Study On The Influence Of Optimization For The Process Of Superfine Grinding And Classification To Zinc Leaching Efficiency

Danxia smelter Sec uses two vertical sand mill as open circuit grinding operations beforeleaching, the particle size D97of the second stage grinding product is about60μm, the result hasa huge differences with the design specifications of Sec grinding particle size D97=17μm. Thelarge particle size of leachinged materials will prolong the reaction time and seriously affect theeconomic efficiency of the smelter.This study focus on the reduce of grinding particle size before the Sec leaching, this paperpresents a possible program for the study as: the appropriate classification equipments isselected in order to explore the appropriate grinding and classification process; explore thereasonable medium diameter, to make the particles get the most effectively crushed.This study chooses the hydrocyclone as classification equipment. When the operatingparameters of the cyclone is Du=12mm、Do=20mm、ΔP=0.18MPa, the content of-17μm inoverflow can be increased to about73.2%, underflow density up to48.98%in the classificationtest of low concentration. In high-voltage classification test, the operating parameters of thecyclone is Do=18mm, ΔP=0.25MPa, Du=16mm, the content of-17μm in overflow is81.6%,the density of the underflow is55.96%. The two test results show that they can beseparate granularity qualified materials for leaching and provide the appropriate concentrationof coarse material for mill.Different medium diameters and filling rates is tested in laboratory, the results showed that:when the mill filling rate is55%corundum ball diameter is3mm, the content of-17μm is80.15%, and the input power is664.3W, energy consumption of generation-17μm is0.037363kWh/kg. From the perspective of particle size and energy consumption, a diameter of3mm and55%grinding filling rate is of better effect.Oxygen pressure leaching tests of the grinding product which is fed by the feeding ofcyclone is also studied. It can be found that the leaching rate with a certain feed particle size,zinc leaching rate is improved because of the extension of leaching time, the leaching rate up to94.05%when supplies,-17μm accounted for70.41%, leach1h.