Advanced Materials Research Vols. 396-398

Abstract: Cyanide tailings have become one kind of the most hazardous solid waste. In order to recycle iron in the cyanide tailings, we present a technique using roasting- water leaching- magnetic separation. After analysis of the different parameters on recovery efficiency of iron, the optimum reaction parameters were proposed as the following: in reduction roasting process, weight ratios of cyanide tailings / activated carbon at 100:10, roasting at 750 °C; the liquid to solid ratio is 15:1 (ml /g), leaching at 60 °C for 5 min at water leaching. The grade of magnetic concentrate 53.8231％Fe and recovery rate of 76.5458％ were obtained. Mineralography of roasted product, water-leached sample were studied by X-ray powder diffraction technique (XRD).

Abstract: In a steel plant, fuel gas caloricity of ignition oven always changes rapidly and largely. Consequently, the temperature of ignition oven can’t keep steady. To overcome this problem we employ intelligent control of ignition oven based on PIDNN (Proportional-Integral-Derivative Neural Network). As we know, ignition oven is a nonlinear, large delay and slow time-varying process, so traditional PID control usually doesn’t work well. Artificial neural networks can perform adaptive control by learning, so we adopt Proportional-Integral-Derivative neural network to tackle the problem taking the advantages of both PID control and neural structure. In order to satisfy the restrictions of industrial instruments, we combine PIDNN control algorithm with expert system mechanism to fulfill the final intelligent control strategy. At a sintering plant in Hangzhou, we deploy the intelligent control strategy turning out a satisfactory result that the ignition oven temperature can be controlled steadily within a much smaller range with significant saving of labor costs and improving of energy efficiency.

Abstract: his paper describes the rules of change of reverse micelle phase separation under acid conditions. Using acetic acid, the reverse micelle system can be separated into an upper and lower phase. After separation with acid, the continuous phase is an organic solution and the polarity of upper phase is lower than that of lower layer. The separation formula is y=1.62+20.84e-x/5.31, where x is the W0 value of ^{Superscript text}the original micelle system, y is the concentration of acetic acid required to separate the reverse micelle system into two phases of equal volume and it can be used to check the formula. Applying this formula to calculate the concentration of acid required to affect separation, the protein of rat serum can be separated under acidic conditions by the reverse micelle extraction method. In this way serum protein of rat can be further separated.

Abstract: Coal vanadium ore from Hunan was pretreated by sulfuric acid for curing. Influences of curing time, curing temperature, sulphuric acid concentration and ore size fraction on vanadium leaching rate were investigated and discussed. Test results showed that: -100 mesh ore size was cured by 20% added quantity of sulphuric acid at 180°C for 24h and was leached by agitation with tap water, the liquid solid ratio of 4: 1 at room temperature for 12h, vanadium leaching rate was 74%

Abstract: Cu-11Ni-2W alloys have been prepared by vacuum non-consumable arc-melting and high-frequency induction melting injection moulding. The effects of melting processes on the resultant microstructure were studied. The results show that the grain of Cu-11Ni-2W alloy prepared by vacuum non-consumable arc-melting is coarse and the microstructure includes α solid solution and W particles. As for the sample prepared by high-frequency induction melting injection moulding, the grain is superfine and the microstructure is α solid solution. Moreover, the thermal conductivity coefficient for the sample prepared by vacuum non-consumable arc-melting is 67.2 W/(m•K), while that for high-frequency induction melting injection moulding is 47.8 W/(m•K). The melting point of Cu-11Ni-2W alloy prepared by vacuum non-consumable arc-melting is 1157.27°C.

Abstract: A composite adsorbent with upper-layer activated carbon (TY) and lower-layer hydrophobic silica gel (HSG) was developed, based on the comprehensive consideration of both adsorption capacity and adsorption heat of activated carbon and hydrophobic silica. For the composite adsorbent, various volumetric ratio of activated carbon to silica gel was designed, and the adsorption capacity and heat effect of the composite adsorbent with different ratio were investigated. The experimental results showed that the optimum ratio was 1:1. Thus, the vapor with high concentration was early adsorbed by the lower-layer hydrophobic silica gel, and then the residual vapor with low concentration was late adsorbed by the upper-layer activated carbon. In this way, incombustibility of silica gel and high adsorption capacity of activated carbon were fully utilized; accordingly the adsorption operation safety was improved and the adsorption capacity of activated carbon was increased owing to that the activated carbon was only used to adsorb the vapor with low concentration.

Abstract: With the deep mining in coal mine, heat damage is one of the technical issues need to be solved. HEMS cooling system in Sanhejian Coal Mine is a process system for high-temperature heat damage controlling in deep coal mine, in which cool energy extracted to reduce work face’s ambient temperature to achieve heat damage controlling. Part of the cool energy is from the level circulating of cooling water in -700 level main raodway, the other is from the mine water. We analyze the energy consumption of every subsystem during operation of the HEMS system, which could provide a theoretical basis and technical guidance on more efficiently running of cooling system deep in the future.

Abstract: Abstract: Based upon questionnaire and survey, available documents, random interview, logical analysis and mathematical statistics, livestock breeding pollution are researched at Shanghai Songjiang during the process of urbanization. In order to sure the health development of livestock and poultry in the future, the problem and research way in control of environmental pollution from stockbreeding were analysed, It is of vital importance for livestock husbandry to have a thorough understanding of such challenges and take corresponding countermeasures against livestock breeding pollution.

Abstract: By using the finite element method (FEM), the stress-strain curves of multiphase steels was simulated based on the stress-strain curves of single-phase ferrite, bainite, and martensite steels; then the measured result was compared with the simulated one. Effective factors such as the different distribution of microstructure, the volume fraction of hard phase and the yield stress ratio between single-phase hard phase steel with single-phase ferrite steel in multiphase steel are discussed in this work. The results show that the simulated result closely fits the measured one, which proves that this FEM built in this work is correct. The coarser the microstructure, the higher the drag effects of bulk structure, and the larger deformation degree of ferrite phase. With the increase of bainite and martensite volume fraction, the maximum stress rise gradually and the maximum strain decreases gradually. Meanwhile, the effects of volume fraction of hard phase on the stress-strain curve of multiphase steels are larger than that of yield stress ratio between single-phase hard phase steels and single phase ferrite steel.

Abstract: nickel and iron was recovered as ferronickel from sodium jarosite residue containing nickel, the processes include alkaline decomposing residue, hydrogen reducing precipitations produced in alkaline decomposition process and magnetic separating reduced precipitations. The effects of alkaline decomposition temperature, the concentration of NaOH solution and solid/liquid ratio on the process of alkaline decomposing residue were examined. Meanwhile, the influence of hydrogen reduction temperature on the reduced products was studied, too. The results shown the natrojarosite in residue can be near completely decomposed to form hydroxide precipitations in the process of alkaline decomposition. In the process of hydrogen reduction, the rise of reduction temperature can increase the percent reduction for both nickel and iron in reduced results. But it is easier to reduce nickel than to reduce iron at the range of 750°C-950°C. When hydrogen reduction temperature was 950 °C, the percent reduction for nickel and iron in hydrogen reduction process was 95.81% and 94.4%, respectively. XRD tests indicated, except for ferronickel, there were still some impurities such as barium sulfate and barium oxide in reduced product. SEM test indicated the particles of precipitations will become fused together during hydrogen reduction process, so it is difficult to magnetic separate ferronickel purely from reduced results. The content of nickel and iron in magnetic separating product was only 11.64% and 62.40%.