Method for extracting potassium salt from lepidolite leachate

• Main Authors: LONG MENG, FU XIAOYAN, SONG QINGRONG, LI FANG, WANG XINRONG, XIAO JIAO, ZHOU MENGYA, LIU SHUQI, WEI DIANPING, LI LIANGBIN, YAN ZHIFAN, WANG BIN
• Format: Patent
• Language: Chinese; English
• Published: 28.06.2024
• Subjects: CHEMISTRY; COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM,RUBIDIUM, CAESIUM, OR FRANCIUM; INORGANIC CHEMISTRY; METALLURGY

The invention discloses a method for extracting sylvite from lepidolite leachate, which comprises the following steps: adding alkaline substances into the lepidolite leachate to remove magnesium and calcium, and then evaporating, concentrating and enriching all components in impurity-removed liquid to obtain lithium sulfate concentrated liquid; adding sodium carbonate into the lithium sulfate concentrated solution to carbonize and precipitate lithium, and filtering and separating to obtain crude lithium carbonate and carbonized mother liquor; adding an organic solvent into the carbonized mother liquor to separate out sylvite and filtrate; evaporating, crystallizing and separating the filtrate to obtain sodium sulfate and sodium precipitation mother liquor; and cooling and separating the sodium precipitation mother liquor to obtain potassium precipitation mother liquor and glaserite. Under an organic solvent system, the saturation degree of sodium sulfate and potassium sulfate can be changed, low temperature i