锅炉酸洗液中剩余EDTA浓度测定方法的探讨

Discussion of the Remaining Boiler Pickling EDTA Concentration Measuring Method

结合EDTA清洗锅炉的原理,考虑清洗液中主要的金属元素,配置了模拟清洗液,试验测定了ZnCl2、CaCl2两种标准滴定溶液与酸铬兰K等3种显色剂的相互搭配时的滴定结果,发现在pH=10的NH3-NH4CL缓冲液中,以酸性铬蓝K为指示剂,以ZnCl2标准滴定溶液进行滴定的清洗液中EDTA含量,其结果误差较小,是一种能够准确判断EDTA清洗锅炉过程中其剩余浓度的检测方法。

Recent years, Ethylenediamine tetraacetic acid （ EDTA） , as a chlorine-free chemical cleaning a-gent, with good cleaning effect, safety and environmental protection, clean short duration, attracted more and more attention. And determination of its residual concentration is important for cleaning process. In this paper, the cleaning solution is prepared in terms with the principle of EDTA boiler cleaning. And tests are made with two standard titration solution ZnCl2/CaCl2 and three kinds of color-developing reagent, and found that PH=10, acid chrome blue K for the indicator and ZnCl2 as standard titration solution are the best combination with most accurate titration results.