Fast Metals has raised $4.3 million to scale a chemical process that extracts iron, aluminium, titanium and rare-earth elements from red mud, a caustic waste produced during alumina refining. Red Mud Contains Valuable MineralsMore than three billion tonnes of red mud are stored in ponds and waste piles around the world. Fast Metals says its hydrometallurgical process removes the iron first and recovers several saleable products across six processing stages. Fast Metals also said it has signed memoranda of understanding with trading partners that could purchase recovered materials. Fast Metals says its process can also use waste carbon dioxide and leave less residual material requiring long-term storage.