Advanced Materials Research Vols. 524-527

Abstract: This paper presents the sulfidisation promotion effect of ammonium sulfate on the sulfidisation flotation of both malachite and copper oxide ores. Copper oxide ores are commonly difficult-to-float due to its molecular structure, and adding sodium sulfide as activator is necessary; however, its dosage to the flotation pulp must be strictly controlled, as it is also a powerful depressant for copper sulfide minerals, and will, if in excess, depress the activated copper oxide minerals. This depression will be alleviated while ammonium sulfate is added, as it accelerates the speed of sulfidisation, and alleviates excessive sulfide ions on the depression of copper oxide minerals. Ammonium sulfate, therefore, may be a sulfidisation promoter, and plays a role of sulfidisation promotion effect; it makes the coating of sodium sulfide on the ore surface more dense and stable, which is ready for xanthate adsorption on the surface of copper oxide minerals. The results of experiments show that the flotation recovery is increased 12.28% while ammonium sulfate is added in the presence of excessive sodium sulfide in the pulp, and the highest recovery is obtainable when the ammonium sulfate and sodium sulfide are in the same dosages. The sulfidisation promotion effect of ammonium sulfate is confirmed by pure copper oxide mineral flotation test and copper oxide ores flotation test, as well as by SEM images of floated malachite.

Abstract: For low-grade iron ore, smelting costs and resource wastage will be increased. Product quality of such ore is affected adversely by an excessive amount of sulfur. This also causes environmental pollution. In accordance with the vanadium-titanium (V-Ti) magnetite concentrate properties with low iron grade and high sulfur content, the joint process of magnetic separation and flotation was carried out. Magnetic separation was conducted to increase the iron grade, while reverse flotation was used to reduce sulfur content. Results show that the feeding mainly contains titanomagnetite, hematite, and pyrite. The sulfur was primarily found in pyrite. The separation effect was influenced by the grinding fineness, magnetic intensity, collector type and dosage, and pH value. At a grinding fineness of −45 μm accounting for 87%, most of the iron minerals exhibited monomer dissociation. An open-circuit experiment was carried out under the best conditions of magnetic intensity, as well as collector and modifier dosage. Good experimental results were obtained as follows: the iron grade increased to 57.17%, iron recovery was 89.94%, sulfur content decreased from 0.66% to 0.26%, reverse flotation of sulfur foam concentrate contained almost 15.68% sulfur, the upgrade ratio was about 23, and the cobalt in the sulfur concentrate was enriched 20-fold. A method for improving the comprehensive utilization level and effect of mineral resources is provided in this study.

Abstract: In this study, factors influencing zinc oxide flotation are investigated. These factors include the dosages of sulfidizing reagent, the pH of the regulator and the activator, the use of sodium carbonate as the pH regulator and activator, the use of copper sulfate as the activator and the use of isoamyl xanthate as the collector. All of the above factors are essential to the effective recovery of zinc oxide. Flotation using mixed collectors (isoamyl xanthogenate + dithionphosphate) showed promising results. The ratio of the mixed collectors and the addition sequence of the mixed collectors were important in attaining a true mixed collector for zinc oxide flotation. In the closed circuit experiment, these agents helped to produce a zinc concentrate with 12.41% Zn, 80.03% recovery and 17.29% Zn in the tailings. The zinc concentrate with 12.41% Zn was used as a material for hydrometallurgy to collect zinc.

Abstract: The ore belongs to a kind of refractory gold ore cotaining arsenic and high-sulfur, contains high-sulfur and low-gold, and arsenopyrite is the main host mineral for Au. Because the floating gold fine with arsenic from sulfur floatation. lead to high content of arsenic in sulfur concentrate. This part of the gold loss in the sulfur concentrate. By optimizing the structure of floatation flow and using the new inhabitor LY100 for arsenic, the indexes of small-scale closed circuit test were obtained: the sulfur concentrate grading at 48.78% with a recovery of 44.76% and with As 0.47%, the arsenic concertrate grading at 15.95% with a recovery of 75.14%.

