Study Of Leaching Lithium From Lepidolite And Preparation Of Lithium Carbonate

Lithium is known as "energy element", which is widely used in chemical industry、electronic science and technology、metallurgy、medicine、aerospace、nuclear energy、energy etc due to its remarkable properties and special functions. Lithium resources are abundant in China with good market prospects, which can be developed and utilized widely. Lepidolite is one of the most important lithium mineral resources, domestic storage is very considerable, and therefore we can investigate its extraction technology using lepidolite as raw materials.First, sulfate method treatment of lithium mica has been studied in this paper, the experiment mainly probed the mass fraction of sulfuric acid、calcining temperature、calcining time、acid consumption ratio、acidification roasting time’s influences on the leaching of lithium during the study, At the same time orthogonal experiment optimization has been used, determining the best technological condition of sulfate method lithium mica:950℃temperature burning1-2h, concentrated sulphuric acid acidification roasting3h, acid mine quantity ratio2.0:1, boiling for6h, which achieved95%rate of lithium leaching.Secondly, sulfuric acid method treatment of lithium mica has been studied, it mainly examines the mass fraction of sulfuric acid、acid consumption ratio to the influence of the leaching ratio of lithium during the study, both70%H2SO4and increasing acid are good for dissolving lithium from lithium mica. At the same time the orthogonal experiment optimization has been used to determine the best technological condition of sulfate method leaching lithium mica:70%H2SO4acidification roasting3h, acid mine quantity ratio2.5:1, boiling for4h, which can achieve over94%rate of lithium leaching.Finally, purifying technology of lithium mica leaching solution has been studied, final operating process conditions:adjust PH of leaching solution value to7-8sequentially, After the suction Filteration, add sodium hydroxide filtrate adjusting the pH value more than13, Suction filtrate then go through enrichment、 extracting calcium completely by a little EDTA、cooling post-mortem sulfate, then we use saturated sodium carbonate solution to get lithium carbonate, the mother liquor hydrofluoric acid replace distilled water as recycling water.