To provide a method for recovering lithium, that is capable of efficiently recovering lithium without containing impurities, such as phosphorus and fluorine, from a lithium-containing solution containing lithium hexafluorophosphate and separated from a lithium ion battery. In the present invention, alkali hydroxide is added to the lithium-containing solution and the solution is made to have pH 9 or more, a precipitate of a phosphate and a fluoride salt is formed, the formed precipitate is separated and removed, and then lithium is recovered from filtrate.

Method for recovering lithium

Method for recycling electrolyte of waste lithium ion battery

PROBLEM TO BE SOLVED: To provide a crystallization reactor which can reduce the level of ions contained in a recovered crystal of a hardly soluble salt. SOLUTION: This crystallization reactor is designed for producing the crystal of the hardly soluble salt by adding a crystallization agent to untreated water containing a substance to be crystallized. In addition, this reactor includes a crystallization reaction tank for producing the crystal of the hardly soluble salt by adding the crystallization agent to the untreated water, an extraction means for extracting at least, a part of slurry containing the crystal produced in the crystallization reaction tank, a dehydration means for dehydrating the extracted slurry, and a cleaning means for cleaning the dehydrated crystal. COPYRIGHT: (C)2009,JPO&INPIT

Crystallization reactor and crystallization reaction method

PROBLEM TO BE SOLVED: To provide calcium fluoride fine particles excellent in sinterability, a calcium fluoride dried body, a calcium fluoride sintered compact, a calcium fluoride transparent sintered compact and a manufacturing methods therefor. SOLUTION: The method for manufacturing the calcium fluoride fine particles includes synthesizing calcium fluoride fine particles by reacting a calcium compound with a fluorine compound in a solution, and heating the solution in which the fine particles are suspended to 100-300°C in an airtight container. COPYRIGHT: (C)2006,JPO&NCIPI

Calcium fluoride fine particle, calcium fluoride dried body, calcium fluoride sintered compact, calcium fluoride transparent sintered compact and manufacturing method therefor

PROBLEM TO BE SOLVED: To provide a method of producing hydrogen fluoride without using natural calcium fluoride (fluorite) poor as resources by finding conditions capable of using only recovered calcium fluoride as the raw material for producing hydrogen fluoride without mixing the same into natural fluorite and a method of increasing the purity of the produced hydrogen fluoride, and to provide a method of converting calcium sulfate by-produced at the time of producing hydrogen fluoride into the bihydrate of calcium sulfate having satisfactory crystallinity and having industrial usefulness by regulating its form. SOLUTION: In the method, calcium fluoride solid matter obtained by treating a fluorine-containing waste liquid with a calcium compound is dried, condensed and solidified. Then, the obtained block is crushed so as to be the particle diameter of several mm or below, and is used as the raw material for producing hydrogen fluoride. At the time when the calcium fluoride solid matter is brought into reaction with sulfuric acid or oleum, they are sufficiently mixed without performing warming in the first stage, and heating is performed in the second stage. By the sufficient mixing with the sulfuric acid or oleum, the greater part of volatile impurities can be removed before the generation of hydrogen fluoride starts. Further, by the lowering of reaction temperature, not only the corrosion of a device material can be alleviated, but also the form of anhydrous calcium sulfate generated as a by-product can be changed from that in the conventional one, and it can be made into the one easy to be converted into bihydrate having industrially high usefulness. COPYRIGHT: (C)2005,JPO&NCIPI

Method of producing hydrogen fluoride using recovered calcium fluoride

PROBLEM TO BE SOLVED: To provide a method and an apparatus for separating/recovering recyclable hydrofluoric acid and silicofluoric acid efficiently from a waste liquid containing hydrofluoric acid and silicofluoric acid. SOLUTION: The method comprises separating the solid in the waste liquid containing hydrofluoric acid and silicofluoric acid and then first concentrating the waste liquid by distillation, and recovering an aqueous solution containing mainly hydrofluoric acid and an aqueous solution containing mainly silicofluoric acid, respectively. Other materials are remained in the distillation pot residue. The aqueous solution containing hydrogen fluoride can be recycled as a chemical etching treatment liquid for glass after adjusting the concentration by adding hydrofluoric acid. The aqueous solution containing silicofluoric acid can be recycled as synthetic raw materials of silicofluoric acid and silicofluoride for sales on the market by converting the hydrofluoric acid to silicofluoric acid by adding silicon dioxide and further by adjusting the concentration to a given one by diluting it with water. COPYRIGHT: (C)2008,JPO&INPIT

