Study On Effect Of Small Molecule Matter And Micro-nano Particles On Slurry Ability Of Coal Water Slurry

Based on coal water slurry(CWS)gasification technology,the application of industrial waste and gasification waste residue in CWS preparation is studied in this paper.The influence of small molecules matters,surfactant and the second particles on slurry ability of CWS and the mechanism of action are studied.The main research contents and conclusions of this paper are as follows:The effect of inorganic small molecule on the slurry ability of CWS was studied.The viscosity of CWS is affected by the valence state of inorganic salt as it is prepared by inorganic salt solution.The monovalent salt has a positive effect on reducing the viscosity of CWS.The proportion of free water in CWS increases when CWS is prepared with monovalent salt solution.The bivalent salt has little effect on the viscosity of CWS.While the divalent salt solution is used to prepare CWS,the efficiency of dispersant on the particle surface increases little.The trivalent salt has a negative effect on reducing the viscosity of CWS.When using trivalent salt solution to prepare CWS,the proportion of free water in CWS decreased and the degree of freedom decreased.CWS is prepared by low concentration of alkali solution,the viscosity reduced.The Zeta potential of CWS decreased while the proportion of free water in CWS increased when using low concentration of alkali solution to prepare CWS.The effect of surfactant on rheological properties of suspension was studied.With the increase of anionic surfactant concentration,the state of suspension changed from fluid states to cream-body states and then to fluid states.As the suspension prepared by anionic surfactant more than 0.2%,the suspension was showed cream-body state.At that time,the particle surface is positively charged and micelles surround the particle.The particles and micelles form a network structure under the action of electrostatic attraction,which makes the suspension showed cream-body state.The influence of cationic surfactant and nonionic surfactant on the rheological properties of suspension is not significant.When preparing CWS with surfactant solution,the viscosity of CWS increases first and then decreases with the surfactant concentration increase.The PCWS prepared by anionic and nonionic surfactant solutions shows obviously shear thinning.The effect of caprolactam waste water on the slurry ability of CWS was studied.Caprolactam waste water is complex in composition and difficult to treat which contains a large number of inorganic and organic substances.Through the use of caprolactam waste water to prepare CWS,the researches were distinguished that the change of viscosity under the influence of both inorganic and organic matter.According to the results,with same concentration of CWS,the viscosity of the CWS prepared by caprolactam waste water solution was little higher than the viscosity of the CWS prepared by pure water.But the viscosity,stability and liquidity of the CWS prepared by caprolactam waste water solution are conforming to the requirements of the industry.The feasibility of hydrophilic gasification fine slag as the second particle used in the preparation of CWS was studied.The fine slag was mixed with kerosene to obtain fine slag kerosene suspension.The coal particles were modified using fine slag kerosene suspension and prepared CWS.In this way,the viscosity was decrease from 1107.1mPa·s to 401.3mPa·s andthe slurry concentration was decreased 2.3 percentage points.In order to improve the gasification efficiency,the preparation technology of ultra-high concentration CWS with good fluidity was studied.Shenhua bituminous coal with a slurry concentration of 61%was modified by nano calcium carbonate and kerosene suspension.When the modified Shenhua particles was used for the preparation of CWS,the CWS with a concentration of 66%,viscosity of nearly 2000mPa·s,good fluidity and flow grade of B-were successfully prepared.