Applied Mechanics and Materials Vols. 675-677

Abstract: Determination of lanthanum in the raffinate by spectrophotometry was studied, using tribromoarsenazo as chromogenic reagent. The addition of ascorbic acid can mask the interference of other metal cations in the solution. Under the conditions of ascorbic acid (10g·L^-1) 5 mL, hydrochloric acid 0.04 mol·L^-1 and tribromoarsenazo (0.5g·L^-1) 2 mL, Beer’s law is obeyed in the range of 0-10 μg·(25mL)^-1 for lanthanum, with correlation coefficient higher than 0.99. Beer’s law can be applicable for the wavelength range of 580-660 nm. There is no linear relation at too high or too low acidic environment.

Abstract: Water inrush is one of the main types of coal mine water disaster. Based on fluid-solid coupling theory, the confined water inrush numerical model is performed using FLAC3D program and similar simulation experiment, and the floor damage field and confined water vector field are simulated. The results show that, in the coupling action of mining stress and pressure of confined water, the mining floor was divided into four zones, namely the mining damage zone, effective confining protection zone, confined water soil-fluid coupling lifting zone, original confined water lifting zone. Confined water-conductive zone with the periodic roof pressure fluctuate, at each pressure and flowing zone height reaches the maximum, rise with height remained unchanged, the distribution shape of a "wave", water inrush is the results of effective connectivity of mining damage zone and Confined water-conductive zone, plate thickness of water-resisting layer exists or not, waterproof performance and the pressure of confined water inrush size is the key

Abstract: By analysis the form of gas percolation in coalfield fire, the follow conclusion is obtained : under the influence of natural wind pressure and fire pressure, natural ventilation system of coalfield outcrop is formed automatically during coal spontaneous combustion, which exists in two forms, one is the fresh airflow percolation in caving zone and its pore, the other is coal combustion gases migration movements in cracks after sliding. The fluent numerical simulations show that natural ventilation system in coalfield outcrop fire district is a vacuum ventilation system; From inlet to combustion area air intake line, air pressure and gas percolation on linear relationship, and gas percolation meets Darcy law in the porous medium percolation theory.

Abstract: Roadway occupies an important position in construction and production of a coal mine. The urgent requirement of evaluation on performance of roadway rapid excavation is emerging with development of various excavation techniques. However, shortages of current definitions and evaluation systems of rapid excavation cause to lack of effective tools in performance comparison between the techniques. The paper presents an excavation quality evaluation system based on the multiple attribute decision making theory, and gives a definition of rapid excavation. The practices show that the system is able to evaluate quality of roadway excavation technology, help companies select the most appropriate excavation method, and promote development of excavation techniques.

Abstract: The tailing in a large lead-zinc-iron-sulfur multi-metallic mine has rich reservation in variety of metallic minerals. It has been difficult to recover because of all kinds of reasons. The challenges faced by lead-zinc ore beneficiation are, low grade and recovery of lead and zinc concentrate for fine disseminated grain size, high oxidation rate and close intergrowth. This paper presents a Pulp Potential Control Flotation by stages technique to improve the flotation performance of the lead-zinc ores. In the electrochemical potential controlling flotation processing, using DDTC as collector, the separation potential range of galena and sphalerite with pyrrhotite can be achieved. Flotation circuit of lead-zinc-silver tailing ore was achieved.

Abstract: under the strategy of invigorating western provinces and autonomous regions with industrialization impetus, nonferrous metallurgy industry scale in Gansu expands unceasingly; Technology and equipment improve constantly;Industry integration trend becomes obvious. From the view of industrial competitiveness, non-ferrous metallurgy industry and mineral resources in Gansu has a comparative advantage in the country, the comprehensive advantages of leading enterprises is obvious, but there are also some problems,such as product structure contradiction, low resources and energy utilization rate,the hign pressure of energy conservation and emissions reduction. Then author put forward non-ferrous metallurgy industry development strategy: to extend the industry chain, optimize the product structure; to increase investment in research and development, to increase innovation capacity ; to adjust the organization structure,to realize the production of industrial cluster; to promote cleaner production, to realize circulation economy and so on.

Abstract: In this study, the leaching effect of copper oxide ore was investigated using ammonium chloride solution as leaching agent. The effects of temperature, concentration of ammonium chloride, average particle size and stirring speed on the leaching of copper oxide ore were investigated. The leaching rate increased with increasing solution temperature, concentration, and stirring speed as well as with decreasing average particle size. Ammonium chloride solution can therefore be used as an effective leaching agent for copper extraction from copper oxide ore.

Abstract: Developing blast furnace model is benefit to understand, control and improve blast furnace iron making process. Multi-fluid blast furnace model was established on computational fluid dynamics, reaction kinetics, transport phenomena and other theories. In the model, complicated motion and heat transfer between phases of gas, liquid and solid were considered and numerous reactions in blast furnace were simplified. Because there were so many equations in the model and there were strong coupling relationships between phases, parallel computing technology using computer group was adopted to solve the model to accelerate convergence velocity of iteration. The model can provide versatile information, it is a useful tool to simulate blast furnace operation.

Abstract: Author thinks that the three factors’ state of person, things, environment is decided by safety input, their different state meeting determined safe production. It can reduce accident by reducing three factors’ occurrence probability and changing safety investment object and quantity. According to the rule, the paper construct coal mine safety system dynamics causality diagram by using system dynamics theory from safety management angle, and made data quantitative analysis by non-linear regression, found out the function relationship that can reflect system elements dynamic change. At last, took one coal mine as an example, it made macroscopic analysis using the model.

Abstract: Thick coal seam BK block the distribution appears below 2500 meters long, loose and mixed carbonaceous mudstone. Release a new borehole pressure after the drill will cause collapse block falling, finally form an approximate elliptical hole, such as malignant accidents caused by its drill, bit freezing trip even well abandonment. Through three times of immersion test evaluation of the anti collapse ability of NH-1 core, NH-1 drilling fluid system has been optimized. Results show that, the drilling fluid has strong inhibition and anti pollution. The plastic viscosity is 24 mPa·s, the shear stress of 11Pa and the permeability recovery value reached (81.9-89.6)%. The success of the test card 21 Ping 1 well shows that the system of NH-1 drilling fluid has strong inhibition can effectively solve the Jurassic coal and carbonaceous shale collapse, the current high lubricating performance, can effectively improve the drilling speed, at the same time, its performance for reservoir protection, control the rheological properties of drilling fluid, improve the anti pollution and reduce the occurrence of downhole complicated conditions. Therefore, it can be in the sloughing formation for drilling operation reference for future.