Advanced Materials Research Vols. 524-527

Abstract: Based on the study of normal emulsion process of floatation reagents, the idea which uses Pneumatic injection to spray the floatation reagents is proposed. The paper introduced the structure and the performance of the Pneumatic injection atomizer. More than 24% of the dosages were saved. Pneumatic injection atomizer offers simple structure and low energy consumption, which is 0.388kw/h.It was proved by the diameter results obtained by the laser particle size analyzer that Pneumatic injection atomizer offers good dispersing effect. When the air pressure is 0.08MPa, the average diameter of droplet is 7.89µm.

Abstract: This paper presented the fundamentals of banana screening method and the structural features of the banana screen. Based on soft-dry ball contact model, banana screening process was simulated by using 3D discrete element method. The results show that the material bed on banana screen possesses a characteristic of thin and constant thickness along the screen plate. The particles velocity on the screen deck shows a decreasing distribution along the screen deck length and the decrease of velocity changes from steep at the feed end to flat at the discharge end. The instantaneous efficiency of banana screen can reach to above 0.95 and the efficiency of steady state is about 0.83. Numerical simulation results can provide references for insight understanding of the banana screening mechanism and optimization of banana screen.

Abstract: Ten strains of silicate bacteria were screened from three bauxite samples in Jiangxi Province and Henan Province in China. The ten strains were determined as B. mucilaginosus according to the results of physiological and biochemical characteristics and desilicon ability. Bioleaching tests showed that the ten strains all can decompose bauxite ore and release silicon from bauxite, but had a large difference of desilicon ability among them.

Abstract: The study aims to comprehensive recovery of Cu, Mo, Co and Fe from copper polymetallic sulphide ore in Sichuan province, China. In the light of the minerals characteristics, a united flow sheet, i.e., flotation-magnetic separation with new powerful flotation reagents were used to effectively recovery copper together with the associated valuable metals (Mo, Co and Fe) from the ore. The result of the closed circuit experiment shows that a copper recovery of 93.38% with a concentrate grade of 21.25%, Mo recovery of 45.72% with a concentrate grade of 45.78%, Co recovery of 46.42% with a concentrate grade of 0.46% and Fe recovery of 38.26% with a concentrate grade of 63.73% were achieved from the ore.

Abstract: A technology of “arsenic removing- sulfuric acid producing- residuals for ironmaking” is proposed for comprehensive utilization of pyrite with high content of arsenic. The effect of roasting temperature and time on arsenic removing was investigated. The arsenic removed residuals obtained under the optimal arsenic removed conditions, was used to be proceeded for sulphur volatilization test. The results demonstrate that final residuals with 63.53% of Fe can be used for steel industry. This technology can be used to fully utilize sulphur and produce high quality concentrate as iron-bearing feed for steel industry, which will help to reduce the pollution of arsenic and extend raw material sourcing for Chinese steel industry.

Abstract: There is a remarkable interaction when fine particles adsorbed calcium ions in Silica-Sphalerite-Mixture (Silica:Sphalerite =4:1) systems, it is not conducive to mineral flotation. The key is how to reduce or eliminate calcium ions. This paper focuses on the changes of Zeta potential and Zeta potential distribution (ZPD) with the single minerals and complex mineral (silica / sphalerite = 4:1) in different concentrations of calcium ions, and interaction of particles was analyzed by Zeta potential and ZPD.

Abstract: The valuable minerals of a copper sulfide ore in Chile, mainly consist of chalcopyrite and chalcocite as well as contain small amounts of cuprite. Gangue minerals are mainly chlorite, quartz, calcite, arsenopyrite, etc. Most are coarse-grained disseminated minerals, while some are fine-grained disseminated minerals. Flotation has been used for processing these ores. The grinding fineness, lime dosage, collector type and dosage all have influences on flotation results. In the present work, the best condition of grinding fineness, lime, and collector dosage was used to separate the copper sulfide and other minerals in the ores. The results showed that, in the grinding fineness of −74 μm accounting for 80%, the vast majority of copper minerals were to monomer dissociation. The flowsheet of one stage roughing, two stage scavenging, and two stage cleaning was adopted. The ideal results of 27.58% and 96.89% for the copper concentrate grade and copper recovery, respectively, were obtained.

Abstract: With the development of powder metallurgy industry, the fine-metal-powder classification becomes one of the vital techniques in powder technology. A pneumatic classifier without screen and mechanical moving parts is designed and developed. Three samples are used in the pneumatic classification experiments and the separation sizes are 45μm， 45μm and 30μm, respectively. The oversize ratio in fine powder can be reduced to less than 5% and the undersize ratio in coarse powder less than 15% when the air flow is suitable, simultaneously. The classification effect is satisfactory.

Abstract: Low-grade oxide copper ore is an important resource, reserves of which are scattered all over the world. In the present study, the characteristics of oxide copper ore are studied using multi-element analysis and X-ray diffraction. The oxide copper minerals in the ore are mainly in the form of cuprite, malachite, chrysocollite and azurite. The effects of grinding fineness and agent regulation on flotation are also investigated. Floatability was unsatisfactory because of the many kinds of oxide copper minerals present in the sample. The flotation results indicate that a concentrate grade of 18.32% at 73.46% recovery can be obtained using the closed circuit process of one-stage roughing, three-stage scavenging and two-stage cleaning flotation under the optimum parameters, with raw ore characteristics of 1.29% Cu, 92.25% copper oxidation rate, and 65.59% slime content.

Abstract: To study mechanisms of coal biosolubilization, this paper investigated the formation of black droplets on the surface of Sabouraud maltose agar (SMA) culture media through coal solubilisation by Hypocrea lixii AH. The black droplets were collected and weighted. Mycelia of Hypocrea lixii AH were characterized by (Full name is required before abbreviation) FTIR spectra and contact angles. The results showed that the first 9 days are black droplets permeation period, solubilized coal in coal pole keep place due to increase of polarity with mycelia aging. Moisture content of the black droplets was 96.4(±0.2) %, largely resulting in high-polarity property of the black droplets. Furthermore, the comparison on moisture contents of coal and black droplets indicated that the water content of black droplets were from the culture media and bio-oxidation instead of coal self.