A soda ash and sodium bicarbonate production method is provided, in which solution mining, pretreatment, stripping, concentration, sodium carbonate decahydrate crystallization, separation, dissolution, sodium carbonate monohydrate crystallization, separation and drying are performed to obtain dense soda ash. A dissolved sodium carbonate decahydrate solution or a concentrated brine 3 is subjected to crystallization, separation and drying to produce sodium bicarbonate. A discharge liquid 1 generated in the sodium carbonate decahydrate crystallization and separation is subjected to causticization and evaporation to recycle sodium carbonate. Causticized sludge generated in causticization is calcined and then recycled for causticization. The process provided herein maximizes the resource utilization.

A soda ash and sodium bicarbonate production method is provided, in which solution mining, pretreatment, stripping, concentration, sodium carbonate decahydrate crystallization, separation, dissolution, sodium carbonate monohydrate crystallization, separation and drying are performed to obtain dense soda ash. A dissolved sodium carbonate decahydrate solution or a concentrated brine 3 is subjected to crystallization, separation and drying to produce sodium bicarbonate. A discharge liquid 1 generated in the sodium carbonate decahydrate crystallization and separation is subjected to causticization and evaporation to recycle sodium carbonate. Causticized sludge generated in causticization is calcined and then recycled for causticization. The process provided herein maximizes the resource utilization.

A method of recovering wood pulping chemicals from black liquor produced in a wood pulping process where the process entails burning the black liquor in a recovery boiler to form ash containing high levels of carbonate as well as sodium, potassium and chloride. The ash is dissolved to form a dissolved ash solution that is directed to a first stage crystallization unit that concentrates the dissolved ash solution and which results in the precipitation of sodium sulfate and sodium carbonate. Thereafter the concentrated dissolved ash solution is directed to a second stage crystallization unit which adiabatically cools the concentrated dissolved ash solution to form a glaserite slurry and a purge stream that is rich in chloride. In order to reduce the tendency of sodium carbonate and burkeite to crystallize in the second stage crystallization unit and to encourage pure glaserite to crystalize in the crystallizer, the method entails mixing a sulfate source, such as sodium sulfate or sulfuric acid, to the concentrated dissolved ash solution upstream of the crystallizer.

A method of recovering wood pulping chemicals from black liquor produced in a wood pulping process where the process entails burning the black liquor in a recovery boiler to form ash containing high levels of carbonate as well as sodium, potassium and chloride. The ash is dissolved to form a dissolved ash solution that is directed to a first stage crystallization unit that concentrates the dissolved ash solution and which results in the precipitation of sodium sulfate and sodium carbonate. Thereafter the concentrated dissolved ash solution is directed to a second stage crystallization unit which adiabatically cools the concentrated dissolved ash solution to form a glaserite slurry and a purge stream that is rich in chloride. In order to reduce the tendency of sodium carbonate and burkeite to crystallize in the second stage crystallization unit and to encourage pure glaserite to crystalize in the crystallizer, the method entails mixing a sulfate source, such as sodium sulfate or sulfuric acid, to the concentrated dissolved ash solution upstream of the crystallizer.

A process for preparing solid sodium carbonate monohydrate from a solution of sodium carbonate is described.

A process for preparing solid sodium carbonate monohydrate from a solution of sodium carbonate is described.

A method of forming lithium carbonate from a lithium-bearing solution including: evaporating the lithium-bearing solution to precipitate a first group of impurities; removing the first group of impurities to form a first purified solution; and performing a flash crystallisation step within a predetermined temperature range to crystallise a second group of impurities from the first purified solution; removing the second group of impurities from the first solution to form a second purified solution, wherein at least 90 wt % of lithium is recovered from the first purified solution; and reacting the second purified solution with a metal carbonate to form lithium carbonate of at least 90 wt % purity.

A method of forming lithium carbonate from a lithium-bearing solution including: evaporating the lithium-bearing solution to precipitate a first group of impurities; removing the first group of impurities to form a first purified solution; and performing a flash crystallisation step within a predetermined temperature range to crystallise a second group of impurities from the first purified solution; removing the second group of impurities from the first solution to form a second purified solution, wherein at least 90 wt % of lithium is recovered from the first purified solution; and reacting the second purified solution with a metal carbonate to form lithium carbonate of at least 90 wt % purity.

The present disclosure relates to the field of sodium-ion battery technology, and specifically, to a method for preparing carbon-coated sodium iron fluorophosphate from waste lithium iron phosphate and the application thereof. The method for preparing carbon-coated sodium iron fluorophosphate from waste lithium iron phosphate includes: mixing a waste lithium iron phosphate material with an alkaline solution for reaction, followed by solid-liquid separation, to obtain an aluminum-containing filtrate and a lithium iron phosphate filter residue; mixing the lithium iron phosphate filter residue, aluminum chloride and sodium chloride uniformly, followed by vacuum calcination, to obtain a calcination material; and mixing the calcination material with at least one of a sodium source, an iron source and a phosphorus source uniformly to obtain a mixture to which a fluorine source, a carbon source and a solvent are added for uniformly mixing, followed by drying and calcination sequentially to obtain the carbon-coated sodium iron fluorophosphate. The method has the advantages of low costs, a high added value, a short process, and a high recovery rate, and the carbon-coated sodium iron fluorophosphate obtained from the method has excellent electrochemical performance.

The present disclosure relates to the field of sodium-ion battery technology, and specifically, to a method for preparing carbon-coated sodium iron fluorophosphate from waste lithium iron phosphate and the application thereof. The method for preparing carbon-coated sodium iron fluorophosphate from waste lithium iron phosphate includes: mixing a waste lithium iron phosphate material with an alkaline solution for reaction, followed by solid-liquid separation, to obtain an aluminum-containing filtrate and a lithium iron phosphate filter residue; mixing the lithium iron phosphate filter residue, aluminum chloride and sodium chloride uniformly, followed by vacuum calcination, to obtain a calcination material; and mixing the calcination material with at least one of a sodium source, an iron source and a phosphorus source uniformly to obtain a mixture to which a fluorine source, a carbon source and a solvent are added for uniformly mixing, followed by drying and calcination sequentially to obtain the carbon-coated sodium iron fluorophosphate. The method has the advantages of low costs, a high added value, a short process, and a high recovery rate, and the carbon-coated sodium iron fluorophosphate obtained from the method has excellent electrochemical performance.