Progress of research related to the comprehensive recovery and utilization of tungsten smelting slag

Tungsten smelting slag is an important secondary resource, it contains tungsten, tin, tantalum, niobium, scandium, and other useful metals, which have great recycling value. However, tungsten smelting slag is a solid waste that can cause groundwater and soil pollution. Further, the progress of the comprehensive recovery and utilization of tungsten smelting slag was reviewed. The process of wolframite and scheelite smelting, the recovery process theories of tin, tantalum, niobium, and scandium, and the reduction of tungsten smelting slag were also presented. Tungsten and tin can be recovered by gravity separation and flotation, which is followed by smelting. This process is easy in case of industrial applications, and the cost is low, however the adaptability is poor, and fine materials cannot be effectively recycled. Tungsten, tin, tantalum, niobium, and scandium can be recovered by hydrometallurgy, which is a complex process that considerably influences the environment. Tungsten smelting reduction is a fundamental requirement for the comprehensive utilization of slag, which is mainly used to manufacture the cement materials, porous materials, and microcrystalline glass.This study introduced the current research status, identifies problems, and provides suggestions for future research. The bottleneck of scandium, tantalum, and niobium extractions depends on the development of an extractant and ion exchange resin. The first principle and chemical coordination theory from the field of materials and chemistry can be used to solve the problem, including poor selectivity of extractant, low exchange capacity of ion exchange resin and large quantity of waste water. Strong selective extractant and ion exchange resin with high exchange capacity will be studied to solve above problems. The interaction mechanism is investigated based on the atomic level, and the efficient extraction agent and ion exchange resin are selected. Future research may be related to the development of a green extraction technology and a short process to produce slag from high value materials.