Research Of Utilizing Coal Gangue In Shi Zuishan District To Produce Series Of Sulphoaluminate Cements

Coal gangue as one kind of solid waste which is about 10% to 25% of total coal exploitation every year was discharged by coal mining and coal washing. As a city of mineral industry and prospered with coal, Shizuishan has become the most important coal-electricity city in China within being developed coal exploitation and the related industry half more century. According to statistics, there was 5 million ton gangues piled on 600 hectares until the end of 2002. Dumped gangues do not only take lots of occupation of land but also pollute air and water. Treatment and utilizing of coal gangues is conducive to regional economic development and environment protection.According to the characteristics of mineralogy petrology and chemistry in Shizuishan gangue which belong to the high-aluminum type, it can be used to produce sulphoaluminate cement. The formula of clinker modulus and mineral composition of Belite-calcium sulphoaluminate, Belite-barium-bearing calcium sulphoaluminate, Blite-calcium sulphoaluminate and Blite-barium-bearing calcium sulphoaluminate has been determined.Groups of raw meal of sulphoaluminate cement prepared with coal gangue limestone gypsum and a bit of fluorite and barite have been designed depend on its mineral composition. By calcining grinding and adding admixture raw meal are made into cements. Compressive strength of Alite-barium-bearing calcium sulphoaluminate purified pulp is up to 45.6MPa in 3 days, which have the highest intensity in those sulphoaluminate cements.We also analyzed clinker mineral and its hydrate, discussed the effects of mineralization agent on the cement performance, analyzed the principle and process of the strength generated by the hydro mineral by X-ray diffraction and SEM. The study indicates that it is feasible to utilize Shizuishan coal gangues to produce sulphoaluminate cement. And it provides a new approach for the utilization of Shizuishan coal gangue, which is significant for achieving the resource environment economic co-development.