Experimental Study And Evaluation On Making Process Of Moulded Coal Based On Permeability Characteristics

In China,coal-bed methane is an abundant kind of resource.It is significant to improve gas production through researching coal-bed methane reservoir permeability Energy.However,most crack structures,stratifications,joints in coal-bed is developed very clear which result that reducing the success rate of drilling the raw coal and stagnant the related research.Therefore,instead of raw coal,the moulded coal can resolves the obstacles in the experiment on the premise of decreasing the differences of raw coal and moulded coal in the seepage characteristic.Our research provides the guidance and the gist for the process of moulded coal in the lab.We choose the coal come from Jinhua palace mine,Datong mining Cop to drill the raw coal and make the moulded coal,using the WTS-800 Electro-hydraulic servo triaxial gas seepage experimental device controlled by computer to make experiments.The experimental conclusion is as follows:(1)When the sodium bentonite as the binder,increasing its content,the peak deviator stress and elastic modulus increase,the initial permeability and the lowest permeability decrease gradually.When the content is 7%,its compressive strength,poisson ratio,permeability is similar to raw coal.But the elastic modulus is far away from raw coal.Increasing its drying temperature,compressive strength,permeability increase,the 105? is the best one.According to the cosine similarity metric analysis.7% content,105? drying temperature is the most similar to the raw coal.(2)When the cement as the binder,increasing its content,the peak deviator stress and elastic modulus increase and then decrease,the initial permeability and the lowest permeability decrease gradually.When the content is 20%,its compressive strength,poisson ratio,elastic modulus and permeability is similar to raw coal.Changing its particle size,80-100 mesh number's permeability is similar to raw coal,other is far away from the raw coal.According to the cosine similarity metric analysis.20% content,80-100 mesh number is the most similar to the raw coal.(3)When the polyvinyl acetate emulsion as the binder,increasing its content,the peak deviator stress increase,the initial permeability and the lowest permeability decrease gradually.When the content is 7%,its compressive strength,poisson ratio,elastic modulus,permeability is similar to raw coal.Increasing its drying temperature,compressive strength,permeability increase,the 90 ? is the best one.Water-binder ratio 1:2 initial permeability and the lowest permeability is bigger than water-binder ratio 1:1.Increasing the forming pressure,the initial permeability and the lowest permeability decrease.At 45 MPa,its compressive strength,poisson ratio,elastic modulus and permeability is similar to raw coal.According to the cosine similarity metric analysis.7% content,90 ?drying temperature,45 MPa forming pressure,1:2 water-binder ratio,80-100 mesh number is the most similar to the raw coal,and its result is 0.991 which is bigger than sodium bentonite and cement binder moulded coal.