JSC “Giredmet”, Moscow, Russia:

O. Yu. Saykina, Industrial Engineer, e-mail: saykina.ol@gmail.com
O. V. Yurasova, Head of Laboratory, e-mail: OVYurasova@giredmet.ru
S. A. Vasilenko, Leading Industrial Engineer

We investigated the sorption method of rare-earth metals extraction during the sulfuric acid leaching of phosphohypsum. The chosen method was simple, economic and ecological. Sulfuric acid sulphocationite KU-2 (КУ-2) was used as a sorbent. The following parameters were researched for investigation of the basic regularities of sorption: time of solution contact with cationite, concentration of sulfuric acid, ratio of solution and sorbent volumes. Sorption behavior of neodymium and yttrium was investigated together with behavior of the basic non-rare-earth impurities (iron and calcium). As a result of investigation of kinetics of rare-earth metal sorption process we made a conclusion about the better sorbtion cerium subgroup elements by sulphocationite. Equilibrium in neodymium-containing system is reached during not more than 45 minutes, and is significantly increased by cationic impurities. There was defined the influence of sulfuric acid content on ionic exchange selectivity. The experiment shown that increasing of H2SO4 concentration maked a negative impact on sorbent selectivity according to rare-earth metals in the presence of calcium and iron ions. There was considered the method of intensification of rare-earth metal extraction in cationite phase, concluded in unification of phosphogypsum and sorption leaching stages. Such approach allows the significant decreasing of the sulfuric acid consumption and time, required for the process.
This work was carried out within the Agreement No.14.579.21.0138 (03.10.2016) with Ministry of Education and Science of Russian Federation; unique identifier of applied scientific investigations RFMEFI57914X0138.

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