Different Particle Sizes Tailings Dry Discharge Technology

The tailings dry discharge process is to dewater the tailings through multiple stages to form tailings slag with a small water content, which can be stored or transported in the form of dry slag. In production, mineral composition, specific gravity, concentration, particle size, and distribution are also different. Tailings can be divided into coarse particle size tailings, medium, and fine particle size tailings, and ultra-fine particle size tailings. So it is necessary to select a suitable dry tailings discharge process for tailings slurry with different particle size distributions.

1. Coarse particle tailings dry discharge process

Coarse particle size tailings slurry refers to solid particles > 0.075mm. The dry discharge process often adopts a two-stage concentration-dehydration scheme, that is, a cyclone + a dehydration screen + a thickener. The tailings dry discharge process utilizes dewatering screen for dewatering, which reduces filter equipment. The final tailings moisture content is 12-15%.

2. Medium and fine particle tailings dry discharge process

Medium and fine particle size tailings slurry refers to solid particles = 0.075-0.023mm. The dry discharge process often adopts a two-stage concentration-dehydration-filtration scheme, that is, a cyclone + a dehydration screen + a thickener + filter press.

The tailings dry discharge process utilizes a cyclone and a dewatering screen to separate and dehydrate the coarse and heavy particles and then dry them, reducing the specifications of the thickener and filter. The under-screen particles of the dewatering screen are fed into the filter to ensure solid-liquid separation, which is convenient for all dry discharge, so as to realize the long-distance transportation of tailings. The filter discharge and cleaning water are returned to the concentrator, which not only ensures the content of solid particles in the recycled water, but also satisfies the quality of the production water. The final tailings moisture content can reach 9-12%.

3. Ultrafine particle tailings dry discharge process

Ultrafine particle size tailings slurry refers to solid particle d50≤0.023mm. The dry discharge process scheme often adopts a two-stage concentration-filtration scheme, that is, a cyclone + a thickener + a filter.

The tailings dry discharge process adopts the series concentration of the cyclone and thickener, which makes full use of the different settling velocities of minerals with different particle sizes. It not only improves the processing capacity of the thickener, avoids its overflow running muddy, but also obtains a high-concentration underflow, and the processing capacity of the tailings dry discharge system is significantly increased.