cement). This may limit where the concrete can be used and how it sets. Furthermore, the various components in brine can cause cracking and structural fragility in concrete structures.

[0004] Regarding the viscosity and structure of concrete products made from this type of concrete, other methods are known to yield better results, such as those described in US 11,655,187. However, these methods do not use brine and therefore cannot provide an environmentally sustainable technology.

[0005] The present invention aims to solve at least some of the above-mentioned problems. Summary of the Invention

[0006] This invention aims to reduce the use of concrete components such as freshwater / drinking water and cement in concrete production, including 3D (three-dimensional) printable concrete and conventional concrete, by using brine produced from seawater desalination instead of water. This reduction in cement will beneficially promote the production of environmentally friendly "green" concrete.

[0007] To provide printable concrete, a concrete composition is needed in which the reaction time of the brine and cement is appropriate so that the viscosity of the concrete mixture increases more slowly than that of existing compositions. This prevents the concrete mixture from clogging the nozzles of the 3D concrete printer when used for 3D printing. Furthermore, such a solution ideally possesses improved flowability, workability, constructability, dynamic yielding properties, and efficient setting time suitable for 3D concrete printing.

[0008] This invention also aims to provide concrete that is not limited by the characteristics of prior art methods. In this regard, it is worth noting that previous attempts have attempted to reinforce concrete with various additives, including salt additives mixed with polymers or metals, water, and brine. However, some salt additives and brine components can lead to brittle concrete, resulting in weak concrete structures. These additives can also cause the concrete to set faster than the time required for it to be processed and deposited by the 3D printer, thus clogging the 3D printer.

[0009] Therefore, the present invention aims to provide a system and method for producing “green” concrete, preferably having optimal fluidity, workability, constructability and dynamic yielding properties, as well as efficient setting time, for use in 3D printing of concrete products.

[0010] This paper discloses systems and methods for desalinating seawater, which generate brine streams with varying mineral salt concentrations and use these streams to produce pumpable cementitious mixtures (PCMs) and pumpable brine mixtures (PBMs), which are then mixed to form 3D-printable concrete mixtures. The use of pumpable brine mixtures with a controlled composition of selected minerals mitigates the brittleness of concrete in the prior art and makes the properties of the concrete mixtures suitable for 3D printing.

[0011] Low-concentration brine streams can be used as a substitute for water when mixed with cement and binders. Alternatively, brine streams or combinations of brine streams with varying concentrations of selected mineral salts can be used to produce accelerators for the generation and setting of concrete.

[0012] By selecting a saltwater stream or combination of saltwater streams with a predetermined calcium ion concentration, the static yield stress and initial setting time of concrete mixtures can be improved. Furthermore, increasing the calcium ion concentration, for example, by increasing the proportion of high-CaCl2 salt water, enhances the compressive strength of concrete structures during 28-day testing.

[0013] This invention advantageously realizes the value of waste brine by using it in the production of 3D-printable concrete and conventional concrete. Applications of concrete produced using waste brine include building structures, such as non-reinforced low-rise buildings and structural building components. Other applications include the manufacture of art installations and artificial reef components. However, concrete produced with brine cannot be reinforced with steel because the high chloride ion concentration in the brine corrodes the metal.

[0014] Compared with concrete produced using drinking water, the system and method for producing concrete of the present invention have the following advantages: (i) The quality and strength of concrete are improved because the salt water contains minerals (such as calcium) and optionally reduces minerals such as magnesium; (ii) Reduce the use of conventional concrete admixtures (such as cement mixed with calcium carbonate) because brine contains high levels of calcium chloride, which has been found to be more beneficial to the compressive strength of concrete than calcium carbonate. (iii) Reduce the amount of fresh / drinking water used in cement production; (iv) The value of waste brine was realized by reusing waste and applying it to valuable, commercially viable products widely used in construction; and (v) Improve the properties of concrete mixtures to make them suitable for 3D printing of building components, coral reef restoration materials and other commercial and decorative concrete products.

[0015] The commercialization of this invention enables the production of "green" concrete with brine as a major component of the concrete mixture, and advantageously reduces CO2 emissions by reducing the use of silicate cement, thereby achieving a circular economy.

[0016] In a first aspect of the invention, a system for producing multiple brine streams for use in concrete production is provided, the system comprising: a selected brine stream production system configured to produce monovalent and polyvalent brine streams from seawater, and to produce at least one other brine stream with a mineral salt concentration different from that of the monovalent and polyvalent brine streams, wherein the monovalent and at least one other brine streams are used in concrete production.

[0017] The selected brine flow production system may include a nanofiltration unit for separating seawater into monovalent and polyvalent brine.

[0018] The system may also include a seawater desalination system connected to a selected brine flow production system.

[0019] The seawater desalination system may include a reverse osmosis unit, which is used to process a portion of the monovalent brine output from the nanofiltration unit into reverse osmosis cut-off liquid and desalinated water.

[0020] The selected brine production system may also include a brine concentration unit for processing the reverse osmosis retentate output from the reverse osmosis unit into a first other brine.

[0021] The selected brine production system may also include at least one mineral settling tank and boron removal unit for processing at least a portion of the first other brine output from the brine concentration unit into a second other brine.

[0022] At least one mineral settling device may include a calcium carbonate settling device and a magnesium hydroxide settling device.

[0023] The selected brine production system may also include at least one mineral removal unit for processing the multivalent brine output from the nanofiltration unit into a third, other brine.

[0024] The at least one mineral removal unit may include a sulfate removal unit and a magnesium removal unit.

[0025] Monovalent brine, as well as a first other brine, a second other brine, a third other brine, or any combination thereof, can be used in the production of concrete.

[0026] In a second aspect of the invention, a method for producing multiple brine streams for use in concrete production is provided, the method comprising: supplying seawater to a selected brine stream production system to produce monovalent and polyvalent brine streams, and producing at least one other brine stream with a mineral salt concentration different from that of the monovalent and polyvalent brine streams, wherein both the monovalent and at least one other brine stream are used in the production of concrete.

[0027] Seawater can be supplied to nanofiltration units in a selected brine flow production system to separate seawater into monovalent and polyvalent brine.

[0028] The method may also include processing a portion of the monovalent brine in a reverse osmosis unit of a seawater desalination system connected to a selected brine flow production system to produce reverse osmosis cut-off solution and desalinated water.

[0029] The method may also include processing the reverse osmosis retentate in a brine concentration unit to produce a first additional brine.

[0030] The method may further include processing at least a portion of the first other brine in at least one mineral settling tank, followed by processing in a boron removal unit to produce a second other brine.

[0031] The at least one mineral settling device may include a calcium carbonate settling device and a magnesium hydroxide settling device.

[0032] The method may also include processing the polyvalent brine in at least one mineral removal unit to produce a third additional brine.

[0033] The at least one mineral removal unit may include a sulfate removal unit and a magnesium removal unit.

[0034] Monovalent brine, as well as a first other brine, a second other brine, a third other brine, or any combination thereof, can be used in the production of concrete.

[0035] First, other saline solutions have a higher concentration of mineral salts than monovalent saline solutions.

[0036] The second other saline solution is a low-calcium chloride saline solution with a calcium chloride concentration of about 5,000 mg / L to about 100,000 mg / L.

[0037] The third other saline solution is a high-calcium chloride saline solution with a calcium chloride concentration of at least about 200,000 mg / L.

[0038] The calcium chloride concentration in the third other saline solution is approximately 200,000 mg / L to approximately 350,000 mg / L.

[0039] In a third aspect of the invention, a system for producing concrete using brine is provided, the system comprising: a selected brine flow production system configured to produce monovalent and polyvalent brine from seawater and to produce at least one other brine having a mineral salt concentration different from that of the monovalent and polyvalent brine; and a concrete production unit wherein at least a portion of the monovalent brine is fed into the concrete production unit together with a binder and aggregate to produce a first mixture, while at least one other brine is fed into the concrete production unit together with a binder and aggregate to produce a second mixture, the concrete production unit being configured to mix the first mixture and the second mixture to form concrete.

[0040] The selected brine flow production system may include a nanofiltration unit for separating seawater into monovalent and polyvalent brine.

[0041] The system may also include a seawater desalination system connected to a selected brine flow production system.

[0042] The seawater desalination system may include a reverse osmosis unit, which is used to process a portion of the monovalent brine output from the nanofiltration unit into reverse osmosis cut-off liquid and desalinated water.

[0043] The selected brine production system may also include a brine concentration unit for processing the reverse osmosis retentate output from the reverse osmosis unit into a first other brine.

[0044] The selected brine production system may also include at least one mineral settling tank and boron removal unit for processing at least a portion of the first other brine output from the brine concentration unit into a second other brine.

[0045] At least one mineral settling device may include a calcium carbonate settling device and a magnesium hydroxide settling device.

[0046] The selected brine production system may also include at least one mineral removal unit for processing the multivalent brine output from the nanofiltration unit into a third, other brine.

[0047] The at least one mineral removal unit may include a sulfate removal unit and a magnesium removal unit.

[0048] A first other saline solution, or a second other saline solution, or a third other saline solution, or any combination of these other saline solutions, may be used to produce a second mixture.

[0049] A concrete production unit may include a first mixer, a second mixer, and a third mixer, wherein a first mixture is produced in the first mixer, a second mixture is produced in the second mixer, and the first and second mixtures are mixed in the third mixer to form concrete.

[0050] A concrete production unit may include a 3D concrete printer.

[0051] The 3D concrete printer includes a first screw pump and a second screw pump, which are used to deliver a first mixture and a second mixture output from a first mixer and a second mixer, respectively.

[0052] The 3D concrete printer also includes an online static mixer, into which a first mixture and a second mixture are fed via a first screw pump and a second screw pump and mixed to form concrete.

[0053] 3D concrete printers also include nozzles that deliver concrete into the nozzles for 3D printing of concrete.

