Advanced Materials Research Vol. 868

Abstract: Development of mining subsidence in the coal mining area is impacted by the geological occurrence conditions and mining design conditions. Therefore, taking the Yushenfu coal mining area in northern Shaanxi province as study area, the research analyzed the key geological and mining impact factors of the mining subsidence respectively with grey correlation analysis method and stepwise regression analysis method. The results show that the perturbation coefficient, synthetical protodyakonov coefficient of overburden rocks, width-depth ratio and the ratio of mining depth and height are selected as the key geological-mining factors impacting mining subsidence in YuShenFu coal mining area. It hopes that the research results can present the scientific guiding function for the prevention of mining subsidence in the future.

Abstract: According to the actual progress of a certain Surface Mine and based on strength reduction method, the deformation and fracture processes of the high dip bedded soft rock slope was simulated with RFPA-SRM, the stability of the slope was calculated. By analyzing the numerical simulation results, the characters of the deformation of high dip bedded soft rock slope and the landslide mode were demonstrated, which could provide a scientific basis for reasonable landslide control measures.

Abstract: Based on concepts and characteristics of sanzi, this paper clarified the logic relationship among sanzi, and it pointed out that mineral resources have both characteristics of nature and society, and that assets-lized control is caused by scarcity of resources; and this paper argued that old concept of mineral resources should be transformed, and the assets nature of resources-assets and associated social resources be admitted; it also argued that sanzi integration management should not be limited to resources management, but be broadened into mining industry management; it at last explained that mining enterprises should be the carrier of sanzi integration operation. Therefore, based on analytical framework created from basic theories of economics and management, the logic relationship among sanzi can be deduced and described as game relationship among government, enterprises, communities, and other interest related parties in mining industry.

Abstract: Through earliest experimental study to tailings of Yangla copper ore known that under the best conditions of the flotation process can be obtained a copper concentrate which copper grade of 1.43% and recovery was 29.71%. Due to copper minerals embedded in this materials at a very fine particle size, and closely symbiosis with iron content and quartz, lead to it difficult to enrichment through ore dressing methods. And copper minerals mainly exist in the form of sulfide copper mineral, it can not by leaching method for processing directly, thus put forward a process to deal with this materials of enriched concentrate conduct to sulfuric roasting-leaching, which on the premise of guaranteed cost is not high, ultimately achieve the goal of recycling all kinds of valuable elements. Through the test of low temperature sulphation roasting - leaching to the flotation of copper concentrate shows that under the conditions of temperature of 450 °C for copper concentrate roasting 135 minutes, and after the calcine cooling, then with concentration of 4% sulfuric acid and Liquid-solid ratio of 3:1 leaching of 80 minutes, ultimately available to the test targets of copper leaching rate of around 81%.

Abstract: The study aimed to explore appropriate flotation reagents to utilize lead minerals from complex and refractory lead oxide ores in Yunnan. 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 scavenging flotation and two concentrate flotation was adopted to perform the closed circuit flotation experiment. The optimum regulator of flotation experiment was determined as sodium silicate, sulfidizing agent as Na₂S and collector as isoamyl xanthogenate. Under such a condition of reagent types and their appropriate reagent dosages, a lead recovery of 76.55% with a concentrate grade of 58.67% was obtained, which effectively improved utilization of lead resource.

Abstract: The optimization condition of flotation reagents of complex and refractory lead oxide ores from Yunnan was studied in this paper. Based on the research on the properties of the material, the grinding fineness and reagent dosages were investigated and a technological flowsheet consisting of one roughing flotation, two scavenging flotation and two concentrate flotation was adopted. The optimum parameters of flotation experiment were determined as grinding fineness of 85%, dosage of sodium silicate at 800 g/t, dosage of Na₂S at 1200 g/t and dosage of isoamyl xanthate at 600 g/t. Under such a condition, a lead recovery of 76.55% with a concentrate grade of 58.67% was obtained, which effectively improved utilization of lead resource.

Abstract: The application of new chelating reagents on the flotation of copper minerals has been paid much attention in recent years. These collectors have successfully extracted the copper minerals from the low-grade refractory ores, and one of the most important collectors is the alkylhydroxamate-based chelating reagent which shows the excellent flotation performance to the copper oxide minerals. Furthermore, the mixture of various chelating reagents can recover the copper sulfides and oxides simultaneously from the complicated copper ores, which is attributed to the synergy among collectors. Thus we conclude that it is an important flotation method by using chelating collectors in conjunction with other traditional collectors, by which the synergy can break through the limitation of single reagent and enhance the flotation efficiency.

Abstract: One of the important directions of the research on coal washing is developing the non-toxic reagents with strong force and high selectivity. Compared with model strains, yeast designated Y21 as surface modifier for fine coal was isolated from lignite by traditional microorganism separation. Colony morphology, physiological and biochemical characteristics and some molecular sequence fragments show that the strain Y21 was Rhodotorula mucilaginosa. Through zeta-potential measurements and contact angle changes of coal samples caused by strain Y21, it was shown that strain Y21 can be selectively adhered onto the fine coal surface through the electrostatic interactions and the hydrophobic interactions. These observations lead to the conclusion that the adhesion of the yeast onto the coal surface could change zeta potential and the contact angle of coal particles. For both coal samples, the contact angle was sharply increased respectively in the pH range 3-4 and 2-4 as a result of Y21 strain adsorption. This indicates that as a result Y21 strain adsorption the coal surfaces have become more hydrophobic. These results indicated that the modified flotation and flocculation rate of fine coal particles were improved using the strain Y21 through changing the surface characteristics of coal.

Abstract: In this study, according to the characteristics of scheelite in run-of-mine, the scheelite was concentrated by adopting the full flotation process with sodium carbonate as regulator agent, sodium silicate as inhibitor for gangue minerals, lead nitrate as activator and ZL pharmacy as collector. 6.15% of the coarse scheelite concentration with tungsten recovery of 96.18% was obtained from the raw ores with grade of 0.86%. The concentration of rough tungsten by heating, by which the high-quality scheelite with tungsten of 62.31% and tungsten concentrate recovery of 93.53% was obtained.

Abstract: The influences of operating parameters (bed height, air flow rate, and separation time) on the separation effect for lump coal were experimentally studied. The results show that shallow bed takes less time to reach steady separation state comparing with the deep bed. Increasing separation time at low air flow rate and decreasing separation time at high air flow rate could improve the separation effect. Separation effect could get the optimal under the condensation of bed height at 90mm, air flow rate at 8m³/h and separation time at 60s.