Slurry Ability Of Coal Water Slurry Preoared By Inner Mongolia Brown Coal And Study Of New Slurry Additives

Coal water slurry (CWS) is prepared by coal, water and a small quantity of additive. It is stable and has the rheological characteristics. Coal water slurry is prepared by bituminous coal anciently and the solid concentration can be above65%. Chinese brown coal resource is abundant. The discoverable brown coal resource is about129billion ton, possessing12.7%of the whole coal resource. Brown coal is a typical kind of low rank coal. The brown coal’s moisture and volatilization contents are high, and the heat value, the ash melting point, the HGI index are low. The direct burning and line-haul of brown coal is improper economically.Brown coal is utilized as the gasification source in the coal industry generally. The favorable rheological characteristics and stability are the precondition of coal water slurry gasification technology. The study of the slurry ability and enhancing slurry’s solid concentration are the active demand for the combustion and gasification of brown coal water slurry. The slurry ability of CWS prepared by Inner Mongolia brown coal is investigated in the paper. The study indicates that the brown coal water slurry’apparent viscosity increases as the solid concentration raises and its non Newtonian behavior increases evidently. The slurry has Newtonian behavior when the solid concentration is low, and has pseudo plastic fluid behavior when the solid concentration is high. As the temperature rises from20℃to50℃, the apparent viscosity decreases continuously. The brown coal water slurry has admirable stability characteristics.The brown coal physical and chemical characteristics are investigated to find the reason why the solid concentration is low in the paper. The brown coal slurry ability is estimated in advance by the coal experiential model. They are tested and analyzed that the surface appearance of brown coal, the surface wet ability, the oxygen functional group and the microcosmic pore structure. And they are used to explain the reason of brown coal water slurry’s low solid concentration. A new technology called MTE (Mechanical and Thermal Expression) is advanced to improve the slurry ability of brown coal water slurry in the paper. The author builds the experimental system of mechanical and thermal expression, and a few researches are carried out. Another method to increase the brown coal water slurry’s solid concentration is preparing the slurry mixed with the petroleum coke. The mixture’s slurry ability, rheological characteristics and stability are studied.The mechanism of CWS additives are investigated in the paper. The petroleum coke water slurry has high solid concentration, but its stability is quite bad. A new kind of additive is exploited to fit in with the needs of blended fuel that mixed by petroleum coke, brown coal and sludge. The mixture slurry’s slurry ability, rheological characteristics and stability are investigated in the paper.