[0054] In a fourth aspect of the invention, a method for producing concrete using brine is provided, the method comprising: a) Supplying seawater to a selected brine flow production system to produce monovalent and polyvalent brine, and to produce at least one other brine with a different mineral salt concentration than the monovalent and polyvalent brine; and (b) Conveying at least a portion of a monovalent brine to a concrete production unit and mixing it with a binder and aggregates to produce a first mixture; conveying at least one other brine to the concrete production unit and mixing it with a binder and aggregates to produce a second mixture; and mixing the first mixture and the second mixture in the concrete production unit to form concrete.

[0055] In a), seawater can be supplied to a nanofiltration unit in a selected brine flow production system to separate the seawater into monovalent and polyvalent brine.

[0056] a) May also include: processing a portion of the monovalent brine in a reverse osmosis unit of a seawater desalination system connected to a selected brine flow production system to produce reverse osmosis cut-off liquid and desalinated water.

[0057] a) May also include: processing the reverse osmosis retentate in a brine concentration unit to produce a first other brine.

[0058] a) may also include: processing at least a portion of the first other brine in at least one mineral settling tank, followed by processing in a boron removal unit to produce a second other brine.

[0059] The at least one mineral settling device may include a calcium carbonate settling device and a magnesium hydroxide settling device.

[0060] a) May also include at least one mineral removal unit for processing the polyvalent brine to produce a third other brine.

[0061] The at least one mineral removal unit may include a sulfate removal unit and a magnesium removal unit.

[0062] A first other brine, or a second other brine, or a third other brine, or any combination of these other brines, may be delivered to the concrete production unit to produce a second mixture.

[0063] The first additional brine can be transported to the concrete production unit to produce the second mixture.

[0064] The second and third additional brine can be delivered to the concrete production unit to produce the second mixture.

[0065] The second other brine and the third other brine can be mixed in a ratio of about 3:2 to produce the second mixture.

[0066] The first and second mixtures can be mixed in a ratio of approximately 1:1 to form concrete.

[0067] First, other saline solutions can have a higher concentration of mineral salts than monovalent saline solutions.

[0068] The second saline solution may have a low calcium chloride concentration of about 5,000 mg / L to about 100,000 mg / L.

[0069] Third, other saline solutions may have a high calcium chloride concentration of at least about 200,000 mg / L.

[0070] The calcium chloride concentration in the third or other saline solution can be from about 200,000 mg / L to about 350,000 mg / L.

[0071] The monovalent brine used to produce the first mixture can be diluted with water, preferably the monovalent brine is diluted with water in a ratio of about 1:1.

[0072] The binder used to produce the first mixture may contain one or more of silicate cement, calcined clay, granulated blast furnace slag powder, or limestone powder.

[0073] The binder may contain silicate cement, calcined clay, and limestone powder.

[0074] The aggregate used to produce the first mixture may contain sand, preferably fine quartz sand.

[0075] The ratio of aggregate to binder in the first mixture can be approximately 1:1.

[0076] The ratio of monovalent brine to aggregate in the first mixture can be approximately 0.28:1.

[0077] The first mixture may also contain about 0.6 wt% to 1 wt.% of a high-efficiency water-reducing agent.

[0078] The spread diameter of the first mixture in the slump flow test can be at least 150 mm.

[0079] The first mixture may contain about 34 wt.% to about 52 wt.% sand, about 17 wt.% to about 26 wt.% silicate cement, about 10 wt.% to about 17 wt.% calcined clay, about 5 wt.% to about 9 wt.% limestone powder, about 10 wt.% to about 20 wt.% monovalent brine and about 0.6 wt.% to about 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water at a ratio of about 1:1.

[0080] The first mixture may contain approximately 44 wt.% sand, 22 wt.% silicate cement, 14 wt.% calcined clay, 7 wt.% limestone powder, 12 wt.% monovalent brine and 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water at a ratio of approximately 1:1.

[0081] The binder used to produce the second mixture may contain limestone powder.

[0082] The aggregate used to produce the second mixture may contain sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

[0083] The ratio of aggregate to binder in the second mixture can be approximately 1:1.

[0084] The ratio of at least one other brine to the binder in the second mixture may be approximately 0.3:1.

[0085] The second mixture may contain about 34 wt.% to about 52 wt.% of sand, about 34 wt.% to about 52 wt.% of limestone powder, and about 10 wt.% to about 20 wt.% of at least one other brine.

[0086] The second mixture may contain about 44 wt.% sand, 44 wt.% limestone powder and 12 wt.% of at least one other brine.

[0087] The first mixture can be produced in the first mixer in the concrete production unit, the second mixture can be produced in the second mixer in the concrete production unit, and then the first mixture and the second mixture can be mixed in the third mixer in the concrete production unit to produce concrete.

[0088] The concrete production unit may include a 3D concrete printer, and a first mixture and a second mixture output from a first mixer and a second mixer are respectively fed to a first screw pump and a second screw pump in the 3D concrete printer.

[0089] The first and second mixtures can be delivered to an online static mixer in a 3D concrete printer via a first screw pump and a second screw pump, where they are mixed to produce concrete.

[0090] Concrete can be deposited through nozzles in a 3D concrete printer to form 3D printed concrete products.

[0091] In a fifth aspect of the invention, a method for producing concrete using brine is provided, the method comprising: mixing a binder, aggregate, and a monovalent brine to produce a first mixture; mixing the binder, aggregate, and at least one other brine having a mineral salt concentration different from that of the monovalent brine to produce a second mixture; and mixing the first mixture and the second mixture to form concrete.

[0092] Monovalent brine can be obtained by passing seawater through a nanofiltration unit.

[0093] The monovalent brine used to produce the first mixture can be diluted with water, preferably the monovalent brine is diluted with water in a ratio of about 1:1.

[0094] A second mixture can be produced using a first other brine, which has a higher mineral salt concentration than the monovalent brine.

[0095] A second mixture can be produced using a second other saline solution and a third other saline solution, the second other saline solution having a low calcium chloride concentration of about 5,000 mg / L to about 100,000 mg / L, and the third other saline solution having a high calcium chloride concentration of about 200,000 mg / L.

[0096] The calcium chloride concentration in the third other saline solution is approximately 200,000 mg / L to approximately 350,000 mg / L.

[0097] The second other brine and the third other brine can be mixed in a ratio of about 3:2 to produce the second mixture.

[0098] The first and second mixtures can be mixed in a ratio of approximately 1:1 to form concrete.

[0099] The binder used to produce the first mixture may contain one or more of silicate cement, calcined clay, granulated blast furnace slag powder, or limestone powder.

[0100] The binder may contain silicate cement, calcined clay, and limestone powder.

[0101] The aggregate used to produce the first mixture may contain sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

[0102] The ratio of aggregate to binder in the first mixture can be approximately 1:1.

[0103] The ratio of monovalent brine to aggregate in the first mixture can be approximately 0.28:1.

[0104] The first mixture may also contain about 0.6 wt.% to 1 wt.% of a high-efficiency water-reducing agent.

[0105] The spread diameter of the first mixture in the slump flow test can be at least 150 mm.

[0106] The first mixture may contain about 34 wt.% to about 52 wt.% sand, about 17 wt.% to about 26 wt.% silicate cement, about 10 wt.% to about 17 wt.% calcined clay, about 5 wt.% to about 9 wt.% limestone powder, about 10 wt.% to about 20 wt.% monovalent brine and about 0.6 wt.% to about 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water at a ratio of about 1:1.

[0107] The first mixture may contain approximately 44 wt.% sand, 22 wt.% silicate cement, 14 wt.% calcined clay, 7 wt.% limestone powder, 12 wt.% monovalent brine and 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water at a ratio of approximately 1:1.

[0108] The binder used to produce the second mixture may contain limestone powder.

[0109] The aggregate used to produce the second mixture may contain sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

[0110] The ratio of aggregate to binder in the second mixture can be approximately 1:1.

[0111] The ratio of at least one other brine to the binder in the second mixture may be approximately 0.3:1.

[0112] The second mixture may contain about 34 wt.% to about 52 wt.% of sand, about 34 wt.% to about 52 wt.% of limestone powder, and about 10 wt.% to about 20 wt.% of at least one other brine.

[0113] The second mixture may contain about 44 wt.% sand, 44 wt.% limestone powder and 12 wt.% of at least one other brine.

[0114] Concrete produced using this method is suitable for 3D printing.

[0115] In a sixth aspect of the invention, a selected brine production system and a seawater desalination system are provided for producing multiple brine streams for use in concrete production. The system includes: a nanofiltration unit for separating seawater into monovalent and polyvalent brine streams; a reverse osmosis unit for processing a portion of the monovalent brine stream output from the nanofiltration unit into reverse osmosis retentate and desalinated water; a brine concentration unit for processing the reverse osmosis retentate stream output from the reverse osmosis unit into a first other brine stream; a calcium carbonate settling tank, a magnesium hydroxide settling tank, and a boron removal unit for processing at least a portion of the first other brine stream output from the brine concentration unit into a second other brine stream; and a sulfate removal unit and a magnesium removal unit for processing the polyvalent brine stream output from the nanofiltration unit into a third other brine stream; wherein the other brine streams have different mineral salt concentrations than the monovalent and polyvalent brine streams, and wherein any one or more of the monovalent and other brine streams are used in concrete production.

[0116] In a seventh aspect of the invention, a method for producing multiple brine streams for use in concrete production is provided, the method comprising: supplying seawater to a nanofiltration unit to separate the seawater into monovalent brine and polyvalent brine; processing a portion of the monovalent brine in a reverse osmosis unit to produce reverse osmosis retentate and desalinated water; processing the reverse osmosis retentate in a brine concentration unit to produce a first other brine; processing at least a portion of the first other brine in a calcium carbonate settling tank and a magnesium hydroxide settling tank, followed by processing in a boron removal unit to produce a second other brine; and processing the polyvalent brine in a sulfate removal unit and a magnesium removal unit to produce a third other brine; wherein the other brine has a different mineral salt concentration than the monovalent and polyvalent brines, and wherein any one or more of the monovalent and other brines are used in the production of concrete.

