铜渣还原-熔分过程中砷的行为特征

对铜渣直接还原和高温熔分过程中砷的行为特性进行了研究。结果表明,直接还原过程中,砷脱除率较低,只有26.0%左右,升高温度、提高配碳量和炉料碱度均不利于砷的脱除,而延长还原时间可促进砷的脱除。在保证球团金属化率的基础上,在还原温度1 300 ℃、C/O比1.2、碱度0.6、还原时间30 min的最优条件下,还原后球团内砷含量最低为0.073%。高温熔分过程中,砷元素富集进入铁相,少部分进入渣相,在保温温度1 455 ℃、CaO添加量4%、CaF₂添加量1%、保温时间30 min时,铁相中砷含量为0.082%。

Behavioral Characteristics of Arsenic in Process of Copper Slag Reduction and Smelting

The behavioral characteristics of arsenic in copper slag during the direct reduction and smelting process were studied respectively. The results show that the removal rate of arsenic is lower by the direct reduction process, just around 26.0%. Increasing the temperature, the carbon content and the alkalinity of the charge are not conducive to the removal of arsenic, but prolonging the reduction time can promote the removal of arsenic. On the basis of ensuring the metallization rate of the pellets, a reduction process was performed at the temperature of 1 300 ℃, with reduction time of 30 min, C/O ratio of 1.2 and alkalinity of 0.6, and the pellets after reduction process show a minimum arsenic content of 0.073%. During the smelting process, the arsenic is mainly enriched into the iron phase, with a small part into the slag phase. With the holding temperature of 1 455 ℃, addition of CaO and CaF₂ at an amount of 4% and 1%, respectively, and holding time of 30 min, the content of arsenic in iron phase is 0.082%.