METHOD FOR PROCESSING MICA CONCENTRATE Russian patent published in 2021 - IPC C22B26/12 C01D15/08 C22B1/06 C22B3/08 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular to the complex processing of mica concentrate to produce lithium carbonate and salts of other alkali metals (rubidium, cesium, potassium, aluminum and fluorine). The method includes heat treatment of mica concentrate with sulfation, leaching of the sulfated product, separation and washing of the siliceous precipitate, step-by-step liming of the Li-containing solution to remove impurities. After that, the purified solution is evaporated with the release of potassium sulfate, followed by reagent precipitation from the evaporated solution of solid lithium carbonate, its dissolution, recrystallization and precipitation of high-purity lithium carbonate, followed by drying. The initial mica concentrate is mixed with 1-4 wt.% of fluorite concentrate, treated with sulfuric acid with a concentration of 60-92.5 wt.% at a temperature of 100-110°C and a holding time of 4-6 hours. The siliceous precipitate is separated by filtration, cooled, and the alum precipitate containing potassium, rubidium, cesium, aluminum, and fluorine is separated. When cleaning the Li-containing solution from impurities by step-by-step liming, alkaline flush water is used from washing the precipitate formed during liming at the next stage.

EFFECT: method allows reducing the duration of the process of opening the concentrate, improving the washability and filterability of the crystalline siliceous precipitate.

3 cl, 1 tbl