Study On Technology And Kinetics Of Mechanical Activation Enhancing Leaching Indium From Hard-Zinc

Based on the review of the treatment technology of hard-zinc as well as the leaching process of mechanical activation enhancing leaching and its application in non-ferrous metallurgy, the method of mechanical activation was put forward. Following several experiments have been researched using hard-zinc provided by Guangxi Liuzhou Zinc Company as test materials in the normal stirring leaching equipment and mechanical activation equipment (stirring mill) respectively:(1) the effect of mechanical activation on indium leaching rate have been confirmed from the contrast experiment between in normal stirring leaching equipment and mechanically activated enhancing leaching equipment respectively,(2) the main influence factors of indium leaching rate and the optimum process conditions have been found from the orthorhombic and single factor experiments, which leaching reaction occurs during the activation process(3) the leaching kinetics of hard-zinc was studied between in normal stirring leaching equipment and mechanically activated enhancing leaching equipment with non-activated and activatied ore.From experiments, conclusions can be drawn as follow:(1) Results in the experiments confirm that mechanical activation is a effective method in enhancing leaching in liquid-solid reaction, which can greatly enhance indiumleaching rate, indium leaching rate can reach from 93% in normal leaching to above 98% in activated leaching; The time is shorten 2/3 from mechanical activation to normal stirring leaching at the same indium leaching rate (93%).(2) From the orthorhombic and the single factor experiments, the effect of each factor on indium leaching rate is: Reaction time>the initial concentration of acid> >particle graininess> liquid-solid ratio> stirring speed. Considering the energy-consumed, operation and indium leaching rate, the optimum process conditions are as follow: reaction time 80 min, the initial concentration of acid 9.92 mol/L, liquid-solid ratio 4, particle graininess 0.175~0.370 mm, stirring speed 450 rpm. Leaching rate can reach 98% in the condition.(3) Chemical activation can be enhanced, reaction speed can be improved, the apparent activation energy and the reacting order can be decreased since the hard-zinc is activated in the Mechanical activation equipment. The kinetics equation with 0 min, 30 min and 60 min can be inferred from the experimental data as follow:(reaction speed unit/mol-s-1 -m-2):(4) This research is important to guide industry production, which is provided new path for enhancing leaching indium from hard-zinc. So, it's meaningful in science value.