Method for treating a process stream of sodium sulfate-containing residue from a battery production process

Abstract

The present invention relates to a method for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery production process or a battery recycling process, the residue process stream being provided from a battery production process or a battery recycling process, the residue process stream being obtained from the production of a battery containing at least sodium and iron (Na, Fe), or from the recycling of a battery containing at least sodium and iron (Na, Fe), optionally water is provided, potassium chloride is provided, a mixture comprising the optional water, potassium chloride, and the residue process stream is provided and reacted to obtain potassium sulfate.

Description

Technical Field

[0001] The present invention relates to a method for providing value-added products from residual process streams from battery production processes.

Background Art

[0002] The increasing awareness of climate change and the limitation of fossil fuel supplies have, for example, enhanced the search for alternative energy sources for vehicle operation. The demand for batteries has been increasing rapidly. This also means an increase in emissions, solids, and liquid residues from battery production. Therefore, recycling and material optimization have become relevant issues in recent years.

[0003] The battery manufacturing industry is continuously striving to minimize residue supply and aims to recycle essential chemicals in processes such as cobalt, lithium, and manganese, which promotes the reduction of facility operating costs. Residues from the battery production process can be hazardous wastes such as aqueous wastewater streams, ammonia, n-methylpyrrolidone, and battery metal components. However, residue streams, especially wastewater streams, can be very large, so reducing the amount of residue and providing value-added components from streams classified as waste improves the overall operation from the perspective of the costs and raw material use of battery manufacturing facilities and enables the reuse of the earth's finite resources. Also, local or national regulations can affect whether battery production is acceptable, especially considering the residues and emissions provided from the process regarding discharges to water receivers. Undesirable elements such as sulfates and sodium can be provided at high levels in battery production, and since disposing of such elements is costly, they negatively impact the residue process stream and, when sent directly to sewers and / or wastewater treatment plants, they impose a significant stress on the downstream processes. Today, the presence or expected presence of large amounts of sulfates and sodium hinders the approval of permits to establish battery production facilities. Sodium sulfate is a by-product that poses a problem for battery manufacturers to process. Considering the amount produced, the cost of processing sodium sulfate can be substantial, and by not dealing with the chemical treatment, companies can be prevented from receiving the permits necessary to continue their production or obtaining new permits for increased production or the construction of new production facilities.

[0004] Today, the sodium sulfate present in the residue process stream can be discarded into the wastewater system via, for example, a drain pipe or sewer, or into a landfill, or separated from the residue stream and sold as a lower-grade chemical. The residue process stream from a battery production facility containing sodium sulfate mainly results from the oxidation step of cathode production. Even if sodium sulfate is regarded as a waste material, as a result, if uses can be provided, sodium sulfate can be present in large quantities and thus can become a valuable asset. The treatment of the obtained sodium sulfate is regarded as an issue for battery manufacturing facilities. However, if sodium sulfate can be directed towards suitable uses, it can become a product with added value for the entire process.

[0005] An issue regarding the current residue process stream of a battery manufacturing facility is that potential valuable chemical substances are not obtained or recycled from the residue process stream. In fact, large amounts of chemical substances are always discharged into landfills, discarded as lower-grade chemicals, or sent to the wastewater system.

[0006] Today, in order to avoid as much waste and loss as possible, much attention is placed on obtaining environmentally sustainable processes and obtaining as many value-added products or recyclable products as possible from the process.

[0007] Therefore, there is a need to obtain more efficient methods. There is a demand for methods to reduce the need to dispose of materials in landfills and the need to discharge valuable chemical substances into the wastewater system. There is also a need to provide additional value-added products that improve the economics of the entire battery production or recycling facility from waste materials from the battery production or recycling facility. Summary of the Invention

[0008] This method enables the obtaining of high-value products, and at the same time provides a solution for waste treatment that is more environmentally sustainable. By providing value-added products that have a demand in the market and can be sold, the overall economics related to battery production or recycling facilities are improved, and the natural resources are used carefully. Also, the method facilitates the feasibility of meeting the requirements and laws related to waste treatment in battery manufacturing.

[0009] According to the present invention, a huge amount of chemicals existing in the residue process stream, namely sodium sulfate, can be used, and the adverse environmental impacts from the battery residue process stream can be eliminated. Since high-grade fertilizers are obtained by the present invention, instead of sending nutrient chemicals to drain pipes or sewers or landfills, or separating them as lower-grade chemicals, it is also possible to send the nutrient chemicals to plants when nutrient chemicals are needed.

[0010] The scope of the present invention follows the appended claims.

