Advanced Materials Research Vols. 550-553

Abstract: The thermodynamic and thermo-elastic properties of ductile intermetallic compounds YAg with B2 structure are investigate with molecular dynamics. The thermodynamic properties at various temperatures, such as lattice parameter, cohesive energy, enthalpy of formation, heat capacity, vibrational entropy and vibrational free energy are computed. The present calculated results show good agreements with available experimental and previous calculated data. At high temperature, the heat capacity tends to a constant with obeys the classical equipartition law. At 300K, the heat capacity of YAg is 23.91 J mol-1 K-1. And those data enrich thermodynamic data-base for YAg. At the whole range 0-600K, the elastic constants follow a normal behavior with temperature that those decrease with increasing temperature, and satisfy the stability conditions for YAg compound. The Cauchy pressure and B/G for YAg increase with elevating temperature. Our results mean that increasing temperature may improve ductility of YAg.

Abstract: Nano-ZnO powders were prepared through gel-sol method with zinc acetate and lithium hydroxide as crude material. Nano-ZnO, as photo-catalyst, was used to decompose Methylene Blue at air lift circulating reactor and Photo-Layer model to describe photocatalytic kinetics. The results show that nano-ZnO has a integrate crystal and its size is 6.6nm with the best photocatalytic performance, when calcined at 350oC. The best ZnO dosage is 0.1g/L with 97% Methylene Blue removal after 30min. The photocatalytic process was the control step in chemical reaction. The •OH concentration inside the photo-layer in different reaction condition were calculated according to Photo-Layer model.

Abstract: This study is to discuss the reaction pathways of vanillin (3-methoxy-4-hydroxy-benzaldehyde) degradation by Gordonia sp.The product structure was analyzed by spectroscopic technique. Vanillin removal kinetics could be best described by a simple recalcitrant first order model:-dS/dt=k _s,1 X(S-S∞),k _s,1 is the vanillin removal rate constant.

Abstract: The mineral processing experimental research was carried out on a high mud content lean hematite. The results showed that using the technological flowsheet of “stage grinding- low intensity magnetic separation for obtaining concentrate - high-intensity magnetic separation for discarding tailings-gravity separation(shaking table)”,a final iron concentrate with TFe grade of 65.89% ,yield of 19.35% and iron recovery of 52.32% from the raw ores with TFe grade of 24.07％ was obtained, with the first stage grinding size being 50% -200 mesh and the second stage,95% -200 mesh.

Abstract: The gold ore is oxidized ores, and it is not suitable for flotation separation. The cyanide leaching is used for the recovery of gold. Experimental studies of cyanidation leaching for a oxidized gold ore were carried out. The factors that influence leaching such as grinding size, sodium cyanide quantity, pulp density, extraction time and segmentation leaching were conducted. And experiment pretreatment test with the copper ion which influences leaching. The results demonstrated that the good index of leaching rate 90.11% could be reach.

Abstract: Experiments were carried out to investigate the characteristic of kaolin on agglomeration mechanism of the black liquor combusted in a bench-scale fluidized bed. The combustion experiments were focused on the influence of different operating conditions at three temperatures (700°C, 750°C and 800°C), and at three kaolin additive dosages(0, 10% and 30%). Sinter of the bed material collected after experiments were analysed by scanning electron microscope (SEM) and X-ray diffractometry (XRD). The results show that kaolin is a significant additive in improving the black liquor combustion in a fluidized bed. With the kaolin dosage increases, the degree of agglomeration decreases.

Abstract: As a kind of raw material, phenol was sulfonated by sulfuric acid, polymerized by fomaldehyde, and grafted by epoxy chloropropane to get the epichlorohydrin modified sulfonated phenolic resin dispersant, which is used in coal water slurry (CWS). Studies on rheological behaviours of CWS with different concentrations and syneresis rates during 72h storing were carried out to analyze the interaction between the dispersants and the surfaces of Shenhua coal of Shaanxi in China. The results show that the CWS had a syneresis rate of 5.9% and an apparent viscosity of 725mPa.S at a shearing rate of 100S-1 when the mass fractions of coals and dispersants are 64% and 0.5% respectively. Epoxy chains of the dispersant combine with the hydrophobic groups on coal surfaces and sulfonic acid groups of the dispersant are hydrophilic. This dispersant increases the stabilities of CWS effectively through steric hindrance effect to keep the coal particles from gathering.

Abstract: With the development of heavy oil reservoirs, it faced a series of problems. Using the theory of thermal-hydrological-mechanical (THM) coupling, a predictive model of reservoir physical properties (RPP) after thermal recovery is established. Based on this model, the changing process of reservoir physical properties is simulated by the method of numerical simulation. The obtained results show that the sand production has a significant influence on RPP. By contrast with rock deformation, it has a smaller influence on RPP. The influence caused by the former is about 5~8 times than latter. During the period of steam injection, resulting from the movement of sand grain and expansion of reservoir, both porosity and permeability of reservoir are on the rise. Due to the sand production and reservoir compression, a reducing tendency is happened in the production period. The changes of RPP in reservoir are huge along the main streamline direction, and it might change because of the presence of high-permeability path.

Abstract: Based on the performance requirements of product in cold rolling, stability, saponification and pH value influence on quality of emulsion was analyzed. The quality indexes of emulsion were established in characteristic of lubricating and cooling system on cold tandem mills. The experiment studied ratio of rolling oil for cold rolling with formula calculating and experimental determination of application. After optimization of long-term effecting observed, it can ultimately determine the efficiency of emulsion with excellent ingredient and performance parameters. It would lay solid foundation for the production of high quality cold rolling strip.

Abstract: This study presents sulfide ores with lead 0.71%, Zinc5.07% from Laos, using a grinding (grinding fineness -0.075mm, 80%). Then, the lead ores is recovered by flotation first. Second, the middling ores is returned in preferential floatation. The mixed collector is used in all flotation such as ethyl xanthogenate , butyl xanthate and SN-9.After flotation, the grade of lead concentrate is 63.63%, and a recovery is 83.26% .In addition, the grade of zinc is 56.33%,a recovery is 86.63%. It can result in obvious increase in yields of mineral processing and economic better effect in production, compared to the old technology.