[0117] In an eighth aspect of the invention, a method for producing 3D-printable concrete using brine is provided, the method comprising: supplying seawater to a nanofiltration unit to separate the seawater into monovalent brine and polyvalent brine; processing a portion of the monovalent brine in a reverse osmosis unit to produce reverse osmosis retentate and desalinated water; processing the reverse osmosis retentate in a brine concentration unit to produce a first other brine; processing at least a portion of the first other brine in a calcium carbonate settling tank and a magnesium hydroxide settling tank, followed by processing in a boron removal unit to produce a second other brine; processing the polyvalent brine in a sulfate removal unit and a magnesium removal unit to produce a third other brine; mixing a binder, aggregate, high-efficiency water-reducing agent, and monovalent brine to produce a first mixture; mixing the binder, aggregate, and the first other brine, or mixing the second other brine with the third other brine, to produce a second mixture; and combining the first mixture and the second mixture to form concrete.

[0118] In a ninth aspect of the invention, a composition is provided comprising about 44 wt.% sand, 22 wt.% silicate cement, 14 wt.% calcined clay, 7 wt.% limestone powder, 12 wt.% monovalent brine and 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water in a ratio of about 1:1.

[0119] Monovalent brine can be obtained by passing seawater through a nanofiltration unit.

[0120] Diluted monovalent saline solution can have the following properties: Figure 8 The composition provided in column b).

[0121] In a tenth aspect of the invention, a composition is provided comprising about 44 wt.% sand, 44 wt.% limestone powder and 12 wt.% brine.

[0122] The salt water can have the following properties: Figure 9 The composition provided in column a).

[0123] Salt water can have the following properties: Figure 9 The composition provided in column b).

[0124] In an eleventh aspect of the invention, a concrete mixture is provided comprising any one of the compositions in segments

[0118] to

[0120] and any one of the compositions in segments

[0121] to

[0123] in a ratio of about 1:1.

[0125] This concrete mixture is suitable for 3D printing.

[0126] In a twelfth aspect of the invention, a system for producing concrete using brine is provided, the system comprising: a concrete production unit wherein a monovalent brine is fed into the concrete production unit together with a binder and aggregate to produce a first mixture, and a brine having a concentration of at least one mineral salt and a concentration of the monovalent brine is fed into the concrete production unit together with the binder and aggregate to produce a second mixture, the concrete production unit being configured to mix the first mixture and the second mixture to form concrete.

[0127] The concrete production unit may include a first mixer, a second mixer, and a third mixer, wherein a first mixture is produced in the first mixer, a second mixture is produced in the second mixer, and the first and second mixtures are mixed in the third mixer to form concrete.

[0128] A concrete production unit may include a 3D concrete printer.

[0129] The 3D concrete printer may include a first screw pump and a second screw pump, which respectively deliver a first mixture and a second mixture output from the first screw pump and the second mixer.

[0130] The 3D concrete printer may also include an online static mixer, into which a first mixture and a second mixture are fed via a first screw pump and a second screw pump and mixed to form concrete.

[0131] The 3D concrete printer may also include a nozzle to which concrete is fed for 3D printing. Attached Figure Description

[0132] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, wherein:

[0133] Figure 1a A block diagram overview of a system according to one embodiment of the present invention is shown, illustrating a selected brine flow production system for producing multiple different brine flows for concrete production;

[0134] Figure 1b A block diagram overview of a system according to another embodiment of the present invention, wherein the system includes Figure 1a The selected brine flow production system and concrete production unit are shown, in which the brine flow is used to produce two mixtures of concrete products.

[0135] Figure 1c A block diagram overview of a system according to another embodiment of the present invention, including Figure 1b The selected brine flow production system and concrete production unit shown are included, wherein the concrete production unit includes a 3D printer for printing concrete structures.

[0136] Figure 2 A detailed block diagram is shown for a system for producing multiple different brine streams for concrete production according to one embodiment of the present invention;

[0137] Figure 3a A schematic diagram illustrating various brine streams and desalinated water that can be produced according to one embodiment of the present invention;

[0138] Figure 3b A more detailed illustration of a method for producing multiple different brine streams and desalinated water according to one embodiment of the present invention;

[0139] Figure 3c for Figure 2 A block diagram overview of the system shown;

[0140] Figure 4 A schematic illustration of a lab-scale 3D concrete printer (3DCP) set up on demand.

[0141] Figure 5a for Figure 4 A block diagram showing the various features of on-demand laboratory-scale 3DCP;

[0142] Figure 5b for Figure 4 and Figure 5a The flowchart shown illustrates the operation method of on-demand laboratory-scale 3DCP;

[0143] Figure 6 A table showing the composition of brine streams according to various embodiments of the present invention is provided;

[0144] Figure 7a A table showing the percentage of aggregate by weight according to aggregate particle size according to various embodiments of the present invention is provided;

[0145] Figure 7b A table showing the weight percentages of components used in adhesives and mortars according to various embodiments of the present invention is provided;

[0146] Figure 8 A table showing the composition of two brine streams used in various embodiments of the present invention is provided;

[0147] Figure 9 A table showing the composition and physical properties of two types of saline streams used in various embodiments of the present invention is provided;

[0148] Figure 10 Methods for producing concrete according to various embodiments of the present invention are shown. Detailed Implementation

[0149] Various exemplary embodiments and details are described below with reference to the accompanying drawings. It should be noted that the drawings may or may not be drawn to scale, and elements with similar structures or functions are indicated by the same reference numerals in each figure. It should also be noted that the drawings are intended only to facilitate the description of embodiments and are not intended as a detailed description of the invention or a limitation on the scope of the invention. Furthermore, the illustrated embodiments are not necessarily to have all the aspects or advantages shown. Aspects or advantages described in connection with a particular embodiment are not limited to that embodiment and may be realized in any other embodiment, even if not so shown or so explicitly described.

[0150] The accompanying drawings are schematic and simplified; for clarity, they show only details that aid in understanding the invention, while other details are omitted. Throughout the drawings, the same reference numerals are used for the same or corresponding parts.

[0151] Figure 1a A schematic diagram of an exemplary system 100 of the present invention is shown. This document uses a selected brine stream production system 106 to generate multiple different brine streams 104a / b / c / d with different mineral salt concentrations. A portion of the brine 104a output from the selected brine stream production system 106 is sent to a conventional seawater desalination system 102, which generates desalinated brine 104. This desalinated brine 104 is returned to the selected brine stream production system 106 for further processing. One or more of the multiple different brine streams 104a / b / c / d output from the selected brine stream production system 106 can then be used to produce concrete, for example, two, three, or four of the brine streams can be used.

[0152] The desalinated brine 104 mentioned above refers to the brine produced by the seawater desalination system 102. However, it should be understood that any brine stream output from the seawater desalination system 102 and further processed by the subsequent systems / units described herein is also desalinated brine. In embodiments of the invention, the seawater desalination system 102 includes a reverse osmosis unit for generating desalinated brine 104, and the output of the seawater desalination system 102 is referred to herein as "reverse osmosis (RO) retentate". This will be referenced below. Figure 2 Further description.

[0153] The brine streams 104a / b / c / d output from the selected brine production system 106 can be directly input into the concrete production unit 216 (e.g., Figure 1b(As shown), or it can be stored for later use and / or at different locations. For example, in one embodiment, the concrete production unit 216 may be located adjacent to the selected brine flow production system 106, so that the brine flows 104a / b / c / d can be directly delivered from the selected brine flow production system 106 to the concrete production unit. In another embodiment, the concrete production unit may be located away from the selected brine flow production system 106, or even at a different production site from the selected brine flow production system 106. In this other embodiment, the brine flows 104a / b / c / d can be stored and transported to the concrete production unit as needed.

[0154] Figure 1b A block diagram of another embodiment of system 100 is shown. (Compared to...) Figure 1a As illustrated in the embodiments described herein, system 100 includes a selected brine stream production system 106 for generating multiple different brine streams 104a / b / c / d with varying mineral salt concentrations. A portion of the brine 104a output from the selected brine stream production system 106 is fed to a conventional seawater desalination system 102, which generates desalinated brine 104. This desalinated brine 104 is returned to the selected brine stream production system 106 for further processing. The brine streams 104a / b / c / d are then used to produce a first mixture 108 and a second mixture 110, both of which contain a binding material (binder). For the first mixture 108, it may contain cement. In one embodiment, brine stream 104a is used to produce the first mixture 108, while one or more of the brine streams 104b / c / d are used to produce the second mixture 110. The first mixture 108 and the second mixture 110 are mixed together in a concrete production unit 216 to produce concrete (also referred to herein as a concrete mixture). This concrete mixture can be used to produce moldable or printable concrete products. Therefore, the physical properties of the first mixture 108 and the second mixture 110 make them suitable for use in printers for concrete structures (e.g., 3D printers). For example, due to their suitable viscosity and flowability, these mixtures can be pumped through various components of the 3D printer, such as nozzles. Therefore, when the first mixture 108 and the second mixture 110 are used in a 3D printer, they are also referred to herein as pumpable mixtures. This will be referenced below. Figure 1c Further discussion.

[0155] Figure 1cA block diagram of another embodiment of system 100 is shown, in which concrete production unit 216 includes 3D printer 112. In this embodiment, the first mixture 108 may also be referred to as pumpable cementitious mixture (PCM), and the second mixture 110 may also be referred to as pumpable brine mixture (PBM). As described above Figure 1b The PCM 108 and PBM 110 also contain a binding material (adhesive), and for the PCM 108, it may contain cement. In one embodiment, brine stream 104a is used to produce PCM 108, while one or more of brine streams 104b / c / d are used to produce PBM 110. PCM 108 and PBM 110 are mixed in a 3D printer to produce a printable concrete mixture that can be used to print concrete structures / products.

[0156] Figure 2 A selected brine stream production system 106 according to an embodiment of the invention is shown in more detail for the production of selected brine streams 104a / b / c / d, which are used for concrete production, for example for the production of moldable or printable concrete. The figure also illustrates how the seawater desalination system 102 and the selected brine stream production system 106 are integrated with each other.

