Florida phosphate rock and the phosphoria formations of Idaho, Montana, Utah and Wyoming have a uranium content ranging from 0.01 to 0.02 per cent. The abundant domestic reserves and the relatively large tonnages of phosphate rock mined each year cause these low-grade uranium sources to be of great potential importance. Mo st phosphate rock is used for the production of normal superphosphate, which is made by acidulating the rock with sulfuric acid to get a form of phosphorus available to plant life. This study was undertaken to develop a method of recovering uranium during the production of superphosphate without destroying the plant nutrient value of tho product.