Study On The Synthesis And Properties Of New Type Polycarboxylic Series Dispersant For Coal Water Slurry

As an technology of clean coal, CWS (coal-water slurry)has been playing animportant role in China’s energy strategy. However, the key technology of CWSis additives. In this study, in oder to solve the problem of Binlong coal andShenfu coal’s low plasma concentrations, two new polycarboxylate dispersants(PAAS-type polycarboxylate dispersants and citric acid ester-type polycarboxylicacid dispersant) were prepared. Then using them respectively during the processof CWS preparation, the plasma characteristics was studied, The variousinfluence factors such as the ratio of monomers, the amount of initiator, reactiontemperature,reaction time to the dispersant performance and the macromonomeresterification of citric acid esterification reaction conditions were discussed,andthe side chain structure to the dispersant performance was analysised, as well ashow to conduct a rational molecular design.The main research results were drawn as follows：when n(APEG):n(AA):n(SSS)=3:4:1, w（initiator）=3%of the total mass, dropping1h,reaction temperature80℃, reaction6hours, the PAAS-type dispersant has thebest performance. The citric acid ester-type polycarboxylic acid dispersant hasthe best performance, when n (CAS):n(AA):n(SSS)=3:4:1, w（initiator）=2%ofthe total mass, dropping1h, reaction temperature75℃, reaction time4hours.Compared to the Naphthalene dispersant and lignin sulfonate dispersanthorizontal comparison, found that the synthesis dispersant of this studyperformance more than the latter two.Finally, through TGA, GPC, IR, and othercharacterization methods, the decentralized structure of the molecules, thethermal properties, molecular weight distributionc was analysized.Also, in this thesis, aromatic group in the molecule side chains, carboxylstructure and side chain length of coal water slurry was studied. By using SASalternative SSS as comonomer, Molecular side chain of dispersant without contain a benzene ring structure was synthesized. Compared to PAAS typedispersant, investigated slurry rheology, the apparent viscosity and thechromatography rate of water in7d of CWS, and found that with PAAS typedispersion agent preparation of coal-water slurry from the slurry flow pattern,stability is better than another;using APEG-800and APEG-1000as comonomer,two molecules side chain length of the PAAS type dispersant was synthesized.Two coal-water slurryrheological properties of the specimen, the apparentviscosity, the chromatography rate of water in7d to1g coal adsorption wasstudied. The results showed that CWSwhich was prepared by using Molecularside chains longerdispersant has higher apparent viscosity and thechromatography rate of water in7d of CWS. Solution of dispersant adsorptioncapacity of coal is small under various concentrations.using Citric acid ester typedispersant and dispersant without adding citric acid dispersant in theesterification process to Shenfu coal pulp, CWS ζ potential value under slurryrheology, the apparent viscosity, the chromatography rate of water in7d anddifferent dispersant dosage was Studied. The results showed that the CWSprepared by the citric acid ester-type dispersion agent has higher ζ potentialvalues, lower apparent viscosity and the chromatography rate of water in7d, andbetter slurry flow patterns.