Phosphate slimes have been produced by the Florida phosphate mining industry at the rate millions of cubic yards per year and the volume is increasing. The water retentive characteristics of the clays which are mined with the rock are such that there is more volume of phosphate slime to dispose of than there was actual rock mined. Small scale tests of the slimes were made to assess the feasibility of their use as building materials. A process was developed and demonstrated to be capable of producing a pelletized, light-weight aggregate, and finally a light-weight concrete from the slimes. The four major processing steps: pumping of clay slurries of 3 to 30% solids; slime drying in a fluid bed dryer; pelletizing the dried product and kilning the product to a suitable aggregate, were investigated in batch and suitable equipment was selected. Aggretage production could use up to 6-8 million tons of clay solids annually, releasing up to 5 billion gallons of water to the environment.

"[Prepared] for the Environmental Protection Agency." "14050 EPU 08/71." Includes bibliographical references. Microfiche.