CPAM/膨润土体系对麦草浆的微粒助留作用

Retention and Drainage Effect of CPAM/Bentonite on Wheat Straw Pulp

用氟化钠做改性剂,对自然界中的钙基膨润土进行中性改性制备膨润土浆液,组成CPAM/膨润土微粒助留体系,并与传统的碳酸钠改性膨润土的助留助滤效果进行了比较。透射电镜观察、粒度、黏度和动态滤水等实验表明,氟化钠改性膨润土呈完全剥离的片状结构,同时具有更好的胶体与分散性能,粒度小、悬浮液流动性好,且对麦草浆具有更好的助留助滤效果,对抄造体系的pH适应性强,尤其是放置4周后仍能保持其良好的助留助滤效果。

Ca-bentonite was ion-exchanged with sodium fluoride to obtain sodium bentonite slurry under the neutral condition. The sodium fluoride modified bentonite was used as the microparticle component of CPAM/bentonite system. Its performance was compared with that of conventional sodium carbonate-modified bentonite. The morphology and suspension properties of the bentonite were observed and evaluated by TEM and conventional analysis methods, respectively. It was found that the sodium fluoride-modified bentonite was dispersed as single layered structure and exhibited better suspensibility, smaller particle size as well as lower sludge viscosity. Naturally, the bentonite modified by sodium fluoride made a greater improvement on the retention and drainage of the wheat straw pulp, showed a better adaptability on pH value of system than the bentonite modified by sodium carbonate. It can sustain its good performance even after four weeks as a suspension.