Recovery of fluorite from tailings to improve resource utilization

The mining and selection joint project of Longquanyu Mine in Zhejiang has been put into production for more than 30 years. The ore is complex in nature. It is mainly composed of fluorite - quartz , fluorite- calcite , quartz-fluorite ore. Since 1995, the ore dressing process was unreasonable and there was no regrind process. A selection of sweeping and discarding resulted in a large amount of fluorite resources being discharged into the tailings. The CaF ₂ content in the tailings averaged over 28.5%, and the ore recovery rate was around 75%. The waste of resources is serious. In order to make full use of mineral resources, Zhejiang Longquan Yankuang Co., Ltd. invested 8 million yuan in 2009. A new flotation plant with an annual processing capacity of 120,000 tons of tailings and 28,000 tons of fluorite concentrate will be built. The technical difficulties in the process are now communicated with the brother mines.

I. Desliming of tailings

The tailings contain a high amount of mud. Our company adopted the second-stage de-sludge method through experiments to solve the problem that when the grinding is fine, the slurry is seriously muddy and the fluorite can be floated poorly. The specific conditions are as follows:

1. Desliming before grinding

The tailings are pumped into a 12-meter concentrator for de-mudging. The mud in the overflow is about 6%, and the fluorite-containing is about 1.5%. The de-sludge effect is better.

2, the use of rough diamonds, selected mud

A section of grinding fineness control - about 200% of 200 mesh, does not produce mud after grinding, the concentration is 25% ~ 28%, into the rough selection, I selected after the rate of desliming, I selected operations The recovery rate is controlled above 93%, and the mud content in the selected mines basically meets the requirements of the next five selections. The mud removal effect is better.

Second, the use of cyclone group - high efficiency grinding machine to improve grinding fineness

Before re-grinding, the high-efficiency cyclone group was used for classification. The overflow of -270 mesh exceeded 80%, and the fluorite reached the monomer dissociation. The re-grinding and swirling groups form a closed-circuit grinding.

The re-grinding machine adopts ¢1500×4200 lattice type ball mill , which has higher grinding efficiency and more than 70% of -270 mesh in mine discharge. Effectively solve the problem of fine grinding difficulty.

By adopting the above methods, our company's tailings comprehensive utilization project uses de-sludge before rough grinding - one rough grinding - rough selection, selected de-sludge - selected concentrate grading and re-grinding - five selected processes, went Concentrate CaF ₂ content of 98% or more, SiO ₂ content of less than 1%, recovery rate of 82% or more, an annual output of 28,000 tons of fluorite concentrate, making full use of tailings turning waste into treasure, reflecting a better economy Benefits and social benefits.

Waste Tyre Pyrolysis Plant