Preparation And Characters Research Of Efficient Polycarboxylate-based Coal Water Slurry Additive

Polycarboxylate-based coal water slurry additive have much significance to be researched because of the long carbon chains, amounts of active adsorption joints and long sub chains of polyoxyethylene ether. With polyethylene glycol and acrylic acid as raw material, polyethylene glycol acrylate was synthesized by means of esterification with catalyst of concentrated sulfuric acid. Then, by aqueous polymerization method, efficient polycarboxylate-based coal water slurry additive was synthesized with ammonium persulfate as initiator, isopropanol as chain transfer agent, four-substance copolymerized with polyethylene glycol acrylate, acrylic acid, methyl methacrylate and acrylamide.Picking the esterification rate as the object of investigation, the main factors were studied basing on the single factor experiments and the orthogonal experiments. The optimum technological parameters of the preparation of polyethylene glycol acrylate were: the ratio of alcohol-acid 2.5:1, the amount of hydroquinone 0.6%, the amount of concentrated sulfuric acid 2%, the temperature 100℃and the reaction duration 4h.Picking the viscosity of CWM as the object of investigation, the effects of the different factors were comprehensive analyzed about the polymerization reaction. The optimum conditions of polymerization were: acrylic acid 0.03mol, methyl methacrylate 0.01mol , acrylamide 0.024mol, polyethylene glycol acrylate 0.02mol that reactant ratio (acrylic acid: methyl methacrylate: acrylamide: polyethylene glycol acrylate) equals to 1.5:1.2:0.5:1, the reaction duration 3h, the temperature 85℃, the amount of initiator 2% and the amount of chain transfer agent 2.5%.The IR spectrum analysised and verified esterification and copolymerization, and there was ester group in the esterification products and there were the carboxyl,amide,unsaturated monomer of side-chain polyoxyethylene group in the copolymerization products. The different concentrations of CWM were made with self-made coal water slurry additive and remixed coal water slurry additive for the coal of wang jia gou in Northern Shaanxi. The analysis shows that the viscosity of the CWM was the minimum when the quantity of polycarboxylate-Based coal water slurry additive was 0.4%, the CWM had a minimal viscosity, which was 764.32mPa·s and the maximal concentration 70%. And the viscosity of the CWM was the minimum when the quantity of the Self-made remixed coal water slurry additive was 0.3%, the CWM had a minimal viscosity, which was 764.32mPa·s and the maximal concentration 70%, meanwhile both the CWM had a good stability, dispersion and fluidity.It was found that the self-made additives had the Features of little dosage, large pulping density compared the self-made additives with the same type additives.