研究了一种快速测定桉木碱法制浆黑液中残余有效碱的方法。该方法是在黑液中加入适量BaCl2溶液后,采用0.100 mol/L的标准盐酸溶液直接滴定,省去标准滴定法中样品静置沉淀及过滤等步骤。对桉木不同蒸煮工艺下产生的黑液样品的滴定结果表明,桉木碱法制浆黑液中残余有效碱直接滴定法的终点pH值为10.2;且终点pH值在10.2±0.05范围内的测定精度可以满足残余有效碱分析的要求。该方法操作简单、准确性好,适用于生产中对桉木黑液残余有效碱的快速测定,也可供其他碱法制浆生产企业参考。
This paper reported a rapid method for the determination of residual effective alkali in black liquors from eucalyptus alkaline pulping.In this method the black liquor after addition of BaCl2 was titrated directly by a 0.100 mol/L HCl standard solution,the procedures for precipitate sediment and sample filtration used in the conventional titration method are omitted.The results showed that the destination pH in the direct titration for residual effective alkali in black liquor was 10.2 and the measurement accuracy is acceptable for the pH range of 10.2±0.05.The present method is simple and accurate;and it is suitable for rapid determination of residual effective alkali in black liquors on mill sites.