Mining Trash Becomes Treasure in the Circular Economy

After valuable minerals have been extracted from ores, they leave behind a slurry of leftover materials called tailings. These are often highly toxic and hard to dispose of properly, but they also contain a small number of minerals that can be reused. If a company mines for gold, it’s the only mineral it would extract due to cost factors. But the waste it produces might harbour minerals like calcite, which could be repurposed by other companies to aid in sustainable practices like carbon sequestration.

US start-up Phoenix Tailings has developed technology for ‘re-mining’ tailings sludge and extracting minerals from them, benefitting domestic manufacturers who are struggling with overseas supply chain issues. Fellow US company Nth Cycle has created a similar system that’s roughly the size of three shipping containers. While inconsequentially small in the world of mining, they can be transported directly to an excavation site, extracting up to 95% of the remaining metals out of waste material.

As reported in-depth in Eliminating E-Waste, the call for more upcycling and clean manufacturing processes is gaining traction across all sectors. And for the mining industry, which produces up to 7% of global greenhouse gases annually (McKinsey, 2020), this push comes at a crucial time.