Properties Of Coal Gangue Research Articles

Effect of Concentration and Suspension Agent (HPMC) on Properties of Coal Gangue and Fly Ash Cemented Filling Material

Cemented coal gangue-fly ash backfill (CGFB) mixtures are utilized as the filling materials for backfilling the underground openings in coal mines. The freshly prepared CGFB slurries are commonly transported into the gobs through a pipeline. The mixture ratio of slurry concentration and suspending agent (HPMC) plays an essential role in transporting the slurry to goaf smoothly and efficiently. In this paper, the influence of slurry concentration and HPMC on the performance of coal gangue-fly ash cemented filling material was studied based on the response surface method. The prediction model of CGFB slurry slump flow, segregation rate, and bleeding rate was constructed. It is concluded that the segregation rate and slump flow of slurry are more sensitive to the variation of concentration. On the other hand, the bleeding rate of slurry is more sensitive to the change of HPMC content. Based on the established model, the reasonable mix proportion range of slurry concentration and suspending agent (HPMC) was obtained. In addition, three new CGFB mixtures have been tested, and the experimental results are in good agreement with the predicted values.

煤矸石利用现状综述

煤矸石是采煤过程和洗煤过程中产生的废弃物，目前已经成为我国产生量和排放量最大的工业固体废弃物之一。煤矸石的堆积造成了我国土地资源的极大浪费，严重的影响了生态环境。本文阐述了煤矸石的性质，总结了目前国内外对煤矸石综合利用情况。最后，分析了利用煤矸石过程中存在的问题，并对其发展提出建议。 Coal gangue is a waste generated in the process of coal mining and coal washing, and has become one of the solid wastes of China’s largest industrial generation and emissions. Gangue accumulation caused great waste of land resources and seriously affected the ecological environment. In this paper, the properties of coal gangue were briefly described, and the utilization status of coal gangue of the current domestic and foreign was summarized. In the end, the problems existed in the process of making use of gangue were analyzed, and some recommendations were put forward for these problems.

Effects of chemistry and mineral on structural evolution and chemical reactivity of coal gangue during calcination: towards efficient utilization

The utilization of coal gangue is usually subjected to calcination to achieve high chemical reactivity and exclude carbon. The correlation between the composition and properties of coal gangue during calcination is essential for its applications. In this paper, the effect of chemistry and minerals of coal gangues on the thermal behavior, structural evolution and chemical states of silicon and aluminum during the calcination process were systematically investigated. The results show that high alumina (AlH) containing coal gangue consists primarily of kaolinite, while in medium and low alumina containing (AlM and AlL) groups, the major mineral phases are quartz, kaolinite, illite with minor impurities. The chemical reactivity of coal gangue mainly contributes to the transformation of kaolinite to metakaolinite, while illite plays a minor role and quartz is inert. The combustion of carbon may promote the dehydroxylation of clay minerals and further affects the structure evolution of coal gangue. The optimal calcination temperature to exclude carbon and achieve high chemical reactivity is therefore suggested as 700 °C. Based on the findings the utilization of coal gangue is discussed in light of composition and structure.