适用于“一步酸溶法”生产氧化铝工艺中稀释料浆的高分子絮凝剂的合成

为达到"一步酸溶法"生产氧化铝工艺中稀释料浆在高温、高酸度工况下进行固液高效分离的目的,以丙烯酰胺(AM)与阳离子(DMDAAC)为共聚单体,通过水溶液聚合法合成了阳离子聚丙烯酰胺(CPAM)絮凝剂。以转化率和相对分子质量为目标,通过单因素分析法确定了最优的合成工艺条件,即反应温度30℃,单体总质量分数为30%,阳离子度5%,K2S2O8和NaHSO3质量分数均为0.005%,2,2′-偶氮二(2-脒基丙烷盐酸盐)(V50)质量分数为0.0025%,乙二胺四乙酸(EDTA)质量分数为0.05%的条件下,反应时间为6 h,获得相对分子质量为1.2×107溶解性能较好的阳离子型聚丙烯酰胺(CPAM)。

Synthesis of a Flocculant for Dilute Slurry in Alumina Production by “One-Step Acid-Dissolving Method”

In order to achieve highly efficient solid-liquid separation of diluted slurry in the alumina process via one-step acid-dissolving method, a cationic polyacrylamide(CPAM) flocculant was synthesized by aqueous solution polymerization with acrylamide(AM) and cation(DMDAAC). With the conversion and relative molecular mass as targets, the optimal synthesis conditions were determined by single factor analysis, namely, the reaction temperature was 30 ℃, the total monomer mass fraction was 30%, the cationicity was 5%, the mass fraction of K2S2O8 and NaHSO3 was 0.005%, the mass fraction of 2,2′-azodi(2-amidine propane hydrochloride)(V50) was 0.002 5%, the mass fraction of ethylenediamintetraacetic acid(EDTA) was 0.05% and the reaction time was 6 h, so that a cationic polyacrylamide(CPAM) having a relative molecular mass of 1.2×107 and better solubility was obtained.