Out team just published a new paper on vanadium recovery from red mud leachates using ion exchange resins. The paper is available on open access here.
Bauxite residue or red mud is an important by-product of the alumina industry, and current management practices do not allow their full valorisation, especially with regard to the recovery of critical metals, like vanadium.
This paper focus on vanadium removal and recovery from the leachates, with emphasis on the environmental remediation of bauxite residue disposal areas or closed legacy sites where vanadium is both a contaminant and a metal with economic interest present in the effluent.
As an environmental pollutant, removal of vanadium from leachates may be an obligation of bauxite residue disposal areas (BRDA) long-term management requirements. Vanadium removal from the leachate can be coupled with the recovery, and potentially can be used to offset long-term legacy treatment costs in legacy sites.
This study has shown that anion exchange resins can be used for metal removal and recovery from bauxite residue leachates in a highly alkaline pH range (up to 13).
The results showed that using simulated undiluted bauxite residue leachate as feed solution limited the resin efficacy, due to the presence of competing ions. However, the resins are very effective at V removal for simulated post-closure bauxite residue disposal areas (BRDA) effluent.
In the column experiments, V was readily eluted from the resins in concentrations similar to some industrial process liquors, which holds promise for recovery and recycling of V into downstream industrial processes.
Further research is required to scale-up laboratory findings. This should include assessment pretreatments and optimisation of operating parameters, such as flow rate and bed height. This will help facilitate life cycle assessments of anion exchange resins as a potentially efficient and cost-effective option for both the treatment of bauxite residue leachates and the recovery of metals of critical importance such as vanadium.