Method of treating byproduct streams containing sodium sulfate

Abstract

The present disclosure relates to new methods and processes of byproduct conversion, wastewater remediation, byproduct upcycling / recycling, and sustainable cyclic methods thereof.

Description

Docket No.: 1149704.092013METHOD OF TREATING BYPRODUCT STREAMS CONTAINING SODIUM SULFATERelated Applications

[0001] The present invention relates to and claims benefit of priority to U. S. Provisional Application Numbers 63 / 725,104, filed on November 26, 2024 and 63 / 755,541 filed February' 7, 2025, and Finnish Application Number FI 20255153, filed on February' 20, 2025, the contents of all of which are incorporated by reference in their entireties herein.

[0002] All patents, patent applications and publications cited herein are hereby incorporated by reference in their entirety. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.

[0003] This patent disclosure contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the U. S. Patent and Trademark Office patent file or records, but otherwise reserves any and all copyright rights.FIELD OF THE INVENTION

[0004] The present disclosure generally relates to new methods and processes of byproduct conversion, wastewater remediation, byproduct upcycling / recycling, and sustainable cyclic methods thereof.BACKGROUND OF THE INVENTION

[0005] Sodium sulfate is a substantial byproduct derived from a variety of industrial sectors including pulp and paper, mining, textiles, and cathode active material production industries. For example, electric vehicle (EV) battery' gigafactories generate substantial quantities of byproduct containing sodium sulfate (Na2SO4). To put this into perspective, circa 4.5 million tons of Na2SO4 is generated annually in the global precursor cathode active material (pCAM) production of 8 million tons. Na2SO4 is not toxic, but high sulfate concentrations cause water salinity7, harm the ecosystem and can be very dangerous to ruminants like moose and cattle.Docket No.: 1149704.092013As the batten- plants ramp up production, byproduct streams and their content are becoming critical considerations for obtaining the legislative and social license to operate.

[0006] The main commercial Na2SO4 treatment technologies are based on NazSCU crystallization or precipitation of sulfate as sparingly soluble compounds, e.g., as gypsum and ettringite. Crystallization is simple but its operating costs are rather high due to its high energy consumption. Precipitation requires huge amount of chemicals and handling of low-value end products. NazSCh can be also upcycled in caustic and acid by bipolar electrodialysis (BPED), but the required purification of the NazSCh feed and concentration of caustic and acid to commercial market concentration make the technology costly and complex.

[0007] Therefore, based on the foregoing, a cost-effective industrial byproduct conversion and recycling process is desired.SUMMARY OF THE INVENTION

[0008] The present invention relates to new methods and processes of byproduct conversion, wastewater remediation, byproduct upcycling / recy cling, and sustainable cyclic methods thereof. Described herein is a cyclic carbonate conversion process for treatment of byproducts comprising NazSO-i. It is a specific object of the invention to provide methods for producing ammonium sulfate and one or more carbonic acid salts from a sodium sulfate byproduct stream and to provide compositions produced by any of the following methods.

[0009] In one aspect, the present invention provides a method of producing ammonium sulfate and one or more carbonic acid salts from a sodium sulfate byproduct stream, the method comprising: (a) contacting the sodium sulfate byproduct stream with a carbonation reagent under carbonation conditions, thereby producing a liquid stream comprising ammonium sulfate and a solid stream comprising one or more carbonic acid salts; (b) isolating the solid stream from the liquid stream, thereby producing a solid stream comprising one or more carbonic acid salts and a liquid stream comprising ammonium sulfate; (c) isolating the one or more carbonic acid salts from the solid stream, thereby producing a carbonic acid salt; and (d) subjecting the liquid stream to a post-treatment process, thereby producing ammonium sulfate.

[0010] In embodiments of the method, the one or more carbonic acid salts comprises sodium bicarbonate.Docket No.: 1149704.092013

[0011] In certain embodiments, the method further comprises prior to step (a): dissolving a solid sodium sulfate byproduct to form the sodium sulfate byproduct stream, and / or concentrating the sodium sulfate byproduct stream.

[0012] In embodiments of the method, a) the carbonation reactant comprises ammonium bicarbonate, ammonium carbonate, a combination of ammonia and carbon dioxide, or any combination thereof; b) the method comprises agitating the sodium sulfate byproduct stream with the carbonation reagent; and c) wherein the carbonation conditions comprise at least one carbonation reactant, a pH of about 8 to about 10, and a temperature of about 20 °C to about 60 °C.

[0013] In embodiments of the method, the carbonation conditions further comprise adding a seed crystal comprising sodium bicarbonate.

[0014] In certain embodiments, the method further comprises subjecting the carbonic acid salts to heat, thereby producing sodium carbonate and carbon dioxide.

[0015] In embodiments of the method, a) the carbonation reactant is recycled from the sodium sulfate byproduct stream; b) the carbon dioxide is produced from the post-treatment process according to step (d) of the method; and / or the heating step of the method; c) the seed crystal comprising sodium bicarbonate is produced by the sodium bicarbonate of the foregoing method; d) the ammonium bicarbonate comprises ammonium bicarbonate produced by reacting ammonia with carbon dioxide produced by the same plant producing the byproduct stream of the method; or e) any combination thereof.

[0016] In certain embodiments, the method further comprises pre-treating the byproduct stream prior to step (a), wherein pretreating comprises: a) filtering the solid impurities from the byproduct stream; b) adjusting the pH of the byproduct stream to a pH of about 6 to about 8, thereby precipitating impurities that precipitate at a pH of about 6 to about 8, and filtering off the impurities; c) adjusting the pH of byproduct stream further to about 8 to about 10, thereby precipitating impurities that precipitate at a pH from about 8 to about 10, and filtering off the impurities; d) allowing metals to precipitate as low soluble carbonates, and filtering off the impurities; e) treating the byproduct stream with one or more ion exchange methods; Ij treating the byproduct stream with adsorbent media or g) any combination of (a)-(f).

[0017] In embodiments of the method, the byproduct stream can be pretreated before or after concentrating the byproduct stream.Docket No.: 1149704.092013

[0018] In embodiments of the method, subjecting the ammonium sulfate liquid stream to a post-treatment process comprises: a) filtering solid impurities from the liquid stream; b) decreasing the pH to about 4 to about 6, thereby releasing CO2; c) adjusting the pH of the liquid stream to about 7 to about 8; d) concentrating the liquid stream, thereby producing a concentrated liquid stream or a dry ammonium sulfate product; or e) any combination thereof.

[0019] In embodiments of the method, subjecting the solid stream to a post-treatment process comprises: a) heating the solid stream comprising carbonic acids salts to about 50 °C to about 500 °C, thereby producing sodium carbonate; b) dissolving the sodium carbonate, thereby producing a solution; and c) re-precipitating the solution, thereby producing sodium bicarbonate.

[0020] In certain embodiments, the method further comprises treating the liquid stream or the solution with Ca(OH)2)) and removing the solids.

[0021] In embodiments of the method, the sodium sulfate byproduct stream comprises a solid, an aqueous solution, and / or an aqueous slurry comprising a sodium sulfate byproduct derived from a battery manufacturing process and / or a precursor cathode active material (pCAM) production process, a mining operation, a hydrometallurgical process, a forest industry operation, a logging operation, a wood product manufacturing process, a paper manufacturing process, a textile manufacturing process, or any industrial process, and further wherein the sodium sulfate byproduct stream comprises: a) a transition metal impurity concentration of about 0.1 mg / L to about 50,000 mg / L; b) a heavy metal impurity concentration of about 0.1 mg / L to about 50,000 mg / L; c) a dissolved organic carbon (DOC) impurity concentration of about 1 mg / L to about 1000 mg / L; and d) a pH and ammonia concentration sufficient to produce carbonation conditions upon addition of CO2 and / or ammonium bicarbonate.

[0022] In another aspect, the present invention provides a composition comprising sodium bicarbonate produced by any of the foregoing methods.

[0023] In another aspect, the present invention provides a composition comprising ammonium sulfate produced by any of the foregoing methods.BRIEF DESCRIPTION OF THE FIGURES

[0024] FIG. 1 shows a non-limiting exemplary schematic for processes described herein. Optional unit processes are indicated by dashed boxes.Docket No.: 1149704.092013

[0025] FIG. 2 shows a non-limiting, exemplary flow diagram of the methods described herein.

[0026] FIG. 3 shows non-limiting, exemplary flow diagram of the methods described herein.

[0027] FIG. 4 shows non-limiting, exemplary flow diagram of the methods described herein.

[0028] FIG. 5 shows non-limiting, exemplary' flow diagram of the methods described herein.

[0029] FIG. 6 shows a non-limiting, exemplary flow diagram of the methods described herein and non-limiting, exemplary7carbonation conditions.

