Recovery of valuable metals from waste diamond cutters through ammonia–ammonium sulfate leaching
来源期刊：International Journal of Minerals Metallurgy and Materials2017年第12期
论文作者：Ping Xue Guang-qiang Li Yong-xiang Yang Qin-wei Qin Ming-xing Wei
文章页码：1352 - 1360
摘 要：Copper and zinc were recovered from waste diamond cutters through leaching with an ammonia–ammonium sulfate system and air as an oxidant. The effects of experimental parameters on the leaching process were investigated, and the potential–pH（E–pH） diagrams of Cu–NH3–SO42-–H2O and Zn–NH3–SO4-2–H2O at 25°C were drawn. Results showed that the optimal parameters for the leaching reaction are as follows: reaction temperature, 45°C; leaching duration, 3 h; liquid-to-solid ratio, 50:1（mL/g）; stirring speed, 200 r/min; ammonia concentration, 4.0 mol/L; ammonium sulfate concentration, 1.0 mol/L; and air flow rate, 0.2 L/min. The results of the kinetics study indicated that the leaching is controlled by the surface chemical reaction at temperatures below 35°C, and the leaching is controlled by diffusion through the product layer at temperatures above 35°C.
Ping Xue1,2，Guang-qiang Li1，Yong-xiang Yang1,3，Qin-wei Qin1，Ming-xing Wei2
1. Key Laboratory for Ferrous Metallurgy and Resource Utilization of Ministry of Education,Wuhan University of Science and Technology2. School of Electromechanical and Architectural Engineering,Jianghan University3. Department of Materials Science and Engineering,Delft University of Technology
摘 要：Copper and zinc were recovered from waste diamond cutters through leaching with an ammonia–ammonium sulfate system and air as an oxidant. The effects of experimental parameters on the leaching process were investigated, and the potential–pH（E–pH） diagrams of Cu–NH3–SO42-–H2O and Zn–NH3–SO4-2–H2O at 25°C were drawn. Results showed that the optimal parameters for the leaching reaction are as follows: reaction temperature, 45°C; leaching duration, 3 h; liquid-to-solid ratio, 50:1（mL/g）; stirring speed, 200 r/min; ammonia concentration, 4.0 mol/L; ammonium sulfate concentration, 1.0 mol/L; and air flow rate, 0.2 L/min. The results of the kinetics study indicated that the leaching is controlled by the surface chemical reaction at temperatures below 35°C, and the leaching is controlled by diffusion through the product layer at temperatures above 35°C.
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