METHOD FOR PRODUCING COBALT SULFATE

• Main Authors: KONDO NATSUKI, OHARA HIDEKI, HIRAGORI SHINICHI, KUDO TAKASHI, KANEKO TAKASHI, WATANABE HIROTO, HIGAKI TATSUYA
• Format: Patent
• Language: English; Japanese
• Published: 04.11.2022
• Subjects: CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; FERROUS OR NON-FERROUS ALLOYS; INORGANIC CHEMISTRY; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a method for producing high-purity cobalt sulfate by separating impurities and cobalt from a cobalt chloride solution containing impurities without using an electrolysis process.SOLUTION: A cobalt chloride solution containing impurities is brought into contact with an organic solvent containing an alkylphosphate-based extractant, followed by a first solvent extraction step S1 to extract and separate/remove zinc, manganese and calcium from the organic solvent, a copper removal step S2 to add a sulfiding agent to the cobalt chloride solution to generate and separate/remove copper sulfide, a second solvent extraction step S3 to bring an organic solvent containing a carboxylic acid extractant into contact with the cobalt chloride solution to extract cobalt in the organic solvent, then back-extract the cobalt with sulfuric acid to obtain a cobalt sulfate solution, and a crystallization step S4 to subject the cobalt sulfate solution obtained through the second solvent extraction step S3 to crystallization, these steps being implemented in order. By this method, impurities including magnesium and cobalt can be separated to directly produce high-purity cobalt sulfate without using an electrolysis process.SELECTED DRAWING: Figure 1 【課題】不純物を含む塩化コバルト溶液から、電解工程を用いることなく不純物とコバルトを分離し、純度の高い硫酸コバルトを製造する方法を提供する。【解決手段】不純物を含む塩化コバルト溶液にアルキルリン酸系抽出剤を含む有機溶媒を接触させ、有機溶媒に亜鉛、マンガンおよびカルシウムを抽出して分離除去する第１溶媒抽出工程Ｓ１、塩化コバルト溶液に硫化剤を添加し、銅の硫化物の沈殿を生成させて分離除去する脱銅工程Ｓ２、塩化コバルト溶液にカルボン酸抽出剤を含む有機溶媒を接触させ、有機溶媒にコバルトを抽出させた後、硫酸でコバルトを逆抽出して硫酸コバルト溶液を得る第２溶媒抽出工程Ｓ３、第２溶媒抽出工程Ｓ３を経て得た硫酸コバルト溶液を晶析工程Ｓ４、を順に実行する。電解工程を用いることなく、マグネシウムを含む不純物とコバルトを分離し、直接に高純度の硫酸コバルトを製造することができる。【選択図】図１