Abstract: Phosphorus mud and other phosphorus-containing waste materials are processed to remove water and phosphorus and to leave a solid mass which is safe for disposal. The phosphorus mud is heated to boil off the water and then to boil off yellow phosphorus, which is subsequently condensed. The residual phosphorus then is removed mainly by burning off in air along with some volatilization, so as to increase the recovery rate of solids from the waste material, when compared to removal of residual phosphorus by volatilization under nitrogen. A significant improvement in processing rate is achieved at the expense of a loss of a minor amount of recoverable phosphorus.