[0030] FIG. 7 shows anon-limiting, exemplary7FTIR of solid phases.

[0031] FIG. 8 shows non-limiting, exemplary7XRD spectra.DETAILED DESCRIPTION OF THE INVENTION

[0032] Described herein is a cyclic carbonate conversion process for treatment of byproducts comprising Na2SO-i. In exemplary embodiments of this process, water comprising Na2SO4 is reacted with ammonium carbonate or bicarbonate salt, or nitrogen containing salt and carbon dioxide, forming NaHCO.fNaiCO? product and ammonium sulfate stream. The NaHCO3 / Na2CO3 product can be recycled back to industrial plant e.g., for use as base in pCAM precipitation, recycling or as pH adjustment chemical for water treatment, or sold elsewhere. The ammonium sulfate can be purified and, for example, used as fertilizer.

[0033] Detailed descriptions of one or more embodiments are provided herein. It is to be understood, however, that the invention can be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the invention in any appropriate manner.

[0034] The singular forms “a”, "an" and “the” include plural reference unless the context clearly dictates otherwise. The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and / or the specification can mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

[0035] Wherever any of the phrases “for example,” “such as,” “including” and the like are used herein, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise. Similarly, “an example,” “exemplary” and the like are understood to be nonlimiting.Docket No.: 1149704.092013

[0036] The term “substantially” allows for deviations from the descriptor that do not negatively impact the intended purpose. Descriptive terms are understood to be modified by the term “substantially” even if the word “substantially” is not explicitly recited.

[0037] The terms “comprising” and “including” and “having” and “involving” (and similarly “comprises”, “includes,” “has,” and “involves”) and the like are used interchangeably and have the same meaning. Specifically, each of the terms is defined consistent with the common United States patent law definition of “comprising” and is therefore interpreted to be an open term meaning “at least the following,” and is also interpreted not to exclude additional features, limitations, aspects, etc. Thus, for example, “a process involving steps a, b, and c” means that the process includes at least steps a, b and c. Wherever the terms “a” or “an” are used, “one or more” is understood, unless such interpretation is nonsensical in context.

[0038] As used herein, the term “about” can refer to approximately, roughly, around, or in the region of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20 percent up or down (higher or lower). In embodiments, the term “about” can be denoted by

[0039] As used herein, the term “substantially the same” or “substantially” can refer to variability typical for a particular method is taken into account.

[0040] The terms “sufficient” and “effective”, as used interchangeably herein, can refer to an amount (e.g.. mass, volume, dosage, concentration, and / or time period) needed to achieve one or more desired result(s).

[0041] Before explaining at least one embodiment of the disclosure in detail, it is to be understood that the disclosure is not necessarily limited in its application to the details set forth in the following description or exemplified by the examples. The disclosure can be used for other embodiments or of being practiced or carried out in various ways. Other compositions, compounds, methods, features, and advantages of the disclosure will be or become apparent to one having ordinary skill in the art upon examination of the following drawings, detailed description, and examples. All such additional compositions, compounds, methods, features, and advantages can be included within this description, and be within the scope of the disclosure.Docket No.: 1149704.092013

[0042] Before describing the invention in detail, the following definitions are provided. Unless stated otherwise all terms are to be construed as they would be by a person skilled in the art.Definitions

[0043] As used herein, the term “adsorption media” can refer to any composition capable of adsorption. For example, the adsorption media can comprise activated carbon and any other adsorption

[0044] As used herein, the terms “aqueous suspension”, “aqueous slurry”, or “slurry” can refer to a heterogeneous mixture of a fluid, such as an aqueous fluid, that contains insoluble or sparingly soluble solid particles. Suspensions and slurries of the present invention comprise precipitates, crystals, large particles sufficiently large to completely settle under gravity, and / or small solid particles, such as colloidal particles, which do not completely settle or take a long time to settle completely under gravity.

[0045] As used herein, the term “concentrating” or “solids concentrating” can refer to any process by which a feed stream, byproduct stream, sodium sulfate byproduct stream, solution, solid-liquid mixture, slurry, or dispersion is treated to reduce liquid volume, thereby increasing the concentration of solutes, total suspended solids, and / or total solids in the concentrated stream. Concentration may be affected by removing all or part of the liquid, such as by gravity or centrifugal thickening, hydrocy cloning, or evaporation. In certain embodiments, concentrating can result in crystallization, precipitation, and / or agglomeration, of solid impurities, which can be subsequently removed by solid-liquid separation. In certain embodiments, concentrating can result in crystallization, precipitation, and / or agglomeration, of one or more desired solids, such as carbonic acid salts, sodium carbonate, and / or sodium bicarbonate, which can be subsequently isolated by solid-liquid separation.

[0046] As used herein, the terms “liquid stream” and “overflow” are used interchangeably and can refer to a liquid phase comprising a supernatant, filtrate, or liquid overflow from a solid-liquid separation process. A liquid stream can comprise any liquid, solution, or slurry' formed from a solid-liquid separation process. A liquid stream can comprise a reduced amount of suspended solids compared to the feed stream for the solid-liquid separation process. In certain embodiments, the liquid stream contains residual particulate matter from the solid stream. In certain embodiments, the liquid stream contains dissolved or partially dissolved material that can precipitate or cry stallize to form a solid material, which can thenDocket No.: 1149704.092013be subjected to a second solid-liquid separation process. Further as used herein, the terms “liquid stream’7and “overflow” can refer to the flow or stream of less dense material in a solid-liquid separation process. For example, the overflow can move from one stage of a process to another and comprise less dense and / or particulate carrying liquid.

[0047] As used herein, the term “post-treating” or “post-treatment” are used interchangeably to refer to one or more methods for treating a liquid stream and / or a solid stream produced according to the inventive carbonation method. In certain embodiments, post-treatment of the liquid stream comprises precipitation or crystallization of carbonic acid salts, followed by settling and / or filtration. In certain embodiments, post-treatment of the liquid stream comprises adjusting the liquid stream to a pH of about 9-12, about 8-11, about 8-10, or about 8-9 by addition of alkaline composition (e.g., NaOH), concentrating the liquid stream, settling, filtration, or a combination thereof, thereby producing said carbonic acid salts as a solid or an aqueous solution. In certain embodiments, post-treatment of the liquid stream comprises converting sodium carbonate to sodium bicarbonate in the liquid stream by adjusting the liquid stream to pH 7-9, 7.5-8.5, or preferably 8-8.5, separating the formed sodium bicarbonate by a solid-liquid separation process. In certain embodiments, posttreatment of the liquid stream comprises converting sodium bicarbonate to sodium carbonate by subjecting the liquid stream or isolated sodium bicarbonate from the liquid stream to heat, thereby producing sodium carbonate, wherein said heat comprises about 80 °C to about 200 °C. In certain embodiments, post-treatment of the liquid stream comprises optionally concentrating and allowing a second crop of crystals or precipitate to form.

[0048] As used herein, the term “precursor cathode active material” (pCAM) can refer to cathode precursor materials used to produce a cathode active material. For example, the precursor cathode active material can be combined with lithium hydroxide to produce a cathode active material (CAM) for battery' production. Byproducts from pCAM and / or battery manufacturing comprises sodium sulfate as a primary component. In certain embodiments sodium sulfate is present in the pCAM byproduct stream at about 0.1-40 wt%, about 0.5-30 wt%, about 1-20 wt%, about 2-18 wt%, about 4-16 wt%, about 5-15 wt%, about 6-14 wt%, about 8-12 wt%, or about 9-10 wt%.

[0049] As used herein, the term “pre-treating” or “pre-treatmenf ’ are used interchangeably to refer to one or more methods for treating a sodium sulfate byproduct stream prior to effecting the inventive carbonation method. In certain embodiments “pre-treatmenf ’ comprises removing one or more impurities comprising one or more solid impurities, transition metalDocket No.: 1149704.092013hydroxides, transition metals, heavy metals, organic impurities, polymeric impurities, or any combination thereof from the sodium sulfate byproduct stream.

[0050] As used herein, the term “recycling’" refers to (i) isolating one or more chemicals produced according to the inventive carbonation method and reusing said chemicals in a subsequent application of the inventive carbonation method, also referred to as a “circular” or “cyclical” process; and / or (ii) isolating one or more chemicals produced according to the inventive method and reusing said chemicals as a raw material or fertilizer in a separate process. In certain embodiments, a liquid or solid stream comprising sodium carbonate (Na2CO?) and / or sodium bicarbonate (NaHCOs) is subjected to acidification, such as by addition of H2SO4, during a post-treatment step to produce carbon dioxide (CO2), which is then captured and reused as a carbonation reagent in a subsequent application of the inventive carbonation method. CO2 can be generated and recycled in this manner from the liquid stream comprising carbonic acid salts (e.g., as the major component) or from a solid stream comprising sodium sulfate salts and carbonic acid salt impurities. In certain embodiments, carbonic acid salt products are recycled to adjust the pH of the sodium sulfate byproduct stream for removal of metal impurities during pre-treatment. In certain embodiments, sodium bicarbonate product(s) are used as seed crystals in carbonation. In certain embodiments, carbonic acid salt product is recycled back to a production plant for mining, battery, textile industry.

