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二氧化硫排放。多年来，提高泡沫浮选选择性分离镍黄铁矿和磁黄铁矿的操作效率一直是淡水河谷国际公司和斯特拉塔公司面临的一个坚韧挑战。 采用二乙烯三胺（DETA）与亚硫酸钠联用抑制镍黄铁矿中的磁黄铁矿。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的强大螯合作用，如果流出物中的重金属络合物水平超过规定限制，则会产生环境问题。使用DETA作为磁黄铁矿浮选剂的另一个问题是进料中的岩石含量对镍黄铁矿与磁黄铁矿的选择性分离的有害影响，这可能是由于DETA分子被岩石矿物竞争性吸附。在Vale Inco操作中观察到，岩石含量越高，镍黄铁矿和磁黄铁矿之间的选择性越低。DETA在抑制磁黄铁矿和增强各种矿物中金属溶解中的作用尚不清楚。

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.