摘要
采用湿法炼锌产出的铅银渣作为实验原料,首次提出利用真空碳热还原法处理铅银渣以回收其中的金属铅。系统研究了冷凝产物的物相随还原温度、配碳比及还原剂的种类的变化而变化的基本规律。通过对碳热还原铅银渣的热力学计算可以得出,常压条件下用C直接还原PbSO_4生成金属铅,氧化铅和硫化铅的理论开始反应温度分别为737,829和532K。当系统压力下降至10Pa时,其理论开始反应温度分别下降至504,562和370K。通过实验分别研究不同还原温度,不同配碳比,不同种类还原剂对冷凝产物的影响。实验结果表明:当以石墨作为还原剂,还原温度为700℃,真空度为10Pa,配碳比C/Pb=2,反应时间为30min的条件下,能够获得相对较纯的铅粉。
Carbothermal reduction of lead-silver slag in vacuum was theoretically analyzed and experimentally evaluated. The impact of the reduction conditions,including but not limited to the reduction temperature and time,molar-ratio of C/Pb,carbon phases（ activated carbon and graphite） and pressure,on the Pbrecovery-rate was investigated with X-ray diffraction and scanning electron microscopy. The calculated results show that at atmospheric pressure,carbon reduced PbSO4 into Pb,PbO and PbS at 737,829 and 532 K,respectively; whereas at 10 Pa,the reduction temperatures decreased to 504,562 and 370 K,respectively. The experimental results revealed that reduced at 10 Pa,700℃ for 30 min. and with a C（ graphite）/Pbmolar-ratio of 2,fairly pure Pb-powder was obtained in the condensate. When it comes to the purity of the reduced Pb-powder,graphite outperforms activated carbon,possibly because of their different reduction mechanisms.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2017年第3期327-331,共5页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(51362012)
红河学院中青年学术骨干培养项目(2015GG0204)
关键词
真空
铅银渣
热力学分析
碳热还原
Vacuum
Lead silver residue
Thermodynamic analysis
Carbothermal reduction
