Orthogonal test on the leaching of a refractory gold ore in Guizhou province by bleaching powder

Orthogonal tests were conducted to study four factors: leaching agent dosage, leaching time, liquid-solid ratio and alkali consumption at three levels. By analyzing the test results, we determined the optimal leaching conditions. It was when 40 g gold ores was soak in the mix of 25 g bleach and 9 g sodium hydroxide for 5 hours with a liquid-solid ratio of 8:1 at the temperature of 25 ℃ that the best leaching effect was obtained. Under that condition, the leaching rate could reach 65.53%.The tests results indicated that the leaching of refractory gold ores by bleaching powder, to some extent, was effective and cost little, deserving further studies.