[0011] The present invention relates to a method for producing a potassium sulfate, i.e., K2SO4-containing fertilizer composition from a battery production process or a battery recycling process. The present invention is directed to a method for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery production process, the residue process stream being provided from a battery production process, the residue process stream being obtained from a battery containing at least sodium and iron (Na, Fe), optionally water being provided, potassium chloride being provided, and providing and reacting a mixture comprising the optional water, potassium chloride, and the residue process stream to obtain potassium sulfate. The present invention is directed to a method for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery production process or a recycling process, the residue process stream being provided from a battery production process or a recycling process, the residue process stream being obtained from the production of a battery containing at least sodium and iron (Na, Fe) or from the recycling of a battery containing at least sodium and iron (Na, Fe), optionally water being provided, potassium chloride being provided, and providing and reacting a mixture comprising the optional water, potassium chloride, and the residue process stream to obtain potassium sulfate. The residue process stream can be provided from a process in the production of a battery containing sodium and iron and optionally cyanide, or from a recycling process of a battery containing sodium and iron and optionally cyanide.

[0012] A method is provided for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery production process, the residue process stream being provided from a battery production process, the residue process stream being obtained from a battery containing at least sodium and iron (Na, Fe), optionally water being provided, potassium chloride being provided, and providing and reacting a mixture comprising the optional water, potassium chloride, and the residue process stream to obtain potassium sulfate. The battery may further contain cyanide.

[0013] According to one embodiment, potassium chloride and the residue process stream are provided in any order or simultaneously with respect to the provision of the mixture. Preferably, optional water and the residue process stream are added prior to the potassium chloride.

[0014] According to one embodiment, an acid is added and mixed into the mixture. Preferably, sulfuric acid and / or hydrochloric acid is used, and more preferably, sulfuric acid is used. Preferably, the acid is added prior to the addition of potassium chloride. Such addition can be done to adjust the pH of the mixture.

[0015] According to one embodiment, the residue process stream contacts potassium chloride.

[0016] According to one embodiment, sodium hydroxide and / or potassium hydroxide is added to the mixture of water, potassium chloride, and the residue process stream. This is done, for example, to adjust the pH when an acid has been added.

[0017] According to one embodiment, glaserite is obtained by the reaction of water, potassium chloride, and the residue process stream, and the glaserite is taken out to provide potassium sulfate and added and mixed with additional potassium chloride and / or leached with water. Then, the potassium sulfate can be taken out for further use or sold. It should be noted that the addition and mixing of potassium chloride and leaching with water can be done in any order. However, in a preferred embodiment, the reaction with potassium chloride is first carried out, and then leaching with water is done.

[0018] According to one embodiment, after the mixture remaining after taking out potassium sulfate is concentrated, any sodium chloride present is taken out for further use.

[0019] According to one embodiment, the taken-out sodium chloride is sent to a cell membrane process that converts the sodium chloride into sodium hydroxide, hydrogen, and chlorine.

[0020] The present invention also relates to the use of the method in the production of fertilizers containing potassium sulfate.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0022] The present invention relates to providing valuable components from the residue process stream of sodium-iron battery production or the residue process stream of sodium-iron battery recycling.

[0023] The method for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery production process comprises the following steps, namely: The residue process stream is provided from the battery production process, and the residue process stream is obtained from the production of a battery containing at least sodium and iron (Na, Fe); a step, Optionally, water is provided; a step, Potassium chloride is provided; a step, Providing a mixture containing the above optional water, potassium chloride, and the residue process stream, reacting, and obtaining potassium sulfate; a step, and optionally, the battery also contains cyanide.

[0024] The method for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery recycling process comprises the following steps, namely: The residue process stream is provided from a battery recycling process, and the residue process stream is obtained from the recycling of a battery containing at least sodium and iron (Na, Fe), step; Optionally, a step where water is provided; A step where potassium chloride is provided; Providing a mixture containing the optional water, potassium chloride, and the residue process stream, reacting, and obtaining potassium sulfate, step. Optionally, the battery also contains cyanide.

[0025] The residue process stream can be mixed with water and at least partially dissolved in water. Preferably, the residue process stream is a solution. The components of the residue process stream are preferably dissolved. The aqueous mixture of the residue process stream can optionally be treated with an acid, preferably sulfuric acid. The optional use of the acid can depend on the composition of the residue process stream.

[0026] The residue process stream can have different chemical substance contents and can contain the following impurities, namely, Na2SO4, sodium, calcium, lithium, aluminum, iron, and manganese. Optionally, for example, when the above acid is added in the method, the next step of pH correction using an alkali compound can be used. Preferably, KOH and / or NaOH are used as the alkali compound. The addition of the alkali compound can be used to increase the pH and achieve the correct stoichiometric relationship for K2SO4 and NaCl.

[0027] Potassium chloride, i.e., KCl, is added to the aqueous mixture containing the residue process stream to obtain potassium sulfate. The solid phase obtained by the method can contain a salt called glaserite composed of potassium and sodium sulfates (K3Na(SO4)2). In one embodiment, the intermediate product obtained by the method after the first addition of potassium chloride is glaserite.

