摘要:
以硫酸溶液为浸出剂,采用常压氧化浸出法处理铜冶炼渣以回收渣中有价金属铜.考察了浸出温度,浸出时间,硫酸浓度,浸出液固比,氧化剂(双氧水)添加量对铜浸出率的影响.试验结果表明:在未加入氧化剂时,主要发生的是铜氧化物的简单酸溶反应,硫化铜几乎不溶于浸出液,因此铜浸出率很低;而随着氧化剂添加量的增加硫化铜被氧化浸出,因此铜浸出率增加很明显.此外,铜浸出率随着浸出温度,浸出时间和浸出液固比的增大而增大.浸出过程最佳的条件为:浸出温度70℃,时间180 min,硫酸浓度2 mol/L,液固比8∶1,氧化剂(双氧水)添加量400 mL/kg.铜浸出率可达到91.2%.通过对浸出渣XRD和SEM-EDS分析可得浸出渣中主要的矿物为磁铁矿.在磁场为2T的条件下,浸出渣磁选可以得到品位53.15%的铁精矿.
Abstract:
Using sulfuric acid solution as leaching agent,copper smelting slag was treated by atmospheric oxidauon leaching process to recover valuable metals of copper from slag.The effects of leaching temperature,leaching time,sulfuric acid concentration,liquid to solid ratio and the dosage of oxidant(hydrogen peroxide)on the leaching rate of copper were investigated.Experimental results show that without addition of the oxidant to leaching solution most of copper existing as copper oxide can be leached through simple acid-dissolution,copper sulfide is almost insoluble in leaching solution,so the copper leaching rate is very low;while with dosage of the oxidant increased the copper sulfide oxidation leaching,so the copper leaching rate increased obviously.In addition,the leaching rate of copper increases with the increase of leaching temperature,leaching time and liquid to solid ratio.The optimum parameters are as follows:the leaching temperature of 70℃ for 180 min,sulfuric acid concentration at 2mol/L,liquid to solid ratio of 8 ∶ 1,dosage of the oxidant(hydrogen peroxide)for 400mL/kg,the copper leaching rate can be reached of 91.2%.The main minerals are magnetite of the leaching residue by the analyses of XRD and SEM-EDS.The grade of 53.15% of the iron concentrate can be obtained under the condition of the magnetic field intensity at 2T.
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