Mg-30Ca合金对铅黄铜除Pb效果的热力学模拟

Thermodynamic Simulation of Deleading of Leaded Brass with Mg-30Ca

基于FactSage软件研究了Mg-30Ca合金对废旧铅黄铜除Pb效果的影响。结果表明,在铅黄铜熔体中添加Mg-30Ca中间合金,Ca易与Pb形成CaPb、Ca2Pb等高熔点化合物。模拟得到铅黄铜液相线温度为824~856℃。随着合金中Mg-30Ca添加量的增加,CaPb、Ca2Pb含量逐渐增加,除Pb效果提升。880℃时添加7%的Mg-30Ca时,除Pb率达99.6%。除Pb率随保温温度的升高而降低。除Pb为热力学动态平衡过程,升高温度不利于铅黄铜除Pb。试生产结果与模拟结果基本一致。

Applied thermodynamics software FactSage,the removal of lead from the scrap brass was simulated by adding Mg-30 Ca alloy,and its thermodynamics of element reactions was analyzed theoretically.Thermodynamic calculation reveals that solid-liquid phase temperature of the scrap leaded brass reaches 824~856 ℃.After adding Mg-30 Ca alloy,high melting point CaPb,Ca2 Pb compounds can be observed in the alloy.With increasing in Mg-30 Ca alloy addition in range of 1%~2%,CaPb and Ca2 Pb compounds are increased,which can improve effectively deleading efficiency.With 7% Ca-Mg alloy addition at 880 ℃,the deleading efficiency can reach up to 99.6%.Deleading efficiency is decreased with increasing in temperature.Deleading process is consistent with the thermal-dynamics balance process,so increase of temperature is harmful for the deleading in lead brass.The trial-production is well agreement with the simulated ones.