Comprehensive Utilization of Boron-Concentrate by Hydrometallurgy

A new eco-friendly process to comprehensively utilize boron-concentrate is proposed in this paper. In process, Iron-concentrate, silicon dioxide, magnesium oxide, and boric acid could be produced from boron-concentrate. The highlight of was minimal waste discharge during the whole process. Iron removal a key step ensure quality oxide. introduced goethite precipitation method remove iron very low level. With addition 3 cm3 H2O2 (5 vol. %) as an oxidizing agent, more than 99% removed leaching liquor. After iron, resulting liquor used prepare precipitate. And optimal preparation conditions were: temperature 30 °C time 60 min, ammonium- ratio 1.5, ion concentration 34.8 g·L?1. Under those conditions, efficiency up 98.5%. Magnesium oxide obtained by roasting precipitate at 550 °C for 2 h. Then mixed crystals ammonium sulfate were evaporating after removing precipitating. Boric separated dissolving ethanol solution.