氯化焙烧综合回收硫精矿中有价金属研究

银山硫精矿含金1.40 g/t,银21.0 g/t,铜0.17%,硫47.08%,铁41.21%,具有较高的经济价值,仅作为硫精矿制酸将造成资源浪费。针对该硫精矿进行了“氧化焙烧-焙砂制粒-氯化焙烧”的工艺条件试验。扩大试验各金属挥发率为金96.72%,银90.91%,铜52.48%,熟球含铁60.72%,抗压强度2.105 kN,达到三级品要求,实现了硫精矿中有价金属的综合回收。由于扩大试验焙烧设备及操作方面的原因,铜的挥发率远低于小型试验,在实际生产中须予以重视。机理分析表明,焙烧时需要采取必要措施抑制氯化钙在低温度下的分解,提高氯化钙的利用率。

Study on Comprehensive Recovery of Valuable Metals in Sulfur Concentrates by Chlorination Roasting

The sulfur concentrate of Yinshan contains 1.40 g/t of Au, 21.0 g/t of Ag, 0.17% of Cu, 47.08% of S and 41.21% of Fe. It has high economic value, and it will cause waste of resources if it is only used as a sulfur concentrate for sulfuric acid production. The process conditions of "oxidizing roasting-calcination granulation-chlorination roasting" were studied for the sulfur concentrate. The large-scale test results showed that the final metal volatilization rates were 96.72%, 90.91% and 52.48% for Au, Ag and Cu, respectively. The resulted iron pellet contains 60.72% of Fe, and its compressive strength is 2.105 kN which meets the requirements of grade III, realizing the comprehensive recovery of valuable metals in sulfur concentrates. Due to the expansion of the calcination equipment and operation in the plant test, the volatilization rate of copper is far lower than that of the small-scale test, which should consider the difference in practical production. The mechanism analysis showed that necessary measures should be taken to inhibit the decomposition of calcium chloride at lower temperature and improve the utilization rate of calcium chloride.