Lithium ion adsorption characteristics of porous Li1.33Mn1.67O4 adsorbent prepared using petroleum-based pitch as a binder

Abstract

The lithium manganese oxide (LMO) Li1.33Mn1.67O4 exhibits a spinel structure and is well known as a highly selective adsorbent for extracting lithium from salt lakes or seawater. For practical use, the LMO powder should be transformed into porous shapes, such as granules, spheres, or foams, by using appropriate binding materials. In this study, we have proposed an alternative approach for the preparation of porous LMO adsorbents; this involves the use of petroleum pitch as a binding material and subsequent formation of a mixture and heat treatment, which provide chemical resistance and mechanical strength. Disc-shaped porous LMO/C adsorbents were prepared without any structural changes in the spinel structure of the LMO powder after heat treatment. The prepared LMO/C adsorbent treated with acid (and converted to HMO/C) showed excellent adsorption capacity and mechanical durability. The theoretical maximum adsorption capacity of the disc-shaped HMO/C adsorbent was 24 mg g−1. We also tested HMO/C adsorbent to the recovery of lithium from actual brine to confirm the feasibility of suggested method.