[0157] The selected brine production system 106 includes a nanofiltration unit 202, a brine concentration unit 206, a mineral settling tank 208, a boron removal unit 210, and mineral removal units 212 and 214. As shown, the seawater desalination system 102 is connected to and integrated with the selected brine production system 106, and this system includes a reverse osmosis unit 204. The desalination system 102 and the selected brine production system 106 produce selected brine streams 104a / b / c / d, which are then used for the production of concrete and desalinated water.

[0158] exist Figure 2 In the current embodiment shown, seawater 200 is processed by a nanofiltration system / unit 202, which separates it into monovalent permeate 104a containing monovalent ions (also referred to herein as monovalent brine, monovalent brine stream, or 3-1 reverse osmosis (RO) feed brine) and polyvalent brine 220 containing polyvalent ions. At least a portion of the monovalent permeate 104a is sent to concrete production (e.g., to concrete production unit 216) as mixing water for cement. This portion of the monovalent permeate 104a output / recycled for concrete production can also be referred to as stream #1 3-1 RO feed brine and can be diluted with water, which can be any suitable water, including tap water or desalinated water, as described below.

[0159] A portion of the nanofiltration monovalent permeate 104a can be further processed by a seawater desalination system 102 including a reverse osmosis (RO) unit 204 to produce desalinated water 218 and demineralized brine 104 (also referred to herein as reverse osmosis (RO) retentate). Because desalinated water 218 is separated from the monovalent permeate 104a input to the RO unit 204, the RO retentate 104 has a higher mineral salt concentration than the monovalent permeate 104a.

[0160] The RO retentate 104 can be further processed in the brine concentration unit 206 to produce a first additional brine 104b. In one embodiment of the invention, the brine concentration unit 206 includes a mechanical vapor recompression (MVR) concentration unit. Therefore, the first additional brine 104b can also be referred to as MVR brine or concentrated MVR brine. The mineral salt concentration of the MVR brine 104b is higher than that of the RO retentate 104, and therefore also higher than that of the monovalent permeate 104a. At least a portion of the MVR brine 104b can be output for concrete production (e.g., output to concrete production unit 216), and this portion of the MVR brine 104b can also be referred to as stream #2 concentrated MVR brine.

[0161] At least a portion of the MVR brine 104b may be further processed in one or more mineral settling tanks 208 (in one embodiment, the mineral settling tanks include calcium carbonate settling tanks and magnesium hydroxide settling tanks), and then processed in a boron removal unit 210 to produce a second additional brine 104c. The second additional brine 104c may also be referred to as low CaCl2 brine or Stream #3 low CaCl2 brine. The CaCl2 concentration in this brine is typically from about 5,000 mg / L to about 100,000 mg / L, suitably from about 20,000 mg / L to about 80,000 mg / L, and suitably from about 40,000 mg / L to about 60,000 mg / L. This second additional brine 104c is output for concrete production.

[0162] The polyvalent brine 220 can be processed in a selected brine stream production system 106 to generate a third additional brine stream 104d. Specifically, the polyvalent brine 220 can be processed by at least one mineral removal unit to remove unwanted contaminants from the polyvalent brine 220 stream. In an embodiment of the invention, the polyvalent brine 220 is processed in a sulfate removal unit 212 and then in a magnesium removal unit 214 to produce the third additional brine 104d, also referred herein as a high CaCl2 brine or stream #4 high CaCl2 brine. The concentration of CaCl2 in this brine is typically at least about 200,000 mg / L. Increasing the concentration of CaCl2 ions can result in higher stiffness in the final produced concrete. While this may be an advantageous property of the final concrete, in embodiments where the concrete is generated in a 3D printer and used to print concrete structures, an excessively high CaCl2 ion concentration can have adverse effects on concrete printing. For example, the concrete mixture generated in the 3D printer may be too hard to print, or may even cause printer clogging. Therefore, in embodiments of producing concrete mixes in a 3D printer using CaCl2 brine 104, the concentration of CaCl2 in the high CaCl2 brine 104d is typically from about 200,000 mg / L to about 350,000 mg / L, suitably from about 200,000 mg / L to about 260,000 mg / L.

[0163] Figure 3aAn exemplary method is shown in system 100 for producing various brine streams 104a / b / c / d from seawater using a desalination system 102 and a selected brine stream production system 106. Seawater 200 is fed into the selected brine stream production system 106 (which is integrated with the seawater desalination system 102, as described above) to produce multiple brine streams 104a / b / c / d and desalinated water 218. As described above, up to four different brine streams can be produced for concrete production. Fewer brine streams, such as one, two, or three, can be produced by stopping the process at a selected point. For example, by stopping the process after seawater nanofiltration, only monovalent permeate 104a can be produced for concrete production. Furthermore, for example, only monovalent permeate 104a and a third, other brine 104c can be produced without using the seawater desalination system 102. It is not necessary to stop the process at a certain point; all four brine streams can be produced as described above, and then those can simply be selected for concrete production. Any one or more brine streams can be selected for concrete production. In some embodiments, monovalent permeate 104a is used in concrete production, while one or more of the first, second, or third other saline streams 104b / c / d are also used in concrete production. In some embodiments, monovalent permeate 104a and the first other saline stream 104b are used in concrete production. In some embodiments, monovalent permeate 104a, the second other saline stream 104c, and the third other saline stream 104d are used in concrete production.

[0164] Figure 3b Showing more details Figure 3a The flowchart illustrates the method. In the first step, seawater is treated using nanofiltration in step 302 to produce nanofiltration monovalent brine and polyvalent brine.

[0165] In step 308, a portion of the output monovalent brine is used for concrete production (flow #1 3-1 RO feed brine), and another portion of the monovalent brine is processed in the reverse osmosis unit to produce desalinated water and reverse osmosis retainer.

[0166] In step 310, the reverse osmosis retentate is then processed in a brine concentration unit to produce a first additional brine, also referred to herein as concentrated mechanical vapor recompression (MVR) brine.

[0167] In step 312, a portion of the output MVR brine is used for concrete production (stream #2 concentrated MVR brine), and another portion of the MVR brine is processed in calcium carbonate settling tanks and magnesium hydroxide settling tanks.

[0168] In step 314, the output materials from the calcium carbonate settling tank and the magnesium hydroxide settling tank are then processed in the boron removal unit to produce a second additional brine, also referred to herein as stream #3 low CaCl2 brine, the output of which is used for concrete production.

[0169] In step 304, the polyvalent brine output from the nanofiltration step is processed in a first mineral settling tank to remove sulfates.

[0170] In step 306, the output material from the first mineral settling tank is then processed in the second mineral settling tank to remove magnesium in order to produce a third additional brine, referred to herein as stream #4 high CaCl2 brine, the output of which is used for concrete production.

[0171] Steps 304 and 306 can be performed concurrently with steps 308 through 314. Alternatively, steps 304 and 306 can be performed before or after steps 308 through 314. Therefore, the numbering of these steps does not necessarily reflect the order in which they are performed.

[0172] Figure 3c As shown Figure 2 The block diagrams of the selected brine flow production system 106 and seawater desalination system 102 are shown in summary.

[0173] Typically, as described herein, the brine streams 104a / b / c / d generated using the system and method of the present invention are used to produce two composite materials, namely a first mixture and a second mixture, which are mixed to form a concrete mixture. The first and second mixtures also contain at least one binder (for the first mixture, the binder may include cement) and aggregates. In one embodiment, brine stream 104a is used to produce the first mixture, while one or more of brine streams 104b / c / d are used to produce the second mixture. The first mixture may also be referred to as a cement-based mixture, and the second mixture may also be referred to as a brine mixture.

[0174] In embodiments where the first and second mixtures are used or suitable for use in a 3D printer to produce 3D-printable concrete, the first mixture may be referred to as a pumpable cementitious mixture (PCM), and the second mixture may be referred to as a pumpable brine mixture (PBM). Using specific combinations of brine streams to configure the brine mixture / PBM can produce concrete with different properties. Selecting an appropriate brine stream provides suitable properties for the specific application of the produced concrete.

[0175] For simplicity, the following discussion will primarily refer to the first and second mixtures as PCM and PBM (which refer to mixtures particularly suitable for 3D printing of concrete). However, these mixtures can also be used to produce moldable concrete.

[0176] The binder material that can be used in PCM and / or PBM comprises CEM I 52.5 silicate cement (PC), calcined clay (CC), granulated blast furnace slag (GGBS), and limestone powder (LP). In one embodiment, CC comprises approximately 50% metakaolin, purchased from Argeco, France. Suitably, silicate cement (PC) is present only in the PCM. Suitably, the PCM may comprise a combination of silicate cement (PC), calcined clay (CC), and limestone powder (LP). Suitably, the PBM may comprise limestone powder (LP).

[0177] Suitablely, when the binder of the PCM comprises a combination of silicate cement (PC), calcined clay (CC), and limestone powder (LP): the weight percentage of PC in the binder can range from about 40 wt% to about 60 wt%, suitablely from about 45 wt% to about 55 wt%, and suitablely from about 48 wt% to about 52 wt%; the weight percentage of CC in the binder can range from about 25 wt% to about 40 wt%, suitablely from about 28 wt% to about 37 wt%, and suitablely from about 30 wt% to about 35 wt%; the weight percentage of LP in the binder can range from about 12 wt% to about 20 wt%, and suitablely from about 15 wt% to about 18 wt%.

[0178] The aggregates suitable for PCM and PBM are fine quartz sand with a particle size (particle diameter) of about 0.125 mm to about 2 mm. Depending on the sand particle size, the PCM and PBM composites / mortars described below contain different weight percentages of sand. These weight percentages are... Figure 7a The information is provided in the text.

