Study On Application And Preliminary Modification Of Ceramic Waste As Filler In Papermaking

The environmental pollution of ceramic waste is getting worse these days.Polished brick waste accounts for more than half of the total ceramic waste.Since the tile waste contains silicon carbide,which will release carbon dioxide at high temperatures,so limits its comprehensive utilization.The study takes polished brick waste as the research object and discusses its research on paper filler.First,the basic characteristics of ceramic waste were studied.The main elements of ceramic waste are Si and Al.The sum of these two elements is close to 90%.The main phase consists of quartz phase?silica?and mullite phase.The pH of ceramic waste is 9.31.The conductivity is 295?s/cm,the zeta potential is-5.7mV,the sedimentation volume is5.86mL/g,and the density is 2.56g/cm3.These basic parameters are similar to the commonly used paper making filler calcium carbonate.However the whiteness of ceramic is 60.57%ISO,which is much lower than the whiteness of common paper making fillers.200-400 mesh,400-600 mesh,600-800 mesh,800-1000 mesh and unscreened ceramic waste were added under the same paper making conditions.And compare the strength properties,printing performance and other properties of the filled paper under 5 different ash contents.The results show that compared with several other particle sizes,the effect of unscreened ceramic waste?D_x?50?=13.3?m?on paper strength properties,printing performance and other properties is at a relatively good level.It not only has less influence on paper strength performance,but also can effectively improve the smoothness of the paper.Using bleached softwood pulp,bleached hardwood pulp and deinked waste pulp as raw materials,calcium carbonate,kaolin,talc and unscreened ceramic waste were compared for paper filling.The experimental results show that the strength and printing properties of paper filled with ceramic waste are not worse than those of paper filled with common paper fillers except for its obvious low whiteness.In the preliminary study of whitening modification of ceramic waste,four kinds of calcium carbonate coating preparation methods were used to modify the carbonation coating of ceramic waste,taking into account the whiteness and production cost of the modified ceramic waste-calcium carbonate composite.Preferably,the calcium hydroxide-carbon dioxide system produces calcium carbonate for whitening modification of ceramic waste.The ceramic waste modification process was optimized by orthogonal experiment.The optimum conditions for the coating modification under the experimental conditions were a stirring rate of 700 rpm and a sodium polyacrylate as a dispersant of 0.25%?relative to the theoretically generated calcium carbonate mass?.The concentration of Ca?OH?₂ is 2%?mass concentration?,the rate of carbon dioxide is 0.5L/min,the reaction starting temperature is15°C,and the amount of zinc chloride used as the crystal form controlling agent is 0.3%?relative to the theoretical formation of carbonic acid?.Eventually,the whiteness of ceramic waste was increased from 60.57%ISO to 82.13%ISO,which was increased by 35.60%,and the coating was uniform without obvious dust.The results show that the ceramic waste-PCC composite has good coating strength.