[0051] As used herein, the term “seed” or “seed crystal” can refer to a small piece of crystalline material, a single crystal, or a polycrystal material from which a larger crystal of typically the same material is grown. A seed crystal can be added to an industrial stream, a solution, suspension, dispersion, or a supersaturated solution to initiate, promote nucleation, or increase the rate of crystallization and / or precipitation of a desired material. In certain embodiments, a seed crystal may be added to a sodium sulfate byproduct stream or a pretreated sodium sulfate byproduct stream. In certain embodiments, the seed crystal can comprise sodium carbonate (Na2COs). or sodium bicarbonate (NaHCOs). or any combination thereof.

[0052] As used herein, the term “solid-liquid separation” can refer to the separation of two phases, a solid phase and a liquid phase, from a suspension, slurry, or dispersion. As used herein, the liquid phase from a solid-liquid separation is referred to interchangeably as a “liquid stream”, “overflow”, or “supernatant” or “filtrate”. As used herein, the solid phase from a solid-liquid separation is referred to interchangeably as a “solid stream” orDocket No.: 1149704.092013“underflow”, or “filter cake”. Solid-liquid separations encompass a wide range of processes, including but not limited to, screening through a screen or mesh, settling of a precipitate, crystals, or solids (i.e., gravity settling of solids), sedimentation, filtration (i.e., gravity filtration, pressure filtration, vacuum filtration, centrifugal filtration), centrifugation, or any combination thereof. Solid-liquid separations are effected by equipment, including but not limited to, gravity settlers, e.g., clarifiers, deep thickeners, lamella separators, settling tanks, lagoons, thickeners; sedimenting centrifuges, e.g., tubular bowl, skimmer pipe, disc, scroll discharge; hydrocyclones, e.g., conical, circulating bed; classifiers, e.g., hydraulic, mechanical, screens, sieve bends; gravity filters, e.g., deep bed, Nutsche; line filters, e.g., cartridges, strainers; pressure filters, e.g., continuous pressure, diatomaceous earth, fiber bed, filter press, horizontal element, pressure Nutsche, vertical element, sand, sheet filter, tubular element; filters with compression, e.g., belt press, membrane plate and frame, screw press, variable volume filter (e.g., tube); vacuum filters, e.g., top / bottom fed drum, disc, leaf, belt, pan, table, precoat drum; filter thickeners or crossflow filters, e.g., delayed cake, dynamic or high shear microfilters, low shear microfilters / ultrafilters; filtering centrifuges, e.g., basket, pendulum, oscillating, tumbling, plough / peeler, pusher, worm screen; flotation; magnetic filters, e.g., low gradient (drum, grid or belt), high gradient, by any solid-liquid separation equipment know n in the art, or any combination thereof.

[0053] As used herein, the terms “solid stream” and “underflow” are used interchangeably and can refer to a solid phase comprising an isolated solid, a crude solid, a solid slurry, isolated solid impurities, a settled solid, a screened solid, or a filter cake from a solid-liquid separation process. A solid stream can comprise any solid or solid slurry formed from a solidliquid separation process. A solid stream can comprise an increased amount of solids or suspended solids compared to the feed stream for the solid-liquid separation process. In certain embodiments, the solid stream contains residual material from the liquid stream. Further as used herein, the terms “solid stream” and “underflow” can refer to the flow or stream of more dense material in a solid-liquid separation process. For example, the underflow can move from one stage of a process to another and comprise denser and / or particulate carrying liquid.

[0054] As used herein, the term “stream” can refer to a continuous flow of material moving through a process. For example, the material can be a liquid, gas, solid, or any combination thereof. In certain embodiments, a stream can be fed as a “feed stream” into any industrial process relating to sodium sulfate byproduct processing or any industrial process referred toDocket No.: 1149704.092013herein. Further as used herein, the term "stream" can refer to a material, or a flow of material derived from or moving through a process, such as a production process, manufacturing process, and / or chemical or biochemical reaction. For example, the material can be a solution, a slurry, a liquid, gas, solid, or any combination thereof. In certain embodiments, a stream can be fed as a “feed stream’' into any industrial process relating to sodium sulfate byproduct processing or any industrial process referred to herein. In certain embodiments, a stream can comprise a “byproduct stream” comprising a secondary product stream, a waste stream, or a wastewater stream from any industrial process. In certain embodiments, a stream can comprise a sodium sulfate stream, a sodium sulfate byproduct stream a sodium sulfate waste stream, or a sodium sulfate wastewater stream from any industrial process. In certain embodiments, a stream can comprise a sodium sulfate stream comprising solid sodium sulfate. In certain embodiments, the solid sodium sulfate can be collected in a warehouse, such as at a battery plant, such as for several months, and / or trucked to an offsite location, and / or dissolved before treatment.

[0055] As used herein, the term “byproduct” can refer to any secondary product derived from any industrial process, production process, manufacturing process, and / or chemical or biochemical reaction. For example “byproduct” can refer to any aqueous solution, aqueous slurry, solid, or liquid material flows and / or streams of byproduct from its source through to recovery, recycling, and / or disposal. For example, byproduct can refer to a solid byproduct, a liquid byproduct, an aqueous byproduct, a byproduct solution, a byproduct slurry, a gaseous byproduct, a waste stream, or wastewater. For example, the source can be an industrial facility. For example, the industrial facility can comprise a pulp and paper facility, a textile facility, a mining facility, or a battery production facility. In certain embodiments, byproduct stream refers to any solid material, liquid material, or mixture thereof produced as byproduct from any process relating to battery manufacturing and / or recycling, pulp and paper manufacturing and / or or recycling, or textile manufacturing and / or or recycling. In certain embodiments, byproduct stream refers to a sodium sulfate byproduct stream comprising a solution, suspension, or slurry that comprises sodium sulfate In certain embodiments “byproduct” refers to an “aqueous byproduct” comprising an aqueous solution and / or slurry of a secondary product, such as sodium sulfate, and optionally further comprising other solid, liquid, or solution phase impurities. In certain embodiments, the “byproduct” comprises solid sodium sulfate, a sodium sulfate solution, or a sodium sulfate slurry. In certain embodiments sodium sulfate is present in the sodium sulfate byproduct stream at about 0.1-40 wt%, aboutDocket No.: 1149704.0920130.5-30 wt%, about 1-20 wt%, about 2-18 wt%, about 4-16 wt%, about 5-15 wt%, about 6-14 wt%. about 8-12 wt%, or about 9-10 wt%.

[0056] In certain embodiments the sodium sulfate byproduct stream further comprises solid impurities, metal impurities, heavy metal impurities, transition metal impurities, transition metal hydroxides, polymeric impurities, organic impurities, or any combination thereof.

[0057] In certain embodiments the sodium sulfate byproduct stream comprises one or more “transition metal impurities.” In embodiments, the transition metal impurities can comprise Ni, Mn, and / or Co. In embodiments, the transition metal impurities can comprise a concentration of about 0.0001-50 g / L, about 0.001-45 g / L, about 0.01-40 g / L, about 0.1-35 g / L, about 0.5-30 g / L, about 1-25 g / L. about 2-20g / L. about 4-15 g / L, about 6-12 g / L, or about 8-10 g / L. Transition metal impurities may comprise any oxidation state, salt form, or coordination state known in the art.

[0058] In certain embodiments the sodium sulfate byproduct stream comprises one or more “heavy metal impurities.” In embodiments, the heavy metal impurities can comprise antimony, arsenic, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, gold, iron, lead, manganese, mercury, nickel, platinum, silver, tellurium, thallium, tin. uranium, vanadium, and / or zinc, concentration of about 0.0001-50 g / L, about 0.001-45 g / L, about 0.01-40 g / L, about 0.1-35 g / L, about 0.5-30 g / L, about 1-25 g / L, about 2-20g / L, about 4-15 g / L, about 6-12 g / L, or about 8-10 g / L. Heavy metal impurities may comprise any oxidation state, salt form, or coordination state known in the art.

