Extraction Of Rare-Earth Elements From The Composition Of Karatau Phosphorites

Karatau phosphorite concentrate is a perspective and unique raw material for complex processing, which allows to obtain strontium, rare earth metal and fluorine compounds along with the main product - phosphorus fertilizers. In spite of the obvious ecological expediency of complex processing of phosphorite, actually, there is the only industrial scheme involving associated extraction of rare-earth elements, strontium and the utilization of fluorine, based on the decomposition of phosphorite with nitric acid.This article presents the results of a study of the decomposition of the Karatau phosphorites (Kokzhon and Koksu deposits) with hydrochloric and nitric acids in a ratio of 1: 1, with an increase in temperature to 85-90 degrees C, for 30 minutes with vigorous stirring. The chemical composition of the products obtained was determined by titrimetric, gravimetric, photocolorimetric, potentiometric methods.Analysis of the samples showed that the mass fraction of rare-earth elements in the concentrate obtained by extraction with nitric acid was 27%, hydrochloric acid - 36% and the extraction rate of rare-earth elements with respect to their content in phosphorite was 75%. It is possible to obtain 20-36 kg of rare-earth metal concentrate in the processing of 1 ton of phosphorite