| In this paper, the flotation behaviors of sulfide minerals such as jamesonite,marmatite and pyrrhotite in DACHANG mine of Guangxi province of China were studied, and relationship between pH, concentration of collector (C) and floatability of sulfide mineral was discussed. Based on the flotation theory of sulfide mineral, the mechanism of sulfide flotation and its practical application was studied.Bioleaching of marmatite with a culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans at high concentration of iron was studied, the results showed the zinc leaching rate of the mixed culture was faster than that of the sole Thiobacillus ferrooxidans; the increasing iron concentration in leach solution enhanced the zinc leaching rate. The SEM analysis indicated that the chemical leaching residues was covered with porous solid layer of elemental sulfur, while elemental sulfur was not found in the bacterial leaching residues. The primary role of bacteria in bioleaching of sphalerite was to oxidize the chemical leaching products of ferrous ion and elemental sulfur, thus the indirect mechanism prevailed in the bioleaching of marmatite. In this paper bioleaching of low-grade zinc sulfide ore and marmatite concentrate was studied, and the mechanism of bioleaching of sphalerite at high concentrate of iron was discussed.The recovery of zinc from low-grade zinc oxide ores with Solvent Extraction- Electrowinning Technique was investigated by using D2EHPA as extractant and 260# kerosene as diluent. The results show it is possible to leach selectively zinc from the ores by heap leaching. The zinc concentration of leach solution in the first leaching cycle was 32.57g/L, and in the sixteenth cycle the zinc concentration was 8.27g/L after solvent extraction. The leaching solution is subjected to solvent extraction, scrubbing and selective stripping for enrichment of zinc and removal of impurities. The pregnant zinc sulfate solution produced from the stripping cycle is suitable for zinc electrowinning. Extra-pure zinc metal is obtained in the electrowinning test under conventional conditions.In bioleaching of zinc sulfide ore, the high concentration of iron released from dissolved pyrrhotite and pyrite accelerate the leaching rate of zinc.The primarily role of the bacterial in bioleaching of marmatite was to oxidize the chemical leaching products of ferrous ion and elemental sulfur, thus the indirect mechanism prevailed in the bioleaching of marmatite.In this research the effect of three flotation regents(Xanthates,Dithiophosphates,D-250) on the activity of bioleaching bacteria was discussed. Oxidized for 34 hours, the concentrations of Fe2+ in the 9K liquid solution added with Xanthates, Dithiophosphates and D-250 separately at the concentration of 4×10-4mol/L changed from 4.03 g/L to 4.64,4.77,5.91 g/L. The result showed that the inhibition of the three regents was from little to much. Experiment of bioleching on the sphlerite concentrate with flotation regents or no was done. After leaching for 23 days, the leaching ratios of the two were 63% and 46%. It has proved the conclusion that the flotation regents (Xanthates,D-250) have effect on the activity of bioleaching bacterias.Jamesonite and marmatite of Pb-Sb-Zn complex sulfide ore can be recovered using flotation and bioleaching processing, the jamesonite can be flotated at first, and the zinc of marmatite can be extracted by bioleaching technology. The results of test show that, the recovery rate of Pb, Sb, Zinc is 80.11%,80.04% and 90.8% respectively.
|
PDF Full Text Request