METHOD FOR TREATMENT OF LOW-GRADE OXIDIZED ZINC ORES AND CONCENTRATES WITH ZINC, MANGANESE, IRON, LEAD, SILVER, CALCIUM AND SILICON DIOXIDE RECOVERY Russian patent published in 2012 - IPC C22B19/00 C22B3/04 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method for treatment of low-grade oxidized zinc ores and concentrates with zinc, manganese, iron, lead, silver, calcium and silicon dioxide recovery. The method comprises crushing, fine crushing, lixiviating, settling-down of the above components from solutions, wherein the lixiviating shall be performed in stages: during the first and the second stage - lixiviation by sulphuric acid solution over the reducing substance, the oxidation-reduction potential φ (ORP): at the first stage φ=380-420 mV, at the second stage φ=420-460 mV. At the third stage lixiviation is performed by an ammonium carbonate solution with the composition (g/dm³): 60-110 NH_{3 general} 30-65 C0_{2 general} while at the fourth stage it is performed by nitric acid NHO_3. At the fifth stage sulphating roasting with H₂SO_{4 term} with further water leaching is performed, the sixth stage being lixiviation with ammonium fluoride aqueous solution of acid NH₄HF₂. The obtained soutions shall be puriied and used for zinc, manganese, iron, lead, silver, calcium, silicon dioxide and sodium sulfate, ammonium nitrate recovery. EFFECT: enhanced zinc recovery and rational utilization of the stock.

16 cl, 1 dwg, 3 ex