Deep-sea mining faces surprise risk of rocks catching fire - Mining.com

Environmental groups warn seabed mining may harm fragile marine habitats and disrupt ecosystems. (Stock image by magdal3na.) Metal-rich rocks recovered from the Pacific Ocean began smoking and heating when researchers broke them apart in a laboratory, highlighting a potential fire hazard for mining seafloor sulphide deposits.

Scientists investigating the possibility of a 'gold rush' on the bottom of the ocean have hit upon an unforeseen 'landmine'. Researchers at the United States Geological Survey (USGS) are now warning that some deep-sea minerals may spontaneously combust when they are brought to the surface. In 2022, that happened to two samples of metal-sulfide rocks collected from the deep seafloor. The event caused temperatures above 100 °C in the lab and completely oxidized the original samples. An article on the discovery, published in Scientific Reports, is being shared early, before full editing, to give the public faster access to new research. According to the USGS, this is a "potential hazard that could merit special consideration if deep-sea mining of seafloor massive sulfide deposits moves forward". "The production of heat through exothermic reactions has not been investigated in seafloor massive sulfide deposits but has the potential to cause rapid onset fires on ships," claims the recent article.