造纸用TiO_(2)-粉煤灰复合粉体的制备及性能研究

Preparation and Performance Study of TiO_(2)-Fly Ash Composite Powder for Papermaking

为实现粉煤灰高附加值,使其可应用于造纸研究,以TiO_(2)对粉煤灰增白改性,考察了粉煤灰-TiO_(2)复合填料用作书写纸造纸填料的可行性。基于酸浸、焙烧和机械力化学法,系统研究粉煤灰除铁除碳和包覆增白的最佳条件,提出了粉煤灰-TiO_(2)复合填料的制备工艺。结果表明,粉煤灰与盐酸反应并焙烧,Fe含量成功降至1.17%且C基本被除去,亨特白度由21.41%提高至65.75%。随后在机械力的作用下,与40%(质量分数,下同)TiO_(2)共混研磨,制得粉煤灰-TiO_(2)复合填料。TiO_(2)成功包覆在粉煤灰表面,使得粉煤灰-TiO_(2)复合粉体亨特白度提高至72.66%,平均粒径在1.5~2.5μm范围,基本达到造纸用轻质碳酸钙填料的水平。当加填10%~20%复合填料制备手抄书写纸时,所得纸页的亨特白度可达78%~80%,符合GB 12654—90书写纸合格品要求,但纸张的物理性能有待进一步提高。

In order to realize the high value-added application of fly ash in papermaking research,TiO_(2)was used to whiten fly ash,and the viability of using fly ash-TiO_(2)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-TiO_(2)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%TiO_(2)under mechanical force to produce fly ash-TiO_(2)composite filler.Fly ash was effectively coated with TiO_(2).The Hunter whitenes of the fly ash-TiO_(2)composite filler reached 72.66%.The average particle size was 1.5-2.5μm,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.