[0179] To ensure PCM has minimal fluidity, a high-efficiency water-reducing agent can be added to the PCM mortar. Suitablely, when the PCM mortar contains a combination of PC, CC, and LP as binders, along with sand, brine (saltwater 104a), and the high-efficiency water-reducing agent: the weight percentage of sand in the mortar can be from about 34% to about 52% by weight, suitablely from about 37% to about 50% by weight, suitablely from about 40% to about 48% by weight, and suitablely from about 42% to about 46% by weight; the weight percentage of PC in the mortar can be from about 17% to about 26% by weight, suitablely from about 20% to about 24% by weight, and suitablely from about 21% by weight. The weight percentage of the superplasticizer in the mortar can be from about 10% to about 17% by weight, appropriately from about 12% to about 16% by weight, or appropriately from about 13% to about 15% by weight; the weight percentage of the LP in the mortar can be from about 5% to about 9% by weight, or appropriately from about 6% to about 8% by weight; the weight percentage of the brine in the mortar can be from about 10% to about 20% by weight, or appropriately from about 11% to about 15% by weight; and the weight percentage of the high-efficiency water-reducing agent in the mortar can be from about 0.6% to about 1% by weight.

[0180] Suitablely, when the PBM mortar contains a binder (limestone powder), brine (one or more brine streams 104b / c / d), and sand: the wt.% of the binder in the mortar can be from about 34 wt.% to about 52 wt.%, preferably from about 37 wt.% to about 50 wt.%, preferably from about 40 wt.% to about 48 wt.%, preferably from about 42 wt.% to about 46 wt.%; the wt.% of the brine in the mortar can be from about 10 wt.% to about 20 wt.%, preferably from about 11 wt.% to about 15 wt.%; the wt.% of the sand in the mortar can be from about 34 wt.% to about 52 wt.%, preferably from about 37 wt.% to about 50 wt.%, preferably from about 40 wt.% to about 48 wt.%, preferably from about 42 wt.% to about 46 wt.%.

[0181] In a test environment, the above system and method were tested using a “synthetic brine stream” prepared based on the mass balance calculation results of the brine stream produced in a brine treatment plant. Figure 6 and Figure 8 This is a table showing these synthetic brine streams 104a / b / c / d, and these brine streams are expected to reproduce the brine streams 104a / b / c / d produced by a full-scale desalination plant. These brine streams were chosen because their composition is best suited for use in 3D-printable concrete (3DPC). Synthetic brine streams of different concentrations were prepared, corresponding to... Figure 3a Different brine streams were used, with the primary limiting factor being the saturation point of the salts employed. Concentration variations were achieved by altering the salt content in each prepared brine. The concentration of the 3-1 RO feed brine (stream #1) was also varied to suit the PCM; however, this was achieved by diluting it with either tap water or desalinated water, as described in further detail below. While both tap water and desalinated water are suitable diluents, tap water offers a lower-cost option, which is industrially advantageous. The results obtained using these brine streams support scaling up the system for application to brine streams generated by a full-scale desalination plant, as described in further detail in the examples below.

[0182] In one embodiment, the PCM is prepared using a limestone-calcined clay-based material and mixed with 3-1 RO feed brine (stream #1) 104a as mixing water. The binder used in the PCM comprises 50 wt.% PC, 16.7 wt.% LP, and 33.3 wt.% CC. The aggregate-to-binder mass ratio of the PCM is 1.0 (also referred to as 1:1), and the mixing water-to-binder mass ratio is 0.28 (also referred to as 0.28:1). To enable pumping, the minimum flowability of the PCM allows for a spread diameter greater than 150 mm in slump flow tests. To meet this flowability requirement, 0.6 wt.% to 1 wt.% of a polycarboxylate ether (PCE)-based high-efficiency water-reducing agent (SP) is added to the PCM. Based on the above binder components by wt.%, the PCM mortar contains approximately 44 wt.% sand, 22 wt.% PC, 14 wt.% CC, 7 wt.% LP, 12 wt.% 3-1 RO feed brine (flow #1) and 1 wt.% high-efficiency water-reducing agent. Figure 7b The weight percentages of the binder components and the relative weight percentages of the mortar components are shown.

[0183] In a preferred embodiment, the mixing water for the PCM is a low-concentration brine, which has Figure 8 Column b) (which lists the ion concentrations) shows the composition of the "target concentration water-mixed brine". This is achieved by using... Figure 8 The 3-1 RO feed brine (stream #1) 104a shown in column a) is diluted with water, preferably using tap water (preferred due to its low cost) or desalinated water 218 produced by the seawater desalination system 102. The final target concentration is achieved by mixing 50% of the 3-1 RO feed brine (stream #1) 104a with 50% of the tap water / desalinated water.

[0184] In one embodiment, a limestone-based mixture (LB) is used to prepare PBM and mixed with a brine used as a concrete accelerator. An exemplary composition of the concrete accelerator brine is shown in [illustration]. Figure 6 —See columns c), e) and i). The brine to binder ratio used in LB mixtures is approximately 0.3 (also known as 0.3:1), where the binder is LP. PBM mortar contains approximately 44% sand, 44% LP and 12% brine.

[0185] In one embodiment, the brine used as a concrete quick-setting agent in the PBM is composed of flow #3 low CaCl2 brine 104c (see example). Figure 6 (i) column) and flow #4 high CaCl2 brine 104d (see example) Figure 6The mixture is prepared by mixing the two streams (e). At a specific ratio of 40% stream #4 104d and 60% stream #3 104c, the mixture of the two streams is superior to using either brine stream alone. The exact composition of this mixture is shown in […]. Figure 6 Column g) (shows mineral salt concentration) and Figure 9 Column b) shows the ion concentration.

[0186] In one embodiment, the concrete accelerator in the PBM is made using Stream 2 concentrated MVR brine 104b because the brine stream has advantageous properties as a curing accelerator. Figure 6 Column c) and Figure 9 Section a) lists the exact composition of the concentrated brine in the MVR. The choice of which brine stream to use as the concrete accelerator in the PBM depends on the desired properties of the concrete. Concrete obtained by mixing 40% stream #4 104d and 60% stream #3 104c is stronger than that obtained using stream #2. However, using stream #2 as the concrete accelerator reduces the risk of corrosion and clogging of the 3D printer. Therefore, the appropriate brine stream should be selected based on the different property requirements of the concrete being produced.

[0187] In one embodiment, the brine mixture / PBM, the cement-based mixture / PCM, and the concrete mixture (concrete mixture) are based on... Figure 10 The method shown produces 1000.

[0188] In one embodiment, the cement-based mixture / PCM is produced by the following method: Tap water, 3-1 RO feed brine (stream #1) 104a, or a mixture of both, and a high-efficiency water-reducing agent are added to a HOBART planetary mixer (first mixer). The binder and cement are then slowly added to the HOBART planetary mixer and mixed at a low speed of 60 rpm for 4 minutes (step 1002). After stopping mixing, the bottom and sidewalls of the container are scraped for 30 seconds (step 1004). In step 1006, mixing continues at a high speed of 124 rpm for 2.5 minutes. Mixing is stopped to collect the cement-based mixture / PCM product in step 1008.

[0189] In one embodiment, the brine mixture / PBM is produced by the following method: 40% high CaCl2 + 60% low CaCl2 (normal concentration brine) or Stream #2 concentrated MVR brine 104b is added to a HOBART planetary mixer (second mixer). Subsequently, the aforementioned binder material is slowly added to the HOBART planetary mixer and mixed at a low speed of 60 rpm for 4 minutes (step 1010). After stopping mixing, the bottom and sidewalls of the container are scraped for 30 seconds (step 1012). In step 1014, mixing continues at a high speed of 124 rpm for 2.5 minutes. Mixing is stopped to collect the brine mixture / PBM product in step 1016.

[0190] In a more detailed description later Figure 5a In the illustrated implementation, the HOBART planetary mixer used to produce PBM and PCM is directly connected to the screw pumps 504a and 504b in the 3D printer.

[0191] In one embodiment, the concrete mixture for the 3D printer is produced by the following method: PCM and PBM are fed separately to the inline static mixer of the 3D printer (e.g., ...). Figure 5a (The mixer shown). Then, in step 1018, PCM and PBM are mixed in an inline static mixer. In step 1020, mixing is stopped, and the resulting concrete mixture is conveyed from the inline static mixer to the nozzle of the 3D printer.

[0192] In one embodiment, the brine mixture and cement-based mixture are used to produce moldable concrete as follows: The brine mixture and cement-based mixture are added to a HOBART planetary mixer (third mixer). In step 1018, the brine mixture and cement-based mixture are mixed at a low speed of 60 rpm for 30 seconds. In step 1020, mixing is stopped, and the resulting concrete mixture can be collected from the HOBART planetary mixer.

[0193] In a preferred embodiment, the mass ratio of the cement-based mixture / PCM and the brine mixture / PBM added to the third HOBART planetary mixer or online static mixer is 1:1. Using this mass ratio, the final mixture contains approximately 250 kg / m³ of silicate cement. 3 This is significantly lower than most proposed 3D-printable cement-based materials, thus supporting the environmentally friendly properties of this concrete.

[0194] Compared to other embodiments described herein, the preferred combination of PBM and PCM in a 1:1 mass ratio has the following related advantages: (i) Minimum dynamic yield stress and apparent viscosity of PBM; (ii) The appropriate initial setting time of the final concrete mixture (45 to 90 minutes); (iii) The highest static yield stress of the final concrete mixture; and (iv) The final concrete mixture shall have a compressive strength of at least 30 MPa at 28 days.

[0195] Calcium ion concentration has a significant impact on the static yield stress and initial setting time of concrete mixtures, which are important factors affecting the formability of 3D printable cement-based materials. In mixtures containing both high-CaCl2 and low-CaCl2 brine, increasing the proportion of high-CaCl2 brine can improve the compressive strength at 28 days.

[0196] Now let's move on to printing concrete using a 3D printer. Figure 4 The diagram schematically illustrates a lab-scale 3D concrete printer (3DCP) that solidifies on demand; the corresponding block diagram is as follows. Figure 5a The relevant operating methods are as follows: Figure 5b The PCM and PBM composites used for 3D printing do not require the high stiffness required by single-component (1K) 3D printing processes. For the 3D printers described herein, the optimal stiffness and yield stress of the PCM and PBM are achieved through the preferred embodiments of the PCM and PBM previously described.

