Method for preparing LITHIUM HYDROXIDE and lithium carbonate directly from Salt Lake Brine with high Magnesium Lithium ratio

摘要

The method of preparing lithium hydroxide and lithium carbonate directly from salt water with high content of magnesium and lithium has been popularized. The method comprises the following steps: (1) stabilizing the salt water extracted after salt alkali extraction in the stabilization tank to form low content boron lithium salt water; (2) The boron in the boron lithium brine is extracted to form boric acid and lithium brine products; (3) - (5) the lithium brine is refined three times to obtain the third refining liquid;(6) The third stage refined solution is allowed to pass through the bipolar membrane ionizer to form lithium hydroxide solution; (7) The lithium hydroxide solution is allowed to pass through the evaporated crystal to produce a single aqueous solid and an evaporated mother solution of lithium hydroxide; (8) The monohydrate solid of lithium hydroxide is washed to form battery grade lithium hydroxide and washing solution;And (9) let the evaporated mother solution and washing solution form lithium carbonate through a gas-liquid reaction reactor carbon dioxide. At present, the centrifuge runs well, which greatly improves the recovery of lithium ion.