[0028] The resulting glaserite salt is removed from the treated residue process stream, the remaining liquid portion of the mixture, and can be further treated with KCl to produce K2SO4. Thereafter, the resulting K2SO4 can be removed.

[0029] The reactions for the production of intermediate glaserite and K2SO4 are disclosed below.

[0030] Glaserite: 6KCl + 4Na2SO4 → 2K3Na(SO4)2 + 6NaCl

[0031] K2SO4: 2KCl + 2K3Na(SO4)2 → 4K2SO4 + 2NaCl

[0032] As an alternative treatment, the resulting glaserite salt can be leached with water to provide K2SO4 after being removed from the treated residue process stream.

[0033] However, in further embodiments, the method can include a combination of both of the recited treatment steps for glaserite in any order. The resulting glaserite salt can then first be treated with KCl and then leached with water to produce K2SO4, or vice versa.

[0034] The potassium chloride used in this method can be subjected to a pretreatment step including washing and optional evaporation before addition to the residue process stream. Pretreatment by washing with water enables the removal of existing by-products or impurities. Potassium chloride products offered on the market often contain some by-products or impurities such as, for example, sodium chloride. By subjecting potassium chloride to water washing, any existing impurities are removed from the potassium chloride, and thus the quality of the potassium chloride added to the residue process stream can be improved. By performing pretreatment using water washing and the subsequent optional evaporation of water, the quality of potassium chloride can be improved, for example, from a sodium chloride content of about 4 wt% to a sodium chloride content of at most 1 wt%. Such an increase in the purity of the potassium chloride used in this method improves the yield of potassium sulfate obtained in the conversion step by at least 5 times when the conversion to potassium sulfate is carried out at a pH of about 5-9, such as about 6-8, preferably about 6-7.

[0035] The treated residue process stream remaining after the separation of K2SO4 can be further treated via a cooling step, for example, to precipitate sodium sulfate and return the sulfate to the process to improve the sulfate yield.

[0036] The treated residue process stream remaining after the separation of K2SO4 can be further treated via evaporation, for example, to precipitate sodium chloride (NaCl) which can be removed as a solid phase. This can then be used, for example, as road salt.

[0037] The present invention can be further complemented by the use of a membrane cell process that can convert the obtained NaCl into NaOH, H2, and Cl2. NaOH is a valuable chemical and is used by battery production and / or recycling plants. The other two products, H2 and Cl2, are collected and can be used as energy in the case of H2 or sold to a third party to improve the economy and profitability of the battery production process.

[0038] In this way, products with higher added value than the fertilizers produced can be obtained and reused or sold in the battery production process or other processes.

Claims

1. A method for producing a potassium sulfate-containing fertilizer composition from a sodium sulfate-containing residue process stream of a battery production process or a battery recycling process, wherein the residue process stream is provided from the battery production process or the battery recycling process, and the residue process stream is obtained from the production of a battery containing at least sodium and iron (Na,Fe), or from the recycling of a battery containing at least sodium and iron (Na,Fe). Water is provided on an optional basis. Potassium chloride is provided. A method comprising providing and reacting a mixture containing the aforementioned optional water, potassium chloride, and residue process flow to obtain potassium sulfate.

2. The method according to claim 1, wherein the residue process flow is obtained from the production of a battery containing sodium, iron, and cyanide (Na, Fe, CN), or from the recycling of a battery containing sodium, iron, and cyanide (Na, Fe, CN).

3. The method according to claim 1 or 2, wherein the water, potassium chloride, and residue process flow are mixed in any order or simultaneously to provide the mixture, and preferably the water and residue process flow are added before the potassium chloride.

4. The method according to any one of claims 1 to 3, wherein the acid is preferably added and mixed into the mixture before the addition of potassium chloride.

5. The method according to claim 1 or 2, wherein the residue process flow is pretreated in an evaporation step to produce a dry product that comes into contact with the water and then with the potassium chloride.

6. The method according to claim 1 or 2, wherein sodium hydroxide and / or potassium hydroxide are added to the mixture of water, potassium chloride, and residue process flow.

7. The method according to claim 1 or 2, wherein the glacelite is obtained by the reaction of the water, the potassium chloride, and the residue process flow, the glacelite is removed to provide potassium sulfate and added and mixed with additional potassium chloride, and / or leached with water.

8. The method according to claim 7, wherein the mixture remaining after potassium sulfate has been removed is concentrated, and any present sodium chloride is then removed.

9. The method according to claim 8, wherein the extracted sodium chloride is sent to a cell membrane process that converts the sodium chloride into sodium hydroxide, hydrogen, and chlorine.

10. The method according to claim 1 or 2, wherein the potassium chloride added to the residue process flow is subjected to a pretreatment step including washing with water and subsequent optional evaporation to remove any impurities present in the potassium chloride.

11. Use of the method according to claim 1 or 2 relating to the production of a fertilizer containing potassium sulfate.

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