During the summer of 1962, a new facility was started in Plant 8 for the production of UF4 by an aqueous precipitation technique known as the Winlo process. The Winlo process was developed for the low-cost chemical conversion of relatively pure uranium concentrates to green salt by a hydrometallurgical process. The feed to the plant Winlo system was made up of a combination of black oxide (U3O8) generated by burning metallic residues, uranyl chloride solutions generated by dissolving massive metal residues in hydrochloric acid, and UAP produced from low-grade residues in the hydrometallurgical recovery system.