Tapping Tungsten and Rare Earths in Mining Waste May Offset Damage from Mines

To achieve the transition to green energy, we need large quantities of critical minerals such as tungsten, manganese, lithium, cobalt, and rare earths. However, mining has led to a certain degree of destruction of mining areas, and the mining of key metals in mining waste may offset the damage to local areas.

In recent years, the extraction of valuable minerals and metals from mining waste has received increasing attention. Although progress has been slow in adopting this method, it holds great promise.

To get to net-zero emissions, we will have to mine more critical minerals, including tungsten, lithium, cobalt, rare earth elements, tin, and indium. These metals are essential for making the wind turbines and electric vehicles needed to transition to a low-carbon economy.

New mining opportunities in Western Australia's major lithium deposits, New South Wales' cobalt resources, and Tasmania's tungsten and tin could mean a socio-economic renaissance.

But some environmentalists are skeptical, with the Bob Brown Foundation calling it a form of "greenwashing. They point out that increased mining will mean more damage to the environment and more waste. Globally, the mining industry produces more than 100 billion tons of solid waste each year. These wastes are often deposited in tailings dams or waste rock piles, both of which are at risk if not done properly: tailings dams have ruptured due to geotechnical problems, causing fatal disasters; another problem is acid mine drainage, where highly acidic water containing heavy metals escapes containment.

For example, at the Luossavaara-Kiirunavaara Aktiebolag mine in Sweden, the tailings from iron ore mining are now one of the largest deposits of rare earth elements in Europe.

Similarly, the world's annual phosphate production is estimated to contain about 100,000 tons of rare earth elements, a significant portion of which ends up in the waste stream. Copper deposits are a well-known source of many key metals, such as antimony and bismuth, as well as cobalt and indium.

Even valuable minerals such as gallium, scandium, vanadium and rare earths can be found in coal ash, the sediment left behind after coal burning.

The extraction of minerals from mining waste has attracted increasing attention, with conferences in Europe on new re-mining and new prospecting activities underway in Australia to explore mining waste. The Queensland government was the first to invest in such secondary prospecting, and it funded sampling at 16 sites. Early results have found cobalt deposits rich enough to attract overseas investment.

A similar program was recently launched in New South Wales, while work is underway by Geoscience Australia, the University of Queensland, and RMIT University to produce Australia's first-ever mine waste atlas.

Once completed, the atlas will be a valuable resource for companies keen to position themselves to extract metals such as tungsten, lithium, cobalt, and rare earths from tailings, such as New Century Resources and Rio Tinto, which has invested A$2 million in a new start-up company, Regeneration, which uses revenue from mine waste mineral recovery to pay for mine site rehabilitation.

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