Mine tailings are large piles of crushed rock that are left over after the metals of interest like lead, zinc, copper, silver, gold and others, have been extracted from the mineral rocks that contained them. In mineral separation process, especially in older mining operations, after the crushing and grinding (milling) processes, some of the metal-containing minerals are left behind as small tailings particles.
Disposal of mine tailings is one of the most important environmental issues for any mine during the project's life. Whilst significant pressure is placed on mining projects in developed countries to conform to stringent environmental standards, many projects in developing nations do not take significant steps to prevent or mitigate environmental damage.
Mine waste and tailing recycling: tailings and waste rock could be mixed together; the mixture generates a blended waste stream with optimized engineering properties of low hydraulic conductivity, high water reserving capacity, high air entry value and low compressibility. The mixed materials could be applied in construction of infrastructure of the mine or backfill the open pits.
There are many usable elements in the mine waste and tailing. The massive mine waste could be crushed and grinded and then used for roadbed or as cement raw materials. The mine tailing could be collected together and refined to useful minerals.