Advanced Materials Research Vols. 201-203

Abstract: A microwave carbonthermal nitridation method under the condition of nitrogen at atmospheric pressure was used to the synthesis of vanadium nitride from vanadium pentoxide and carbon black. In the present work, the effects of synthesis temperature, flowing rate of nitrogen, heating rate and soaking time on the apparent density and the nitrogen content of the microwave sintered samples were studied. The experimental data indicated that the apparent density and the nitrogen content of the microwave sinter sample was 4.1 g/cm³ and 13.8 %, respectively under the optimum conditions of flowing rate of nitrogen 50 L/h, heating rate of 6 °C/min to 1400 °C and soaking time of 50 min. The denser pellet was preferred to generated in the centre of the samples of which was beneficial to the expulsion of stoma and the diffusion of nitrogen due to the opposite temperature gradient compared with traditional heating.

Abstract: The mathematical model of burden movement for bell-less top of BF is described in detail, and the model of burden movement on rotating chute is improved combined with collision of burden to chute and effect of coriolis force. The influence degree of charging parameters on coke main striking position and stock flow width is investigated though establishing burden model. The research shows that: The changing of coke main striking point position is obvious under increasing decline angle of chute and length of chute, and for the stock flow width, the effects of decline angle of chute and depth of stock line are most important.

Abstract: The circumferential distribution characteristics of airflow in bustle pipe and each tuyere have been simulated and researched through establishing mathematical model of blast furnace (BF) hot blast systems. The disputes on the circumferential distribution characteristics of airflow in bustle pipe at home and abroad were settled. The results show that, under the premise of uniform pressure distribution in hearth and tuyere section area, except that of the nearest ones, the velocity of airflow in these tuyeres which are near to the main pipe is lower than those far away from the main pipe because of the existence of vortex. However, both the fluctuation range of all tuyeres’ air velocity and its influence on tuyere raceway depth are small and can be ignored.

Abstract: Micro–sintering equipment was applied to simulate sintering process of iron ore. FeO content of sinter-samples under different fuel structures was measured, and then the effect of fuel structure on fluidity of liquid phase and strength of bonding phase were analyzed in this paper. The proper fuel structure was finally discussed under low FeO sintering condition. The results show that: when anthracite was adopted as partial substitution of coke breeze as part of solid fuel, FeO of sinter reduces and self-strength of bonding phase increases. Although fluidity of liquid phase reduces, the fluidity index it is still above 0.8, which can meet the liquid volume needed for sintering. When CDQ powder is used as part of solid fuel, FeO of sinter also reduces, but fluidity of liquid phase and self-strength of bonding phase reduce a little due to its low combustibility. Taking experimental results and practical production together into account, it can be concluded that proper fuel structure that meets low FeO sintering should be “70% coke+30% anthracite”.

Abstract: The shape feature of tuyere raceway possesses an important effect on hearth state and BF operation. With analyzing channel for permeating gas and liquid in the hearth section in the position of tuyere raceway, it can be seen that the channel amount is mainly determined by section of raceway and section between the raceways. On the basic of theoretical and statistical analysis on practical production data, the new evaluation index of indicating tuyere raceway shape feature was proposed. In the condition of high blast volume, the new index AITR tended to increase and BF production was improved gradually as blast volume increases. The good evaluation character of this new index AITR has been validated with practical production data in this work.

Abstract: This study was concerned with the effects of mechanical activation (MA) on structural characterization for neutral leach residue of zinc calcine (NLR) and kinetics of indium extraction from NLR in sulphuric acid. The X-ray diffraction (XRD) analysis showed that MA caused the decrease in crystalline phase and increase in lattice distortion. The activation time, reaction temperature and H₂SO₄ concentration had positive effect on indium extraction from NLR. The activation energies of the unactivated, milled for 30 and 60 min NLR samples calculated for indium extraction were 39.3, 32.1, and 30.4 kJ/mol, respectively, which indicated that MA increased the leaching kinetics of indium extraction from NLR. The empirical orders of the unactivated, activated for 30 and 60 min samples for extracting indium with respect to H₂SO₄ concentration were 0.52, 0.51, and 0.51, respectively.

Abstract: The microwave magnetic roasting process of low-grade hematite under low temperature was studied experimentally. The effects of roasting temperature, carbon content and roasting time on the reduction and magnetic separation were investigated. It shows that the best percent reduction is 10.96％(near to theoretical value 11.11%)which can be obtained under the condition of roasting temperature of 650°С , carbon content of 1.0% and roasting time of 10 minute. The results of magnetic separation show that the best magnetic separation grade for the sintered ore occurs at 570 instead of 650°С owing to the sintering of ore powders at high temperature of 650°С . Further ball-milling and magnetic separation of this concentrate produces two kind of final concentrate, one of which is in grade 65.6% with the recovery being 45.3%, and the other is in grade 63.4% with the recovery being 62.6％. After the magnetic separation, concentrate ore meets the iron-smelting requirements because of its low S and P content and high grade. This magnetic process results in the enrichment of RE and Nb in tailing ore, which can be reused for the extraction of Rare Earth and Nb.

Abstract: Techniques are applied for the sorption of rhenium from the leaching solution of the fume of calcinating molybdenite concentrate by 201×7 strong base anion exchange resin. By analyzing the main ion from the leaching solution be pretreatmented, the 201×7 strong base anion exchange resin be used in experiment. The influencing factors on the sorption were investigated, with medium pH, the existing form of the ion in the solution and the pH are greatly related to the ion exchange capacity , the result show that the resin not only have higher adsorption rate of ReO₄^-, but also have higher separation factor of ReO₄^- and MoO₄^2- when the leaching solution was pretreated pH at 9.0. The separation factor of ReO₄^- and MoO₄^2- reached to 980.5. 5%NH₄OH+9%NH₄Cl solution is a effective desorption reagent for molybdenum, the desorption rate is 96% and nitric acid solution is a effective desorption reagent for rhenium on the loaded resin after desorpted the MoO₄^2-,the desorption rate of ReO₄^- is 98%.

Abstract: For the selection of the double ellipsoid heat source parameters, the thermal cycle of different process was measured and compared with the simulation result. The experimental results were according to the actual conditions and the simulation results were obtained by finite element method. The sensitivity of heat source parameters was discussed. Pattern search method was used to obtain the most accurate parameters corresponding to the specific process. By summarizing all of the processes of experiment, the relationship between the experimental process parameters and the corresponding double ellipsoid heat source parameters was obtained. The artificial neural network algorithm was applied to predict the relationship between all possible process and the double ellipsoid heat source parameters. The verification experiment showed that the prediction model was accurate.

Abstract: This template explains and demonstrates how to prepare your camera-ready paper for In this paper, the pulse vibrating suction method (PVSM) for wall climbing robot is presented, which is based on the principle of vibrating suction method. To analyze this method in depth and evaluate its performance, a simplified mathematical model based on some assumptions is built, and a new experimental platform for single suction cup is developed as well. Experiments on single suction cups indicate that the experimental results match the mathematical model well with only small deviation, which is caused by some unknown factors. Then experiments are carried out on a vibrating suction module which was developed previously. With the PVSM, the suction module can stay on the wall stabely, which verifies the vadality of this vibrating method. Suction failures for the module are also analyzed with different control parameters.