Influence of Water Content in the Pores of Hydrophobic Aluminum‐Based Adsorbent Particles on Lithium Adsorption Performance From Salt Lake Brine

ABSTRACT

Hydrophobic aluminum‐based (Al‐based) adsorbent particles are used for the improved strength but sharply reduced adsorption capacity during lithium (Li) recovery from salt lake brines. Adequate wetting of hydrophobic particles is regarded as a key factor to achieve outstanding Li ⁺ adsorption performance. In this work, Al‐based adsorbents are granulated with hydrophobic binder and wetted with different physically adsorbed water contents of 0%, 7.2%, and 28.0%. The effects of water content are systematically investigated. Compared with the unwetted particles, the wetted particles exhibit a shorter Li ⁺ adsorption equilibrium time by 25.0%, a higher Li ⁺ saturated adsorption capacity by 33.6%, and a lower Mg/Li (mass ratio) in the eluent by 29.0%. The wetted particles also have good cyclic stability and mechanical stability. The acting forces between brine and particles during the adsorption are analyzed and show that brine is difficult to flow into the pores of hydrophobic particles. The adequate wetting is critical for the enhancement of Li ⁺ adsorption capacity and adsorption speed and the reduction of Mg/Li.