[0059] In certain embodiments the sodium sulfate byproduct stream comprises one or more “metal impurities” comprising one or more alkaline earth metals, one or more transition metals, and / or one or more heavy metals. In embodiments, the metal impurities can comprise Ca, Mg, Fe, and / or Al. In embodiments, the metal impurities can comprise a concentration of about 0.0001-50 g / L, about 0.001-45 g / L, about 0.01-40 g / L, about 0.1-35 g / L, about 0.5-30 g / L, about 1-25 g / L, 2-20g / L, about 4-15 g / L, about 6-12 g / L. or about 8-10 g / L. The metal impurities may comprise any oxidation state, salt form, or coordination state known in the art.

[0060] In certain embodiments the sodium sulfate byproduct stream comprises one or more “organic impurities” at concentration of dissolved organic carbon (DOC) of about 1-1000 mg / L, about 5-950 mg / L, about 10-900 mg / L, about 20-850 mg / L, about 30-800 mg / L, about 40-750 mg / L, about 50-700 mg / L. about 60-650 mg / L, about 70-600 mg / L, about 80-550Docket No.: 1149704.092013mg / L, about 90-500 mg / L, about 100-450 mg / L, about 150-400 mg / L, about 200-350 mg / L, or about 250-300 mg / L. Organic impurities may comprise any organic chemical or polymeric material known the art.CARBONATION REAGENTS AND PRODUCTS

[0061] As used herein, the terms "carbonation" and “carbonate conversion'’ are used interchangeably to refer to treatment of a sodium sulfate byproduct stream according to the inventive carbonation method.

[0062] As used herein, the terms “carbonation conditions” and “carbonate conversion conditions” are used interchangeably to refer to a process by which a sodium sulfate byproduct stream or a pre-treated sodium sulfate byproduct stream is treated with a “carbonation reagent” to produce (i) a solid stream comprising one or more sodium sulfate salts and (ii) a liquid stream comprising one or more carbonic acid salts via a double displacement reaction. “Carbonation conditions” also refers to the specific reaction conditions (e.g., temperature and pH) under which the reaction is performed. For example, the pH of the carbonation conditions can comprise a pH of about 8 to about 10.

[0063] As used herein, the term “carbonation reagent” can refer to (i) ammonium bicarbonate (NH₄CO₃), (ii) carbon dioxide CO₂ and ammonia (NH₃), or (iii) any combination thereof. In some embodiments, the carbonation reagent is ammonium bicarbonate. In some embodiments, CO2 and ammonia are reacted to produce ammonium bicarbonate. In some embodiments, sodium bicarbonate can be added to the carbonation reaction. For example, the sodium bicarbonate can be added as a seed crystal.

[0064] As used herein, the term “carbonic acid salts” can refer to a compound comprising a carbonate salt (CO₃²⁻) or bicarbonate salt (H₂CO₃). For example, the carbonic acid salts can comprise sodium carbonate (Na₂CO₃), sodium bicarbonate (NaHCO₃), or a mixture thereof.UNITS

[0065] As used herein, the term “ppm” refers to parts per million, mass fraction of a solute in a solvent, or dry mass (mg) of added material (e.g., additive, solute, and / or particle) per mass (kg) of solvent, with units of mg / kg. For aqueous solutions, ppm refers to dry mass (mg) of added solute per volume (L) of water, with units of mg / L.

[0066] As used herein, the term “wt %” refers to dry mass of material (e.g., additive, solute, and / or particle) per mass (kg) of solvent, multiplied by 100%.Docket No.: 1149704.092013

[0067] As used herein, “ammonia"’ can refer to a composition consisting of a nitrogen atom and hydrogen atoms. As used herein, the terms “ammonia” and “ammoniacal nitrogen” can be used interchangeably. For example, ammonia can refer to a non-ionic ammonia (NH3) and ammonium ion (NHr+) in any form. For example, ammonia can refer to ammonium hydroxide (NFh OH ) or ammonium salt, such as ammonium carbonate ((NH₄⁺)₂CO₃²⁻). ammonium bicarbonate (NH₄⁺HCO₃⁻) and ammonium chloride (NH₄⁺Cl⁻). In embodiments, the ammonia described herein can be in a liquid, solid, or gaseous phase.

[0068] As used herein, the terms “recycle” and “upcycle” can be used interchangeably to refer to transforming a byproduct material into a product of higher value and / or quality, converting the byproduct material into a raw material, and / or reusing the byproduct material.Detailed Description

[0069] The present invention relates to methods of treating industrial byproduct streams and upcycling byproducts thereof. In embodiments, the present invention provides a method of producing ammonium sulfate and one or more carbonic acid salts from a sodium sulfate byproduct stream, the method comprising: (a) contacting the sodium sulfate byproduct stream with a carbonation reagent under carbonation conditions, thereby producing a liquid stream comprising ammonium sulfate and a solid stream comprising one or more carbonic acid salts; (b) isolating the solid stream from the liquid stream, thereby producing a solid stream comprising one or more carbonic acid salts and a liquid stream comprising ammonium sulfate; (c) isolating the one or more carbonic acid salts from the solid stream, thereby producing a carbonic acid salt; and (d) subjecting the liquid stream to a post-treatment process, thereby producing ammonium sulfate.

[0070] In embodiments, the carbonic acid salts can comprise sodium bicarbonate, sodium sulfate carbonate, sodium sulfate, and / or double salts thereof. For example, the carbonic acid salts can comprise double salts of sodium bicarbonate and carbonate and / or double salts of sodium carbonate and sodium sulfate. For example, the carbonic acid salts can comprise NaHCO₃, Na₂CO₃·NaHCO₃·2H₂O, Na₆(CO₃)(SO₄)₂, or any combination thereof. In embodiments, the carbonic acid salts can primarily comprise sodium bicarbonate.

[0071] In embodiments, step (a) can comprise agitating and / or mixing the sodium sulfate byproduct stream while under carbonation conditions. In embodiments, carbonation conditions comprise at least one carbonation reactant, a pH of about 8 to about 10, and aDocket No.: 1149704.092013temperature of about 20°C to about 60 °C. For example, the carbonation conditions can comprise a temperature of less than about 20°C. about 20°C, about 25°C. about 30°C, about 35°C, about 40°C, about 45°C, about 50°C, about 55°C, about 60°C, or greater than about 60°C. In embodiments the carbonation conditions can comprise a pH of less than about 7, about 7.5, about 8, about 8, about 8.5, about 9, about 9.5, about 10, about 10.5, or greater than about 10.5.

[0072] In some embodiments, the carbonation reaction can first be run at an elevated temperature, and subsequently left to mix in the reactor at room temperature, thereby precipitating carbonic acid salts from the liquid stream. In embodiments, the elevated temperature can comprise a temperature greater than about 20 °C and room temperature can comprise about 20 °C.

[0073] In embodiments, the carbonation conditions can comprise a pressure of about 1 bar to about 5 bar. For example, the carbonation conditions can comprise a pressure of about 1 bar, about 1.5 bar, about 2 bar, about 2.5 bar, about 3 bar, about 3.5 bar. about 4 bar, about 4.5 bar, about 5 bar, or greater than about 5 bar.

[0074] In embodiments, the at least one carbonation reactant comprises ammonium bicarbonate, ammonium carbonate, a combination of ammonia and carbon dioxide, or any combination thereof. In exemplary embodiments, the carbonation reactant can be ammonium bicarbonate (NH₄HCO₃). In embodiments, the ammonia can comprise gaseous or liquid ammonia. In embodiments, one or more of the carbonation reagents can be recycled and / or upcycled from the sodium sulfate byproduct stream or treatment processes described herein. For example, the carbon dioxide can comprise carbon dioxide produced from any of the methods described herein. For example, the carbon dioxide can comprise carbon dioxide produced by the post-treatment process described herein. For example, the ammonium bicarbonate can comprise ammonium bicarbonate produced by reacting ammonia and carbon dioxide produced by the same facility or process producing the sodium sulfate byproduct stream described herein.

[0075] In embodiments, the carbonation reaction can further comprise adding a seed crystal comprising sodium bicarbonate to the carbonation conditions. In embodiments, the seed crystal comprising sodium bicarbonate can comprise sodium carbonate produced by any one of the methods described herein. For example, the sodium bicarbonate can be produced fromDocket No.: 1149704.092013the carbonation conditions described herein. In some embodiments, if the byproduct stream comprises ammonia, the ammonia can be used in the carbonation reaction.

[0076] In embodiments, the carbonation reaction can comprise a molar ratio of NH₄⁺:SO₄²⁻ less than about 1.5: 1, about 1.5:1, about 1.75:1, about 2:1, about 2.25:1, about 2.5:1, or greater than about. For example, the molar ratio of NH₄⁺:SO₄²⁻ can be about 2:1. In embodiments, the carbonation reaction can comprise a molar ratio of Na⁺:NH₄⁺ in the range of less than about 0.5:1, about 0.75:1, about 1:1, about 1.25:1, about 1.5:1, or greater than about 1.5:1. For example, the molar ratio of Na⁺:NH₄⁺ can be about 1:1.

