Process for extracting lithium from salt lake brine by manganese dioxide

Abstract

The present invention is manganese dioxide process of extracting lithium from salt lake brine, and the process is suitable for producing lithium carbonate and lithium chloride with lithium-containing Qinghai saline lake brine, including concentrated lithium-containing Qinghai saline lake brine. The process includes sun shining saline lake brine to obtain concentrated lithium containing brine, selective adsorption of lithium ion with MnO2 adsorbent, eluting adsorbed lithium ion with hydrochloric acid solution, and refining and concentrating the elutriant to obtain material for preparing lithium carbonate and lithium chloride.

Description

technical field [0001] The invention relates to a technology for extracting lithium from a solution, especially a technology for extracting lithium by using a manganese dioxide ion sieve adsorbent to absorb and extract lithium from lithium-containing salt lake brine and concentrated lithium-containing old brine in salt fields. Background technique [0002] Lithium ions coexist with a large amount of alkali metals and alkaline earth metals. To economically recover lithium from the natural multi-water salt system with high magnesium-lithium ratio salt lake brine depends not only on the concentration of lithium but also on the concentration of magnesium and calcium ions. Due to the similar chemical properties of magnesium and lithium, the separation of magnesium and lithium is difficult. Lithium extraction from brine produced abroad is limited to brine with low magnesium concentration, and the ratio of magnesium to lithium is less than 6:1, while the ratio of magnesium to lithi...

AI Technical Summary

Problems solved by technology

The tributyl phosphate extraction method uses concentrated lithium-rich and high-magnesium brine as the production raw material. The recovery rate is relatively high, but the process is long, the equipment is severely corroded, and the production cost is high. Further industrialization cannot be realized.

The roasting method will produce a large amount of hydrochloric acid and heavy MgO by-products, among which heavy MgO faces the problem of narrow sales market, hydrochloric acid is very serious for equipment corrosion, and the whole process consumes a lot of energy, and only indoor research work has been carried out

The precipitation method is feasible, but the process is long, the turnover of materials is large, the operation is complicated for multiple calcination and filtration, the concentration of lithium in the hydrothermal decomposition or roasting leaching solution is low, and a large amount of evaporation water is required for concentration.