Study On Application Of Fly Ash And Fly Ash Fibre In Papermaking

Fly ash is a kind of industrial waste from fuel electric plant, which exists in the coal-power boiler as fine particle power after the burning of coal through1000～1500℃. Fly ash fiber (FAF) is a kind of inorfil which uses the fly ash as raw material mixed with desulfurated ash after the procedure of high temperature melting, silk spraying and cooling. Appling the fly ash and FAF into the papermaking industry can lower cost and be good for the environment, and also step a further way for the multipurpose use of fly ash.This research investigated the possibility of using fly ash as paper filler and CPAM as retention aid for papermaking. The result indicated that it is feasible to use fly ash as paper filler after screening, floatation for carbon removal, and mixing with high brightness paper filler. The brightness increased3%ISO after floatation for carbon removal and40.4%ISO for mixture, which partly eliminates the disadvantages for the application of fly ash in highgrade packing paper products. The opacity increased when certain amount of fly ash was added.The dispersion efficency of fly ash fiber by SDBS, SDS, OP-10, CMC and CPAM was studied. The result showed that CMC performs best, and its optimum concentration is0.6%.The impact of beating degree on the property of paper sheet made from fly ash fiber and plant fiber was investigated. The optimum conditions are as follows:beating degree of39～51°R and fly ash fibre of40%for softwood pulp, and beating degree of40～45°SR and fly ash fibre of20%for hardwood pulp. The retention of fly ash fibre increased with increasing beating degree of plant fiber pulp.The influences of calcium silicate coating on the whitening of fly ash fiber and the mixing papermaking of fly ash fiber and plant fiber on the paper property were investigated. The calcium silicate coating conditions optimized via orthogonal experiment are as follows: calcium chloride concentration of0.15mol/L, stirring time of20min, reaction time of10min, and temperature of50℃. Under these conditions, the brightness of fly ash fiber was72.3%ISO, and increased26.9%ISO compared with the original fly ash fiber. The property of paper sheets made from the mixture of original or whitened fly ash fiber and plant fiber was studied.This study discussed the application of fly ash and fly ash fiber in papermaking, which expands the application area of fly ash and its by-product, and is significant for the industrialization of fly ash.