Abstract: Effects of ratios of feldspar to CaCl₂ to NaCl, roasting temperature ,roasting time and particle size on the melting-out rate of potassium from feldspar was studied by roasting. Results showed that the highest melting-out rate of potassium reached at 95.35% under the ratio of 1.8:1.1:0.6 of feldspar to CaCl₂ to NaCl, particle size 220mesh, roasting temperature 800°C, roasting time 1h.

Abstract: In this study, the regeneration behavior of modified semi-coke supported (Fe, Zn, Ce) sorbents were investigated using a fixed bed reactor. The effects of the regeneration temperature, space velocity and oxygen concentration have been considered in order to obtain suitable regeneration conditions. The most suitable regeneration conditions were obtained including 650°C regeneration temperature, 4vol.% of oxygen content and 4000h-1 of space velocity. Typical properties of the sorbents before and after regeneration were characterized using XRD and BET methods. Then the sorbents were tested 3 cycle experiments of desulfurization and regeneration for the purpose of duration test. The breakthrough curves changed slightly and the sulfur capacity only decreased 14.2%, it proved that the sorbents had good regenerability, which implied that the sorbents could be used for hot gas desulfurization.

Abstract: Gas outburst has been a major disaster in high gas mine. Flow law of gas in coal seam was studied, and gas drainage measures were proposed were extraordinarily useful for mine safety and rational use of gas. Finite element numerical method was applied to study changing law of gas pressure before and after the high-pressure water injection and damage deformation of coal under high-pressure water based on fluid-solid coupling and gas-solid coupling and damage theory. This research shows that: (1) a damage area was generated in coal seam under high-pressure water injection. Range of the damage area increase rapidly at the start of water injection and gradually slow down with the passage of time, eventually be more stable. (2) The permeability of rock mass of coal under high-pressure water injection. (3) High-pressure water injection had significant effect on gas drainage in a certain area. It provided a theoretical basis for selecting reasonable design programs to product gas by high-pressure water injection technology.

Abstract: In order to reduce the flow resistance of a water-based drilling fluid, emulsifiers tend to be added into the drilling fluid mixed with oil at the same time. However, inappropriate proportion or oil-based pipe free agent with low HLB value could easily trigger the phase inversion of the drilling fluid, causing its stability loss or even water–solid separation. Therefore, starting from the root cause of the phase inversion, the surfactivity of solid-phase materials in the drilling fluid was changed from hydrophobicity to hydrophilicity by adding surfactants with high HLB value. Then its colloidal properties were reestablished by combining alkali diluting agent, and the drilling fluid with phase inversion of well Lianhua 000-X2# was treated indoors. The results of the field application in the well show that high-HLB surfactant can solve the phase inversion of a water-based drilling fluid properly, and that barite sedimentation and well control problem, caused by the phase inversion of the water-based drilling fluid with high-density, can be avoided.

Abstract: Nitration-oxidation lignosulfonate (NOLS) was prepared using lignosulfonate (LS) as raw material. The product was characterized by Fourier Transform Infrared spectroscopy (FT-IR). The performance as a drilling fluid additive was evaluated with regard to rhology, filtration and temperature resistance. The results showed that NOLS can improve the viscosity under room temperature, decrease the viscosity under high temperature and reduce the filtration more effectively than that of lignosulfonate, which display its good temperature resistance. So NOLS may be used as sustained release nitrogen fertilizer in agriculture as it was abandoned after the drilling process.

Abstract: For the enormous potential of beam pumping unit’s energy saving, the frequency energy-saving control system of smart pumping unit with the function of self-learning has been developed on the basis of advanced technology and methods both in the domestic and abroad. The application of frequency converter not only has solved the impact problem at startup, but also improved the power factor significantly. For the solution to the shortage of oil wells, the system is to sample the parameters of Motor unit continuously under the conditions of relatively original and the conditions of normal working. The working liquid level as object to be controlled, the system is to adjust the liquid withdrawal rate to be sure the ability to match with the fluid through VVVF, and then a better energy-saving effect be obtained. The application of practical operation shows that the system can run efficiently and realize energy saving of the pumping.