METHOD FOR EXTRACTING LITHIUM PHOSPHATE WITH HIGH PURITY FROM BRINE

摘要

PURPOSE: A method for extracting lithium phosphate of high purity from brine is provided to cost effectively extract lithium from the brine without the evaporation and the concentration of the brine. CONSTITUTION: Hydroxide anions are introduced into brine to precipitate and eliminate impurities containing magnesium, boron, or calcium from the brine. A phosphorus supplying material is introduced into remaining liquid to precipitate lithium from the brine as lithium phosphate at a temperature higher than the room temperature. The hydroxide anions are the anions of sodium hydroxide. A method for eliminating the impurities includes the following: the hydroxide anions are introduced into the brine to obtain magnesium hydroxide; boron is absorbed with the magnesium hydroxide to co-precipitate magnesium and boron to collect the co-precipitated magnesium and boron; and the pH value of the remaining liquid is kept to be more than or equal to 12 to precipitate calcium.