[0197] exist Figure 4 In one embodiment shown, the 3DCP 400 includes at least two pumps 402a, 402b and an inline mixer 404. The two pumps 402a, 402b receive mixtures or materials such as PCM or PBM as described in the embodiments herein. The mixtures or materials are delivered to the inline static mixer 404 for combination (mixing) and printing to form a 3D-printable concrete structure 406.

[0198] exist Figure 5aIn one embodiment shown, the 3DCP 500 comprises three components: a three-degree-of-freedom computer numerical control (CNC) machine 502, two screw pumps 504a and 504b, and a custom printhead 506 connected to an in-line static mixer 508. The printhead 506 uses a dual-tube system comprising a metal tube 510 with two inlets and a static in-line mixer 508 with 16 mixing baffles. The CNC machine is controlled by a computer 512 to control the movement of the 3D printer, particularly the printhead, operating within a print volume of 290 mm in height (approximately 255 mm print height), 1100 mm in length, and 720 mm in width. Two commercial PFT Swing-M delivery pumps 504a and 504b (38-liter hopper capacity) based on a rotor-stator configuration are used. The printhead and delivery pumps are connected using two 5 m long PFT material hoses (maximum pressure 40 bar) with an inner diameter of 25 mm. The pipe inner diameter is 25 mm. Each baffle of the static online mixer 508 is approximately 3 mm thick and approximately 40 mm long. Two adjacent baffles rotate in opposite directions. The printhead 506 is connected to a nozzle 514 with an inner diameter of 25 mm.

[0199] exist Figure 5b One embodiment shown illustrates a method for printing concrete. Two pumpable composite materials (e.g., PBM and PCM) are mixed and delivered to the printhead using two screw pumps (step 522). In step 524, the two composite materials are mixed online in the printhead, and in step 526, they are deposited via nozzles to form a printed filament / layer.

[0200] Examples of generating 3D-printable concrete

[0201] In this embodiment, a concrete mixture was generated and a concrete structure was printed using a 3D printer. The concrete mixture was generated by mixing PBM and PCM at a 1:1 ratio in the inline static mixer of the 3D printer. The 3D printer in this embodiment includes the on-demand, laboratory-scale 3D concrete printer schematically shown and described above. Figure 5a The operating method is as described above. Figure 5b As stated above.

[0202] PCM is produced using a binder, aggregate (sand), mixing water, and a high-efficiency water-reducing agent. The binder contains 50 wt.% PC, 16.7 wt.% LP, and 33.3 wt.% CC. As described above, the PCM mortar contains approximately 44 wt.% sand, 22 wt.% PC, 14 wt.% CC, 7 wt.% LP, 12 wt.% diluted 3-1 RO feed brine (stream #1 – diluted as described below), and 1 wt.% high-efficiency water-reducing agent.

[0203] The mixing water for PCM has Figure 8 The low-concentration brine shown in column b) is composed of the "target concentration water-mixed brine" components. This is achieved by using a low-concentration brine with... Figure 8 The components shown in column a) were prepared by diluting Flow #1 3-1 RO feed brine 104a with tap water. The final target concentration was achieved by mixing 50% Flow #1 3-1 RO feed brine 104a with 50% tap water.

[0204] PBM is produced using aggregates and a binder mixed with brine. The binder contains 100 wt.% LP, and the brine acts as a concrete quick-setting agent. The PBM mortar contains approximately 44% sand, 44% LP, and 12% brine.

[0205] The effects of different brine compositions as concrete accelerators in PBMs were tested. The different brine compositions included: Flow #2 concentrated MVR brine 104b (composition shown in...). Figure 6 Column c) and Figure 9 Column a); Flow #4 high CaCl2 saline 104d (components shown in...) Figure 6 Column e); Flow #3 low CaCl2 saline 104c (components shown in...) Figure 6 (Column i); and a mixture of 40% flow #4 high CaCl2 brine 104d and 60% flow #3 low CaCl2 brine 104c (components shown in column i). Figure 9 (Column b). The mixture of 40% flow #4 high CaCl2 brine 104d and 60% flow #3 low CaCl2 brine 104c is also referred to herein as 40% high CaCl2 + 60% low CaCl2.

[0206] To determine the most favorable concrete accelerator, several physical properties of PBM and printed concrete were measured. The measured physical properties of PBM included dynamic yield stress and plastic viscosity, and the results are shown in Table 1 below.

[0207] Table 1: Physical properties of PBMs using different salt water flows as concrete accelerators

[0208] The physical properties of the final concrete mix measured included initial setting time, constructability, static yield stress, and 28-day compressive strength. Constructability is an indicator of the final concrete mix's improved durability; therefore, it is preferable that at least 10 layers of concrete can be stacked without collapse, with each layer having an optimal width and length of approximately 30 mm. To ensure good durability of the final concrete mix, constructability was assessed by whether seventeen layers of concrete could be stacked without collapse, with each layer having a length and width of approximately 25 mm to approximately 50 mm and a thickness of approximately 12 mm to approximately 30 mm. The relevant results are shown in Table 2 below.

[0209] Table 2: Physical properties of printed concrete using different brine streams as concrete accelerators in PBM

[0210] The required physical property ranges for the PBM and the final concrete mixture are given in Tables 1 and 2 above, respectively. Specifically, since the PBM needs to be pumped to be delivered to the online static mixer of the 3D printer, the PBM must meet pumpability requirements. These requirements include relatively low dynamic yield stress and low plastic viscosity. As shown in Table 1, the lowest dynamic yield stress and plastic viscosity were achieved when using Stream #3 low CaCl2 brine as the concrete accelerator in the PBM. However, relatively low dynamic yield stress and plastic viscosity values ​​were also achieved when using a mixture of 40% high CaCl2 + 60% low CaCl2 brine or Stream #2 MVR as the concrete accelerator.

[0211] Furthermore, the final concrete mixture should ideally have an initial setting time of 45 to 90 minutes. This requirement can be met by using any one of the following as a concrete accelerator: Flow #2 MVR concentrated brine, Flow #3 low CaCl2 brine, or a mixture of 40% high CaCl2 and 60% low CaCl2.

[0212] In addition, any one of the four fluids used as concrete accelerators in PBM tests meets the constructability requirement, meaning that seventeen layers of concrete can be stacked sequentially without causing the printed structure to collapse.

[0213] Although the low CaCl2 brine of Flow #3 resulted in the lowest dynamic yield stress and plastic viscosity for the PBM, the properties of the concrete mixes shown in Table 2 indicate that other brine flows produced stronger concrete. For example, Flow #3 did not meet the minimum requirement of at least 30 MPa in compressive strength after 28 days of printing (see Table 2). Static yield stress is closely related to the constructability of freshly printed concrete mixes; therefore, relatively high static yield stress in concrete mixes results in strong concrete with good constructability. The highest static yield stress was achieved using a 40% high CaCl2 + 60% low CaCl2 mix as a concrete accelerator.

[0214] Furthermore, compared to concrete mixtures produced using Flow #3 low-CaCl2 brine, the compressive strength values ​​of concrete mixtures produced using a 40% high-CaCl2 + 60% low-CaCl2 mixture or Flow #4 high-CaCl2 brine indicate that increased CaCl2 concentration leads to higher compressive strength after 28 days of printing. However, the concrete produced using Flow #2 MVR concentrated brine exhibits the highest compressive strength, as Flow #2 MVR concentrated brine has a higher concentration of other salts, such as... Figure 9 The higher TDS values ​​are shown.

[0215] The results shown in Tables 1 and 2 support the conclusion that the mixture of 40% flow #4 104d and 60% flow #3 104c (40% high CaCl2 + 60% low CaCl2) is superior to using either brine flow alone to produce concrete. Specifically, although the concrete printed using flow #4 high CaCl2 had a higher compressive strength at 28 days than the mixture using 40% flow #4 104d and 60% flow #3 104c, using only flow #4 high CaCl2 resulted in a concrete mixture that set too quickly, making it unsuitable for 3D printing concrete structures. Furthermore, the concrete mixture produced using the 40% high CaCl2 + 60% low CaCl2 mixture exhibited higher static yield stress and 28-day compressive strength compared to concrete produced using flow #3 low CaCl2.

[0216] The results shown in Table 2 further support the conclusion that concrete produced using a mixture of 40% high CaCl2 and 60% low CaCl2 has a higher static yield stress but a lower 28-day compressive strength compared to concrete produced using concentrated brine from flow #2 MVR. Therefore, a suitable brine flow can be selected based on the desired properties of the produced concrete.

[0217] When practicing the claimed invention, those skilled in the art can understand and implement variations of the disclosed embodiments based on their study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprise / comprising" does not exclude other elements or steps, and the indefinite article "a / an" does not exclude multiple. The mere fact that certain features are listed in mutually different dependent claims does not indicate that a combination of these claims cannot be used advantageously. Any reference numerals in the claims should not be interpreted as limiting the scope.

Claims

1. A system for producing multiple brine streams for use in concrete production, the system comprising: The selected brine production system is configured to produce monovalent and polyvalent brine from seawater, and to produce at least one other brine with a different mineral salt concentration than the monovalent and polyvalent brine, wherein the monovalent and at least one other brine are used to produce concrete.

2. The system of claim 1, wherein the selected brine flow production system includes a nanofiltration unit for separating seawater into monovalent and polyvalent brine.

3. The system according to claim 1 or 2, wherein the system further comprises a seawater desalination system connected to the selected brine flow production system.

4. The system according to claim 3, wherein the seawater desalination system includes a reverse osmosis unit, the reverse osmosis unit being used to process a portion of the monovalent brine output from the nanofiltration unit into reverse osmosis retaining liquid and desalinated water.

