China Nonferrous Metallurgy

Arsenic trioxide is a toxic and harmful substance, and the storage and transportation risks are very high. This paper introduces a hydrometallurgical process for preparing elemental arsenic by using arsenic trioxide, so as to meet the needs of minimization of arsenic trioxide as well as harmless storage and transportation of arsenic trioxide. With arsenic trioxide as a raw material, this process uses R as reducing agent to prepare elemental arsenic through reduction. The reducing agent R in the process can be aluminum powder, cadmium powder or a mixture of these two metal powders in any proportion. The test results show that the reduction rate of arsenic is greater than 99% and the grade of crude arsenic is greater than 97% under the optimum process conditions of reduction temperature being 60℃, reduction time being 5h, initial acidity being 7.5%, and dosage of reducing agent being 1.8times. Elemental arsenic with a grade of more than 99% can be obtained by crude arsenic refining. This process has the advantages of simple process, high recovery rate, low cost and environmental friendliness. It meets the requirements of arsenic trioxide minimization and harmless disposal, and opens up a new way for the commercial application of arsenic solid waste in non-ferrous smelting industry.