[0077] In embodiments, isolating the solid stream from the liquid stream in (b), can comprise settling, centrifugation, and / or filtration to form an isolated solid. In embodiments, the isolated solid can comprise sodium bicarbonate. For example, the solid and liquid stream can be separated by solid / liquid separation. For example, see the flow diagrams of Figures 2, 3, 4, 5 and 6 for non-limiting, exemplary methods of isolating the solid stream and liquid streams and post-treatment thereof. For example, the liquid stream can be cooled and allowed to settle. For example, the liquid stream can be cooled to about room temperature or below room temperature for about 5 hours to about 48 hours. As used herein, the term “room temperature’' can refer to about 25 °C to about 15 °C. For example, the liquid stream can be cooled to about 25 °C to about 5 °C. In some embodiments, the liquid stream can be cooled to below 5 °C. For example, the liquid stream can settle for less than about 5 hours, about 5 hours, about 10 hours, about 15 hours, about 20 hours, about 25 hours, about 30 hours, about 35 hours, about 40 hours, about 48 hours, or great than 48 hours. In some embodiments, precipitate can be crystallized by cooling to RT or below room temperature. In embodiments, the precipitate can comprise a NaHCOs main phase in a first filtration step. In embodiments, the precipitate can be combined with initial filtrated phases or treated separately. In embodiments, the precipitate can comprise NaHCO₃, Na₂SO₄, or a combination thereof. In embodiments, the sodium sulfate byproduct stream comprises a solid sodium sulfate byproduct, which can be dissolved to form a solution or a slurry prior to step (a). In embodiments, the sodium sulfate byproduct stream can be concentrated prior to step (a). The byproduct stream can be concentrated by any method known in the art known to a person of ordinary skill in the art. For example, the byproduct stream can be concentrated by evaporation. In embodiments, the byproduct stream can be concentrated to about 10 wt % to about 40 wt % sodium sulfate. For example, the sodium sulfate byproduct stream can be concentrated from an initial concentration of about 1-20 wt%, about 1-15 wt%, about 2-14Docket No.: 1149704.092013wt%, about 4-12 wt%, or about 6-10 wt% of sodium sulfate to a concentration of about 20-50 wt%. about 25-45 wt%, or about 30-40 wt% of sodium sulfate.

[0078] In certain embodiments of the method, the sodium sulfate byproduct stream comprises a solid, an aqueous solution, and / or an aqueous slurry comprising a sodium sulfate byproduct and / or wastewater. In embodiments, the sodium sulfate byproduct stream can be sourced from any process and / or facility producing a byproduct and / or waste stream comprising sodium sulfate. In embodiments, the process can comprise a manufacturing process. For example, the byproduct stream can comprise byproducts and / or wastewater comprising a solid, an aqueous solution, and / or an aqueous slurry comprising a sodium sulfate byproduct derived from a battery manufacturing process; byproducts and / or wastewater from a precursor cathode active material (pCAM) production process; byproducts and / or wastewater from a lithium-ion battery recycling process; and / or byproducts and / or wastewater from a mining operation, a hydrometallurgical process, a forest industry operation, a logging operation, a wood product manufacturing process, a paper manufacturing process, or a textile manufacturing process.

[0079] In certain embodiments of the method, the sodium sulfate byproduct stream comprises byproducts and / or wastewater from a battery manufacturing process and / or byproducts and / or wastewater from a precursor cathode active material (pCAM) production process.

[0080] In embodiments, the byproduct stream can comprise one or more metal impurities. For example, the metal impurities can be transition metal impurities, heavy metal impurities, or a combination thereof. For example, the byproduct stream can comprise a transition metal concentration of about 0.0001-50 g / L, about 0.001-45 g / L, 0.01-40 g / L, about 0.1-35 g / L, about 0.5-30 g / L, about 1-25 g / L, about 2-20g / L, about 4-15 g / L, about 6-12 g / L, or about 8-10 g / L; one or more heavy metal impurities at concentration of about 0.0001-50 g / L, about 0.001-45 g / L, about 0.01-40 g / L, about 0.1-35 g / L, about 0.5-30 g / L, about 1-25 g / L. about 2-20g / L, about 4-15 g / L, about 6-12 g / L, or about 8-10 g / L; one or more organic impurities at concentration level of dissolved organic carbon (DOC) of about 1-1000 mg / L, about 5-950 mg / L, about 10-900 mg / L, about 20-850 mg / L, about 30-800 mg / L, about 40-750 mg / L, about 50-700 mg / L, about 60-650 mg / L, about 70-600 mg / L, about 80-550 mg / L, about 90-500 mg / L, about 100-450 mg / L, about 150-400 mg / L, about 200-350 mg / L, or about 250-300 mg / L; a pH and ammonia concentration sufficient to produce the desired product. In embodiments, the transition metals can comprise Ni, Mn, and / or Co. In embodiments, the heavy metals can comprise comprising Cu, Cr, Pb, and / or Zn.Docket No.: 1149704.092013

[0081] In some embodiments, the concentration of the compounds in the byproduct stream can be used to determine whether the byproduct stream is concentrated before or after pretreatment. For example, if the metal concentration is less than about 10 mg / L, the byproduct stream can be concentrated before pre-treatment. In some embodiments, water hardness can be used to determine whether the byproduct stream is concentrated before or after pretreatment. For example, if the water hardness is less than about 200 mg / L, the byproduct stream can be concentrated before pretreatment. In embodiments, metal quantification in the byproduct stream can occur before pre-treatment, after pre-treatment, or both before and after pre-treatment.

[0082] In embodiments, the pretreatment can comprise: (a) filtering the solid impurities from the byproduct stream; (b) adjusting the pH of the byproduct stream to a pH of about 6 to about 8, thereby precipitating impurities that precipitate at a pH of about 6 to about 8, and filtering off the impurities; (c) adjusting the pH of byproduct stream further to about 8 to about 10, thereby precipitating impurities that precipitate at a pH from about 8 to about 10, and filtering off the impurities; (d) allowing metals to precipitate as low soluble carbonates, and filtering off the impurities; (e) treating the byproduct stream with one or more ion exchange methods; (!) treating the byproduct stream with adsorbent media, any pre-treatment method of steps (a)-(f).

[0083] In embodiments, impurities that precipitate at a pH of about 6 to about 8 can comprise transition metal salts, transition metal oxides, transition metal hydroxides, organic material, polymeric material, and preferably one or more aluminum salts and / or iron salts, wherein the aluminum salts and / or iron salts precipitate as one or more corresponding metal oxides or metal hydroxides comprising Fe(OH)2, Fe(OH)₃, Al(0H)3, and / or A1(OH)4.

[0084] In embodiments, impurities that precipitate at a pH from about 8 to about 10 can comprise alkaline earth metals, remaining transition metals, and / or heavy metal impurities to precipitate as one or more metal hydroxides comprising Ca(OH)2, Mg(OH)2, Ni(0H)2, Mn(0H)2, Co(OH)2, Cr(OH)3, Fe(OH)3, Pb(OH)2, Zn(OH)2, and / or Cu(OH)2); and / or (ii) allowing metals to precipitate as low soluble carbonates selected from the group consisting of CaCO3, MgCO₃, MgCO₃·3H₂O. MnCOs, FeCOs, PbCO3. NiCOs. ZnCO₃ or ZnCO₃·H₂O.

[0085] In embodiments, the pH adjustment can occur in a settler or clarifier. For example, as a result of the pH increase, the metals in the byproduct stream can form metal hydroxides which can more easily precipitate. In embodiments, longer retention times in settlers canDocket No.: 1149704.092013allow small, agglomerated metal hydroxides to precipitate. In some embodiments, a flocculant can be added to increase the settling rate. Non-limiting, exemplary flocculants can comprise polymers, including but not limited to copolymers. In embodiments, the polymers can be anionic, cationic, or neutrally charged polymers. For example, non-limiting, exemplary flocculants can comprise polyacrylamides, starches, celluloses, carboxymethyl cellulose, chitosan, a copolymer thereof, and / or any combination thereof. For example, the flocculants can comprise polymers and co-polymers comprising acrylamide moieties. For example, the polymers can comprise acrylamide with different charges, cationic, anionic or non-ionic. For example, the polymers can comprise acrylamide (AMD), (2-acrylamido-2-methyl-1-propanesulfonic acid) (AMPS), acrylic acid (AA). For example, the polymers can comprise a copolymer of acrylamide and one or more cationic monomer (e.g., acryloyloxy ethyltrimethylammonium chloride, methacryloyloxy ethyltrimethylammonium chloride, acrylamidopropyltrimethylammonium chloride andmethacry lamidopropyltrimethylammonium chloride). In embodiments, the polymer can comprise polysaccharides and / or poly phenolic compounds. For example, the polysaccharides can comprise cellulose, starch, chitin and chitosan compounds or any combination thereof. For example, polyphenolics can comprise tannin or lignin or any combination thereof.

