湿法炼锌酸浸液中三价铁的锌精矿还原工艺

Reduction Process of Zinc Concentrate with Ferric Iron in Acid Leaching Solution of Zinc Hydrometallurgy

硫化锌精矿还原湿法炼锌酸浸液中三价铁存在还原效率偏低、锌精矿用量大、利用率低等问题。开展温度、锌精矿粒度、锌精矿用量及反应时间对还原液中三价铁浓度及还原率的影响等研究。结果表明:反应温度是影响硫化锌精矿还原溶液中三价铁浓度的主要因素,锌精矿粒度在低温还原时影响较为明显。低温还原所需时间长,所用锌精矿量大,80℃下锌精矿粒度小于58μm、锌精矿加入系数1.8以上、反应时间3 h以上才能使还原液中三价铁浓度小于0.5 g/L;升高温度可缩短反应时间,减少锌精矿用量,120℃下锌精矿粒度150μm、锌精矿加入系数1.5、反应时间1 h即可使还原液中三价铁浓度小于0.5 g/L。采用加压工艺提高还原温度,可有效提高锌精矿的利用率和三价铁的还原率,降低还原渣量,有利于还原渣后续处理。

The reduction process of ferric iron in acid leaching solution by zinc concentrate has some problems such as low reduction efficiency,large amount of zinc concentrate and low utilization rate of ferric iron.The effects of temperature,particle size of zinc concentrate,dosage of zinc concentrate and reaction time on concentration and reduction rate of ferric iron in reducing solution were studied.The results show that reaction temperature is the main factor affecting of ferric iron reducing in solution,and the influence of zinc concentrate particle size is more obvious at low temperature reduction.Low temperature reduction requires a long time and a large amount of zinc concentrate.At 80℃,the particle size of zinc concentrate is less than 58μm,the addition coefficient of zinc concentrate is more than 1.8,and the reaction time is more than 3 h,so that the concentration of ferric iron in the reducing solution is less than 0.5 g L.The increase of temperature can shorten the reaction time and reduce the amount of zinc concentrate.At 120℃,the particle size of zinc concentrate is 150μm,the addition coefficient of zinc concentrate is 1.5,and the reaction time is 1 h,the concentration of ferric iron in the reducing solution is less than 0.5 g L.Using pressure process to increase reduction temperature can effectively improve the utilization rate of zinc concentrate and the reduction rate of ferric iron,reduce the amount of reduction residue,which is conducive to the subsequent treatment of reduction residue.