Mining is full of materials that are not the ore or mineral being targeted for excavation. In fact, over 90% of the total raw material removed from a site is generally left at the end as a waste product. This means that filling in the mine pit is actually feasible, but that is not always the best way to finally dispose of the tailings and other materials. In fact, tailings may be useful for other forms of reuse while the mine is still in operation. Most reuse opportunities are on the mining site itself, reducing the need to transport the materials long distances just to put it to good use.
Building Embankments, Dams, and Berms
The most direct use of tailings on the mining site is to create new, water control and containment structures. Embankments, dams, and berms are often built from any available tailings, even if they were generated by a nearby mine rather than the planned one. Tailings that are compacted and sealed under liners are stable and leach relatively few hazardous compounds into the surrounding environment. However, it’s best to apply liners under these structures built with tailings to ensure this is the case. Mixing the material into concrete or asphalt that’s used as a core or coating for the structure may work instead to keep it encapsulated and unable to affect the environment.
Additional Processing
Processing the tailings to extract small percentages of metals or minerals, also known as re-mining, can go on for many cycles before the material is completely exhausted. Many older tailing piles are so rich in valuable materials that they are being targeted for re-mining over new in-ground excavations. Proper storage of the tailings to keep them stable and intact is key to holding them until new techniques emerge to make re-mining worthwhile for older materials. Make sure to line all ponds and pits used for holding tailings for re-mining, even if they will be processed in tanks, retorts, or other freestanding facilities.
Backfill for Other Construction
Depending on the exact composition of the tailings material, it is likely useful for at least some form of construction as a backfill material. High density paste is made by mixing dry tailings with a specific amount of liquids until it’s a dense and thick paste. When it dries, it can be nearly as stabilizing and strong as concrete. It is primarily used for stabilizing underground areas compromised by mining at this point, but a number of engineering facilities are experimenting with it as a building material to reduce concrete costs. Tailings are already widely used in some countries for gravel and sand in road construction, trapping the material where it has relatively little effect on the environment.
Manufacturing Bricks and More
Aside from on-site construction, tailings may be useful for crafting building materials as well. Bricks, in particular, have been constructed with high percentages of tailings without compromising durability or water resistance. In fact, using tailings can make blocks and bricks tougher and more resistant to damage while keeping the hazardous materials inert and encapsulated.
Why dig pits to store the material underground when it could be turned into roads, bricks, and more? Reusing tailings even just on the mining site can go a long way in reducing the amount that needs permanent storage in a pit or basin. Even if tailings will only be held temporarily on the site until they are reused, the holding tanks or pits must be lined to prevent contamination. BTL Liners has the affordable and reliable RPE liners to make tailings storage as easy as possible.