[0086] In embodiments, the flocculant concentration can comprise about 0.1 ppm to about 1000 ppm. In embodiments, the flocculant can comprise any flocculant known in the art.

[0087] In embodiments, isolating the one or more carbonic acid salts from the solid stream in step (c) can comprise rinsing the solids, filtering the solids, or any combination thereof. For example, the rinsing can comprise washing the precipitate with warm water. In embodiments, the one or more carbonic acid salts isolated form the solid stream can comprise NaHCCh, Na₆(CO₃)(SO₄)₂, Na₆(CO₃)(SO₄)₂. In embodiments, the one or more carbonic acid salts can primarily comprise sodium bicarbonate. In embodiments, the one or more carbonic acid salts and further comprise sodium sulfate.

[0088] In embodiments, the sodium bicarbonate isolated from the solid stream can subjected to a temperature sufficient to produce sodium carbonate. In embodiments, the temperature can comprise about 50 °C to about 500 °C. For example, the temperature can comprise less than about 50 °C, about 50 °C, about 55 °C, about 60 °C, about 65 °C, about 70 °C, about 75 °C, about 80 °C, about 85 °C, about 90 °C, about 95 °C, about 100 °C, about 105 °C, about 110 °C, about 115 °C, about 120 °C. about 125 °C, about 130 °C, about 135 °C, about 140 °C, about 150 °C, about 160 °C, about 165 °C, about 170 °C, about 175 °C, about 180 °C,Docket No.: 1149704.092013about 190 °C, about 200 °C, about 225 °C, about 250 °C, about 275 °C, about 300 °C, about 325 °C, about 350 °C, about 375 °C, about 400 °C, about 425 °C. about 450 °C, about 475 °C, about 500 °C, or greater than about 500 °C. In embodiments, the process can comprise roasting, calcination, and / or drying of carbonic salts to sodium carbonate.

[0089] In embodiments, the sodium carbonate produced can be recycled back into the industrial process. In some embodiments, the carbonic acid salts produced (e.g., sodium carbonate and / or sodium bicarbonate) can be dissolved, thereby producing a solution. In embodiments, the solution can be reprecipitated thereby producing sodium bicarbonate with increased purity. In embodiments, the solution can be treated (e.g., with lime, Ba(OH)2 and / or sodium aluminate to precipitate sulfate and remove the precipitate) by solid liquid separation and reprecipitate thereby producing sodium bicarbonate with higher purity. In embodiments, the reprecipitation can comprise adjusting the pH of the solution to about 8 to about 9. In some embodiments, the sodium bicarbonate is recycled back into the carbonation reaction as a seed crystal comprising sodium bicarbonate. In some embodiments, the sodium carbonate can be recycled to produce carbon dioxide. In embodiments, the carbon dioxide can be recycled back into an industrial process or into the byproduct stream treatment process.

[0090] In embodiments, subjecting the liquid stream to a post-treatment process, thereby producing ammonium sulfate. In embodiments the post-treatment process can comprise filtering, a pH adjustment, concentrating the liquid stream, recycling of ammonium as ammonia or precipitated ammonium bicarbonate, recycling of sodium sulfate impurity from the liquid stream, or a combination thereof. For example, subjecting the ammonium sulfate liquid stream to a post-treatment process can comprise (a) filtering solid impurities from the liquid stream; (b) decreasing the pH to about 4 to about 6, thereby releasing carbonate as CO2; (c) adjusting the pH of the liquid stream to about 7 to about 8; (d) concentrating the liquid stream, thereby producing a concentrated liquid stream or a dry ammonium sulfate product; or any combination thereof. In embodiments, the ammonium sulfate liquid stream can be treated with lime (Ca(OH)2), thereby forming a CaSO₄ (e.g., CaSO₄, CaSO₄·0.5H₂O or CaSO₄·2H₂O) solid and ammonia-water solution. In embodiments, the solids can be removed. In embodiments the ammonia-water solution can be recycled back to the process as carbonation chemical (e.g., reacted with CO2 to form NH₄HCO₃). In embodiments, the temperature of the liquid stream can be adjusted to about 30-40 C, or to 20-30 C, or 10-20 C to reduce the solubilities of the salts in the liquid stream.Docket No.: 1149704.092013

[0091] In embodiments, step (b) of the post treatment process can further comprise concentrating the liquid stream, thereby increasing the concentration of carbonic salts in the liquid to saturation or supersaturation point and thereby precipitating the carbonic salt or salts from the liquid stream. In embodiments, the concentration of the ammonium sulfate can be retained at 20-30 wt-%, or 30-40% wt-%, maximum at 40-50 wt-% (e.g., below the saturation or supersaturation point of the ammonium sulfate). For example, the concentration liquid stream can be concentrated to precipitate out carbonic acid salts or a sodium impurity as ammonium bicarbonate and / or sodium sulfate. For example, the ammonium bicarbonate and / or sodium sulfate can be recycled back into the carbonation reaction.

[0092] In embodiments, the solid impurities can comprise carbonic acid salts. In embodiments, the carbonic acid salts can comprise sodium bicarbonate. In embodiments, the sodium bicarbonate can be subjected to heat, thereby producing sodium carbonate. In embodiments, the sodium carbonate produced can be recycled back into the industrial process. In some embodiments, the sodium carbonate produced can be dissolved, thereby producing a solution, and reprecipitated, thereby producing sodium bicarbonate. In some embodiments, the sodium bicarbonate is recycled back into the carbonation reaction as a sodium bicarbonate seed crystal. In some embodiments, the sodium carbonate can be recycled to produce carbon dioxide. In embodiments, the carbon dioxide can be recycled back into an industrial process or into the byproduct stream treatment process.

[0093] In embodiments the method comprises using and / or recycling the produced sodium carbonate and / or sodium bicarbonate back into a process stream related to (i) a battery manufacturing process; (ii) a precursor cathode active material (pCAM) production process; (iii) a lithium ion battery recycling process; and / or (iv) a mining operation, a hydrometallurgical process, a forest industry operation, a logging operation, a wood product manufacturing process, a paper manufacturing process, or a textile (e.g. viscose) manufacturing process.

[0094] In embodiments the method further comprises: (i) recycling the produced carbonic acid salts for use as an alkaline pretreatment for removal of said metal impurities (e.g., Ca2+, Mg2+, Mn at any oxidation state, and Zn at any oxidation state) from the sodium sulfate byproduct stream or as alkaline reagent for pH adjustment; (ii) recycling the produced bicarbonate as seed crystals for formation of the solid stream comprising sodium sulfate salts; (iii) recycling any unreacted carbonation reagent back into step (a); (iv) recycling or using the produced ammonium sulfate as a fertilizer; (v) recycling the CO2 formed in post-treatment ofDocket No.: 1149704.092013the solid stream comprising sodium sulfate salts as said carbonation reagent, (vi) production of the carbonation reagents (e.g., CO₂, sodium bicarbonate, and / or sodium carbonate) by the same plant producing the sodium sulfate byproduct stream; (vii) a cyclical process wherein one or more of said at least one carbonation reactants (e.g., CO2, sodium bicarbonate, and / or sodium carbonate) are originally obtained from the sodium sulfate byproduct stream; (viii) a cyclical process wherein the produced sodium bicarbonate and / or sodium carbonate is recycled back into said process stream related to said pCAM production process for use as (i) a base for pCAM precipitation or pCAM recycling; and / or (ii) as a pH adjustment chemical for water treatment; (ix) recycling part or all of CO2 isolated from the solid stream and / or the liquid stream for use as a recycled carbonation reagent; or (x) any combination of (i)-(ix). (i) recycling any unreacted carbonation reagent back into step (a); and / or (ii) separating the liquid stream comprising said carbonic acid salts and said unreacted carbonation reagent and recycling all or part of the liquid stream back into step (a).

[0095] In embodiments, the disclosure is drawn towards a carbonic acid salt composition or product. For example, the carbonic acid salt product can comprise sodium bicarbonate, sodium carbonate, or a combination thereof. In embodiments, the sodium bicarbonate and / or sodium carbonate comprises a purity in the range of about 60-95 wt%, about 70-95 wt %, about 80-95 wt %, or about 90-100 wt%. For example, in some embodiments, the product or composition can comprise primarily either sodium bicarbonate or sodium carbonate. In some embodiments, the composition or product comprises only sodium bicarbonate. In embodiments, the composition or product comprises only sodium carbonate.

