粉煤灰联产新型活性硅酸钙作为造纸填料的可行性探讨

Application of Calcium Silicate Generated from Fly Ash as Filler in Papermaking

关键词:  活性硅酸钙  白度  不透明度  抗张指数  撕裂指数

Key Words:calcium silicate  brightness  opacity  tensile index  tearing index

摘要:研究了粉煤灰联产新型活性硅酸钙填料的填料性能及其作为填料在纸张中的加填性能，探讨了活性硅酸钙不同加填量对纸张性能的影响，并与商品轻质碳酸钙(PCC)填料进行了对比。结果表明，活性硅酸钙粒子呈蜂窝状，具有多孔性，比表面积较大，平均粒径为10.63 μm，吸油值为2.178 g/g，沉降体积为4.0 mL/(10 g·24 h)，白度为90.5%，较适于作为造纸填料。活性硅酸钙加填纸性能检测发现，随着活性硅酸钙用量的增加，纸张白度和不透明度都有较大程度的提高，纸张的抗张指数有较大降低，加填量不超过30%时，撕裂指数基本上保持不变。与商品PCC相比，加填量均为30%时，纸张白度和抗张指数基本相当，不透明度低5.1个百分点，撕裂指数高1.3 mN·m2/g，从加填后纸张的SEM图可以看出，活性硅酸钙与纤维之间有较好的交织。

Abstract:In this paper, the properties of calcium silicate generated from fly ash and its effect on the paper property when it was used as paper filler were investigated. The results were compared with those from PCC- filled sheets under the same conditions. Scanning electronic microscopic observation revealed that the particles of CaSiO₃ generated from fly ash had a honeycomb pattern, which was responsible for their highly porous surface structure and high specific surface area. The average diameter of the particles was 10.63 μm, the oil-absorbed value was 2.178 g/g, the sediment volume was 4.0 mL/(10 g·24 h), and the brightness was 90.5%, which proved to be suitable for use as paper filler. The results showed that with the increasing content of the CaSiO₃, the paper had higher opacity and higher brightness, but lower tensile strength, tearing strength almost unchanged when CaSiO₃ content was no more than 30%. When the dosages of fillers were 30%, compared with the papers loaded with PCC, the brightness and tensile of the paper loaded with CaSiO₃ were almost the same, while the opacity was 5.1% lower and tearing index was 1.3 mN·m2/g higher. SEM photo of the paper loaded with CaSiO₃ showed the fibers were well intertwined with CaSiO₃.