Advanced Materials Research Vol. 1089

Abstract: The influence on polyester knitted fabrics’ dielectric constant of each fabric organization structure of knitted fabrics were discussed by a single factor test method, and made a good choice from various polyester knitted fabric knitting parameters so as to the polyester knitted fabric was provided with the maximum real part and imaginary part of the dielectric constant. The results showed that when the structure of polyester knitted fabric was 2+2 rib, polyester knitted fabric had a good microwave absorbing property in these knitting parameters.

Abstract: In this paper, the comprehensive property of shielding fabrics was analyzed by the mathematic method-grey cluster analysis. Eight samples of shielding fabrics were selected as research objects in the experiment. The electromagnetic shielding effectiveness in different frequencies and wearing comfort, including tensile and bending property, abrasive resistance, permeability and color fastness were measured and then analyzed. Grey cluster analysis was carried out to evaluate the comprehensive property of the chosen samples by eight clustering objects and nine clustering indexes. In the process of data operation, MATLAB7.0 was used to calculate experimental results due to its high efficiency and accuracy. According to cluster analysis results, the eight samples were divided into three gray classes, namely, 2#, 5# belonging to “first-rate”, 4# and 7# belonging to “medium” and 1#, 3#, 6#,8# belonging to “low-rate”.

Abstract: The character of one refractory gold copper mine located in the west of the Sichuan province is so complex, that the valuable element of the ore cannot be recovered by the traditional beneficiation processing. In this paper, a series of tests were conducted to optimize the suitable collector and develop a new beneficiation processing to recover the valuable associated minerals as while as the copper minerals. The results of the tests showed that the bulk-concentrate with 14.73% of Cu grade, 40.59×10^-6 of Au grade and 2360.00×10^-6 of Ag grade can be obtained from the recommended bulk flotation processing. The recommended processing showed in this paper could greatly improve the copper mineral recovery and reduce emissions of copper tailings, which is very important for the copper beneficiation technology development and the protection of the environment.

Abstract: According to the properties of a medium-and-low grade collophanite, a contrast testing study was conducted on the basis of three kinds of flotation process. The result suggests that it is difficult to obtain high-quality phosphate concentrate from removing carbonate minerals only by the use of reverse flotation process. In contrast, with the use of direct-reverse flotation process and double reverse flotation process, the separation of phosphorus minerals and gangue minerals in the ore can be realized effectively, as the result, the P₂O₅ grades of phosphorus concentrate are 32.29% and 31.26%, respectively. Considering the above factors, we recommend direct-reverse flotation process as the method to deal with the medium-and-low grade refractory collophanite.

Abstract: Cr/NbCr₂ alloy containing with 91at.%Cr and 9at.% Nb was prepared by mechanical alloying and hot pressing .Then it was annealing at 1200°C for10h, 30h,50h,100h ,respectively in vacuum condition. The results show that the relative density of Cr/NbCr₂ alloy increases slightly with the annealing time. Meanwhile, Vickers hardness of Cr/NbCr₂ alloy decreases with the annealing time. After annealing at 1200 °C for 100 h, the relative density and Vickers hardness of Cr/NbCr₂ alloy vary from 98.9% to 99.7% and 5.6 GPa to 3.78 GPa, respectively. Due to the good plasticity of chromium solid solution, obvious plastic deformation appears during room temperature compression tests. After annealing at 1200°C for 10h, the compression properties of Cr/NbCr₂ alloy, such as compressive strength, yield strength and strain, get the maximum value.

Abstract: The condition tests on the metallic roasting process and the magnetic separation process for the Exi oolitic hematite, are discussed. The results demonstrate that the oolitic hematite is roasted best with excess coal as reductant at the temperature of 1050°C for 3 hours, and a iron concentrate with the grade of 94%, the metallization rate of 95% and the recovery of 88% is obtained through permanent magnet roughing of coarse grains and magnetic media desliming after grinding.

Abstract: Cu - SiC composite powders were discussed in this paper the microstructure after ball mill, through to the ball mill after Cu-SiC composite powder particle size and lattice constant analysis, confirmed the high-energy ball mill to Cu-SiC micro structure of the binary alloy. The experimental results show that the ball mill after 20 h, Cu particle size has a larger extent reduce after high-energy ball mill and SiC lattice constant increase.

Abstract: The study on potential-controlled flotation test of differential flotation process was carried out in the light of the change of a certain ore properties. The test used self-developed EMZ-91, as well as conventional collectors of ethyl thio carbamate and butyl xanthate for the flotation of copper, lead and zinc ores respectively, in which the copper sulfate was used as the activator of zinc mineral. The new differential flotation process, which is using lime to regulate pulp potential, produced the copper concentrate grading 27.18% copper at 73.37% recovery, the lead concentrate grading 66.00% lead at 63.00% recovery, and the zinc concentrate grading 55.27% zinc at 87.69% recovery.

Abstract: The environment of fresh water has been changed greatly because of eutrophication, which made the corrosion behaviors of metals in this water become more and more complex. Presently, the study on the corrosion behaviors and mechanism of metals in eutrophic fresh water was very rare; therefore, we considered the research on this field was a very meaningful work. In this paper, the corrosion behaviors of carbon steel in eutrophic fresh water were studied by electrochemical methods, the influence of temperature, value of pH and dissolving oxygen content on the electrochemical corrosion behavior of carbon steel were investigated mostly.

Abstract: In order to replace traditional gas nitriding with vacuum ion nitriding process, the 38CrMoAIA cylinder is used for the experimental research. Based on the 10 groups of cylinder specimen analysis of experimental results, surface hardness, hardness gradient, brittleness levels, nitriding depth and size change all meet the requirements of the technology of the cylinder liner. Aiming at the important link in the experiment, some problems needing attention in the process of nitride are put forward. Vacuum ion nitriding due to mature technology, good effect of nitride can be applied to mass production.