Recovery of zinc from low-grade zinc oxide ores by solvent extraction

Abstract

The recovery of zinc from low-grade zinc oxide ores with solvent extraction-electrowinning technique was investigated by using D2EHPA as extractant and 260^# kerosene as diluent. The results show that it is possible to selectively leach zinc from the ores by heap leaching. The zinc concentration of leach solution in the first leaching cycle is 32.57 g/L, and in the sixteenth cycle the zinc concentration is 8.27g/L after solvent extraction. The leaching solution is subjected to solvent extraction, scrubbing and selective stripping for enrichment of zinc and removal of impurities. The pregnant zinc sulfate solution produced from the stripping cycle is suitable for zinc electrowinning. Extra-pure zinc metal was obtained in the electrowinning test under conventional conditions.

Keywords

zinc / low-grade zinc oxide ores / heap leaching / solvent extraction

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