Advanced Materials Research Vol. 826

Abstract: Adsorption of sodium cyanide on pyrite particle surface was studied. And influences of adsorbing time, dosage of pyrite, and pH on adsorbing effect were investigated. IR spectra, SEM, EDS and Element Area Scanning of samples before and after adsorption were measured. Results showed that adsorption of sodium cyanide on pyrite particle surface is a fast adsorbing process. As soon as adsorbing time is 1 min, adsorbing equilibrium is reached. At the condition of concentration of NaCN 24mg/L, adsorbing time 5min, and stirring rate 2000r/min, when dosage of pyrite particles is 5g/L, adsorbing rate is up to 80%, and at the time adsorbing capacity is the largest, 381.4mg/g. When pH is within 8.0-11.0, pH has little influence on adsorbing effect. IR and EDS results showed that at the particle range of-45μm is 93%, the surface of pyrite particles is easy to be oxidized and hydroxylated. S atoms on the surface of pyrite lattice are oxidized, while Fe atoms on the surface of pyrite lattice are hydroxylated. There exists hydrogen bond function between CN^- and OH^-, and there exists monomolecular chemical bond function between CN^- and pyrite. And-Fe (CN)_n^m-(n<6) is produced on the surface of pyrite, thus the superficial properties of pyrite is changed.

Abstract: In recent years, recovering zinc from low grade oxidized zinc ore has been a matter of discussion. In this paper, the investigation for recovering zinc and iron from gossan ores was carried out. In generally, the conventional physical separation methods, such as flotation, gravity separation and magnetic separation, were used to treat the low grade ore, and flotation is the most commonly used method for beneficiation and pretreatment of oxidized zinc minerals. However, gravity separation and magnetic separation are used to deal with the gossan ores because of the special zinc oxide ore bearing iron 40.2% in this study. The effects of grinding fineness and magnetic intensity were investigated, respectively. The results show that the grade of zinc and iron increase slightly, and the best result is that the grade of zinc and iron are 13.35% and 40.25%, the recovery of zinc and iron are 53.45% and 52.19%.

Abstract: A comparative study on the collecting effect to cassiterite was studied using a new carboxylic acid modified collector DXS and traditional collector salicylaldehyde hydroxamic acid as collectors, respectively. In addition, the relationship between floatability of DXS and crystal structure of cassiterite was investigated. By means of infrared spectroscopy analysis of the cassiterite surface before and after adsorbing DXS molecules, the adsorption mechanisms of DXS on the surface of cassiterite were analyzed.Keywords: carboxylic acid modified collector DXS; cassiterite; flotation mechanism

Abstract: In this paper, coal-based reduction on flotation middling from iron ore containing carbonate at donganshan was studied, during which the effect of reduction temperature, reduction time, C/O mole ratio and feed layer thickness on reduction process were carried out. The results showed that the optimal reduction conditions required a temperature of 1250°C,a duration of 70min, a C/O mole ratio of 2.0 and a feed layer thickness of 25mm, and the iron powder containing 90.27% Fe with iron recovery of 93.36% was obtained after three stages low intensity magnetic separation, which could be used to make steel. According to the chemical analysis, most of the iron minerals were reduced to metallic iron. Coal-based reduction proved to be an alternative and promising process to conduct the fine particles and powders.

Abstract: A new type of column magnetic separator has been developed, and a series of experiments have also been carried out in this paper. The structureseparating mechanismexperiments of column magnetic separator are introduced. The results show that the separator can produce concentrate from rough grinding products directly. The findings of orthogonal experiment show that the cycle of magnetic-field, the electrical current intensity and the position of magnetic system have remarkable effect on the experiment results. The optimized cycle of magnetic system is 0.2s, the optimized volume flow of the feed is 10cm³/s, the optimized electrical current is 11A ; the optimized water flow velocity is 11.1mm/s; the optimized position of magnetic system 20mm from the edge of cleaning area. Under the condition of the feed containing 47.99% TFe, an iron concentrate containing 66.27% TFe with 61.63% Weight ratio are obtained by using it to separate the rough grinding products of Nanfen ore dressing plant.

Abstract: In this paper, the mineral properties of the lean magnetite in RongTian mine corporation was studied, during which the analysis of the mineral properties, prelimenary separation on the lump mine, two-section grinding, one section fine screening and three-section low intensity magnetic separation process were carried out. The results showed that if the suitable mineral processing flowsheet is adapted, we can achieved such index:concentrate grade of 63.65%, Fe recovery of 47.12% based on the ore grade of 10.05%.. According to the experimental result analysis, most of the iron minerals could be used to support the steel production of LingGang Group.Single magnetic process proved to be an suitable and promising process to conduct the fine particles of lean magnitite.

Abstract: The main elements can be recovered for mineral processing in a mineral containing titanium of Baoding area were Ti, Fe and V, and the elements in the main gangue minerals were Si and Al. Gravity concentration, gravity concentration-high intensity magnetic separation and gravity concentration-flotation tests were performed on the ore sample respectively. The results showed that, in the test of shaking table, when the grinding fineness was -0.074mm 93%, the productivity of concentrate can reach 32.24%; when grinding fineness was -0.074mm 93%, after gravity concentration-magnetic separation, 30.25% of concentrate productivity can be attained; when the grinding fineness was -0.074mm 85%, after gravity concentration-flotation, the productivity of concentrate was 3.31%. Maybe it's the condition of the tests wasn't controlled well, especially adjusting pH value in the flotation stage, it's hard to control, so the results were not very good.

Abstract: In order to improve the separating index of ilmenite to separate the concentrate by high intensity magnetic separation, the Heishan iron ore in Chengde did some work. Separate the sulfide ore out by flotation under the conditions of concentration by weight in feed 32%, consumption of xanthate 200g/t and 2^# oil 40g/t. Use sulfate to adjust the pH of the low sulphur product of flotation, the mixture of EM351-2 and EM351-3 as foaming agent, after one roughinging and four fold concentrating, got the final titanium concentrate, the grade of which is 47.23%, and the recovery is 58.29%. During the procedure of roughing, the consumption of the reagent as follows: sulfate 2kg/t, EM351-3 1kg/t, EM351-2 900g/t. The consumption of sulfate during fourfold concentrating is 1kg/t. The index is more stable when the concentration in feed is 18%~26% during flotation. The index is stable during the continuous 26 work time for the process under this reagent system. The screen analysis of the flotation concentrate indicates that this reagent system has a better effect on the flotation of +0.074mm particles, and a bad effect on the flotation of-0.045mm particles.

Abstract: The experimental sample consists of talc, magnesite and a little quartz, the grade of talc is 80%. By the floatation flowsheet of rougher and two times cleaner, and middling after regrinding return to rougher, the high grade talc concentrate can be obtained. The concentrate contains talc 95.67% (SiO₂ 61.68%). Talc recovery rate is 89.43%. By this way, the output of high class talc product is increased and talc resources are exploited very well.