As和MgO的加入对铜冶炼渣中砷玻璃化的影响

Effect of As and MgO addition on arsenic vitrification in copper smelting slag

研究FeO−SiO_(2)−Fe_(2)O_(3)−B_(2)O_(3)−CaO−Al_(2)O_(3)−(MgO)体系铜冶炼渣中砷(As)的玻璃化。通过XRD、SEM、FTIR和XPS分析手段系统地研究As玻璃化机制。结果表明,As与铁硅酸盐炉渣表现出良好的相容性。FTIR和XPS分析结果表明,As可以部分替代硅形成Si—O—As结构,从而提高熔体的聚合度。[BO_(3)]^(3−)结构单元随着As含量的增加而趋于减少,而加入MgO后则观察到相反的行为。此外,MgO增加了熔体的非桥氧数量(NBO)。TCLP、SPLP和pH依赖性测试结果表明,As的浸出毒性随着As含量的增加而增加,但随着MgO的加入而降低。DSC分析结果表明,As和MgO的加入均可以改善含As玻璃的热稳定性。

The arsenic(As)vitrification in copper smelting slag derived from the FeO−SiO_(2)−Fe_(2)O_(3)−B_(2)O_(3)−CaO−Al_(2)O_(3)−(MgO)system was studied.The vitrification mechanism of As was systematically investigated by XRD,SEM,FTIR and XPS analysis.It is determined that As exhibits favorable compatibility with the iron-silicate slag.FTIR and XPS analysis indicates that As can partially substitute for silicon to form the Si—O—As structure,thereby enhancing the degree of polymerization of the melt.The[BO_(3)]^(3−)unit tends to decrease with the increase of the As content,while the opposite behavior is observed with the addition of MgO.Additionally,MgO increases the non-bridging oxygen(NBO)number of the melt.TCLP,SPLP and pH dependence tests show that the leaching toxicity of As increases with the increase of the As content but decreases with the addition of MgO.DSC analysis demonstrates that the incorporation of both As and MgO can improve the thermal stability of the As-containing glass.