Synthesis Of Modified Lignin Sulfonate And Its Properties For Coal-water Slurry

Coal-water slurry is a new kind of clean fuel, it is made up by about 60% of the coal,40% of water and 1% of additive, they throgh a variety of programs to mixture. The use of additive are very few, but it is important for the flow performance and stable performance of coal water slurry. Dispersant is the most important category in coal water slurry additive,it is also one of the important factors in the process of coal water slurry preparation. Coal water slurry dispersant mainly include naphthalene sulfonic acid-formaldehyde condensation compound, polyolefin sulfonic acid salts, poly carboxylic acid, lignin sulfonate in current industrial applications. Papermaking waste reprocessing product lignin of coal water slurry dispersant, it is commonly use in industrial, the advantages of the abundant of raw materials, good stability of water slurry, and less water, but this kind of dispersant also has a lot of disadvantages, inculde large viscosity, poor liquidity and so on.Changes in performance and reduce the viscosity has become the research focus on coal water slurry additive. Due to the price of industrial naphthalene are rising in recent years,leading to the synthesis of naphthalene sulfonic acid formaldehyde condensation product -cost is also rising, and the condensation compound as coal water slurry dispersant, itself also has many insufficiencies, so it has become inevitable to grafting modification for it.Sulfonated alkali lignin was synthesized by sulfonation reaction using alkali lignin as raw material. The reaction conditions on the influence of sulfonated alkali lignin yield was studied through orthogonal experiments. The results showed the optimized process conditions are as follows: temperature is 95?, reaction time is 3h, dosage of formaldehyde is 40%, reaction pH=9, the yield is 84%. And the sulfonated product characterization of infrared, thermogravimetric and electron microscope scanning, illustrates the sulfonation reaction.A series of graft copolymer dispersant were synthesized by using ligninsulfonate(LA)and allyl polyether(APEG) of different molecular weight (300, 500, 700 and 500) as raw materials. The optimized synthesis conditions was studied through orthogonal experiments.The results showed the optimized process conditions are as follows: amount of initiator 3.0 wt% and APEG 30 wt%, APEG molecular weight 500, reaction temperature 85?. The infrared spectrum analysis and SEM analysis were applied to the surface features and analysis on the grafted products synthesized by the optimal experimental conditions. The results show that it has good ability in reducing the slurry viscosity and enforcing the CWS stability.?-naphthalenesulfonate formaldehyde condensate (SNF) were synthesized by using industrial naphthalene and sulfuric acid and formaldehyde as raw materials.Lignin-naphthalene graft polymer were synthesized by using SNF and ligninsulfonate (LA)as raw materials. The optimized synthesis conditions was studied through orthogonal experiments. The results showed the optimized process conditions are as follows: reaction time is 4h, SNF/ LA is 4(mass ratio), the reaction temperature is 95 ?. Infrared analysis characterization of graft product proved modified successfully. Comparison SNF and lignin-naphthalene grafted polymer as dispersion properties of coal water slurry is different,it is concluded that the Lignin-naphthalene grafted polymer distribution effect is more superior.The sodium lignosulphonate compound with SNF according to the different proportion,and the minimum of viscosity of coal water slurry is 972 mPa.s when sodium compound with content of 30%.