Optimization of operation conditions for extracting lithium ions from calcium chloride-type oil field brine

Al(OH)3 was prepared to extract lithium ions from calcium chloride-type oil field brine. The influences of four factors, namely temperature, Al³⁺/Li⁺ molar ratio, OH^-/Al³⁺ molar ratio, and contact time between Al(OH)₃ and the brine, on the yield of lithium ions were investigated. It is found that their optimal values are 35℃, 4.5, 2.6, and 6 h, respectively. In the course of the experiment, the apparent pH value was observed. The results reveal that the apparent pH value has no remarkable influence on the yield of lithium ions. Meanwhile, the effects of the concentrations of calcium ions and magnesium ions in the brine on lithium recovery were studied. The results indicate that calcium ions have minor negative influence on the yield of lithium ions under optimal conditions, and magnesium ions slightly influence the yield of lithium ions.