The Activation Study Of Unburned Coal Gangue By Microwave Radiation In Yunnan

Coal-gangue is the antiquated rock discharged in coal exploitation and processing. As China being the largest producing and consuming country, coal-gangue has become one of the biggest solid industrial wastes. Compared to studies of other solid wastes in our country, the research of coal-gangue is rather weak, and also the investigate of activating its potential activities is the conventional calcinations'activation.The condition of making use of the coal-gangue as a supplementary cementation material and the inadequacy of the conventional calcinations'activation is discussed and analyzed in the paper. Through analyzing and researching the basic theory of microwave heating, the paper has made using microwave radiation to activation of Yunnan unburned coal-gangue as a supplementary cementation material added to the cement.By breaking the Si-0 and Al-0 of SiO2 and Al2O3 in coal-gangue, forming activity SiO2 and Al2O3, the principle of microwave radiation and the conventional cementation is the same after reading relevant infermation.The phase composition and microstructure about coal-gangue is changed significantly. Thus the activity of coal-gangue is enhanced. Herein, this paper uses the coal-gangue of Laibing Coal in Xuanwei of Yunnan as example. Through the entire analysis and X-ray diffraction analysis, the main composition of rude ore is kaolin. After activating, it can be used as supplementary cementation material added to the cement. The paper focus on the use of microwave radiation technology to activation coal-gangue, with the conventional calcinations'activation is reference. According to the front analysis, on the base of the basic theory of microwave technique, the experiment adds a certain amount of the material which is easy to absorb microwave powder mixed with coal-gangue. Using strong absorption of microwave material absorbs microwave warming rapidly, through the ways of contact transmission of heat and microwave energy input, the weak microwave absorption material's temperature increased quickly, to achieve the purpose of activation of coal-gangue. By joining sawing wood, coal, MnO2, coke, water and adjusting the ratio between coal-gangue and blending material, with 2450Hz, 1.0kW microwave generator, the best combination is coal-gangue:coke= 4:1, adding more water (after mixing the mixture looks thick), irradiating 16min under microwave. With 2450Hz,3.5kW microwave generator, the best combination is coal-gangue:coke= 4:1, without water, irradiating 12min under microwave.Using activated coal-gangue added to ordinary Portland cement by the quality of 40%,50%,60%, CaO by the quality of 5%, surveyed and evaluated the performance of the coal-gangue cement which the content of activated coal-gangue is 50%, arrived at the initial setting time of mixed cement is 202min, final setting time is 383min, also there was micro-expanse, the volume expansion rate was 8.61%. The mixed cement's stability was qualified measured by way of test cake. The test had surveyed and evaluated the intensity of the mixed cement with GB/T17671-1999 "cement mortar strength test method (ISO method), the conclusion is microwave radiation can activate coal-gangue indeed. By analyzing the economic about the microwave radiation technology, it is a most important significance that a new suggestion presented in the paper is a reference material on how to propose the coal-gangue by an environmental protection method.