Lithium recovery from Qarham brine using adsorption-membrane separation hybrid system

Lithium uptake from brine has attracted great interest in recent years. An adsorption and membrane separation coupling system used for recovery lithium from brine with high ratio of magnesium to lithium. Lithium ion sieve H_1.6Mn_1.6O₄ (HMO) was obtained from o-LiMnO₂ which was prepared by one-step hydrothermal synthesis and its adsorption property in Qarham brine was studied. The results showed that the particle size of HMO was between 100 to 500 nm and its adsorption capacity of Li⁺ in brine reached 31.44 mg·g^-1. Ceramic membrane with pore size of 50 nm showed the highest permeation flux (150 L·m^-2·h^-1) and 100% rejection of lithium ion sieves. During the adsorption-membrane continue process, the extraction rate of lithium was more than 97%, and backflushing could effectively enhance the membrane filtration process. The fouled ceramic membrane was recovered with HCl and H₂O₂ solution. The results implied that the adsorption-membrane separation hybrid system could be used for lithium extraction from brine with high Mg/Li ratio, and had a good application prospect.