铅冶炼物料工艺矿物学与热力学平衡研究

Technological Mineralogy and Thermodynamic Equilibrium for Lead Smelting Process

富氧熔池熔炼-液态高铅渣直接还原工艺因对原料适应性强、熔炼炉运行稳定可靠、金属回收率高及氧化炉熔炼烟气中二氧化硫浓度高,在铅冶炼工业中占有越来越重要的地位。但目前对于该工艺的理论基础研究较为薄弱,亟需对该工艺冶炼过程热力学平衡等进行理论研究,为工艺的优化提供理论支持。首先对冶金过程物料如铅精矿、高铅渣及还原渣进行了工艺矿物学研究,然后通过FactSage8.1热力学软件计算,研究了氧化段氧气系数、熔炼温度及还原段还原剂用量对体系中Pb分配率和熔炼渣中Pb、S等元素含量的影响规律。计算得出,铅富氧熔池氧化熔炼中铅的直收率在氧气系数1.0、熔炼温度1200℃左右时达到最高;温度的升高与FeO、CaO的加入有利于高铅渣还原反应的进行,在还原剂用量大于5.7%时铅的还原率达到91%。

Due to its strong adaptability of raw materials,stable and reliable operation of smelting furnace,high metal recovery rate and high sulfur dioxide concentration in smelting flue gas of oxidation furnace,the process of direct reduction of high liquid lead slag in oxygen-rich blowing bath smelting plays an increasingly important role in lead smelting industry.However,at present,the theoretical basis of the process is relatively weak,and it is urgent to carry out theoretical research on the thermodynamic balance of smelting process,so as to provide theoretical support for the optimization of process.The process mineralogy of metallurgical process materials such as lead concentrate,high lead slag and reduction slag was studied.The influence law of oxygen coefficient in oxidation section,melting temperature and reducing agent dosage in reduction section on Pb distribution rate and content of Pb,S and other elements in smelting slag was studied by FactSage8.1 thermodynamic software calculation.It is calculated that the direct yield of lead in oxygen-rich bath oxidation smelting reaches the highest when the oxygen coefficient is 1.0 and the melting temperature is about 1200℃.The increase of temperature and addition of FeO and CaO are beneficial to the reduction of high lead slag.When the amount of reducing agent is more than 5.7%,the reduction rate of lead can reach 91%.