5. The system of claim 4, wherein the selected brine flow production system further comprises a brine concentration unit for processing the reverse osmosis retentate output from the reverse osmosis unit into a first other brine.

6. The system of claim 5, wherein the selected brine production system further comprises at least one mineral settling tank and a boron removal unit, the mineral settling tank and boron removal unit being used to process at least a portion of the first other brine output from the brine concentration unit into a second other brine.

7. The system of claim 6, wherein the at least one mineral settling device comprises a calcium carbonate settling device and a magnesium hydroxide settling device.

8. The system according to any one of the preceding claims, wherein the selected brine flow production system further comprises at least one mineral removal unit for processing the multivalent brine output from the nanofiltration unit into a third other brine.

9. The system of claim 8, wherein the at least one mineral removal unit comprises a sulfate removal unit and a magnesium removal unit.

10. The system according to any one of claims 5 to 9, wherein the monovalent brine, and the first other brine or the second other brine or the third other brine or any combination thereof are used to produce concrete.

11. A method for producing multiple brine streams for use in concrete production, the method comprising: Seawater is supplied to a selected brine flow production system to produce monovalent and polyvalent brine, and to produce at least one other brine with a different mineral salt concentration than the monovalent and polyvalent brine, wherein the monovalent and at least one other brine are used to produce concrete.

12. The method of claim 11, wherein seawater is supplied to a nanofiltration unit in the selected brine flow production system to separate the seawater into monovalent and polyvalent brine.

13. The method according to claim 11 or 12, wherein the method further comprises: A portion of the monovalent brine is processed in a reverse osmosis unit within a seawater desalination system connected to the selected brine flow production system to produce reverse osmosis cut-off liquid and desalinated water.

14. The method of claim 13, wherein the method further comprises: The reverse osmosis retentate is processed in a brine concentration unit to produce a first other brine.

15. The method of claim 14, wherein the method further comprises: At least a portion of the first other brine is processed in at least one mineral settling tank and then in a boron removal unit to produce a second other brine.

16. The method of claim 15, wherein the at least one mineral settling device comprises a calcium carbonate settling device and a magnesium hydroxide settling device.

17. The method according to any one of claims 11 to 16, wherein the method further comprises: The polyvalent brine is processed in at least one mineral removal unit to produce a third additional brine.

18. The method of claim 17, wherein the at least one mineral removal unit comprises a sulfate removal unit and a magnesium removal unit.

19. The method according to any one of claims 14 to 18, wherein the monovalent brine, and the first other brine or the second other brine or the third other brine or any combination thereof are used to produce concrete.

20. The method according to any one of claims 14 to 19, wherein the first other brine has a higher mineral salt concentration than the monovalent brine.

21. The method according to any one of claims 15 to 19, wherein the second additional brine is a low calcium chloride brine having a calcium chloride concentration of about 5,000 mg / L to about 100,000 mg / L.

22. The method according to any one of claims 17 to 21, wherein the third additional brine is a high calcium chloride brine having a calcium chloride concentration of at least about 200,000 mg / L.

23. The method of claim 22, wherein the calcium chloride concentration of the third additional saline solution is from about 200,000 mg / L to about 350,000 mg / L.

24. A system for producing concrete using brine, the system comprising: The selected brine flow production system is configured to produce monovalent and polyvalent brine from seawater and to produce at least one other brine with a mineral salt concentration different from that of the monovalent and polyvalent brine. as well as A concrete production unit wherein at least a portion of the monovalent brine is fed into the concrete production unit together with a binder and aggregate to produce a first mixture, and the at least one other brine is fed into the concrete production unit together with a binder and aggregate to produce a second mixture, the concrete production unit being configured to mix the first mixture and the second mixture to form concrete.

25. The system of claim 24, wherein the selected brine flow production system includes a nanofiltration unit for separating seawater into monovalent and polyvalent brine.

26. The system of claim 24 or 25, wherein the system further comprises a seawater desalination system connected to the selected brine flow production system.

27. The system of claim 26, wherein the seawater desalination system includes a reverse osmosis unit for processing a portion of the monovalent brine output from the nanofiltration unit into reverse osmosis cut-off liquid and desalinated water.

28. The system of claim 27, wherein the selected brine flow production system further comprises a brine concentration unit for processing the reverse osmosis retentate output from the reverse osmosis unit into a first other brine.

29. The system of claim 28, wherein the selected brine flow production system further comprises at least one mineral settling tank and a boron removal unit, the mineral settling tank and the boron removal unit being used to process at least a portion of the first other brine output from the brine concentration unit into a second other brine.

30. The system of claim 29, wherein the at least one mineral settling device comprises a calcium carbonate settling device and a magnesium hydroxide settling device.

31. The system according to any one of claims 24 to 30, wherein the selected brine flow production system further comprises at least one mineral removal unit for processing the polyvalent brine output from the nanofiltration unit into a third other brine.

32. The system of claim 31, wherein the at least one mineral removal unit comprises a sulfate removal unit and a magnesium removal unit.

33. The system according to any one of claims 28 to 32, wherein the first other brine or the second other brine or the third other brine or any combination of the other brines is used to produce the second mixture.

34. The system according to any one of claims 24 to 33, wherein the concrete production unit comprises a first mixer, a second mixer, and a third mixer, wherein the first mixture is produced in the first mixer, the second mixture is produced in the second mixer, and the first mixture and the second mixture are mixed in the third mixer to form concrete.

35. The system of claim 34, wherein the concrete production unit includes a 3D concrete printer.

36. The system of claim 35, wherein the 3D concrete printer comprises a first screw pump and a second screw pump, a first mixture output from a first mixer is fed into the first screw pump, and a second mixture output from a second mixer is fed into the second screw pump.

37. The system of claim 35 or 36, wherein the 3D concrete printer further comprises an online static mixer, wherein the first mixture and the second mixture are delivered to the online static mixer via the first screw pump and the second screw pump and mixed to form concrete.

38. The system of claim 37, wherein the 3D concrete printer further comprises a nozzle for delivering concrete into the nozzle for 3D printing of concrete.

39. A method for producing concrete using brine, the method comprising: a) Supplying seawater to a selected brine flow production system to produce monovalent brine and polyvalent brine, and to produce at least one other brine with a mineral salt concentration different from that of the monovalent brine and the polyvalent brine; as well as b) Transporting at least a portion of the monovalent brine to a concrete production unit and mixing it with a binder and aggregates to produce a first mixture; transporting the at least one other brine to the concrete production unit and mixing it with a binder and aggregates to produce a second mixture; and mixing the first mixture and the second mixture in the concrete production unit to form concrete.

40. The method of claim 39, wherein in a), seawater is supplied to a nanofiltration unit in the selected brine flow production system to separate the seawater into monovalent brine and polyvalent brine.

41. The method according to claim 39 or 40, wherein a) further comprises: A portion of the monovalent brine is processed in a reverse osmosis unit within a seawater desalination system connected to the selected brine flow production system to produce reverse osmosis cut-off solution and desalinated water.

42. The method of claim 41, wherein a) further comprises: The reverse osmosis retentate is processed in a brine concentration unit to produce a first other brine.

43. The method of claim 42, wherein a) further comprises: At least a portion of the first other brine is processed in at least one mineral settling tank and then in a boron removal unit to produce a second other brine.

44. The method of claim 43, wherein the at least one mineral settling device comprises a calcium carbonate settling device and a magnesium hydroxide settling device.

45. The method according to any one of claims 39 to 44, wherein a) further comprises: The polyvalent brine is processed in at least one mineral removal unit to produce a third additional brine.

46. ​​The method of claim 45, wherein the at least one mineral removal unit comprises a sulfate removal unit and a magnesium removal unit.

47. The method according to any one of claims 42 to 46, wherein the first other brine or the second other brine or the third other brine or any combination of the other brines is conveyed to the concrete production unit to produce the second mixture.

48. The method of claim 47, wherein the first additional brine is delivered to the concrete production unit to produce the second mixture.

49. The method of claim 47, wherein the second additional brine and the third additional brine are conveyed to the concrete production unit to produce the second mixture.

50. The method of claim 49, wherein the second other brine and the third other brine are mixed in a ratio of about 3:2 to produce the second mixture.

51. The method according to any one of claims 39 to 50, wherein the first mixture and the second mixture are mixed in a ratio of about 1:1 to form concrete.

52. The method according to any one of claims 42 to 51, wherein the first other brine has a higher mineral salt concentration than the monovalent brine.

53. The method according to any one of claims 43 to 52, wherein the second additional brine is a low calcium chloride brine having a calcium chloride concentration of about 5,000 mg / L to about 100,000 mg / L.

54. The method according to any one of claims 45 to 53, wherein the third additional brine is a high calcium chloride brine having a calcium chloride concentration of at least about 200,000 mg / L.

55. The method of claim 54, wherein the calcium chloride concentration of the third additional saline solution is from about 200,000 mg / L to about 350,000 mg / L.

56. The method according to any one of claims 39 to 55, wherein the monovalent brine used to produce the first mixture is diluted with water, preferably the monovalent brine is diluted with water in a ratio of about 1:

1.

57. The method according to any one of claims 39 to 56, wherein the binder used to produce the first mixture comprises one or more of the following: silicate cement, calcined clay, granulated blast furnace slag powder, or limestone powder.

58. The method of claim 57, wherein the binder comprises silicate cement, calcined clay, and limestone powder.

59. The method according to any one of claims 39 to 58, wherein the aggregate used to produce the first mixture comprises sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

60. The method according to any one of claims 39 to 59, wherein the ratio of aggregate to binder in the first mixture is about 1:

1.

61. The method according to any one of claims 39 to 60, wherein the ratio of the monovalent brine to the aggregate in the first mixture is about 0.28:

1.

62. The method according to any one of claims 39 to 61, wherein the first mixture further comprises about 0.6 wt.% to 1 wt.% of a high-efficiency water-reducing agent.

63. The method of claim 62, wherein the first mixture has a spreading diameter of at least 150 mm in the slump flow test.

