METHOD FOR RECOVERING LITHIUM FROM LOW CONTENT EXTRACTION TAILWATER, AND METHOD FOR RECYCLING EXTRACTION TAILWATER

摘要

A method for recovering lithium from low content extraction tailwater, comprising the following steps: adding calcium to lithium-containing extraction tailwater and removing fluorine; performing evaporative crystallization; removing impurities; recovering condensate water; precipitating a lithium sa and recycling the mother liquor. Sodium hydroxide is added to the extraction raffinate obtained after cobalt, nickel, and manganese are extracted, the pH value is regulated to 8-13, a calcium-containing material is added, the F/Ca ion molar ratio is 1/1-5, reaction continues for 0.5-4 hours, filtration and washing are performed, and the filtrate is an evaporation stock solution; by means of evaporative concentration and crystallization, the stock solution is concentrated to 1/4-16, so that the sodium sulfate in the stock solution is crystallized, the content of lithium in the concentrate reaches 5-30g/L, and the condensate water is recovered; a saturated sodium carbonate solution is added to the concentrate water, and the lithium ion is precipitated as lithium carbonate to be recovered.