METHOD OF REWORKING BADDELEYITE CONCENTRATE Russian patent published in 2005 - IPC

FIELD: production of compounds of rare elements; synthesis of zirconium oxo-chloride of basic zirconium sulfate and zirconium dioxide.

SUBSTANCE: baddeleyite concentrate is sintered at 1150°C with calcium oxide or carbonate in presence of calcium chloride. Sinter thus obtained is subjected to decomposition by means of hydrochloric acid accompanied by heating for obtaining pulp containing liquid phase with zirconium oxo-chloride and calcium chloride and insoluble baddeleyite sediment. In the course of cooling the pulp, crystallization of zirconium oxo-chloride from liquid phase occur. Zirconium oxo-chloride is separated together with insoluble baddeleyite sediment from calcium chloride solution through filtration and is washed-off with 22-27-% hydrochloric acid in counter-flow mode. Washed-off zirconium oxo-chloride and baddeleyite sediment are treated with water for obtaining zirconium oxo-chloride solution from which baddeleyite sediment is separated. Ammonium sulfate is introduced into zirconium oxo-chloride solution for sedimentation of basic zirconium sulfate from which high-purity zirconium dioxide is formed through calcination. After separation of zirconium oxo-calcium chloride and insoluble sediment, calcium chloride solution may be added to pulp before or in the course of its cooling. Hydrochloric acid solution is used for washing at sinter decomposition stage.

EFFECT: enhanced efficiency due to increased degree of extraction of zirconium and excluding complex evaporation operation.

5 cl, 4 ex