蒙脱石的结构形态及钠化方法与其微粒助留作用

Montmorillonite: Morphology, Modification Methods and Microparticle Retention Effect on Wheat Straw Pulp

X射线衍射和化学分析表明,实验所用几种膨润土的主要矿物成分均为钙基蒙脱石,只是蒙脱石类型有所不同。用碳酸钠和柠檬酸钠可分别将各钙基蒙脱石转变为钠基蒙脱石,其中,采用碳酸钠改性时钠基蒙脱石的收获率稍高,而结晶度较低的低电荷型蒙脱石经改性提纯后较结晶度较高的高电荷型蒙脱石收获率高。经透射电镜观察、粒度和ζ电位测定发现,各改性蒙脱石的外貌形态、干燥研磨后的粒度及与干燥前的相对粒度差异均很大,而各干燥样的ζ电位则差别不大,干燥样的平均粒度与其膨胀容具有一致的关系。手抄片实验结果表明,蒙脱石的微粒助留作用主要取决于其本身的结构形态和改性方法,而不同的蒙脱石样品之间仅从其于燥后的粒度、膨胀容和ζ电位并不能判断其相对微粒助留作用。

Three different calcium montmorillonite samples were selected as model montmorilionite, and two modifiers, sodium carbonate and sodium citrate, were used to modify the montmorillonites in order to investigate the effects of morphology and modification methods on the microparticle retention behavior of montmorillonite. The modification was confirmed by X-ray diffraction spectrums, and the processes were monitored by the swelling value of montmorillonite samples. The morphology was observed by transmission electron microscopy. The particle size and zeta potential were measured to further illustrate the properties of the montmorillonite samples. The result showed that the micropar- ticle retention effect of montmorillonite on rosin containing wheat straw pulp is related to the morphology of montmorillonite rather than the particle size and zeta potentials of it.