Formation and working mechanisms of layered TiO2⋅H2O adsorbents for effectively recovering Li+ from oil-gas field brines

Abstract

How to effectively recover Li+ from liquid mineral brines with high Mg2+/Li+ ratio and low Li+ concentration is very significant and important for promoting the carbon peak and carbon neutrality plan valid. Therefore, taking the application merits and formation scheme into consideration, well-crystallized β-Li2TiO3 precursors for obtaining TiO2⋅H2O adsorbents were prepared through a classical solid-phase method under the optimized conditions. Interestingly, both Li+ desorption and titanium dissolution loss ratio of TiO2⋅H2O adsorbents depend on the HCl concentration and delithiation temperature. The Li+ escaping routes from LTO precursors to TiO2⋅H2O adsorbents is dramatically distinctive with that in the next adsorption/desorption cycles. Accordingly, as-prepared TiO2⋅H2O adsorbents owns the high adsorption capacity up to 51.25 mg/g at 60 °C and low Ti-dissolution loss ratio around 1.08%. The initial adsorption capacity of TiO2⋅H2O adsorbents in real original oil–gas field brines containing 100 ppm Li+ is 20.14 mg/g. According to the structure–property relationship, formation and working mechanisms of TiO2⋅H2O adsorbents was proposed.