Production Of Water-reducing Agent By Utilizing Coking Waste

With the development of coal chemical industry, the coking waste outputing causesserious pollution in environment. The preparation of cement water-reducing agent withcoking waste acid tar,2-naphthol waste and coumarone as starting material can solve thepollution problems of coking waste. A simple component analysis of acid tar and2-naphthol waste is carried out. The upper liquid mixture of tar acids after standing andstratification is mainly benzene and toluene, and the content of those is10%. The viscousunderlying solid is sulfonate substances and polymer resin material. The2-naphtholwaste is mainly composed of sodium after drying, and the content is65%. Removingimpurities, the remaining main component contains2-naphthalene sulfonate and a smallamount of2-naphthol sodium. Sulfonate-rich substances are included in tar acid and2-naphthol waste. And sulfonate superplasticizer in cement is the main active ingredient.Coking waste is used for preparing water-reducing agent after sulfonation, condensation,and other steps. The preparation conditions of water-reducing agent are explored, and thecompound and chemical modification of water-reducing agent preparated are studied.The structure of product is analyzed through IR spectrum. The Water-reducing effects bychanging sulfonation temperature, sulfonation time, condensation temperature,condensation time, molar ratio and so on are investigated with grout fluidity experiment.The optimal dosage of superplasticizer is identified through grout fluidityexperiments. The best dosage of acid tar water-reducing agent,2-naphthol reducing agent,2-naphthol residues concentrated waste water reducer, and coumarone superplasticizerare respectively0.8%,1.0%,2.0%,1.0%; the water reduction rate reaches respectively6.0%,5.0%,3.0%,10.0%. A serious problem on the loss of the water-reducing agent isimproved through compound and chemical modification.Surface tension, zeta potential and adsorption capacity of water-reducing agentsolution are measured to further explain the effect on water reducing superplasticizer ofsurface tension, zeta potential and adsorption capacity. Strength test and SEM analysisare carried out by using test block of hardened cement paste. The results show that thehardened cement paste slurry admixing superplasticizer is denser and higher intensity.The XRD date of concrete test block show that admixing superplasticizer does notchange the hydration products.