摘要
铅锌氧化渣熔融还原是得到金属铅和锌的重要步骤,但氧化渣中锌含量升高和铅含量降低会导致熔化温度增加,使得还原工艺条件发生较大变化.本文对高锌含量铅锌渣(Zn≈25%)的还原工艺条件和渣型制度进行了研究,主要考察了还原煤量、还原温度、还原时间、Fe/SiO2、CaO/SiO2 对铅锌氧化渣中Pb、Zn、Cu回收率的影响.试验结果表明,铅锌渣Pb、Zn、Cu金属回收率随着还原煤量、还原温度、还原时间的增加而增加,但过高的煤比和还原温度不利于Pb、Cu回收率的提高;铅锌渣Pb、Zn、Cu金属回收率随着Fe/SiO2和CaO/SiO2的增加而增加,但Fe/SiO2增加至0.78,CaO/SiO2 增加至0.8 时,继续增加Fe/SiO2和CaO/SiO2将降低Pb、Zn、Cu金属回收率.试验用铅锌渣的适宜还原条件为煤比1.2～1.4、还原温度1623～1673 K、还原时间90～120 min、Fe/SiO2=0.78～1.17,CaO/SiO2=0.5～0.8.在上述工艺条件下,铅锌氧化渣中Pb、Zn、Cu回收率分别可达84.01%、94.51%、85.8%以上.
Abstract
Lead and zinc oxide slag with high zinc content was synthesized at high temperature using high lead slag as raw material,and anthracite was added as reducing agent for direct reduction experiment.The experiment studied the effects of reducing coal amount,reducing temperature,reducing time,Fe/SiO2,CaO/SiO2 on the recovery rates of Pb,Zn,and Cu in lead and zinc oxide slag.The experimental results showed that the recovery rates of Pb,Zn,and Cu of lead and zinc oxide slag increased with the increase of reduction coal amount,reduction temperature,and reduction time.However,excessive coal ratio and reduction temperature are not conducive to the improvement of Pb and Cu recovery rates;The recovery rates of Pb,Zn,and Cu of lead and zinc oxide slag increased with the increase of Fe/SiO2 and CaO/SiO2.However,as Fe/SiO2 increased to 0.78 and CaO/SiO2 increased to 0.8,continuing to increase Fe/SiO2 and CaO/SiO2 would reduce the recovery rates of Pb,Zn,and Cu.The suitable conditions for the reduction of lead and zinc oxide slag were:coal ratio of 1.2～1.4,reduction temperature of 1 623～1 673 K,reduction time of 90～120 minutes,Fe/SiO2=0.78～1.17,CaO/SiO2=0.5～0.8.Under the above process conditions,the recovery rates of Pb,Zn,and Cu in lead and zinc oxide slag could reach 84.01%,94.51%,and 85.8%,respectively.
基金项目
广东省重点领域研发计划(2022B0111130002)
NETL
NSTL
万方数据