Applied Mechanics and Materials Vols. 295-298

Abstract: This article based on Real measurement data of mine, then use Probability integration and Numerical Simulation that most commonly used methods in movement and deformation prediction to compute. By comparing the final sinking graph of the two methods and the actual data, to achieve the applicability and accuracy of two ways. The research have certain reference significance and revelatory effect on the selection of different methods of the surface subsidence prediction.

Abstract: This paper discussed the probability and variability risk of water inrush from No.9 coal seam floor during mining under high pressure. The grey-risk model is used to calculate and evaluate the risk base on the statistical data about water levels of existing bursting points, maximum water yield and specific capacity discharge. It is concluded that the risk is very great to mine the lower group coal seam under the high pressure in Guoerzhuang mine.The author proposes that the measures, including mining by areas and mining-detecting, should be taken in advance to reduce emergency.

Abstract: According to situation of coal mine methane drainage and utilization, the five experienced development stages of coal mine methane drainage technology was summarized, the reasons of low rate of coal mine methane drainage were analyzed. Coal-seam methane utilization was analyzed from methane purification, methane generating electricity, chemical production, methane for civil utilization and utilization as automobile fuel etc. With the coal seam methane drainage quantity is more and more, the emissions requirements is more and more strict, so the emission reduction and effective utilization of this energy is important to accelerate efficient utilization of coal methane, reduce greenhouse gas emissions, protect environment, alleviate the supply contradiction of energy and realize sustainable development of coal mine etc.

Abstract: The run of mine ore grade of Gan Shang Yan is 47.83%, iron ore grade is higher, but harmful element sulfur and impurity silica content is relatively high. This experiment using a simple process low intensity magnetic separation-high gradient magnetic separation, for the ultimate index for comprehensive grade of iron concentrate is 58.41%, at a total recovery of 80.85%, and obtain good experiment index, the harmful elements and impurity content can meet the standard.

Abstract: The test ore is a kind of relatively high grade of sulphide copper-lead ore, the difficulties of test is the effective separation of copper and lead, the lead grade of 13.08% and copper grade of 1.33% in comprehensive core sample. After the exploring test of principle flow sheet, the flotation process of depress lead and float copper is used. As a result, the grade of copper is 25.25% and lead is 6.23% in the copper concentrate, the grade of lead is 51.23% and copper is 2.44% in lead concentrate. The test research has certain guiding significance about copper and lead separation on production.

Abstract: The copper mine is the sulfide-oxidized copper ore. The grade of copper is 0.5%, with the oxidation of 22%. According to the properties of the ore; a systematic study was did for the ore, include collectors, activators and grinding fineness. Under the optimized conditions, copper concentrates grade of Cu 16.56% with a recovery of 85.62% was obtained through the locked cycle flotation of twice roughing, four times cleaning, once scavenging and middling return in order.

Abstract: Talcum is a common gangue with which sulphide ores are associated, it has an adverse impact on sulphide ores flotation and product index due to its high natural floatability. In this paper it takes talcum-bearing copper sulphide ores from DongChuan in Yunnan province as experimental samples, and a series of tests on depressing talcum in the copper suphide ore flotation were carried out. Results show that when took the composed CMC and sodium hexametaphosphate as depressant with respective dosage 200g/t and 300g/t, it obtained a favourableeffect. In addition, depression effect can get improved with the dosage of collector increasing properly, it shows that when took the composed CMC and sodium hexametaphosphate as depressant, it can make the flotation process stable.It employed rougher-scavenger-three cleaners system as the closed-circuit flowsheet, and attained a Cu concentrate product of whom grade and recovery is 16.16%, 78.78% respectively.The results might contribute to dispose some similar talcum-bearing sulphide ores in the future.

Abstract: The grinding process has been one of the most important part for mineral processing,combined with the basic principle of selective grinding and grinding medium application,a low grade phosphorite in Yunnan province which was grinded by the precise size and ratio of iron segments, and with the same specifications compared with low chrome steel balls under the same condition.The obtained results shown that iron segments could get a fine grinding with level(+0.10mm) 1.89 percentage points lower, pulverization level(-0.01mm) 0.07 percentage points lower,intermediate easy level(0.074～0.038mm) 9.29 percentage points higher,which further explains the iron segments has a better selective grinding effect,and could be used as a kind of ore fine grinding medium.

Abstract: The multi-scale features are the foundation of the inner laws existing in the multi-phase flow process. Computational fluid dynamics (CFD) method was used to study the inhomogeneous distribution and multi-scale features of the solid particles in DTB crystallizer. Suspension and flow field distributions of the particles under different stirring speed and different particle diameter were observed. The result showed: the higher the stirring speed, the smaller the particle diameter and the more homogeneous the suspension distribution. The inhomogeneous distribution of the particles in the crystallizer was mainly caused by vortex. The particle concentration was much lowers in the vortex center, meanwhile, the higher the stirring speed, the more the particles and vortex number, the vortex strength getting greater as well.

Abstract: The multi-scale method was applied to solve the multi-phase multi-scale problem in the industrial crystallization process. The fluid dynamics model was considering under the grid scale, and the population balance model was considering under subsystem scale. The macro model was used to interact with the environment. The crystallization process of potassium chloride was simulated by CFD and MATLAB. The result of the simulation shows the distribution of the supersaturation is strongly affected by the distribution of the suspended crystal volume fraction.