(中國科學(xué)院 化工冶金研究所， 北京 100080)
摘 要: 通過電化學(xué)研究， 考察了氨溶液中砷黃鐵礦的陽極氧化反應(yīng)。 實驗表明氧化生成的表面膜對反應(yīng)有抑制作用，該膜具有多孔性， 可使反應(yīng)繼續(xù)進行。 低溫時， 陽極氧化過程由電化學(xué)反應(yīng)控制； 高溫時， 反應(yīng)受擴散過程控制。 氨濃度對氧化過程的反應(yīng)速率沒有顯著影響， 溶液中Cu2+ 能降低氧化峰電位， 改變氧化表面膜的形態(tài)， 使膜的孔隙增大， 反應(yīng)速度加快。 砷黃鐵礦的陽極氧化總反應(yīng)為FeAsS+11H2O=Fe(OH)3 + SO42-+ HAsO42- +18H + +14e。
關(guān)鍵字: 砷黃鐵礦； 陽極氧化； 氨溶液； 電化學(xué)
（Institute of Chemical Metallurgy, Chinese Academy of Sciences， Beijing 100080, P.R.China）
Abstract:Anodic process of arsenopyrite in ammonia solutions was studied by electrochemical methods. The process is an irreversible reaction with formation of a ferric oxidized film and slowed down by the film. The process rate is controlledby the electrochemical reaction on the electrode surface in the low temperaturerange, or alternatively by the diffusion process through the film in the highertemperature range. The concentration of ammonia has no remarkable effect on theprocess, and cupric ion in solutions makes the anodic peak potential shift negatively and the surface film porous， resulting in oxidation process to be accelerated. The overall reaction can be expressed as FeAsS+11H2O=Fe(OH)3 + SO42- + HAsO42- + 18H+ +14e
Key words: arsenopyrite; anodic process; ammonia solution
