真空碳热还原法处理铅银渣热力学分析及实验研究
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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 PbSO_4 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.
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 PbSO_4 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.
引文
[1]赵宏.铅银渣综合利用新工艺探讨[J].有色金属(冶炼部分),2001,(4):16-19
[2]章顺英,龚鸿翔.硫酸铅渣电热熔炼[J].有色冶炼,1979,(1):21-32
[3]李黎婷.利用铅银渣综合提取锌铅银的试验研究[J].矿产综合利用,2010,(3):15-19
[4]刘群.熔池熔炼处理铅锌冶炼渣的高温脱硫及碳热还原研究[D].长沙:中南大学化学化工学院,2014
[5]戴兴征,王侠前,张浩杰,等.湿法炼锌铅银渣烟化挥发热力学研究[J].中国有色冶金,2011,(5):49-53
[6]马永涛,王凤朝.铅银渣综合利用探讨[J].中国有色冶金,2008,(3):44-49
[7]刘沧龙,何乐琼,杨守明,等.铅银渣火法处理回收铅银工艺[P].中国:200910058590.2,2009
[8]张荣良,丘克强,唐淑贞,等.含锑铅复杂氧化物的酸浸渣真空碳热还原[J].中国稀土学报,2006,24(专辑):445-450
[9]罗启,曲涛,刘大春,等.红土镍矿真空碳热还原特性[J].真空科学与技术学报,2012,32(11):1026-1032
[10]孙红燕,孔馨,森维,等.真空碳热还原处理铅锌烟尘实验研究[J].真空科学与技术学报,2014,34(7):758-762
[11]燕春培,郁青春,刘大春,等.真空碳热还原分解硫酸钙热力学分析及实验探究[J].真空科学与技术学报,2014,34(5):517-521
[12]史谊峰,刘大方,尧世文,等.铜冶炼烟尘还原熔炼机理分析及优化途径[C].中国:昆明,全国重有色金属冶金技术交流会,2014:1-7
[13]杜士元.铜转炉烟尘硫酸铅渣直接鼓风炉还原熔炼[J].云南冶金,1989,(3):28-33
[14]叶大伦,胡建华.实用无机物热力学数据手册[M].北京:冶金工业出版社,2002:6-9,175,194,767-779,881
[2]章顺英,龚鸿翔.硫酸铅渣电热熔炼[J].有色冶炼,1979,(1):21-32
[3]李黎婷.利用铅银渣综合提取锌铅银的试验研究[J].矿产综合利用,2010,(3):15-19
[4]刘群.熔池熔炼处理铅锌冶炼渣的高温脱硫及碳热还原研究[D].长沙:中南大学化学化工学院,2014
[5]戴兴征,王侠前,张浩杰,等.湿法炼锌铅银渣烟化挥发热力学研究[J].中国有色冶金,2011,(5):49-53
[6]马永涛,王凤朝.铅银渣综合利用探讨[J].中国有色冶金,2008,(3):44-49
[7]刘沧龙,何乐琼,杨守明,等.铅银渣火法处理回收铅银工艺[P].中国:200910058590.2,2009
[8]张荣良,丘克强,唐淑贞,等.含锑铅复杂氧化物的酸浸渣真空碳热还原[J].中国稀土学报,2006,24(专辑):445-450
[9]罗启,曲涛,刘大春,等.红土镍矿真空碳热还原特性[J].真空科学与技术学报,2012,32(11):1026-1032
[10]孙红燕,孔馨,森维,等.真空碳热还原处理铅锌烟尘实验研究[J].真空科学与技术学报,2014,34(7):758-762
[11]燕春培,郁青春,刘大春,等.真空碳热还原分解硫酸钙热力学分析及实验探究[J].真空科学与技术学报,2014,34(5):517-521
[12]史谊峰,刘大方,尧世文,等.铜冶炼烟尘还原熔炼机理分析及优化途径[C].中国:昆明,全国重有色金属冶金技术交流会,2014:1-7
[13]杜士元.铜转炉烟尘硫酸铅渣直接鼓风炉还原熔炼[J].云南冶金,1989,(3):28-33
[14]叶大伦,胡建华.实用无机物热力学数据手册[M].北京:冶金工业出版社,2002:6-9,175,194,767-779,881