[0096] In embodiments, the disclosure is drawn towards an ammonium sulfate composition or product. In embodiments, the ammonium sulfate composition or product comprises a purity in the range of about 50-95 wt%, about 70-95 wt %, about 80-95 wt %, or about 90-100 wt%.EXAMPLES

[0097] Examples are provided herein to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only, since alternative methods can be utilized to obtain similar results.EXAMPLE 1Docket No.: 1149704.092013

[0098] Example 1: Non-Limiting, Exemplary Na2SO4 treatment process by carbonate conversion

[0099] Reaction with ammonium bicarbonate / carbonate:

[0100] 1. Na2SO4(aq) stream is optionally concentrated from< 10 wt-% concentration to>= 20 wt-% in an evaporator

[0101] 2. Na₂SO₄(aq) is reacted with ammonium bicarbonate and / or carbonate at pH> 7. For example, the reaction pH range is adjusted between about 8-9. The reaction temperature is to about > 25 °C. For example, between about 30-40 °C.

[0102] 3. The formed first product with lower solubility (primarily NaHCO₃) is separated from the liquid stream by Solid / Liquid (S / L) separation process

[0103] 4. The first product NaHCO₃ is optionally purified with rinsing and filtration.

[0104] 5. The first product NaHCO₃ is optionally converted to Na₂CO₃, e.g., by heating and / or pH adjustment

[0105] 6. The first product (NaHCO₃ or Na₂CO₃) can be recycled back to battery plant and used e.g., in the pCAM precipitation, recycling and / or as pH adjustment chemical, or sold elsewhere.

[0106] 7. The second product (ammonium sulfate stream) can be purified e.g., with pH adjustment, filtration, ion exchange and / or sorption, and used as fertilizer.

[0107] Reaction with carbon dioxide and nitrogen salt:

[0108] 1. Na2SO4(aq) stream is optionally concentrated from about < 10 wt-% to about >= 20 wt-%.

[0109] 2. Na2SO4 is reacted with carbon dioxide and nitrogen containing salt, favorably an ammonium salt. The reaction pH range is adjusted to about > 7. favorably adjusted between pH 8-9. The reaction temperature is favorably about > 25 °C, more favorably between about 30-40 °C at pressure higher than 1 bar.

[0110] 3. The formed first product with lower solubility (primarily NaHCO₃) is separated from the liquid stream by solid liquid separation process.

[0111] 4. The first product (NaHCO₃) is optionally purified with rinsing and filtration.Docket No.: 1149704.092013

[0112] 5. The first product (NaHCO₃) is optionally converted to Na₂CO₃, e.g., by heating or pH adjustment.

[0113] 6. The first product (NaHCO₃ or Na₂CO₃) can be recycled back to battery plant and used e.g., in the pCAM precipitation, recycling and / or as pH adjustment chemical, or sold elsewhere.

[0114] 7. The second product (ammonium sulfate stream) can be purified e.g., with pH adjustment, filtration, ion exchange and / or sorption, and used as fertilizer.

[0115] The examples below describe the method to treat battery byproducts containing sodium sulfate with ammonium bicarbonate to obtain sodium bicarbonate / carbonate and ammonium sulfate products. The efficiency of the carbonation reaction was studied by characterizing the solid and liquid streams of the process by X-ray diffraction (XRD), ion chromatography (IC), acid dissolution tests, inductively coupled mass plasma spectrometry (ICP-MS) and Kjeldahl method.

[0116] Example la. about 20 wt-% sodium sulfate dissolved in tap water, Na2SO4(aq), is treated with ammonium bicarbonate (NH₄HCO₃) using about 2: 1 molar ratio of NH₄HCO₃: Na2SO4. The reaction is done at room temperature, and at pH range of about 8-8.4. The reaction pH is adjusted using about 10 wt-% NaOH(aq). After about 60 minutes reaction time, the formed precipitate is filtered using 0.45 pm filter. The solid filtrate is dried at about 50 °C overnight. The gravimetric yield of the solid is determined (theoretical yield of solid) is determined according to reaction equation (1) and the solid is characterized qualitatively and semi-quantitatively with XRD. Sulfate and ammonium concentrations of the liquid phase are determined with IC, ICP-MS and Kjeldah N analysis.

[0117] Theoretical yield of carbonate conversion is calculated from the stoichiometric yield of NaHCOs according to Equation I.Na2SO4+ 2 NH₄HCO₃— >2 NaHCO3(s) + (NH4)2SO4(Eq. I)

[0118] The stoichiometric yield of NaHCO₃ can be about 237 g / kg if the about 20 wt-% Na2SO4 (aq) is used as the feed.

[0119] Example lb. The reaction is proceeded as in Example la. but the reaction temperature is changed to about 30 °C.

[0120] Example 1c. The reaction is proceeded as in Example la, but the reaction temperature is changed to about 40 °C.Docket No.: 1149704.092013

[0121] Example Id. The reaction is proceeded as in Example la, but the reaction temperature is changed to about 30 °C and the reaction time to about 30 minutes.

[0122] Example le. The reaction is proceeded as in Example la, but the reaction temperature is changed to about 30 °C and the reaction pH to about 8.8 to about 9.2.

[0123] The non-limiting, exemplary results of the precipitation experiments conducted according to Examples la-le are presented in Table 1.Example t T pH Yield Solid composition, crystalline phases (%) Liquid, recovery (min) (°C) (%) (%)NaHCOs N3fi(COa)(SO4);‘ Na? COrNaHCOr NazSOq SO / .21 60 RT 8-8.4 60 1® 63 6 14 96% - 2 60 30 8-8.4 52 66 14 13 7 89% 76% 3 60 40 8-84 50 61 16 8 16 83% 76% 4 30 30 8-8.4 55 - 81%5 60 30 8.8-9.2 21 68 13 0 11 63%

[0124] Table 1. Characterization of carbonate conversion reaction products

[0125] Majority of the formed solid is sodium bicarbonate / carbonate and only small fraction of Na2SO4 is precipitated when the precipitation conditions are optimal (from the examples above, Example lb resulted in highest carbonate recovery', good solid yield and highest sulfate concentration in the liquid stream).

[0126] The solid yield (primarily NaHCO₃ / Na₂CO₃) could be increased by i) lengthening the reaction time, ii) increasing the stoichiometric ratio of NH₄HCO₃:Na₂SO₄ to >2 and iii) and / or by adding another settling and filtration step (see Examples If, 1g and Ih). The reaction can be also conducted as continuous process mode instead of batch process, as described in Example li.

[0127] Example If. The reaction is proceeded as in Example la-lc, but the reaction time is changed to about >lh, for example to about l-10h.

[0128] Example 1g. The reaction is proceeded as in Examples la-lc, but NH4HCCh: Na2SO4 molar ratio of about >2: 1 is used. The excess NH₄HCO₃ in the liquid stream (containing primarily ammonium sulfate, (NH4)2SOr) can be optionally treated with pH adjustment using sulfuric acid, H2SO4, to convert the excess NH₄HCO₃ to (NHr SCft. The carbonate is released as carbon dioxide in the reaction.

[0129] Example li. The reaction is proceeded as in Examples la- If, but the first filtrate is left to stand in settlement tank for about 1- about 10 hrs. After settling, the filtrate is filtered second time. The solid can be either combined w ith the precipitate formed from the firstDocket No.: 1149704.092013filtration step, or it can be treated separately as second solid fraction (disposed, processed further or sold as low quality NaHCO3 / Na2CO3).

[0130] Example 1j. The conversion is done in continuous process mode, i.e., continuously- removing solid product and part of the liquid stream from the 1st settler (see Figure 1), and continuously adding Na2SO4 byproduct feed and NH₄HCO₃ reagent.

[0131] Schematics of the process according to Examples la-lh are presented in Figure 1. EXAMPLE 2

[0132] Example 2: Non-limiting, exemplary- method of treating industry byproducts comprising sodium sulfate:

[0133] For example, the sodium sulfate (SS) concentration in the byproducts can comprise about 5-15 wt%. The treatment can optionally comprise pretreatment of heavy metals (e.g., Zn in textiles), organic impurities, solids. Pre-treatment can comprise i) s-1 filtration, ii) adsorption e.g., using AC, iii) ion exchange, iv) pH adjustment to 8-9 with NaOH. The water can be concentrated to a concentration of about 20-30 wt-% sodium sulfate solution. For example, we can achieve, but are not limited to, a high solid yield of 50-60% with 20 wt-% Na2SO4. The reaction can be performed with solid NH₄HCO₃. For example, NH₄HCO₃ can be formed prior the treatment from NH4 and CO2. For example, the ratio of NH4: Na can be about 1 to about 1.3, with a temperature of about 20-40 °C. at a pH of about 8 to about 9. In embodiments, the pH is adjusted in pre-treatment. The method can further comprise S / L filtration where solid sodium sulfate carbonate is separated from the liquid stream by S / L separation. In embodiments, the liquid stream can cool and stand for 24 h (5h-2 days). Some precipitate (NaHCOs main phase, as the initial solid separated in the first filtration) can be cry stallized by cooling to RT. The precipitate can be combined with the filtrated phase or treated separately. Further, the liquid (NH4)2SO4 stream can be purified by pH adjustment using H2SO4 to release the carbonate as CO2.EXAMPLE 3

[0134] Example 3: Non-limiting, exemplary reaction parameters and analysis thereof.

