SEPARATION OF ROASTED COATING AND CORE IN DOUBLE-LAYERED PELLET ROASTING FOR PRETREATMENT OF SULFUR AND ARSENIC-BEARING GOLD CONCENTRATE

摘要

Compared with other pretreatments of sulfur & arsenic-bearing gold, double-layered pellet roasting has an advantage that sulfur dioxide and arsenic trioxide volatilizing from this refractory gold ores can be solidified into the coating without emission during the roasting. However, the separation of coating from roasted double-layered pellet should be focused on in the novel pretreatment. Based on the difference of physicochemical characteristics between roasted solidified coating and pellet core, several separation methods including grinding, drop impact and water quenching method had been systematically studied in this paper. The results showed that magnetic and gravity concentration could not obtain a satisfactory separation effect. The optimum separation rate of grinding was only 38.94% at grind time 12min, but it increased to 85.05% by drop impact under drop height 0.75m, drop times 20 and impact angle 45°, and that of water quenching taking advantage of slaking reaction of lime could approach 75.32%.