64. The method according to any one of claims 39 to 63, wherein the first mixture comprises about 34 wt.% to about 52 wt.% sand, about 17 wt.% to about 26 wt.% silicate cement, about 10 wt.% to about 17 wt.% calcined clay, about 5 wt.% to about 9 wt.% limestone powder, about 10 wt.% to about 20 wt.% monovalent brine and about 0.6 wt.% to about 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water at a ratio of about 1:

1.

65. The method according to any one of claims 39 to 64, wherein the first mixture comprises about 44 wt.% sand, 22 wt.% silicate cement, 14 wt.% calcined clay, 7 wt.% limestone powder, 12 wt.% monovalent brine and 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water in a ratio of about 1:

1.

66. The method according to any one of claims 39 to 65, wherein the binder used to produce the second mixture comprises limestone powder.

67. The method according to any one of claims 39 to 66, wherein the aggregate used to produce the second mixture comprises sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

68. The method according to any one of claims 39 to 67, wherein the ratio of aggregate to binder in the second mixture is about 1:

1.

69. The method according to any one of claims 39 to 68, wherein the ratio of the at least one other brine to the binder in the second mixture is about 0.3:

1.

70. The method according to any one of claims 39 to 69, wherein the second mixture comprises about 34 wt.% to about 52 wt.% of sand, about 34 wt.% to about 52 wt.% of limestone powder, and about 10 wt.% to about 20 wt.% of at least one other brine.

71. The method according to any one of claims 39 to 70, wherein the second mixture comprises about 44 wt.% sand, 44 wt.% limestone powder and 12 wt.% at least one other brine.

72. The method according to any one of claims 39 to 71, wherein the first mixture is produced in a first mixer in the concrete production unit, the second mixture is produced in a second mixer in the concrete production unit, and the first mixture and the second mixture are mixed in a third mixer in the concrete production unit to produce concrete.

73. The method of claim 72, wherein the concrete production unit comprises a 3D concrete printer, a first mixture output from a first mixer is fed to a first screw pump in the 3D concrete printer, and a second mixture output from a second mixer is fed to a second screw pump in the 3D concrete printer.

74. The method of claim 73, wherein the first mixture and the second mixture are conveyed to an online static mixer via a first screw pump and a second screw pump and mixed to form concrete.

75. The method of claim 74, wherein concrete is deposited via a nozzle in a 3D concrete printer to form a 3D printed concrete product.

76. A method for producing concrete using brine, the method comprising: The binder, aggregate, and monovalent brine are mixed to produce a first mixture; A binder, aggregate, and at least one other brine with a mineral salt concentration different from that of the monovalent brine are mixed to produce a second mixture; and the first mixture and the second mixture are mixed to form concrete.

77. The method of claim 76, wherein the monovalent brine is obtained by processing seawater through a nanofiltration unit.

78. The method according to claim 76 or 77, wherein the monovalent brine used to produce the first mixture is diluted with water, preferably the monovalent brine is diluted with water in a ratio of about 1:

1.

79. The method according to any one of claims 76 to 78, wherein a first other brine is used to produce the second mixture, the first other brine having a higher mineral salt concentration than the monovalent brine.

80. The method according to any one of claims 76 to 78, wherein the second other brine and a third other brine are used to produce the second mixture, the second other brine having a low calcium chloride concentration of about 5,000 mg / L to about 100,000 mg / L, and the third other brine having a high calcium chloride concentration of at least about 200,000 mg / L.

81. The method of claim 80, wherein the calcium chloride concentration of the third additional saline solution is from about 200,000 mg / L to about 350,000 mg / L.

82. The method according to claim 80 or 81, wherein the second other brine and the third other brine are mixed in a ratio of about 3:2 to produce the second mixture.

83. The method according to any one of claims 76 to 82, wherein the first mixture and the second mixture are mixed in a ratio of about 1:1 to form concrete.

84. The method according to any one of claims 76 to 83, wherein the binder used to produce the first mixture comprises one or more of the following: silicate cement, calcined clay, granulated blast furnace slag powder, or limestone powder.

85. The method of claim 84, wherein the binder comprises silicate cement, calcined clay, and limestone powder.

86. The method according to any one of claims 76 to 85, wherein the aggregate used to produce the first mixture comprises sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

87. The method according to any one of claims 76 to 86, wherein the ratio of aggregate to binder in the first mixture is about 1:

1.

88. The method according to any one of claims 76 to 87, wherein the ratio of the monovalent brine to the aggregate in the first mixture is about 0.28:

1.

89. The method according to any one of claims 76 to 88, wherein the first mixture further comprises about 0.6 wt.% to 1 wt.% of a high-efficiency water-reducing agent.

90. The method of claim 89, wherein the first mixture has a spreading diameter of at least 150 mm in the slump flow test.

91. The method according to any one of claims 76 to 90, wherein the first mixture comprises about 34 wt.% to about 52 wt.% sand, about 17 wt.% to about 26 wt.% silicate cement, about 10 wt.% to about 17 wt.% calcined clay, about 5 wt.% to about 9 wt.% limestone powder, about 10 wt.% to about 20 wt.% monovalent brine and about 0.6 wt.% to about 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water at a ratio of about 1:

1.

92. The method according to any one of claims 76 to 91, wherein the first mixture comprises about 44 wt.% sand, 22 wt.% silicate cement, 14 wt.% calcined clay, 7 wt.% limestone powder, 12 wt.% monovalent brine and 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water in a ratio of about 1:

1.

93. The method according to any one of claims 76 to 92, wherein the binder used to produce the second mixture comprises limestone powder.

94. The method according to any one of claims 76 to 93, wherein the aggregate used to produce the second mixture comprises sand, preferably fine quartz sand with a particle size of about 0.125 mm to 2 mm.

95. The method according to any one of claims 76 to 94, wherein the ratio of aggregate to binder in the second mixture is about 1:

1.

96. The method according to any one of claims 76 to 95, wherein the ratio of the at least one other brine to the binder in the second mixture is about 0.3:

1.

97. The method according to any one of claims 76 to 96, wherein the second mixture comprises about 34 wt.% to about 52 wt.% of sand, about 34 wt.% to about 52 wt.% of limestone powder, and about 10 wt.% to about 20 wt.% of at least one other brine.

98. The method according to any one of claims 76 to 97, wherein the second mixture comprises about 44 wt.% sand, 44 wt.% limestone powder and 12 wt.% at least one other brine.

99. The method according to any one of claims 76 to 97, wherein the concrete produced by said method is suitable for 3D printing.

100. A selected brine stream production system and seawater desalination system for producing multiple brine streams for use in concrete production, comprising: Nanofiltration units are used to separate seawater into monovalent and polyvalent brine. The reverse osmosis unit is used to process a portion of the monovalent brine output from the nanofiltration unit into reverse osmosis retainer and desalinated water; A brine concentration unit is used to process the reverse osmosis retentate output from the reverse osmosis unit into a first other brine. A calcium carbonate settling tank, a magnesium hydroxide settling tank, and a boron removal unit are used to process at least a portion of a first other brine output from a brine concentration unit into a second other brine. The sulfate removal unit and magnesium removal unit are used to process the multivalent brine output from the nanofiltration unit into a third type of brine. The other brine salts have different mineral salt concentrations than the monovalent and polyvalent brine salts, and The monovalent brine and any one or more of the other brines are used to produce concrete.

101. A method for producing multiple brine streams for use in concrete production, the method comprising: Seawater is supplied to a nanofiltration unit to separate it into monovalent and polyvalent brine. Part of the monovalent brine is processed in the reverse osmosis unit to produce reverse osmosis retainer and desalinated water; The reverse osmosis retentate is processed in a brine concentration unit to produce a first additional brine; At least a portion of the first other brine is processed in a calcium carbonate settling tank and a magnesium hydroxide settling tank, and then processed in a boron removal unit to produce a second other brine. The polyvalent brine is processed in a sulfate removal unit and a magnesium removal unit to produce a third other brine; The other brine salts have different mineral salt concentrations than the monovalent and polyvalent brine salts, and The monovalent brine and any one or more of the other brines are used to produce concrete.

102. A method for producing 3D-printable concrete using salt water, the method comprising: Seawater is supplied to a nanofiltration unit to separate it into monovalent and polyvalent brine. Part of the monovalent brine is processed in the reverse osmosis unit to produce reverse osmosis retainer and desalinated water; The reverse osmosis retentate is processed in a brine concentration unit to produce a first other brine. At least a portion of the first other brine is processed in a calcium carbonate settling tank and a magnesium hydroxide settling tank, and then processed in a boron removal unit to produce a second other brine; The polyvalent brine is processed in a sulfate removal unit and a magnesium removal unit to produce a third additional brine; The binder, aggregate, high-efficiency water-reducing agent and the monovalent brine are mixed to produce a first mixture; To produce a second mixture, the binder, aggregate, and the first other brine are mixed, or the binder, aggregate, and the second other brine are mixed with the third other brine. The first mixture and the second mixture are mixed to form concrete.

103. A composition comprising about 44 wt.% sand, 22 wt.% silicate cement, 14 wt.% calcined clay, 7 wt.% limestone powder, 12 wt.% monovalent brine and 1 wt.% high-efficiency water-reducing agent, wherein the monovalent brine is diluted with water in a ratio of about 1:

1.

104. The composition of claim 103, wherein the monovalent brine is obtained by processing seawater through a nanofiltration unit.

105. The composition according to claim 103 or 104, wherein the diluted monovalent saline solution has the components provided in column b) of FIG8.

106. A composition comprising about 44 wt.% sand, 44 wt.% limestone powder and 12 wt.% brine.

107. The composition according to claim 106, wherein the brine has the components provided in column a) of FIG9.

108. The composition according to claim 106, wherein the brine has the components provided in column b) of FIG9.

109. A concrete mixture comprising a mixture of the composition of any one of claims 103 to 105 and the composition of any one of claims 106 to 108 in a ratio of about 1:

1.

110. The concrete mixture of claim 109, wherein the concrete mixture is suitable for 3D printing.

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