| Utilization of low grade and high caium zinc oxide ore has become a world challenge for the mineral processing area, so systematic mineral processing experiments were carried out to extract zinc in the low grade high caium zinc oxide ore from LanPing, and good concentrate index was obtained, furthermore a few flotation reaction mechanism were investigated too.Process mineralogy investigate of the ore indicated the ore contains 7.47% of zinc, oxygenation rate is 93.93%, CaO grade is 22.23%, is a typical low grade, high oxygenation rate, high CaO content zinc oxide ore. The mainly available minerals of the ore are hemimorphite and smithsonite,the mainly gangue minerals of the ore are calcite, quartz, dolomite, limonite and so on.The ore is fragile, in the process of crushing and grinding could easily be heavy slliming,that is unfavourable for the flotation of available zinc oxide ore.Based on the process mineralogy investigate of the ore, gravity experiments and flotation experiments were carried out to explore the washability of the ore, results show that although gravity separation could obtain high grade rough zinc oxide concentrate, but large amount of fine zinc mineras were lost in the tailing which is difficulty to recover. Sulphidation-amine flotation experiments show, the application of collector HHA, sulfurizing agent TZ-1, use sodium silicate in combination with sodium hexametaphosphate as depressor, could not only preconcentrate the zinc grade and efficiently remove most of alkalescent gangue minerals, but could also supply superior quality material for the sulfuric acid leaching.Both "whole grain flotation" and "predesliming flotation" flowsheet were adopted to optimizing the flotation condition. Results show the optimal processing parameters of whole grain flotation flowsheet were:grinding fineness of 85%-74μm, sulphide ore flotation condition were xanthate dosage of 100g/t, pine wine oil dosage of 60 g/t, zinc oxide ore flotation condition were sulfurizing agent TZ-1 dosage of 15000g/t, HHA dosage of 800g/t. depressor dosage of 1200g/t, under these optimal flotation condition, flotation index were:the grade of rough zinc oxide concentrate was 15.28%, which recovery was 85.80%. the grade of rough sulphide concentrate was 8.39%, which recovery was 5.24%,total zinc recovery was 91.04%, furthermore 72.12% of CaO were concentrated in the tailing. As the dosage of whole grain flotation was too high, pre-desliming flotation processing was consequently adopted. Results indicated the optimal flotation condition of predesliming flotation were:after removing 20% yield of-20μm sliming, the oversize product were grinded to fineness of 89%-74μm, sulphide ore flotation condition were xanthate dosage of 100g/t, pine wine oil dosage of 60 g/t, oxide ore flotation condition were depressor dosage of 1200g/t, sulfurizing agent dosage of 8000g/t, HHA dosage of 900g/t, under these optimal flotation condition the pre-desliming flotation index were:the grade of rough zinc oxide concentrate was 18.19%, which recovery was 72.47%, the grade of rough sulphide concentrate was 7.92%, which recovery was 3.02%, the grade of slime was 7.01%, which recovery was 17.88%, the total zinc recovery of 95.07%, and 63.66% of CaO were concentrated in the tailing. Compare with the all fraction flotation flowsheet, predesliming flotation flowsheet was more suitable for ultilizing the zinc in the ore, for it's flotation agent consumption was lower.Acid leaching experiments were carried out in order to investigate the feasibility of predesliming-amine flotation-acid leaching technological process; Experiments were focused on rough concentrate and sliming. Results indicate that under the condition of:80g/L of sulfuric acid,liquid ratio of 6:1,leaching time of 60min, zinc leaching rate could reach to 92.64%,sulfuric consumption was 2.55t/t.Zn. Slime leaching experiments indicated under the condition of:200g/L of sulfuric acid, liquid ratio of 7:1, leaching time of 50min, zinc leaching rate could reach to 90.32%, sulfuric consumption was 8.04t/t. Zn.Adopted "cacium removal and preconcentrate by flotation-acid leaching" technical flowsheet ultilizing the zinc in the low grade high cacium zinc oxide ore, the total zinc recovery could reach to 85.35%.The reaction mechanism between mineral surface and flotation agent(focused on regulator) were studied via pure mineral flotation experiments, results shows the application of sodium carbonate obviously increased the recovery of hemimorphite, use sodium silicate in combination with sodium hexametaphosphate could strengthen the inhibitory action on calcite and quartz. |
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