Key Flotation Technologies for Fine-Grained Scheelite

Fine-grained white tungsten ore is relatively brittle and contains extremely fine particles; it is highly susceptible to over-grinding during the grinding process. This makes it difficult to separate using conventional flotation processes, leading to significant loss of ore and low recovery rates, resulting in a substantial waste of tungsten resources. Consequently, the development of specialised flotation technology tailored to fine-grained white tungsten ore is key to achieving efficient recovery of low-grade, fine-grained tungsten resources. Current industry research is primarily focused on three core areas: flotation processes, reagent optimisation and equipment optimisation.

Whilst high-grade concentrates can be obtained from conventional-sized white tungsten ore through simple roughing, conventional processes struggle to effectively separate ultrafine white tungsten ore due to its minute particle size and similar floatability to calcium-bearing gangue. In production, specialised processes such as ambient-temperature flotation and heated flotation must be specifically employed, combined with various innovative fine-grain flotation processes or composite combined processes, to overcome the challenges of complex ore separation and significantly improve tungsten ore recovery efficiency.

There are currently numerous innovative achievements in flotation processes for fine-grained white tungsten ore, with mainstream technologies falling into three categories. Selective flocculation flotation relies on the interaction between flocculants and mineral particles to cause fine-grained white tungsten ore to aggregate into flocs, effectively resolving the issue of fine particles failing to float. While it demonstrates outstanding flotation potential, its shortcoming lies in the poor selectivity of polymeric flocculants, making industrial implementation challenging. Shear flocculation flotation utilises high-intensity agitation and shear forces to promote the agglomeration of fine-grained minerals, thereby increasing particle size and significantly enhancing flotation rates and recovery rates. However, precise control of parameters is required during production to prevent non-selective flocculation, which could lead to a decline in concentrate grade. Carrier flotation is divided into two modes: self-carrier and external carrier. By utilising surfactants and shear forces, fine-grained wolframite is attached to the surface of coarse-grained carriers, thereby improving separation efficiency and offering exceptional adaptability.

To compensate for the technical limitations of single-process methods, the industry widely employs various combined separation processes to accommodate complex ore processing scenarios. Among these, composite processes such as the GY method roughing – centrifuge pre-concentration – complexation method concentration, flotation – magnetic separation – gravity separation, and combined column-machine flotation have overcome the limitations of single technologies. They offer high adaptability and stable separation performance, making them particularly suitable for large-scale industrial production.

The flotation of fine-grained white tungsten ore is a key research area in mineral processing. Through process optimisation and the application of combined technologies, it is possible to effectively reduce the loss of fine-grained tungsten resources and achieve the comprehensive utilisation of associated tungsten resources. In the future, the industry will focus on optimising flocculant selectivity, deepening research into the mechanisms of carrier flotation, and streamlining process flows. This will promote the large-scale and industrial adoption of flotation technology for fine-grained white tungsten ore, thereby supporting the green and efficient development of tungsten ore resources.