Arsenic trisulfide (As₂S₃) is known as one of the possible precipitates in arsenic removal from metallurgical waste streams. The advantage of precipitation in the form of arsenic trisulfide is its high arsenic content (up to 61% theoretically). However, arsenic trisulfide is unstable, especially under alkaline and oxidizing conditions, which is a significant barrier to arsenic fixation in the form of arsenic trisulfide. To further understand its stability, a series of laboratory leaching tests were performed under fully-controlled conditions to quantify the effect of pH, dissolved oxygen concentration, and temperature on the total arsenic and sulfur released. The experimental results show that the release rate of arsenic and sulfur increased with pH, the dissolved oxygen concentration, and temperature. In less alkaline conditions, the aqueous arsenic to sulfur ratio by weight was higher than the stoichiometric value of 1.6 in the solid As₂S₃, suggesting the formation of secondary phases or precipitates enriched in sulfur. The rate law derived from the kinetic modeling suggests that the rate-limiting step in the arsenic release process is the surface chemical reaction.

三硫化二砷（As ₂ S ₃）是从冶金废物流中去除砷的可能沉淀之一。以三硫化二砷形式沉淀的优点是砷含量高（理论上高达61％）。但是，三硫化二砷是不稳定的，尤其是在碱性和氧化条件下，这是三硫化二砷形式对砷固定的重要障碍。为了进一步了解其稳定性，在完全受控的条件下进行了一系列实验室浸出测试，以量化pH，溶解氧浓度和温度对释放的总砷和硫的影响。实验结果表明，砷和硫的释放速率随pH值，溶解氧浓度和温度的升高而增加。在弱碱性条件下₂ S ₃，表明形成了富含硫的第二相或沉淀。从动力学模型得出的速率定律表明，砷释放过程中的速率限制步骤是表面化学反应。