Studies On The Recovery Of Coal Gangues In Fuxin District, Liaonin Province,China

As one of the coal mining wastes, coal gangue is the largest amount of emissivity in China mining districts. It is estimated that, by the end of 1996, there had existed more than 1,500 gangue hills, whose total stack capacity had amounted to over 30 billion tons and occupied 12,000-hectare land. Moreover, with the development of coal industry, the amount of gangues has increased at 130 million tons each year. Not only does the large amount of gangues take up much land including farmland, but also cause environmental pollution to different degrees. Strengthening the gangue's comprehensive utilization and research can convert wastes into useful materials, saving the limited mineral resources on the earth, protecting the environment against pollution and safeguarding the people's interests, bringing about matters of interest to the world. The contribution will benefit the people for all time.In the view of "applied mineral and petrology", the gangue can be considered as the product during human exploitation process of natural geological substances. It has dual nature: gangues are wastes emitted in the process of producing the coal on the one hand while they are nonmetallic mineral resources composed of rocks and minerals, which can be comprehensively utilized on the other. Due to their complex compositions and diversified utilization channels, the key to multipurpose use of the gangue resources lies in the correct assessment of their special resource property so that rational approach of using resources can be optimized, which is feasible technically as well as economically and become the real sense "resource". "Convert wastes into useful resources and we have an advantage in resources". We provide technique support for the districts whose resources are exhausted.As one of the earliest source of coal energy, Fuxin is a well-known "Coal-electricity City" in China, the establishment and development of which is dependent on the coal, and now is faced with economic diversions because the coal resources are exhausted. In 2001, it was delimited by the State Council as the only experimental city whose resources are exhausted. The present dissertation regard the vast amount of stacking gangues as a new mineral resource and conducts its investigation and assessment according to the property of the resource, and then put forward the way of prospecting, assessment and classification of the resource. ON the basis of systematic research and analyses of the resource characteristicsof Fuxin gangues, the dissertation takes advantage of mineralogical research method and finishes producing microcrystalline glass with Fuxin gangues and building a laboratory doing research on the high-quality cement of sulphoaluminate, which will provide a new technique for the use of Fuxin gangues.The main research points are as follows:(1) The outline of China gangues (including the distribution of gangues, the condition of its comprehensive utilization as well as the discussion about the classification of using gangue resources). The dissertation provides mineralogical and petrological basis for the dual nature of gangues, that is, they are wastes and on the other hand can convert into useful materials.(2) Studies on the resources property for gangues of Fuxin. It is found that there are 23 gangue hills taking up 42021-acre land. The dissertation has a discussion about the geological background of Fuxin mining districts and the geological property of gangues and coal fields, doing research on gangue resource assessment with remote sensing technique and on-the-spot geological investigation from the perspective of geological resources.(3) Mineralogical and petrological studies on Fuxin gangues. It involves the classification of gangues, petrological chemistry, trace elements, pernicious elements. The dissertation employs chemical analyses, X-ray diffraction, scanning electric microscope, differential heating analyses, infrared spectrum for the main gangue minerals and conclude that the gangues are mostly sandstones and less aluminous (Al2O₃15¹8%), which are difficult to use. The dissertation attempts to assess how to make use of the gangue resources.(4) According to Fuxin gangues' mineralogical and chemical properties, the dissertation has finished research on the new product of gangues and produced gangue microcrystalline glass and high-quality cement of gangue sulphoaluminate and done mineralogical research manually on the researched and produced materials.The innovate characters of the thesis are as follows:(1) The dissertation proposes that gangues have dual nature: they are wastes on the one hand and can be converted into useful materials on the other. Such mineralogical and petrological basis provides theoretical foundation for the use and assessment of gangue resources.(2) On the basis of comprehensive analyses and summarizing the characteristics of...