Experimental Study on Hot Pressing of Dry Lignite Powder without Additive

In order to gain the rule of lignite powder in eastern inner-Mongolia molding strength with temperature and load variation without additive, the hot pressing experiment of lignite powder was carried out using hydraulic machines and resistance furnace in the laboratory. Experimental results show that compressive strength of lignite powders increases first and then decreases along with the temperature increasing, a parabola-shaped rule is appeared under certain load conditions and the lignite can’t be formed after the temperature reaches ignition point, lignite powders’ molding strength increases with the load increasing, a exponential rule is appeared under certain temperature conditions and molding strength tends to a fixed value when reaches a certain load, under the same load and temperature conditions, the lignite particle size is smaller, the stronger surface force and molding strength are higher. According to the experimental results there is a conclusion that the elastic-plastic of lignite powder is a factor which affects molding strength. Under the conditions of heating, when temperature increases and the ignition is not obtained, the coal tar and humic acid precipitation play a bonding role and the molding strength is enhanced, the combustion of coal tar and volatile when ignition point is reached results deterioration of lignite coal powder and can not be forming with hot pressing. It is significant that rule is obtained from molding experiments to industrialized production of lignite powder and optimization with hot pressing.