Advanced Materials Research Vol. 454

Abstract: In alkaline condition, experiments were taken to investigate the influence of different regulators on the flotation behaviors of brucite and serpentine when sodium oleate was the collector. The regulators used in experiments included sodium silicate, tannin and calcium lignosulphonate. The results showed that sodium silicate had a great effect on the flotation. When the regulator was the sodium silicate, serpentine recovery rate was less than 10% and brucite recovery was about 90% in the pH of 10. After analysis, brucite and serpentine may be separated effectively by sodium silicate. At last, the function mechanism of sodium silicate was probed. The electrostatic adhesion between serpentine and sodium silicate accured, and the surface of serpentine was negative so that it was difficult to be collected by sodium oleate; Instead, the impact of sodium silicate on brucite was weak, and the surface of brucite was still positive so that it could be collected easily.

Abstract: According to the refractory lead-zinc ore properties with high pyrite, the experimental studies were conducted on floatation reagent conditions and closed circuit tests for comprehensive recovering of all types useful minerals. In comparison to the test results of different process flowsheets and different types of flotation reagents, adopting prior flotation lead (Pb)—Zn selective flotation (reagent removal and regrinding of rough concentrate)—S-selective flotation with Zn-tailings. The closed circuit tests were achieved: the grade of lead concentrate was 50.55% with a recovery of 92.25%; The grade of zinc concentrate was 40.12% with a recovery of 85.82%; The grade of sulfur was 48.58% with a recovery of 56.59%; The tailings grades of lead, zinc and sulfur were 0.27%, 0.31%, 3.90% respectively.

Abstract: A new flotation technology of carbonate-containing hematite was introduced in this paper, The results show that iron minerals are mainly composed of hematite, siderite, magnetite, limonite, ankerite, quartz, hornblende, and a small amount of chlorite, etc. The increase of iron carbonate can deteriorate the normal flotation of hematite, but now a new flotation technology can weaken the negative influence of iron carbonate on flotation, by which we can obtain the iron concentrate with grade of Fe 66.26 %, recovery of Fe 70.23%. It has been comprehensively demonstrated that the dispersant plays an important role in the selective separation of hematite from iron carbonate and iron silicate.

Abstract: This article describes the theory foundation of X-ray separation technology and introduces the study status, configuration and work principle of X-ray separator. This paper also conducts X-ray separating experiment on the low grade ores of Mo and Ni respectively in Liaoning province. The low grade Mo ore experiment can obtain a good result with the concentrate recovery, enrichment ratio and concentrate grade being 73.11%, 2.03 and 0.130% respectively and the tailings discarding ratio being 63.70%. The low grade Ni ore experiment can obtain a good result with the concentrate recovery and enrichment ratio concentrate grade being 61.92%, 1.45and 0.64% respectively and the tailings discarding ratio being 61.63%.

Abstract: The composition of Deoxidized Samples of Bayan Obo Oxidized Iron Ore is complex with high content of residual reducing C, Fe phase in the RDP is ferrous metal what is hard and malleable resulting in pessimistic grindability. Gravity-magnetic separation process flow is adopted with C pre-rejecting, stage grinding (-0.074mm -57.18%, -0.074mm -85.66%) and coarse-fine fraction separate treatment base on RDP process characteristic. The final concentrate has 92.02% Fe with 93.27% Fe recovery, 94.18% Fe metallization which may utilize as rough materials for steelmaking and the final tailings has 15.10% REO with 97.15% REO recovery which may utilize as rough materials for REO concentration.

Abstract: The results show that under the condition of grinding fineness(-200 mesh content) of 52.88% and magnetic field intensity of 0.2T, the index of concentrate yield is 13.25%, concentrate grade is 58.75% and concentrate recovery is 57.32% with preconcentration technology by magnetic separation.

Abstract: Mine drainage is a widespread environmental problem associated with both working and abandoned mining operations, resulting from the microbial oxidation of pyrite in presence of water and air, affording a solution that contains toxic metal ions. The present study aimed at evaluating the use of low-cost modified mordenitem to remove heavy metals ions from mine drainage. We elucidate the important parameters (including the pH, temperature, contact time, particle size and dosage) responsible for the removal the heavy metal ions. In addition, selectivity of modified mordenitem for metal removal was, in decreasing order, Pb²⁺> Cd²⁺ > Cu²⁺ > Zn²⁺. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of mine drainage.

Abstract: According to the bentonites properties and mineral composition, three bentonites with 32-36% montmorillonite content(MC) from Laiyang, Shandong, China, are purified for utilizing low grade bentonite sufficiently. Research shows that the purification is effective by separating –325 mesh products from raw bentonite after soaking, stirring and rubbing in water. Firstly, the three bentonites are combined into one and soaked in water for 24h with the ratio of liquid and solid 15:1, and then, the bentonite is purified using –325 mesh sieve after stirring and rubbing in water for 1h with pulp density of 26%. Methylene blue index(MBI) of the product is 22.52g/100g, swell index(SI) is 5.5mL/2g, water absorption(WA) is 184.3%, water content(Wa.C) is 9.7%, and the indexes meet the stantard of three grade Ca-bentonite(TGCB)applying to iron ore pellets.

Abstract: The changing characteristics of iron mineral along with the reduction time in reduction of a high phosphorus oolitic hematite by carbon were discussed in the paper. The grain growth of metallic iron was investigated in detail. The results showed that the iron mineral in reduction of the oolitic hematite changed as Fe₂O₃→Fe₃O₄→FeO→Fe, and finally was reduced to metallic iron. As the reduction time elongated, the small grain of metallic iron gathered toward the larger one and grew up. The metallic iron existed in the reduction products in the form of larger grains of metallic iron.

Abstract: The depressing function of bacteria of LKD on diaspore and kaolinite is studied through flotation experiments, mineral ζ-electric potential and infrared spectroscopy analysis. Waste beer has better selective and depressing effects on diaspore in the range pH 2-10 than starch-like substances do. The analysis of mineral ζ-electric potential and infrared spectra shows that the bacteria of LKD is chemically adsorbed to diaspore via its –COOH and stays on the surface of mineral firmly. Meanwhile, the functional groups -OH of yeast itself and some -COOH are hydrophilic, which helps the mineral being hydrophilic as well. Although the structure of phyllosilicate kaolinite determines its good floatability on the condition of strong acid, the recovery of diaspore by yeast is 30% more than kaolinite when the diaspore is depressed by bacteria of LKD on the condition of weak acid, pH-6. It indicates the possibility of Al-Si separation by reverse-flotation under neutral conditions.