草浆白泥碳酸钙的性能及应用

Research on the Application of Calcium Carbonate Prepared from Chemical Recovery in Straw Pulping as Filler

对比分析了传统草浆白泥碳酸钙、精制草浆白泥碳酸钙及商品轻质碳酸钙的物理性能及其作为填料对纸张性能的影响。研究发现,精制草浆白泥碳酸钙平均粒径为6.36μm,10μm以下粒径约占82%,其粒径与商品轻质碳酸钙相近;而传统草浆白泥碳酸钙粒度分布范围宽,10μm以上粒径的约占66%,平均粒径达12.78μm。精制草浆白泥碳酸钙吸油值高、沉降体积小,用于纸张加填时,精制草浆白泥碳酸钙及商品轻质碳酸钙都能使纸张白度得到提高,而传统草浆白泥碳酸钙使纸张白度降低;精制草浆白泥碳酸钙对纸张不透明度有良好提高效果,商品轻质碳酸钙次之;相对于传统草浆白泥碳酸钙,精制草浆白泥碳酸钙加填的纸张在施胶度和物理强度方面都有了明显的改善,因此可以代替商品碳酸钙用作造纸填料。

The physical characteristics of conventional lime mud from straw pulping process, the refined lime mud and the commercial precipitated calcium carbonate were investigated, and the potential of applying these mineral materials as filler was also studied. The results showed the refined lime mud with an average particle size of 6.36 μm, and about 82% particles less than 10 μm, which were similar to commercial precipitated calcium carbonate. However, the conventional lime mud had a wide size distribution, with an average particle size of 12.78 μm, and 66% particles above 10μm. The refined lime mud had higher oil absorption and lower sedimentation volume. The effect of conventional lime mud and refined lime mud loading on paper properties were also investigated and compared with that of commercial precipitated calcium carbonate loading. The results showed that loading with refined lime mud and commercial precipitated calcium carbonate could increase paper whiteness, on the contrary, loading with conventional lime mud decreased the paper whiteness. The refined lime mud was found to impart good opacity, and the commercial precipitated calcium carbonate took the second place for improving opacit . The paper loaded with refined lime mud improved apparently in sizing effect and strength properties compared with conventional lime mud. Thus it can be concluded that the refined lime mud can take place of commercial precipitated calcium carbonate as filler, while conventional lime mud cannot be accepted as filler.