Advanced Materials Research Vols. 156-157

Abstract: Silver-zinc slag, containing a lot of Bi, Ag, Cu, Zn, Pb and a little Au, has high comprehensive utilization value. This paper describes a preparation method of high-purity nanometer bismuth trioxide (Bi2O3) from silver-zinc slag by hydrometallurgical method. The results showed that Bi could be effectively leached out from silver-zinc slag using sodium chlorate, hydrochloric acid and sodium chloride as leaching agents, and the leaching rate of Bi was up to 99.03% under the optimum conditions. The contents of Pb2+ and Ag+ in BiCl3 solution could be reduced to about 1mg/L by using silver-zinc slag as reductant and sodium iodide (NaI) as precipitant, respectively. Crystalline form of Bi2O3 is affected greatly by concentration of NaOH, conversion temperature and time. The suitable temperature of BiOCl converting to Bi2O3 was 90 , and the suitable surfactant was polyvinyl alcohol. The average particle size of Bi2O3 obtained was about 86 nm, the purity of Bi2O3 was up to 99.75%, and the yield was 98.21%.

Abstract: Mineral polymer is a new category of inorganic non-mental materials, which was manufactured from fly ash in this paper. Changes of fly ash in the polymerization can be described as: (1) Q4(0Al) is the main form of Si element in fly ash, with 67.5%content.During the solidification of mineral polymer, the content of Q4(0Al) decrease from 38.7%(3d) to 28.2%(7d) and 26%(14d), then increased to 37.8% in 28 d product; (2) the intensity of Q2(0Al) and Q3(1Al) decrease at first stage, then increase finally during the solidification of mineral polymer; (3) content of Q4(2Al)increase from 14.6%(3d), 39.2%(7d), 40.6% (14d) and decreased to 23.1% in product curing for 28 d product;(4)octahedral aluminum were the main form of Al element in fly ash, which decreased during the polymerization, simultaneously, tetrahedral aluminum increased. The experimental results provided a good basis for understanding the reactive mechanism of polymerization.

Abstract: This experiment composes irreversible cells using ultrafine electrolyte materials and platinum slices, to measure the ionic conductivity the cells at normal temperatures with the help of impedance 1286 spectroscopy. We have calculated the ionic conductivities, which indicate that the ionic conductivities of the merchant LaF3 polycrystalline powder and the powder by microwave method are higher than the ones of LaF3 crystal and the powder by Sol-Gel method, to achieve 10-6 Scm-1, so, they are better ionic conductors at normal temperature and can be used as sensor base materials. The experimental data show that O- participates in ionic conduction.

Abstract: The tailings and slag based geopolymers was prepared by sodium silicate, sodium hydroxide alkali-activated tailings and slag. The compressive strength in 7 d under different raw material proportion were tested. The result indicated that tailings and slag based geopolymers has high compressive strength . As the tailings in slag is 80%, the compressive strength in 7d can reach 45.10 MPa . As the Na2SiO3 to NaOH ratio is 0.5, the compressive strength in 7d can reach 63.79 MPa. As the NaOH and sodium silicate concentration in the solution is 35%, the compressive strength in 7d can reach 38.35 MPa respectively; As the curing period is 14 d , the compressive strength can reach 71.25 MPa. As the steel scoria in solid is 20%, the compressive strength in 7d can reach 61.86 MPa respectively.

Abstract: This study proposes a framework design for eco-industrial park’s waste management system including functional orientation of the system and flow chart of the waste exchange in an EIP. The core function of the waste management system is waste exchange. Also, other functions of the park management are contained in the system such as technological exchange, product trading etc. A flow chart of the waste exchange has been designed in detail. Waste source account including six procedures is the key to achieve waste exchange. To identify the realness of reported data by computer system, we calculate materials balance and emission coefficient in this study. The whole waste exchange management by internet includes ten steps. After completion of the on-line processing, the wastes can be transported to the user.

Abstract: The kinetic equation of ball milling of quartz powder was deducted. by grinding quartz experiments in a intermittent ball mill. The results showed that: (1) Conventional first-order kinetic equation which describe the velocity of quartz grinding is not concordant with theory. Dynamics parameters are not constant, but time-related. (2) The kinetic equation of time correction can more clearly express their grinding speed. Fitted regression equation has a more accuracy prediction for the instantaneous concentration of particle size, and obtain the dynamics constants. (3) The grinding speed has a maximum value over time because of the particle size distribution and grading comminution. (4).The time index is not only related with the material nature and conditions of the grinding, but also with the particle size distribution. To predict accurately, the grade range should be narrow. (5). Different grinding time distribution of particles in the ball mill should be measured in the continuous grinding process. The comminution results can be predicted by the kinetic equation mentioned above.

Abstract: The high-temperature tube furnace was applied to simulate the rotary hearth furnace (RHF) for the direct reduction of the zinc-bearing dusts from steel plants. The soot generated in the direct reduction process was studied by chromatography, X-ray diffraction (XRD), .and scanning electron microscopy (SEM) etc. The results suggested that the main phases of the soot were ZnO, KCl, NaCl and Zn5(OH)8Cl2H2O. Furthermore, the contents of Zn reach to 64.2% which could be used as secondary resources for zinc making. It is concluded that KCl and NaCl resulted from the volatilization from the briquettes at the experimental temperature of 1573K, while the ZnO were produced by the oxidation of the Zn vapor reduced from briquettes.

Abstract: The iron tailings are the main source of solid waste of mining, as well as the potential resource. Regarding the characteristic and scale of iron tailings in China, this paper discusses the current situation and urgency of developing and utilizing of massive mining tailings, and the progresses of related researches on metal recovery, tailings processing and mutual utilization between tailings and mine-out stope. This paper also presents that using the tailing back-fill the mine-out stope currently is the best approach for massive resource utilization, based on sufficient metal elements recovery. This approach addresses the conflict of lands occupation due to the surface waste stacks, and gives the developing orientation of massive tailings resource utilization.

Abstract: The transient heat transfer characteristics of a regenerative oxidation bed placed in a coal mine methane thermal reverse-flow reactor during preheating process are numerically investigated in this paper. The regenerative oxidation bed is modeled in a three-dimensional, unsteady state and laminar flow system, and is assumed as a semitransparent porous media. The calculating results indicate that increasing the inlet mass flow could shorten the time of preheating, specific heat and porosity have a great influence on the heat storage capacity of the regenerative oxidation bed, and the contribution of the solid phase radiation to heat transfer can not be ignored. All these work can help to understand the heat transfer phenomena and mechanism in a regenerative oxidation bed during the preheating process.

Abstract: We have analyzed the types of combined window patterns’ basic figures, their variations, and their regular layouts’ characteristics of 2×2 module. According to the jacquard and printed fabrics’ characteristics of the forms in use and the means of achieving the patterns, combined with practical cases, we studied and explored how to expand the layouts’ characteristics of combined window patterns to textile’s artistic design.