Influence of Acids on Extraction Efficiency of Zirconium and Rare Earth Metals in Eudialyte Concentrate Leaching
V. A. Chanturia, V. G. Minenko, E. V. Koporulina, M. V. Ryazantseva, A. L. Samusev
Academician Melnikov Institute of Comprehensive Exploitation of Mineral Resources, Russian Academy of Sciences, Moscow, 111020 Russia
Keywords: кислотное выщелачивание, эвдиалитовый концентрат, цирконий, редкоземельные металлы, силикатный гель, потери ценных компонентов, Acid leaching, eudialyte concentrate, zirconium, rare earth metals, silica gel, loss of valuable components
Abstract
The influence of nitric, sulfuric and chlorohydric acids on the morphology, composition of elements, structural and chemical transformation of mineral surface and leaching of eudialyte concentrate is studied using a set of the modern analytical techniques. Specific features are revealed in the nature and degree of eudialyte decomposition under the influence of different acids. These features affect the intensity of removal of basic cations of Al, Na, Ca, Mg, K, Ti, Mn, Fe, Sr and Zr from the mineral surface. The behavior and regular patterns in the formation of silica gel and secondary phases during dissolution of eudialyte concentrates are examined. Sulfuric acid, which ensures the highest extraction of Zr and rare earth metals in pregnant solution, contributes to maximum formation of silica gel and considerable quantity of gypsum and insoluble sulfates, which results in high loss of Zr and rare earth metals. The use of nitric and chlorohydric acids reduces the loss of Zr and rare earth metals by 2-5 times.
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