METHOD FOR PROCESSING HIGH-POTASSIUM NEPHELINE FELDSPAR RAW MATERIAL Russian patent published in 2019 - IPC C01F7/02 C01B33/113 

FIELD: hydrometallurgy.

SUBSTANCE: invention relates to hydrometallurgy and can be used in processing high-potassium nepheline-feldspar raw material, in form of synnyrites. Raw material is treated in slightly concentrated (1–3 %) sulfuric acid, insoluble residue is mixed with potash and subjected to thermal treatment at temperature 800–1,000 °C. During thermal treatment, microcline from charge is converted into acid-soluble phases: kalsilite and potassium metasilicate. Obtained product is treated with slightly concentrated (1–3 %) sulfuric acid. Sulfuric solutions of two treatment steps are combined and subjected to vacuum crystallization to obtain recycled water and alumina potassium alum. Insoluble residue is mixed with potash and subjected to thermal treatment at temperature of 500–600 °C. Produced sinter is processed into alumina and potassium sulphate. Sulfur gas released during sintering is dissolved in water to obtain sulfuric acid and directed to first stage of processing source raw material in amount of 30–35 vol%.

EFFECT: developed method enables to efficiently process high-potassium nepheline-feldspar raw material.

1 cl, 2 tbl