Preparating Arsenic Trioxide with Sulfuric Acid Wet Oxidation

摘要

The technology of the acidification is adopted to prepare arsenic trioxide (As2O3). With a concentration of 98% of concentrated sulfuric acid and Orpiment made into a certain ratio of the slurry suspension. Arsenic trioxide's content is 99.94%, extraction yield can reach to 98.92%. The optimal conditions is reaction temperature at 120°Cand the reaction time in 2.5 h; the slurry ratio is less than 1/6 and particle size is less than 0.080 mm. Arsenide is a highly toxic substance, but is an indispensable resource for the development of the national economy [1]. At present, the domestic and foreign technology preparation or recovery of arsenic trioxide method, according to the technical features can be divided into two categories [2-3]: a pyrometallurgical treatment after roasting, arsenic vapor sublimation separation with other materials, secondary oxidation with bags and electrostatic dust collection; pyrometallurgical processing arsenic sulfide ore, slag, mature technology, the process is short, but its handling dry state of arsenic trioxide, harm to operating personnel, can easily cause secondary pollution of the environment [4] and high energy consumption, low product purity, arsenic extraction recovery [5]; the other is wet, to use the acid leaching, alkaline leaching or salt leaching processing [6], arsenic acid with sulfur dioxide reduction for arsenic acid,and then further concentrated cooling crystallization of arsenic trioxide. This experiment, the use of concentrated sulfuric acid in place of the dilute sulfuric acid used in the conventional method, the process is relatively simple, low energy consumption, the processing costs are relatively low.