竹材硫酸盐法蒸煮中偏铝酸钠与硫酸镁的协同留硅机理

The Mechanism of Silicon-remain Synergy Effect between Sodium Metaaluminate and Magnesium Sulfate in Bamboo Sulfate Cooking Process

通过在竹材硫酸盐法蒸煮过程中添加偏铝酸钠及硫酸镁,研究了其协同留硅效果及机理。结果表明:添加留硅剂后,预浸段黑液硅的去除率为64.05%,成浆段硅的去除率达74.32%。SEM观测可知,与空白样纸浆相比,添加留硅剂后的纸浆纤维表面有较多的团状物质附着。SEM-EDAX检测结果显示,等量硅酸钠替代竹材蒸煮后的两种沉淀物的微米级结构均为片状,片状间相连形成一个具有闭合区域的类似蜂窝状球体,闭合区域被某些物质填充,沉淀物中Mg和O两种元素出峰明显。XRD检测结果显示,两种沉淀物均含有Mg(OH)2成分。因此,沉淀物的蜂窝状球体为水镁石,闭合区域增大了比表面积,增强了对硅的吸附效果,从而提高了硅的去除率。

In this paper, sodium metaaluminate and magnesium sulfate were added in the bamboo sulfate cooking process. The silicon -remain synergy effect and mechanism were investigated. The results showed that the rate of desilication in the first stage was 64.05% , the rate of desilication in the second stage can reached 74.32%. The SEM observation showed that mass of substance was covered in the fibre surface. Equivalent sodium silicate was replaced bamboo, the two kinds of precipitate were observed by SEM - EDAX, the precipitates were all expressed plate, the plates were linked together to form honeycomb -like sphere with closed area, the area was filled with certain substance. Magnesium and oxygen showed a great content in the precipitate. XRD anylysis indicated that magnesium hydrate was found in the two precipitates. In conclusion, honeycomb - like sphere of the precipitate was brucite, the closed area increased the specific surface area, enhanced the adsorbing effect with the silicon, thus improved the rate of desilication.