The International Information Center for Geotechnical Engineers

Monday, 04 March 2019 01:00

Mining waste disposal: A challenging issue

Copper mine tailings Copper mine tailings.

The time for Mining industry to change its approach about waste disposal techniques has arrived.

On January, 2019, an upstream dam collapsed in Brazil releasing a wave of red iron ore and contaminating a vast area. The dam was owned by Mining Company Vale and was utilized to store mining waste. But this was just sort of the last straw. Mining industry has caused severe tragedies in the past years worldwide and therefore companies must search for alternative methods of storing mining waste.

Following the above-mentioned incident, Brazil decided to ban upstream dams that consisted a cost-efficient method to store mining waste. Currently, Vale Company is withdrawing all those dams that share the same technology.

By its nature, mining is a process that produces large amounts of waste which companies must handle. Dumping those wastes on public areas provokes the risk of contamination and dramatically reduces the reliability of those enterprises.

An apparent solution for mining companies would be to develop new waste-disposal techniques to mitigate the potential hazard. However, applying this approach, especially in the forth-coming years, is not an easy task.

First of all, the ore grades (the concentration of an element of interest in a potentially mineable deposit) are continuously decreasing. For example, copper concentration in mines was 0.59% in 2017 when the correspondent proportion in 2005 was 0.79%. The difference may seem minor, but actually, an additional millions of tons excavation is needed to produce the same quantity as before. The result has been a great increase in waste production which reached 14 billion metric tons in 2010. Having to address such quantities, mining companies had decided to utilize the risky but low-cost disposal methods which must now be eliminated.

Moreover, sustaining a safe waste disposal facility has become more difficult due to climate change. More intense wet and dry seasons increase the pace of embankment erosion and causes the soil to expand and contract rapidly. Additionally, heavy rainfall can push the facilities beyond their design limits.

In conclusion, mine industry must find how to address efficiently the increasing quantities of waste with the minimum risk for the surrounding environment.


Read 239 times Last modified on Monday, 04 March 2019 14:27

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