A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

The present disclosure discloses a preparation method for 4-phenylthio-benzenethiol. The preparation method comprises the following steps: subjecting phenyl sulfide as a raw material to a halogenation reaction to obtain 4-halophenyl sulfide; subjecting the 4-halophenyl sulfide to a sulfhydrylation reaction to obtain a 4-phenylthio-phenylthiolate; and subjecting the 4-phenylthio-phenylthiolate to acidification. The preparation method of the present disclosure avoids the use of materials such as thiophenol which pollutes the environment, and realizes efficient recycling of the reaction materials, solvents, water and the like. The preparation method of the present disclosure is a green process for the synthesis of 4-phenylthio-phenylthiol without organic waste, waste acid and waste water discharge.

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NOR, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NOR, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

The present invention relates to the production of lithium from liquid resources such as natural and synthetic brines, leachate solutions from clays and minerals, and recycled products.

A process for the production of potassium sulphate by conversion of potassium chloride and sulphuric acid using a muffle furnace, said furnace comprising a reaction chamber and a combustion chamber, wherein in the reaction chamber potassium chloride (KCI) and potassium hydrogen sulfate (KHSO.sub.4) are reacted to form potassium sulphate while supplying heat to the reaction chamber from the combustion chamber, wherein the combustion chamber has at least a pair of regenerative burners and wherein the process comprises the steps of alternatingly causing one of the regenerative burners to perform a combustion operation in the combustion chamber to heat the reaction chamber and another of the regenerative burners to perform a heat-regenerating operation in a regenerator, wherein the pressure in the combustion chamber is kept at a pressure of between 0.2 and 3 mbarg.

A process for the production of potassium sulphate by conversion of potassium chloride and sulphuric acid using a muffle furnace, said furnace comprising a reaction chamber and a combustion chamber, wherein in the reaction chamber potassium chloride (KCI) and potassium hydrogen sulfate (KHSO.sub.4) are reacted to form potassium sulphate while supplying heat to the reaction chamber from the combustion chamber, wherein the combustion chamber has at least a pair of regenerative burners and wherein the process comprises the steps of alternatingly causing one of the regenerative burners to perform a combustion operation in the combustion chamber to heat the reaction chamber and another of the regenerative burners to perform a heat-regenerating operation in a regenerator, wherein the pressure in the combustion chamber is kept at a pressure of between 0.2 and 3 mbarg.

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NO.sub.x, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

A process for recovering lithium phosphate and lithium sulfate from a lithium-bearing silicate is described. The process includes adding from 800 kg/t to 1600 kg/t of sulfuric acid to a slurry of the lithium-bearing silicate and from 40 kg/t to 600 kg/t of a source of fluoride to produce a leach mixture and heating said leach mixture. A lithium-bearing solution is then separated from the leach mixture and its pH is increased sequentially to pH 3.5 to 4, pH 5.5 to 6 then pH 10.5 to 11 to precipitate, respectively, a first, second and third set of impurities therefrom. The first, second and third sets of impurities are separated from the lithium-bearing solution and lime is added to maintain a soluble Ca concentration of at least 30 mg/L. The lithium-bearing solution is then softened by adding a two sequential amounts of phosphate to precipitate fluorapatite and apatite, respectively. A third amount of phosphate is added to produce a lithium phosphate precipitate which is then separated. The separated lithium phosphate precipitate is then digested in sulphuric acid to produce a digestion mixture from which a lithium sulfate precipitate is separated. An alkali metal hydroxide is added to the separated solution to produce an alkali metal phosphate solution and this is recycled for use as phosphate in the process.

A process for recovering lithium phosphate and lithium sulfate from a lithium-bearing silicate is described. The process includes adding from 800 kg/t to 1600 kg/t of sulfuric acid to a slurry of the lithium-bearing silicate and from 40 kg/t to 600 kg/t of a source of fluoride to produce a leach mixture and heating said leach mixture. A lithium-bearing solution is then separated from the leach mixture and its pH is increased sequentially to pH 3.5 to 4, pH 5.5 to 6 then pH 10.5 to 11 to precipitate, respectively, a first, second and third set of impurities therefrom. The first, second and third sets of impurities are separated from the lithium-bearing solution and lime is added to maintain a soluble Ca concentration of at least 30 mg/L. The lithium-bearing solution is then softened by adding a two sequential amounts of phosphate to precipitate fluorapatite and apatite, respectively. A third amount of phosphate is added to produce a lithium phosphate precipitate which is then separated. The separated lithium phosphate precipitate is then digested in sulphuric acid to produce a digestion mixture from which a lithium sulfate precipitate is separated. An alkali metal hydroxide is added to the separated solution to produce an alkali metal phosphate solution and this is recycled for use as phosphate in the process.