Continuous recovery of lithium and boron from Jezechake Salt Lake brine using fixed-bed adsorbers

Abstract

Jezechake Salt Lake brine in China is rich in lithium ions coexisting with relatively high concentrations of carbonate and borate anions. Both carbonate and borate anions have a pH-buffering ability to accept the exchanged H⁺ ions of lithium ion sieves, enhancing the adsorption process of Li⁺ ions. When Jezechake Salt Lake brine passes through a titanium-type ion-sieve-packed column, good lithium breakthrough occurs owing to the pH-buffering action in the brine, which is of great significance for effective lithium recovery from brines in industrial production. In addition, the boron content of Jezechake Salt Lake brine is high, and its recovery is valuable for industrial applications. Here, an N-methylglucamine resin-packed column was connected in series behind a titanium-type ion-sieve-packed column to obtain boron simultaneously with the aim of lowering the energy consumption and cost of lithium recovery. During the adsorption process, Jezechake Salt Lake brine was successively fed into the lithium and boron adsorption columns. The two packed columns were then desorbed independently through acidic solution washing to obtain the Li and B eluents. The breakthrough behavior and elution performance of Li and B in the packed columns were investigated experimentally, and the practicability and efficacy of the proposed process were assessed.