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以铅冶炼厂烟化段生产的铅锌烟尘为原料利用真空碳热还原法综合回收铅锌。采用X射线衍射、扫描电镜和化学分析等手段研究了铅锌烟尘原料性质、还原产物的物相和显微结构的变化规律。通过热力学计算得出当系统压力从105Pa依次降为104,103,102,10 Pa时,ZnO用碳还原的临界温度从1179.35 K依次降为990.97,854.48,751.03,669.93 K,而PbO用碳还原的临界温度则从554.92 K依次降为499.75,454.56,416.86,384.94 K。通过实验研究不同配碳比,还原温度,保温时间,得出当系统压力为20 Pa,配碳比为2.5,还原温度为1173 K时,真空碳热还原处理铅锌烟尘60 min能获得较高纯度的铅锌混合物,锌和铅的回收率分别74.99%和42.28%。
Lead and zinc soot produced by the fuming section of lead smelter was used as raw materials to synthesize lead and zinc by vacuum carbothermal reduction. The properties of raw materials, the phase and microstructure of the reduced products were studied by means of X-ray diffraction, scanning electron microscopy and chemical analysis. Thermodynamic calculations show that when the system pressure is decreased from 105Pa to 104,103,102,10 Pa, the critical temperature for the reduction of ZnO with carbon decreases from 1179.35 K to 990.97, 854.48, 751.03, 669.93 K, and the critical temperature for PbO reduction with carbon From 554.92 K to 499.75,454.56,416.86,384.94 K. The experimental results show that when the system pressure is 20 Pa, the carbon ratio is 2.5 and the reduction temperature is 1173 K, the results of vacuum carbothermal reduction of lead-zinc dust for 60 min can get higher Purity of the lead-zinc mixture, zinc and lead recovery rates were 74.99% and 42.28%.