Characters Of High Amount Comprehensive Utilization In The Cement Production Process Based On Coal Gangue Of Wanbei Areas

In mining coal, gangue refers discharged carbonaceous rocks.So far,China’s gangue has accumulated 4.5 billion tons, accounting for about 25% of the country’s industrial waste, and the rate of 3 to 4 million tons per year. Only the content of coal gangue in Huainan and Huaibei areas is 1 billion tons, about 40% of the total area of the solid waste in Anhui province. Gangue long-term storage, occupation of land, air and groundwater pollution, environmental pollution resulting in three-dimensional, and the spontaneous combustion of coal gangue, debris flow, seriously endanger people’s lives and property safety.Therefore,coal gangue comprehensive utilization of resources to strengthen the delay.This paper conducts the experimental study on the comprehensive utilization of coal gangue cementitious materials in construction in Wanbei areas. Discussing coal gangue mineral composition,chemical composition, morphology, etc by fluorescence analysis,X-ray diffraction analysis,scanning electron microscopy, nuclear magnetic resonance analysis;utilization of mechanical activation, thermal activation and chemical activation on gangue stimulate activity;comprehensive consideration the impact of the calcination temperature, holding time, particle size on the activity of coal gangue orthogonal test is designed;the activation verification coal gangue mixed with cement in the activity;preparation of low clinker portland cement with activated coal gangue instead of cement clinker;found an influence on cement clinker-gypsum system through altering the content of activated coal gangue, gypsum, slag, lime;to find optimization proportion of the preparation to meet the physical and mechanical properties of low clinker Portland cement;comparing the undisturbed coal, activated coal gangue, coal cinder mixed with cement clinker- gypsum system against the influence of the compressive strength.Studies have shown that its main chemical composition is silicon oxide and aluminum oxide, the main mineral composition is kaolinite,belongs to clay rocky gangue. The optimum conditions of coal gangue is: the calcination temperature is 700℃, holding time is 1h, the particle size is less than 0.08 mm.The use of activated coal gangue formulated low clinker Portland cement to meet the complex requirements of standard Portland cement,and the late development of higher intensity.The use of activated coal gangue content of 30%, slag addition 10%, to prepare composite Portland cement, 3 days compressive strength of up to 13.2MPa, 28 days compressive strength of up to 40.7MPa;after the introduction of additives, early compressive strength increases,when the additive content is 0.7%, the activated coal gangue content is 30%, the slag content is 10%, to prepare composite Portland cement, 3 days compressive strength of up to 17.0MPa, 28 days compressive strength of up to 40.1MPa;can meet the complex requirements of Portland cement 32.5 mechanical properties.Preparation of cement activated coal gangue and cement cinder in the same content, which intensity was significantly higher than the former, indicating higher cinder activity.By scanning electron microscope, the flocculation of C-S-H gelatum and columnar crystal is more in the preparation of low clinker of Portland cement early hydration products. The latter with hydration of gelatum and more flocculent reaction were generated. Therefore, the cement cement performance is improved. In addition, the original coal gangue and calcined coal gangue NMR analysis shows that after 29 Si of coal gangue calcined at high temperature the NMR spectrum moves to the high field, kaolinite crystal structure is gradually destroyed, generating activity of metakaolin and the activity of silica and alumina.The topics to promote the progress of coal gangue, coal gangue provide a theoretical basis for the preparation composite Portland cement.