Advanced Materials Research Vols. 807-809

Abstract: In recent years, the steel industry is in decline. To reduce environmental pollution, increase corporate profits and promote the sustainable development of China's steel industry, developing steel metallurgical slags comprehensive utilization has a very important significance. This article describe the present situation and problems in China's steel metallurgy slag comprehensive utilization, and reach the conclusion that the present method should be improved and the new method of comprehensive utilization should be further developed.

Abstract: One of the difficult issues in underground mining is the ground control of roadway subject to mining induced stresses. As a longwall face advances, the state of initial stresses dramatically changes. Accordingly, lateral abutment pressure forms on the pillar and frontal abutment pressure on the roof and lateral sides of the roadway. These pressures will lead to severe deformation and deterioration of the rock mass surrounding the entries. In this paper, a systemic study on this issue is proposed using the combination of numerical modeling and in-situ monitoring which was carried out at a coal mine in the Lu.An Group, China. The condition of stress redistribution caused by mining-induced stresses and the state of the surrounding rock mass of the roadway situated in front the work face are systematically investigated. Different patterns of support and reinforcement as well as their effects on the stability of the roadway are also presented.

Abstract: This paper use CFD software for geometric modeling and structural mesh for the Cone Hindered Settling Hydro-sizer and then apply the Fluent software for three-dimensional CFD simulation. Using RNG K-ε two-equation turbulence model and Swirl Dominated Flow model respectively, and the top speed of different feeding liquid two-phase flow of water under medium CFD numerical simulation results grader internal flow field characteristics.

Abstract: In order to study the influence of tunnel fire on the airflow stability in diagonal network of single diagonal network ventilation, according to the principle of similitude air supply system of 4101 working face of Huhewusu was taken for research object. In a proportion of 1:20, simulation device for angle connection roadway was established. By means of this simulation device and the method of experimental simulation, change law of the air volume and wind direction of diagonal branch in single diagonal network was studied. The results showed that in a particular period of mine fire, air volume decreased in fire roadway and windage increased; air volume in diagonal branch decreased and with the process of fire the wind direction would change. After the change of wind direction, with the changing of fire scale the reverse air volume would show the same changing process.

Abstract: The study aimed to explore appropriate flotation reagents to recover copper minerals from a high content of slime and refractory oxidized copper ores. Based on the research on the properties of the material, the reagent regime was investigated and a technological flowsheet consisting of one roughing flotation, two concentrate flotation, three scavenging flotation and one concentrate-scavenging flotation was adopted to perform the closed circuit floatation experiment. The optimum depressor of flotation experiment was determined as CHO, activator as (NH₄)₂SO₄ and collector as isoamyl xanthogenate. Under such a condition of reagent types and their appropriate reagent dosages, a copper recovery of 75.03% with a concentrate grade of 18.01% was obtained.

Abstract: The application of FLAC2D software long ditch coal mine extraction tunnel without support boltgrouting. Anchor when the anchor rope supporting and strengthening supporting state ofroadwaywere simulated and analyzed the change of roadway surrounding rock under differentsupport forms. Demonstrated the possibility that the current anchor cable anchor supporting andanalysis under the condition of the coal wall broken grouting bolt is the necessity of reinforcement.

Abstract: Flotation behavior on ammonia leaching residue of alkaline zinc oxide ore from Lanping has been studied in traditional flotation, and the performance of bulk flotation showed that residue has a better floatability than raw ore when they are in the same process and same conditions, an operation recovery of lead and zinc can reach to 49.34% and 57.03% respectively in 3minutes. The followed verification test showed that phase recovery of zinc sulfide reach up to 76.5 in rough concentrates that from bulk flotation, the dissolution and activation affect of ammonia leaching residue is evidently.

Abstract: The coal molecule model and the absorption model of coal and methane were established according to Van der Walls force. The coal molecule model and the absorption model of coal and methane were optimized and obtained absorption energy and equilibrium structure with the DFT method with 6-311G++ basic sets. The effects of coal molecule on the absorption position, absorption energy and absorption distance of CH₄ were presented by analyzing the Mulliken atomic charges of coal molecules.

Abstract: This paper analysis open-pit coal mine slope stability in the first mining with FLAC3D, reveal the mechanism of slope deformation, through analysis the stress and strain nephogram of model ZK8 of the first mining slope, and calculation safety stability coefficient, finally concluding stope slope of the first mining occur slip as circular form under their own gravity. The safety factor of model ZK8 is more than stope slope safety coefficient 1.20, slope is in steady state, obtained the accurate and reliable analysis results of stability.

Abstract: Shuangliu mine is located in the middle of Hedong coalfield, Lvliang City , Shanxi Province. It is one of the typical NorthChinaType coalfields. The upper strata of the lower-group coal seams (8#, 9# seam) have several thin-layer limestones of the Taiyuan Formation, and the underlying strata of the lower-group coal seams have thick Ordovician limestone. Water inrush accident has ever happened in other mine in its vicinity. Therefore, whether the lower-group coal seams could be mined safely is related to the medium-and long-term program and sustainable development of Shuangliu Mine. Based on experimental study of physical and mechanical properties of main rocks of the roof and floor of the under-group coal seams, and the application of "Up Three Zone" Theory of coal seam roof (the caving zone, water flowing fractured zone and bending sinking zone), "Down Three Zone" Theory of coal seam floor (mining damage zone, water-resisting zone, water-conductive zone) and Water inrush coefficient Theory, we analyzed the water inrush risk and divided potential dangerous subareas of water inrush from coal seam floor while mining lower-group coal seams. The research findings can provide scientific basis for mining design and safe mining of lower-group coal seams in Shuangliu Coal Mine.