Reduction of indium(III) oxide to indium through mechanochemical route

A nonthermal reduction of indium(III) oxide (In₂O₃) to metallic indium (In) was achieved through mechanochemical route in this work. A mixture of In₂O₃ and lithium nitride (Li₃N) under ammonia (NH₃) and/or nitrogen (N₂) gas environments was milled in a planetary ball mill with uni-size ZrO₂ balls to induce mechanochemical reaction between the starting materials. Metallic indium was obtained after milling for 120 min, and the results are confirmed by X-ray diffraction (XRD) analysis. Washing of the milled product with water to remove by-products using the planetary ball mill for a further 10 min resulted in formation of pellets which were analyzed by EPMA, results clearly show that high purity indium metal was obtained.