Method and apparatus for separating and recovering acid components from waste liquid containing hydrofluoric acid and silicohydrofluoric acid

PROBLEM TO BE SOLVED: To provide a recycling method of fluorine by recovering calcium fluoride with a particle size and purity suitable for manufacturing hydrogen fluoride from a fluorine-containing waste solution or a hydrofluoric acid-containing solution. SOLUTION: The reaction between the fluorine-containing waste solution and the hydrofluoric acid-containing waste solution is performed under hydrochloric acid acidic conditions in which the solubility of calcium fluoride is relatively large. The calcium fluoride with high purity and a large particle size is deposited. In that case, the remained hydrochloric acid or the produced hydrochloric acid is allowed to react with an inexpensive calcium compound such as calcium hydroxide, calcium oxide and calcium carbonate to prepare an aqueous calcium chloride solution. The aqueous calcium chloride solution is reused for the treatment of the hydrofluoric acid-containing waste solution. The resulting calcium fluoride can be utilized as it is as a raw material for manufacturing hydrogen fluoride and the excess aqueous calcium chloride solution can be served as other applications in an industrial use. COPYRIGHT: (C)2005,JPO&NCIPI

Manufacturing method of calcium fluoride,and reusing method and recycling method thereof

PROBLEM TO BE SOLVED: To provide an effective treating method of lithium hexafluorophosphate in an organic electrolyte containing lithium hexafluorophosphate used for a lithium ion battery and a lithium battery, and also provide a treating method capable of recovering and reusing as a hexaphosphate and lithium fluoride. SOLUTION: Lithium hexafluorophosphate is separated in lithium fluoride and potassium hexafluorophosphate by adding a solvent mainly comprising primary, secondary, or tertiary alcohol represented by formula, CnH2n+1OH in which (n) is 2-5, and an agent mainly comprising potassium fluoride. By adding an agent mainly comprising ammonium fluoride in place of lithium fluoride, lithium hexafluorophosphate is separated in lithium fluoride and ammonium hexafluorophosphate.

Treating method of organic electrolyte containing lithium hexafluorophosphate

PROBLEM TO BE SOLVED: To immobilize most part of fluorine from hydrofluoric acid-containing wastewater as calcium fluoride having purity and grain diameter suitable for hydrogen fluoride manufacture, moreover, to recycle calcium fluoride recovered by this treatment method, and furthermore, to make concentration of residual fluorine in the treated wastewater a fluorine regulated value or lower. SOLUTION: Under the condition that crystals or particles of calcium fluoride are dispersed, hydrogen fluoride-containing wastewater and a calcium salt solution are introduced into a reaction system at a time. The immobilization of fluorine and crystal growth of calcium fluoride are performed at a time. The calcium fluoride grown or generated is continuously or intermittently extracted and filtrated, thus recovering the calcium fluoride. An acidic effluent discharged in the above method is neutralized by using an alkaline solution or diluted slurry. As a result, the residual fluorine is immobilized as calcium fluoride to make the concentration of fluorine in the wastewater the regulated value of fluorine or lower. COPYRIGHT: (C)2006,JPO&NCIPI

Immobilization method for fluorine, recycling method for calcium fluoride recovered by this method, and concentration regulation method for residual fluorine

邦堯百田

Papers

Method of producing hydrogen fluoride using recovered calcium fluoride

Method and apparatus for separating and recovering acid components from waste liquid containing hydrofluoric acid and silicohydrofluoric acid

Manufacturing method of calcium fluoride,and reusing method and recycling method thereof

Treating method of organic electrolyte containing lithium hexafluorophosphate

Immobilization method for fluorine, recycling method for calcium fluoride recovered by this method, and concentration regulation method for residual fluorine

邦堯 百田

Papers

Method of producing hydrogen fluoride using recovered calcium fluoride

Method and apparatus for separating and recovering acid components from waste liquid containing hydrofluoric acid and silicohydrofluoric acid

Manufacturing method of calcium fluoride,and reusing method and recycling method thereof

Treating method of organic electrolyte containing lithium hexafluorophosphate

Immobilization method for fluorine, recycling method for calcium fluoride recovered by this method, and concentration regulation method for residual fluorine

邦堯百田