Recovery of Gallium from Bauxite Residue Using Combined Oxalic Acid Leaching with Adsorption onto Zeolite HY

Abstract

Bauxite residue, the byproduct of alumina production, may potentially be a valuable source of strategically important metals, e.g. Gallium. Ga is considered critical element for the EU. To ensure adequate supply of Ga for the future, secondary sources such as bauxite residue should be exploited with efficient extraction methods. Therefore, in this study, mineral acids (H 2 SO 4 , HCl, and HNO 3) and an organic acid (H 2 C 2 O 4-oxalic acid), were evaluated for their efficiencies to extract Ga from bauxite residue. Using H 2 C 2 O 4 , the highest Ga leaching efficiencies were achieved, compared to other acids. The achieved leaching experimental results were considered for the construction of a design of experiment (DOE) model to achieve optimal conditions for Ga extraction using H 2 C 2 O 4. These values were validated by experiments which resulted in ~ 94% accuracy. In the second part of the study, using pure Ga solution, the adsorption of Ga onto zeolite HY was studied. The effects of adsorbent dosage, temperature, and contact time on the adsorption of Ga from solution by zeolite HY were studied. The obtained adsorption experimental results were used to construct a DOE model to achieve optimal conditions for Ga adsorption on to zeolite HY. The DOE-achieved optimal conditions were evaluated by experiments in pure Ga solution, which resulted in an efficiency of ~ 99.4 %. In the third stage, the bauxite residue was leached in H 2 C 2 O 4 under the optimal DOE conditions which resulted in 71% efficiency; thus the resulting bauxite residue solution was subjected to adsorption using zeolite HY under the optimal DOE conditions achieved. The Ga adsorption onto the zeolite was only 16% compared to the Ga adsorption of 99.4 % under the pure Ga solution, thus, representing the influences of the other leachates in the solution, which are minimizing the Ga adsorption onto the zeolite HY and providing an opportunity for future studies on the different mechanisms involved.

Recovery of gallium by silica‐based polymer TBP/SiO2‐P obtained from hydrochloric acid solution

“…Comparisons with other adsorbents, such as the oxidized and unmodified coir, 36 activated carbon 37 and zeolite HY 38 are listed in Table 4. The result shows that TBP/SiO 2 ‐P has a relatively high‐adsorption capacity and a much shorter equilibrium time.…”

Extraction of Valuable Elements from Red Mud with a Focus on Using Liquid Media—A Review

“…To reduce the loss of more expensive oxalic acid before leaching, red mud was neutralized by diluted hydrochloric acid of 3 mol/L at a liquidto-solid ratio of 2 mL/g for 1 h at room temperature. As a result of pretreatment, the loss of Ujaczki et al [74] studied selective recovery of gallium by the leaching of red mud using 1-2 M solutions of HCl, HNO 3 and H 2 SO 4 , in addition to 1 M C 2 H 2 O 4 . The degree of gallium recovery from the suspension of 100 g of red mud in 1 L of the solution after the treatment at 60 • C for 24 h varied depending on the type of acid, and was 34.8% for HCl, 27.9% for HNO 3 , 28.6% for H 2 SO 4 , and 42.0%, the highest value, for C 2 H 2 O 4 .…”

“…The most important lixiviant among the investigated organic acids is oxalic acid, which enables selective dissolution of Fe [71][72][73] and Ga [74] from red mud. This method can be used as an alternative approach to iron recovery instead of pyrometallurgical methods.…”

A perspective on developing solid-phase extraction technologies for industrial-scale critical materials recovery

“…6 Liquid crystal displays (LCDs), on the other hand, are a candidate for indium extraction, 7 while tellurium could potentially be recycled from the photovoltaic cells that drive their demand. 8 In addition to recycled electronic materials, the myriad other underutilized potential feedstocks include spent catalysts, 9 acid mine drainage, 10 geothermal fluids, 11 mining wastes like red mud 12,13 and coal byproducts, 14,15 and many others (Table 1). This wide array of abundant and easily obtainable resources could help to mitigate the existing CM supply limitations and environmental impacts if the appropriate extraction and purification systems can be developed.…”