碳热还原−低碳精炼处理含铜污泥分离富集有价金属

Separation and enrichment of valuable metals from copper-containing sludge treated by carbothermal reduction-low carbon refining

含铜污泥含有铜、锌、镍、锡、铅等多种有价金属,为了回收其中的有价金属,本研究提出了“碳热还原焙烧−低碳氧化还原精炼”创新工艺。首先通过碳热还原焙烧将锌、锡、铅等有价金属挥发入烟气得以回收,在还原温度为1473 K,碳含量为20%,反应时间为60 min的条件下,铅、锡和锌的脱除率分别达到90.77%、95.14%和99.92%。然后通过低碳氧化还原精炼,在氧化温度为1573 K,加入SiO2量为6%,反应时间为180 min条件下,可得到适用于建筑材料的水淬渣,最后在还原温度为1473 K,碳加入量为8%,反应时间为20 min,将铜、镍富集于阳极铜板中,阳极板中铜含量可达98%以上,符合铜电解的要求。本研究实现有价金属的全回收,较现有的含铜污泥处理工艺,具有流程短,能耗低,有价金属回收率高,经济环保等显著优点。

This paper proposes an innovative“carbothermal reduction roasting-low carbon redox refining”process for recovering valuable metals including copper,zinc,nickel,tin and lead from copper-containing sludge.First,valuable metals are volatilized into the flue gas by carbothermal reduction roasting.At a reduction temperature of 1473 K,a carbon content of 20%,and for a reaction time of 60 min,the ratio of Pb,Sn and Zn removal reached 90.77%,95.14%and 99.92%,respectively.At an oxidation temperature of 1573 K,a SiO2 content of 6%and a reaction time of 180 min,a water quenching slag suitable for building materials was obtained by low-carbon oxidation reduction refining.Finally,at a reduction temperature of 1473 K,8%C addition,and a reaction time of 20 min,copper and nickel were enriched on an anode copper plate and the copper content reached more than 98%,meeting the requirements for copper electrolysis.This study realizes the full recovery of valuable metals.Compared with the existing copper-containing sludge treatment process,it has the obvious advantages of short process,low energy consumption,high recovery rate of valuable metals,economy and environmental protection.