Extraction of lithium halides from calcium-containing brines in the presence of urea and alcohol-ketone

Claim 1

THE PROCESS OF RECOVERING LITHIUM VALUES FROM AN AQUEOUS BRINE CONTAINING LITHIUM SALTS, SELECTED FROM THE GROUP CONSISTING OF LITHIUM CHLORIDE, LITHIUM BROMIDE, LITHIUM IODIDE AND MIXTURES THEREOF, AND OTHER SALTS DISSOLVED THEREIN INCLUDING CALCIUM SALTS, WHICH COMPRISES: (A) ADMIXING WITH SAID BRINE AN ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC MONOALCOHOLS CONTAINING FROM 3 TO 6 CARBON ATOMS PER MOLECULE AND ALIPHATIC KETONES CONTAINING FROM 4 TO 7 CARBON ATOMS PER MOLECULE IN A RATIO OF THE ORGANIC SOLVENT TO THE BRINE WITHIN THE RANGE OF FROM ABOUT 0.5 TO ABOUT 10 BY VOLUME IN THE PRESENCE OF UREA, SAID UREA BEING PROVIDED IN A MOLE RATIO WITH CALCIUM SALTS PRESENT IN THE BRINE WITHIN THE RANGE OF FROM ABOUT 0.5 TO ABOUT 2.5 AND BEING BETWEEN FROM ABOUT 10 AND ABOUT 40 WEIGHT PERCENT OF THE WEIGHT OF THE BRINE; (B) AGITATING THE MIXTURE AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 0* TO ABOUT 70*C. FOR A PERIOD OF TIME SUFFICIENT SUCH THAT THE ORGANIC SOLVENT EXTRACTS A SUBSTANTIAL PORTION OF THE LITHIUM VALUES FROM THE BRINE; (C) STOPPING SAID AGITATION AND SEPARATING SAID MIXTURE INTO A LIGHTER ORGANIC PHASE CONTAINING A SUBSTANTIAL PORTION OF THE LITHIUM VALUES AND A HEAVIER AQUEOUS PHASE CONTAINING A SUBSTANTIAL PORTION OF THE CALCIUM VALUES; AND (D) SEPARATING THE ORGANIC PHASE FROM THE AQUEOUS PHASE.