A new startup in Boulder, Colorado says it has developed a way to use discarded rocks to remove carbon dioxide from the atmosphere. Travertine Technologies is among the latest entrants in the fast-growing field of ​“carbon dioxide removal.” Hundreds of early-stage ventures and research initiatives are attempting everything from building enormous air filters and planting kelp forests to improving soil health and, in Travertine’s case, accelerating geological processes — all in an effort to draw down planet-warming CO2. What makes Travertine unique is that it’s also focused on cleaning up the mining sector. When mining companies dig for metals and minerals, they leave behind enormous piles and ponds of residual rocks, chemicals and contaminated water. Deposits of mine ​“tailings” are only expected to grow in the coming years as the demand for metals soars, driven by the increasing need for electric-vehicle batteries and other clean energy technologies. Source: https://www.canarymedia.com/articles/carbon-capture/meet-a-startup-that-plans-to-use-mining-waste-to-capture-carbon-dioxide