[0135] Described herein, are samples with corresponding reaction parameters (Table 2), analysis data (Table 3) and non-limiting exemplary CO₃ and SO₄ content calculated based on specific chemical formulae (Table 4). FTIR qualitative detection of solid phases of samplesDocket No.: 1149704.0920132, 3, and 5 can be found in Fig. 7. XRD spectra of solid phases of samples 1, 2, 3, and 5 can be found in Fig. 8.

[0136] Table 2: Non-Limiting exemplary reaction parametersReaction parametersSample ID ReactionTemperatureNH4 / Na time pH(°C)(min)NH₄HCO₃-1 0.84 60 RT 8-8.4NH₄HCO₃-2 0.84 60 30 8-8.4NH₄HCO₃-3 0.84 60 40 8-8.4NH₄HCO₃-4 0.84 60 30 6.8-7.2NH₄HCO₃-5 0.84 60 30 8.8-9.2NH₄HCO₃-6 0.84 15 30 8-8.4NH₄HCO₃-7 0.84 30 30 8-8.4NH₄HCO₃-8 0.84 30 30 8-8.4NH₄HCO₃-9 0.84 120 30 8-8.4NH₄HCO₃-10 0.84 120 30 8-8.4NH₄HCO₃-11 0.9 120 30 8-8.4NH₄HCO₃-12 1.1 120 30 8-8.4NH₄HCO₃-13 1.05 120 30 8-8.4NH₄HCO₃-14 1.26 120 40 8-8.4NH₄HCO₃-15 0.9 120 40 8-8.4NH₄HCO₃-16 1.1 120 40 8-8.4NH₄HCO₃-17 1.05 120 40 8-8.4

[0137] Table 3: Non-Limiting, Exemplary Analysis DataDocket No.: 1149704.092013* S04 yield (wt-%) in liquid determined as w(S04, feed) / [w(tot)-w(solid)] * 100%** NH4 yield (wt-%) in liquid determined as w(NH4, feed) / [w(tot) - w(solid)]*100% where w(tot) = w(Na2SO4, feed) + w(H20, feed) + w(NH₄HCO₃, feed)w(solid) = mass of precipitated solid, filtrated and dried at 50 C overnight*** g / gSS = weight ratio of precipitated solids and sodium sulfate in the feed.**** CO₃ and SO₄ contents of solid phases are determined using the contents of phases determined by XRD and the following weight ratios of CO₃ and SO₄ in pure solids.

[0138] Table 4: Non-Limiting Exemplary CO? and SO4 content percentages calculated from the chemical formula.Phase CO3 (%) SO4 (%)NaHCO₃ 0.71 0.00Na₂CO₃ 0.57 0.00Na2CO3- NaHCO3- 0.53 0.00Na6(CO3)(SO4)2 0.15 0.49Na2SO4 0.00 0.68EQUIVALENTS

[0139] Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the following claims.

Claims

Docket No.: 1149704.092013CLAIMSWhat is claimed is:

1. A method of producing ammonium sulfate and one or more carbonic acid salts from a sodium sulfate byproduct stream, the method comprising:a) contacting the sodium sulfate byproduct stream with a carbonation reagent under carbonation conditions, thereby producing a liquid stream comprising ammonium sulfate and a solid stream comprising one or more carbonic acid salts; b) isolating the solid stream from the liquid stream, thereby producing a solid stream comprising one or more carbonic acid salts and a liquid stream comprising ammonium sulfate;c) isolating the one or more carbonic acid salts from the solid stream, thereby producing a carbonic acid salt; andd) subjecting the liquid stream to a post-treatment process, thereby producing ammonium sulfate.

2. The method of claim 1, wherein the one or more carbonic acid salts comprises sodium bicarbonate.

3. The method of claim 1 or 2, further comprising prior to step (a): dissolving a solid sodium sulfate byproduct to form the sodium sulfate byproduct stream, and / or concentrating the sodium sulfate byproduct stream.

4. The method of any one of the preceding claims, wherein:a) the carbonation reactant comprises ammonium bicarbonate, ammonium carbonate, a combination of ammonia and carbon dioxide, or any combination thereof;b) the method comprises agitating the sodium sulfate byproduct stream with the carbonation reagent; andDocket No.: 1149704.092013 c) wherein the carbonation conditions comprise at least one carbonation reactant, a pH of about 8 to about 10, and a temperature of about 20 °C to about 60 °C.

5. The method of any one of the preceding claims, wherein the carbonation conditions further comprise adding a seed crystal comprising sodium bicarbonate.

6. The method of any one of the preceding claims, further comprising subjecting the carbonic acid salts to heat, thereby producing sodium carbonate and carbon dioxide.

7. The method of any one of the preceding claims, wherein:(a) the carbonation reactant is recycled from the sodium sulfate byproduct stream; (b) the carbon dioxide of claim 4 is produced from the post-treatment process of claim 1 step (d) and / or the heating step of claim 6;(c) the seed crystal comprising sodium bicarbonate of claim 5 is produced by the sodium bicarbonate of claim 2;(d) the ammonium bicarbonate of claim 4 comprises ammonium bicarbonate produced by reacting ammonia with carbon dioxide produced by the same plant producing the byproduct stream of claim 1; or(e) any combination of two, three or all of (a) to (d).

8. The method of any one of the preceding claims, further comprising pre-treating the byproduct stream prior to step (a), wherein pretreating comprises:a) filtering the solid impurities from the byproduct stream;b) adjusting the pH of the byproduct stream to a pH of about 6 to about 8, thereby precipitating impurities that precipitate at a pH of about 6 to about 8, and filtering off the impurities;c) adjusting the pH of byproduct stream further to about 8 to about 10, thereby precipitating impurities that precipitate at a pH from about 8 to about 10, and filtering off the impurities;Docket No.: 1149704.092013 d) allowing metals to precipitate as low soluble carbonates, and filtering off the impurities;e) treating the byproduct stream with one or more ion exchange methods;f) treating the byproduct stream with adsorbent media org) any combination of two, three, four, five or all of (a)-(f).

9. The method of claim 8, wherein the byproduct stream is optionally pretreated before or after concentrating the byproduct stream.

10. The method of any one of the preceding claims, wherein subjecting the ammonium sulfate liquid stream to a post-treatment process comprises:a) filtering solid impurities from the liquid stream;b) decreasing the pH to about 4 to about 6, thereby releasing CO2;c) adjusting the pH of the liquid stream to about 7 to about 8;d) concentrating the liquid stream, thereby producing a concentrated liquid stream or a dry ammonium sulfate product; ore) any combination two, three or all of (a) to (d).

11. The method of any one of the preceding claims, wherein subjecting the solid stream to a post-treatment process comprises:a) heating the solid stream comprising carbonic acids salts to about 50 °C to about 500 °C, thereby producing sodium carbonate:b) dissolving the sodium carbonate, thereby producing a solution; andc) re-precipitating the solution, thereby producing sodium bicarbonate.

12. The method of claim 10 or claim 11, further comprising treating the liquid stream of claim 10 or the solution of claim 11 with Ca(OH)2 and removing the solids.

13. The method of any one of the preceding claims, wherein the sodium sulfate byproduct stream comprises a solid, an aqueous solution, and / or an aqueous slurry comprising aDocket No.: 1149704.092013 sodium sulfate byproduct derived from a battery' manufacturing process and / or a precursor cathode active material (pCAM) production process, a mining operation, a hydrometallurgical process, a forest industry operation, a logging operation, a wood product manufacturing process, a paper manufacturing process, a textile manufacturing process, or any industrial process, and further wherein the sodium sulfate byproduct stream comprises:a) a transition metal impurity7concentration of about 0.1 mg / L to about 50,000 mg / L b) a heavy metal impurity' concentration of about 0.1 mg / L to about 50,000 mg / L; c) a dissolved organic carbon (DOC) impurity7concentration of about 1 mg / L to about 1000 mg / L; andd) a pH and ammonia concentration sufficient to produce carbonation conditions upon addition of CO2 and / or ammonium bicarbonate.

14. A composition comprising sodium bicarbonate produced by any of the foregoing claimed methods.

15. A composition comprising ammonium sulfate produced by any of the foregoing claimed methods.

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