Advanced Materials Research Vols. 807-809

Abstract: The scandium concentrate used in the leaching experiment was obtained from the rare earth ore containing scandium in Yunnan Province, the sample used in experiment is leaching liquid containing scandium which the content of scandium is 3.6g/t, with complex impurity composition. The main influencing factors of extraction in hydrochloric acid solution were acidity, mixing time, phase ratio etc. and the condition experiments about these factors were conducted. The results show that extraction of scandium from the hydrochloric acid solution in TBP is feasible. The optimal conditions are that pH of the solution is 1.26, dosage of TBP is 5% of the solution, dosage of kerosene is 10% of TBP, mixing time is 3 min, phase ratio is 1:10, washing time is 2, the oscillating time of stripping is 1~2 min and the stripping rate reach 99.89%.

Abstract: Coal-rock mass in gobs is the porous medium mixed by the organic and inorganic. The motor process of the air flow obeys the rule of the unsteady-state flow, which is the substantial cause of the coal spontaneous combustion. The change law of the porous medium equation and the seepage coefficient was build. In addition, the discipline of the diffusion equation was obtained. It provides a reliable theoretical basis for coal spontaneous combustion prevention technology in gobs.

Abstract: Based on the Feng Huang Coalmine 1402^# coalface, applying the vertical three zones of overlying strata theory and O-ring theory, this paper discusses the migration paths of pressure-relieved gas in stope and the abundant gas region. By means of optimizing the roof crossing borehole method and high-position borehole in gob method, the gas drainage efficiency and extraction concentration have been improved, the gas emission arising from coalface has been reduced, and the gas accumulation phenomenon has been eliminated, which verifies the accuracy of this research and realizes the safe and efficient gas extraction goal as well.

Abstract: With a view to ventilation network resolution and current flow diffusion, modules of resolution and one-dimensional gas diffusion in the ventilation network under unsteady state are established. Furthermore, above modules are combined organically so as to simulate coal and gas outburst incident in a mine. Simulation result fits quite close to the spot, and can give a good explanation for related phenomenon of gas outburst, which provides technique methods for research on influences of coal and gas outburst to the ventilation network.

Abstract: Aiming at the multiple-stage coordinate mining problem for multiple mining areas with same coal, an optimization method based on genetic evolution is proposed. Firstly, a mathematical optimization model with the objective to maximize the total sale of synthetic coal is established. Then, the model is simplified to another mathematical optimization model with the objective to maximize price of synthetic coal of each stage because of the great difficulty to resolve the model. Thirdly, a genetic algorithm for coordinate mining of multiple mining areas is presented and designed to resolve the simplified model. Finally, the effectiveness of the proposed method is validated by case study.

Abstract: This paper mainly describes the relation between the overflow quantity, separation size, classification efficiency and Reynolds number under the stable stage of vibration lamella thickener. Using a device with one tilting-narrow flow classification element, experiments on classification of pure quartz slurry have been carried out.we can conclude that the overflow quantity is proportional to the separation and classification is best under the condition of turbulent flow.

Abstract: Based on Bernoulli law, a average flow meter for short duct is usually designed with a rectifying grille, a series of sectional distributed pressure points and a large pressure-averaging vessel. As rectification is one of the key characteristics of this method, the effect of grille on rectifying is numerically simulated. The predicted results show that the grille in the 800mm×500mm section is very effective on regulating the originally disordered flow in the wind box branch duct. The velocity distribution tends to be uniform when the arrayed pitch is decreased while the rectifying effect is not closely associated with the relative location of the grille. The grille thickness plays a determining role as the rectifying becomes gradually weakened when the thickness is over 200mm. When a 5×4 grille with a thickness of 200mm is mounted at 200mm from the main duct outlet horizontally in downstream duct of the main wind box, the averaged pressure of each subsection is in good linear relation with the average gas velocity in the branch duct. The linear relationship is well maintained when the static pressure is measured at specific position and the dynamic pressure point is installed with error of 4o. This indicates that the grille-type flow meter is very reliable on measuring average gas velocity in short ducts. The application of this method on a 200MW industrial boiler shows that it possess promising potentials on optimizing combustion and emission, which could bring admirable environmental, economic and social benefits.

Abstract: Based on the FLOEFD analysis and the indoor experiment tests, the characteristic of valve internal leakage under different transfer pressure have been studied. It is found that the oil which leaked from the center of the hole has the highest velocity and after leakage, the oil velocity first increased and then decreased. The leakage velocity peak value increased with the increase of the transfer pressure and decrease of leakage area. The mass flow of the oil leaked through the smallest hole is the smallest and it increased with the increase of the transfer pressure.

Abstract: It’s more difficult to remove dibenzothiophenic sulfur in diesel. Adsorption performance of self-made metal-organic framework on Cu-BTC, MCM-22, alumina and silica gel for 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene(4,6-DMDBT) in simulated diesel at room temperature were investigated. The results show, BET surface area of Cu-BTC is up to 1501m²/g. When the initial concentration of sulfur in 4-MDBT is 46.80mg S/L, the static equilibrium adsorption capacity of Cu-BTC for 4-MDBT in simulated diesel is 2.40mg S/g_ads, which is about 20 times than that of other adsorbents. When the initial concentration of sulfur in 4,6-DMDBT is 48.47mg S/L, the equilibrium adsorption capacity of Cu-BTC for 4,6-DMDBT in simulated diesel is 2.04mg S/g_ads. The adsorption isotherms of Cu-BTC for 4-MDBT and 4,6-DMDBT indicate that when the equilibrium concentration of sulfur is 50mg S/L, the adsorption performance of Cu-BTC for 4-MDBT and 4,6-DMDBT following the order is 4-MDBT>4,6-DMDBT.

Abstract: Drag reduction with the nanomaterial is a new technique for EOR aiming at the problem of high injection pressure but shortage of injection rate in oilfield. The ShUNP2-10 is a nanomaterial which was prepared for this drag reduction technology. The structure and properties of nanomaterial ShUNP2-10 were characterized by transmission electron microscope (TEM), laser particle analyzer (LPA) and other methods. The microstructure and the wettability of the core surface before and after adsorbed by ShUNP2-10 were investigated. Drag reduction effects of the nanomaterial ShUNP2-10 in microchannels was studied by core displacement experiments (CDE) and field tests. The results show that the ShUNP2-10 is a spherical particle with 10~20nm in diameter, and particle surface have many hydrophilic groups and many hydrophobic groups, but the nanomaterial exhibits high hydrophobic. It was observed that many nanoparticles adsorbed firmly on core surface and formed nanoparticle layers with micro-and nanostructure. The nanolayers changed the core surface wettability from strong hydrophilicity to high hydrophobicity. The water phase permeability (WPP) of these cores displaced with the nanomaterial increased averagely more than 130.6% by CDE and a maximum injection pressure reduction of 12.5 MPa was achieved in-situ test. All these results indicate this nanomaterial ShUNP2-10 has significant drag reduction property and important practical value in Oilfield.