Study On The Resources And Utilization Of Smelting Waste Of Zinc

The paper researched on two different smelting waste of zinc. First, the paper was based on the treatment process and the characteristics of ammonia leaching residue of the low grade zinc oxide ore in lanpin of yunnan, using flotation to improve the recovery of total zinc; then, the paper studied on the mineralogy of historical zinc smelting slag in Guizhou province, and presented the flotation method the new process of the flotation method of recycling the carbon of the slag.The ammonia leaching slag that acquired from the new process called "ammonia leaching-solvent extraction-electrowinning" for dealing with low grade zinc oxide ore in Lanping area of Yunnan province mainly contained sphalerite, francklinite and zinc oxide that had not been leached. The recovery of zinc in the new process was less than80%, because the content of zinc in the slag was high. Therefore, improving the recovery of zinc in the whole process through recovering sphalerite and zinc oxide that had not been leached by floating ammonia leaching slag was expected. In this paper, the flotation technology for zinc oxide and sphalerite by xanthate with sulfuration was developed. The results showed that, through grinding and flotation process including a rough flotation step, twice scavenger steps and twice cleaner steps the zinc concentrate was obtained with grade of22.16%and recovery of68.97%. And in the "ammonia-leaching slag flotation" process, the recovery of zinc was92.57%. And the optimum conditions in the rough flotation step were:the grinding time was4min; the concentration of Na2S, CaO, CuSO4and309xanthate was1.2kg/t,6k/t,300g/t and100g/t respectively. The concentrations of309xanthate in the twice scavenger steps and twice cleaner steps was50g/t,30g/t,20g/t and lOg/t respectively.The historical zinc smelting slag in Guizhou province (the time of piled up was one hundred years) were found to be dark color silt and particle size was uneven. Many coarse particles were angular and porous. The mineral compositions including vitreous, microcrystalline and transition phase of different minerals were complex. The concentration of zinc in the slag was7.51%and mainly distributed in silicate mineral and franklinite. The concentration of lead in the slag was0.46%and mainly distributed in anglesite. The total concentration of iron in the slag was13.06%and mainly distributed in red limonite, silicate mineral and magnetite. The gangue minerals of the slag were SiO2and Al2O3. In addition, huge amount of carbon was found in the slag and the concentration of carbon is17.00%.Using flotation processes including a rough flotation step, once scavenger steps and triple cleaner steps the carbon concentrate was obtained with grade of59.15%and recovery of92.97%. And the optimum conditions in the rough flotation step were:the grinding time was7min and the impeller speed was2200r/min; the concentration of kerosene、caprylic and Na2Si04was300g/t,300g/t and2kg/t respectively. The concentrations of kerosene and caprylic in the scavenger step was150g/t and150g/t respectively.