Experimental Study on Optimization of Flotation Process for Quality Improvement and Silica Reduction of a Low-grade Lead-Zinc Sulfide Ore
The main valuable elements in the ore are Pb and Zn,with the contents of 0.69%and 3.70%,respectively.Lead exists mainly in the form of galena,the distribution rate is about 87%,and zinc exists mainly in the form of zinc sulfide,the distribution rate is about 88%.The ore belongs to low grade lead-zinc sulfide ore.In the production process,the concentrator adopts the one-stage grinding process of selective flotation of lead and flotation of zinc from lead tailings,which has long existed the problem that the content of SiO2 in zinc concentrate products is higher than 10%,seriously affecting the economic benefits of the concentrator.In order to solve this problem,based on the study of ore process mineralogy,the zinc concentrate product was obtained by simulating the on-site process flowsheet,and the reasons for the high content of SiO2 in the zinc concentrate product under the on-site process flowsheet conditions have been found out through the process mineralogy study,and finally the process optimization test has been carried out.The results of MLA analysis show that the main reason for the high content of SiO2 in zinc concentrate is that the intergrowth of+0.074 mm quartz and sphalerite enters the zinc concentrate,thus affecting the quality of zinc concentrate.Fine grinding should be carried out to further improve the monomer liberation degree of quartz and sphalerite.Stage grinding and stage beneficiation process of zinc rough concentrate regrinding and re-concentration is proposed to optimize the process.The effective liberation of sphalerite and quartz in zinc concentrate is realized by regrinding the zinc rough concentrate to 80%-0.045 mm.After optimization,the lead concentrate with Pb grade of 55.23%and Pb recovery of 80.79%is obtained in the locked-cycle flotation tests.Zinc grade of zinc concentrate is 54.11%and the recovery of zinc is 83.48%.Compared with the flotation indexes before optimization,the grade and recovery of Pb in lead concentrate changed little,but the grade of Zn in zinc concentrate increased by 3.20 percentage points,and the content of SiO2 in zinc concentrate decreased by 6.20 percentage points,which show that the effect of quality improvement and silicon reduction is remarkable.The research results provide an important technical support for the concentrator to improve economic efficiency.
lead-zinc sulfide oreimprove quality and reduce siliconstage grindingprocess optimization
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