Fundamental study of diethylenetriamine (DETA) as pyrrhotite depressant for selective flotation of pentlandite

Vale Inco的Clarabelle工厂的关键业务之一是拒绝磁黄铁矿，以减少萨德伯里地区的SO2排放。多年来，提高泡沫浮选选择性分离镍黄铁矿和磁黄铁矿的运行效率一直是淡水河谷和斯特拉塔面临的一项艰巨挑战。研究了二乙三胺(DETA)与亚硫酸钠联用对镍黄铁矿浮选过程中磁黄铁矿的抑制作用。关键问题是DETA与溶液中的金属离子和来自各种矿物的金属有很强的螯合作用，如果废水中DETA-金属络合物的水平超过规定限值，就会造成环境问题。使用DETA作为磁黄铁矿抑制剂的另一个问题是，原料中的岩石含量对选择性分离镍黄铁矿和磁黄铁矿有不利影响，这可能是由于岩石矿物对DETA分子的竞争吸附。淡水河谷国际公司观察到，岩石含量越高，对镍黄铁矿和磁黄铁矿的选择性就越低。DETA在磁黄铁矿凹陷和促进各种矿物中金属溶解中的作用还不是很清楚。

One of the key operations at Vale Inco's Clarabelle mill is to reject pyrrhotite in order to reduce SO2 emission in Sudbury area. The improvement in operation efficiency in selective separation of pentlandite from pyrrhotite using froth flotation has been a tough challenge at both Vale Inco and Xstrata for many years. Diethylenetriamine (DETA) in combination with sodium sulfite has been used in the depression of pyrrhotite during pentlandite flotation. The key issue is the powerful chelating of DETA with metal ions in solution and the metals from various minerals, which creates an environmental problem if the level of DETA-metal complexes in the effluents exceeds the regulation limits. Another issue with the use of DETA as pyrrhotite depressant is the detrimental effect of rock content in the feed on the selective separation of pentlandite from pyrrhotite, probably due to competitive adsorption of the DETA molecules by rock minerals. It was observed at Vale Inco operations that the higher the rock content is, the less selectivity between pentlandite and pyrrhotite. The role of DETA in pyrrhotite depression and enhanced dissolution of metals from various minerals are not well understood.