Transformation of the rare earth elements and impurity elements combinations in the course of pH pregnant solution modification

Currently, the scientific and engineering progress is mainly associated with the rare earth elements application. A lot of spheres of effective REEs use are numbered as in military so the civil industries. Additional raw materials sources of the REEs concentration and probable extraction are explored due to the increased demand in the last two decades. The man-made mineral formations (MMF) after phosphate ores processing is one of them. The REEs’ content reaches 5.0%. The MMF processing technology consists of the following stages: a feedstock development; pregnant solutions treatment from impurities; and the REEs concentrate extraction. A loss of 30% of REEs at the second stage is the main failure, which is due to their co-precipitation with the impurity elements at pH pregnant solution adjustment. To find means and methods of making the REEs co-precipitation lower the solutions and residues generated in the course of pH standardized test solutions modification set based on the REEs and impurity elements content in the pregnant solutions have been studied by the physical and chemical methods. As part of studies, the pH initial solutions were improved within the values range of 1.7-4.0 pH by sodium hydroxide and ammonia. According to a counteracting solution, the various ways of combinations transformation of the REEs and impurity elements are provided. Appropriate conditions of pregnant solutions treatment are determined at driving to the least of the REEs co-precipitation based on the results.