A precipitation method for arsenite ion in aqueous solution as natural mineral by hydrothermal mineralization

Abstract

There is no effective method to recover arsenic dissolved in aqueous media in spite of its high toxicity. The cause for this problem resides in the difficulty to form precipitates with low solubility in water under normal pressure and temperature conditions. We developed a new technology to recover arsenite ion (AsIIIO33-) as arsenate apatite (Ca5 (AsO4) 3 (OH) ) from its aqueous solution by a hydrothermal mineralization treatment. A wide range of initial concentration of arsenite ion (1-2000 mg L-1) was found to reduce to 0.04-0.06 mg L-1 after the treatment. The precipitate is natural minerals, Johnbaumite, which is easily reused as a raw material for the production of industrial-grade arsenic compounds.