Lead Blast Furnace Dust Recycling

In this paper, a new process was studied to separate arsenic and extract Indium and zinc from lead blast furnace dust contaning Indium, zinc and arsenic.The distributiones of Zinc and Indium and Arsenic in the leaching process of the lead blast furnace dust from YunnanTin Co.were studied. A new process, which consist of middle acid circle leching, heat preservation filtering, arsenic oxide crystalizing were introduced. In the experiments, separating Zinc and Arsenic and extracting Indium according to the process were studied mainly. The suitable process and technological parameters were determined for the practical application.The experiments include two parts: condition experiments and circle leaching. Base on the solubility of ZnSO₄ and As₂O₃ was different on the conditions of different acidity and temperature, separating Zinc and Arsenic were achieved by the way of changing the temperature and leaching acidity. Some influence factors: temperature, acidity, liquid/solid and leaching time, etc were studied.The results from the laboratory experiment showed that when the acidity was 7mol/l, the temperature was 85℃, the liquid/solid was 4:1 and the leaching time was 1.5h, a rough As₂O₃ amount to 74.90% was gained in the crystal step, a rough ZnSO₄·7H₂O amount to 84.73% was gained when the acidity get to 13mol/l after seventh leching rounds, and a 82.46% extraction rate of Indium was achieved.The process has the advantages of simplicity, low cost, high recovery rate for valuable metals, high production and a little pollution, etc. A new idea is provided to deal with containing arsenic materials.