Preparation and Performance Study of TiO2-Fly Ash Composite Powder for Papermaking
In order to realize the high value-added application of fly ash in papermaking research,TiO2 was used to whiten fly ash,and the viability of using fly ash-TiO2 composite filler as writing paper papermaking filler was invesgated.Based on acid leaching,roasting and mechanical force chemical methods,the best conditions for removing iron and carbon from fly ash and coating brightening were systematically investigated,and a fly ash-TiO2 composite filler preparation process was suggested.The results showed that when fly ash was reacted in hydrochloric acid and calcined,Fe content was effectively reduced to 1.17%and C was virtually removed,while Hunter whiteness increased from 21.41%to 65.75%.Subsequently,it was co-mingled and milled with 40%TiO2 under mechanical force to produce fly ash-TiO2 composite filler.Fly ash was effectively coated with TiO2.The Hunter whitenes of the fly ash-TiO2 composite filler reached 72.66%.The average particle size was 1.5-2.5 μm,nearly reached the level of the lightweight calcium carbonate filler for papermaking.The Hunter whiteness of the writing paper could reach 78%-80%when 10%-20%composite filler was filled,which was in compliance with the GB 12654-90 requirements of qualified writing paper.However,the physical characteristics of the paper still require improvement.
fly ashmechanical force chemical methodscoating brighteningtitanium dioxideapplication of papermaking