METHOD OF PROCESSING EUDIALYTE CONCENTRATE Russian patent published in 2018 - IPC C22B34/14 C22B59/00 C01B33/12 C22B3/08 

FIELD: chemistry.

SUBSTANCE: invention can be used to produce compounds of zirconium, rare-earth elements (REE) and silicon dioxide. The method comprises decomposing the concentrate with sulfuric acid, separating the residue from the zirconium-containing solution, washing it with water, isolating zirconium from the solution, and recovering the REE from the silica-containing residue. The decomposition of the concentrate is carried out with 30-40% sulfuric acid at a temperature of 80-120°C and acid consumption of 125-200% with respect to stoichiometry. Extraction of REE is carried out by washing the residue in two stages. At the first stage, the water flow is 2.5-3.5 l per 1 kg of the concentrate with washing of the remainder of the zirconium-containing solution. Resulting wash water is mixed with a zirconium-containing solution. At the second stage, the water flow is 10-20 l per 1 kg of the concentrate with transfer to the wash solution of sulfates of REE, after which silica is extracted from the silica-containing residue.

EFFECT: providing a high rate of pulp filtration with a reduction in the number of reagents and a reduction in the amount of solid waste.

7 cl, 7 ex