Tailings Re-election Commonly Used Equipment and Application

Tailings, as the ‘solid waste’ of mining, contain rich valuable resources. With the development of mineral processing technology, re-election, magnetic separation and flotation equipment have become the core tools for tailings reelection, and their efficient application significantly improves the resource recovery rate. The following are the characteristics and application status of the three types of commonly used equipment:

Re-election equipment: low-cost and high-efficiency recovery

With the advantages of simple process and no pollution, re-election method is widely used to recover valuable minerals in coarse and medium-grained tailings, and its key equipment includes:

Spiral chute: such as rotary spiral chute, BL-1500 spiral chute, etc., through the composite force field to achieve fine-grained minerals sorting. For example, the rotary spiral chute can increase the tin grade from 0.3% to more than 3.5%, with a recovery rate of about 20%, when treating tin tailings from cloud tin sand; when treating tin tailings (-0.074mm accounts for 95%), the recovery rate of the tin concentrate of BL-1500-A2 model reaches 50.6%.

Centrifuges: represented by Falcon high-efficiency centrifuge and SLO centrifuge, which are good at treating fine-grained minerals, Falcon centrifuge treats Yunnan polymetallic mine tailings (-37μm accounts for 75%), the grade and recovery of tin concentrate reaches 40.42% and 42.36%, respectively; SLO centrifuge treats Hainan ferric iron tailings (-0.019mm accounts for 50%), and the recovery of iron ore concentrate reaches 58%. The recovery rate of SLO centrifuge is 58%.

New type of re-election equipment: such as suspension cone concentrator, using vibration dispersing pressure to separate fine mud, the tin recovery rate reached 45.4% when treating tin tailings in Guangxi Dafang.

 Magnetic separation equipment: targeted recovery of magnetic minerals

Magnetic separation equipment is suitable for the re-election of ferrous metal and some rare metal tailings, mainly including:

BKW type magnetic separator: specially designed for tailings, when treating the tailings of Shougang Iron & Steel (iron grade 10.89%), it can obtain 66.95% grade of iron concentrate, with a magnetic iron recovery rate of 89.88%.

SLO High Gradient Magnetic Separator: integrating magnetic separation and re-election, when treating Hebei Chengde ilmenite tailings (TiO₂ grade 8.28%), the grade of concentrate was increased to 20.21%, with a recovery rate of 50.5%.

YK C-type permanent open gradient magnetic separator: suitable for roughing low-grade tailings, when treating the tailings of Handxing Xishimen iron ore (all iron 3.82%), the recovery rate of magnetic iron reaches 75.58%.

flotation equipment: key technology for fine and complex tailings

Aiming at the characteristics of ‘poor, fine and miscellaneous’ tailings, the flotation equipment improves the sorting efficiency by optimising the role of bubbles and slurry:

Tailings re-election special flotation machine: such as Beijing Institute of Mining and Metallurgy developed equipment, designed for high concentration, easy to sink tank tailings, a mine in Chengde used 40m³ special flotation machine to deal with magnetic separation tailings, an annual increase in economic benefits of 23.2 million yuan.

Flotation column: Microbubble flotation column uses small-diameter bubbles to strengthen the capture, and the recovery rate of fine-grained (-38μm) exceeds 65% when treating scheelite tailings in Hunan Province; cyclone-static microbubble flotation column treats nickel tailings in Jinchuan, and the recovery rate of nickel reaches 12.67%.

Filled flotation column: extending the sorting path by wave packing, when treating mica tailings in Lingshou, the grade of mica concentrate reaches 98.54% and the recovery rate is 91.42%.

Development trend

In the future, tailings re-election equipment will be developed towards large-scale, automation and specialisation, combined with composite force field (such as centrifugal force and magnetic synergy) to improve the efficiency of micro-fine grains sorting, and strengthen the research and development of joint process equipment to adapt to the demand for high-efficiency recovery of complex tailings.