Recovery of rare earth elements from phosphorites in the USSR

Data on the main rare earth compositions in the USSR are presented, showing that the most promising sources are phosphorites and apatites. The rate earth oxide content in the above ore concentrates reaches 1%. Technological schemes for recovering the total and individual rare earth oxides as byproducts have been developed. Extraction methods are used for recovering rare earths from nitrate solutions, with individual oxides more than 99.9% pure being obtained. Apatites are decomposed by nitric acid, yielding apart from fertilizers, strontium carbonate, sodium fluorosilicate, chalk and oxides of rare earth elements.