拟薄水铝石逆流洗涤研究

来源期刊：中南大学学报(自然科学版)1997年第3期

论文作者：侯春楼 刘今 吴若琼 周济苍 湛雪辉

文章页码：238 - 241

关键词：逆流洗涤； 过滤； 拟薄水铝石

Key words：countercurrent washing； filtrate； pseudo-boehmite

摘    要：拟薄水铝石有广泛的用途，由于生产过 程中洗涤净化困难，以致虽然洗涤次数多，耗水量大，产品中Na₂O含量仍时常超过0．3%(质量分数)的规定，产品质量的不稳定和成本偏高也影响了其应用 范围的扩大和产量的提高．作者根据拟薄水铝石在碱性水溶液中的分散特性，采用添加剂使Na₂O脱附，在用水量大大减少、洗涤次数减少的条件下，使Na₂O 含量稳定在0.3%以下，通过小试验及工业规模试验证明了本方法的正确性，对方法原理作了必要的解释和理论探讨．本方法对细分散物料洗涤有一定的参考意义．

Abstract: A study on removing Na₂O from pseudo-boehmite by means of countercurrent washing was performed. It is difficult to reduce the Na₂O content to less than 0.3% by the existing methods. because they expend too much water and can't insure good quality of products. Pseudo-boehmite Al₂O₃·H₂O is a kind of suspension system that contains fine particles and particle pieces. lt has large specific surface area. Its crystal lattice is not complete.So it contains greater surface Gibbs free energy. In the basic solution,reaction on the surface of particles produces AlO₂^- and adsorbs large amounts of AlO₂^- and Na⁺ ions,and then forms a stable chemical adsorption layer that prevents Na+ from being washed away from particle surface. It has been proved by tests that the removal of Na⁺ from particle surfaces can be done only by adding some surface-active substances that carry different ions in nature into the solution to break the double-layer structure. With some surface-active substances,washing water can be reduced to 1/2-1/3 of the amount used by the existing methods to meet the requirement of Na₂O content. Theoretical analyses of washing temperature,surface-active agents, washing method and solid-liquid separation method were also carried out.