New Technology Helps to Eliminate Mining Wastewater by 90 Percent

Researchers from Commonwealth Scientific and Industrial Research Organization (CSIRO) have developed a new technology that can effectively treat mining wastewater and reduce sludge by up to 90 percent.  

The new technology, known as ‘Virtual Curtain’, relies on the formation of compounds in wastewater called hydrotalicities to clean itself. The curtain reduces the sludge, a semi-solid by-product of wastewater treatment by up to 90 percent.

“Our treatment produced only a fraction of the sludge that a conventional lime-based method would have and allowed the mine water to be treated in a more environmentally sound way,” CSIRO scientist Dr. Grant Douglas said.

Hydrotalicities are layered crystal structures of carbonates, magnesium, and aluminum that trap impurities within themselves. As the crystals form, numerous waste substances become trapped, helping to separate out the sludge in wastewater.

Dr. Grant Douglas and his team have successfully tested the Virtual Curtain technology at a Queensland mine where it was used to remove metal contaminants from mining wastewater.

“Reducing the amount of sludge is beneficial because the costly and timely steps involved to move and dispose it can be reduced,” he said.

"If required, the treated water can be purified much more efficiently via reverse osmosis and either released to the environment or recycled back into the plant, so it has huge benefits for mining operators in arid regions such as Australia and Chile," Douglas added.

The new technology can also produce a material high in metal value, which can be reprocessed to increase a mining company’s overall recovery rate and partially offset treatment costs.

"It is a more efficient and economic way to treat wastewater and is enabling the global mining industry to reduce its environmental footprint and extract wealth from waste."

The Australian mining industry is estimated to generate hundreds of millions of tons of wastewater each year.