直接还原法回收铜渣中铁、铜和锌的热力学

Thermodynamics of recovering iron,copper,zinc in copper slag by direct reduction method

为了实现铜渣中的铁与硅及其他元素分离,提出了含碳球团-转底炉直接还原工艺综合回收铜渣中的铁、铜和锌等有价元素,首先对水淬铜渣配碳还原进行了热力学分析,然后采用Fact Sage热力学计算软件中的Equilib模块对碳热还原过程进行了理论计算,研究了温度、碱度和配碳量等工艺参数,对水淬铜渣碳热还原产物组成及收得率的影响。计算结果表明:Fe的收得率主要受温度的影响较大,碱度的影响不大,配碳量有一定影响,铁的收得率最高可以达到91%以上;Zn的收得率主要受温度的影响较大,900℃左右达到最大;Cu的收得率最高可达99%,并且受上述因素的影响相对小。为了保证铁的收得率,建议优化的工艺条件为:配碳量(C/O比)大于1.2、还原温度大于1 200℃、碱度大于0.6。

In order to achieve the separation of iron,silicon,and other elements in copper slag,a method of comprehensive recovery of valuable elements such as iron,copper,and zinc in copper slag,which uses a direct reduction of carbon pellet rotary hearth furnace process,will be proposed. First,carbon reduction thermodynamic analysis on granulated copper slag was carried out,and then carbon thermal reduction process theoretical calculations from Fact Sage thermodynamic calculation software module Equilib were used in order to discuss the impacts of temperature,basicity,carbon content,and other process parameters on the water quenching carbothermic reduction composition of products and recycle rate. The results showed that the recycle rate of iron was mainly affected by the temperature,while basicity had little effect and carbon content had a certain influence;the highest recycle rate was 91%. The recycle rate of zinc was mainly affected by temperature,and was maximized at approximately 900 ℃. The highest recycle rate of copper was 99%,and the effects of the above factors were relatively small. In order to ensure that the recycle rate of iron is achieved,optimization of the process conditions is recommended; the carbon content（ C / O ratio） should be more than 1. 2,the reduction temperature should be higher than 1 200 ℃,and the basicity should be greater than 0. 6.