摘要 |
Boron, as well as magnesium and sulfate impurities, are removed from or at least substantially reduced in a lithium containing brine to minimize lithium losses on further concentration of the brine by adding to the brine an aqueous slurry of slaked lime and a solution of calcium chloride to form a calcium borate hydrate, magnesium hydroxide and calcium sulfate dihydrate, the last named compound being precipitated and separated from the brine. On further concentration of the brine, calcium boron hydrate and magnesium hydroxide precipitate and they are also removed from the brine. In an alternate procedure, the pH of the brine is adjusted to 8.0-8.4 by addition of hydrochloric acid to form a calcium borate hydrate, which on further evaporation, is also separated from the brine. The brine is then concentrated further to recover lithium values. |