The direct leaching kinetics of an iron-poor zinc sulfide concentrate in the tubular reactor was examined.All tests werecarried out in the pilot plant.To allow the execution of hydrostatic pressure condition,the slurr...The direct leaching kinetics of an iron-poor zinc sulfide concentrate in the tubular reactor was examined.All tests werecarried out in the pilot plant.To allow the execution of hydrostatic pressure condition,the slurry with ferrous sulfate and sulfuric acidsolution was filled into a vertical tube(9m in height)and air was blown from the bottom of the reactor.The effects of initial acidconcentration,temperature,particle size,initial zinc sulfate concentration,pulp density and the concentration of Fe on the leachingkinetics were investigated.Results of the kinetic analysis indicate that direct leaching of zinc sulfide concentrate follows shrinkingcore model(SCM).This process was controlled by a chemical reaction with the apparent activation energy of49.7kJ/mol.Furthermore,a semi-empirical equation is obtained,showing that the order of the iron,sulfuric acid and zinc sulfate concentrationsand particle radius are0.982,0.189,-0.097and-0.992,respectively.Analysis of the unreacted and reacted sulfide particles bySEM-EDS shows that insensitive agitation in the reactor causes detachment of the sulfur layer from the particles surface in lowerthan60%Zn conversion and lixiviant in the face with sphalerite particles.展开更多
基金the Zanjan Zinc Khalessazan Industries Company (ZZKICO) for the financial and technical support of this work
文摘The direct leaching kinetics of an iron-poor zinc sulfide concentrate in the tubular reactor was examined.All tests werecarried out in the pilot plant.To allow the execution of hydrostatic pressure condition,the slurry with ferrous sulfate and sulfuric acidsolution was filled into a vertical tube(9m in height)and air was blown from the bottom of the reactor.The effects of initial acidconcentration,temperature,particle size,initial zinc sulfate concentration,pulp density and the concentration of Fe on the leachingkinetics were investigated.Results of the kinetic analysis indicate that direct leaching of zinc sulfide concentrate follows shrinkingcore model(SCM).This process was controlled by a chemical reaction with the apparent activation energy of49.7kJ/mol.Furthermore,a semi-empirical equation is obtained,showing that the order of the iron,sulfuric acid and zinc sulfate concentrationsand particle radius are0.982,0.189,-0.097and-0.992,respectively.Analysis of the unreacted and reacted sulfide particles bySEM-EDS shows that insensitive agitation in the reactor causes detachment of the sulfur layer from the particles surface in lowerthan60%Zn conversion and lixiviant in the face with sphalerite particles.
