高碱性烟气脱硫灰中亚硫酸钙含量分析方法

Analysis of Calcium Sulfite in High Alkaline Flue Gas Desulfurization Ash

针对烟气脱硫灰中的亚硫酸钙含量测定方法没有国家标准和行业标准,在参考不同标准中亚硫酸盐的测定方法基础上,对碘量法测定烟气脱硫灰中亚硫酸钙含量的方法进行实验研究。通过自制烟气脱硫灰模拟样的滴定,结果表明高碱性脱硫灰在滴定前应采用先加碘后加酸的顺序进行处理,并使用盐酸或磷酸作为酸化剂,而不宜使用硫酸酸化;采用磷酸（1＋1）作酸化剂,控制溶液pH值在2.49~1.40之间,可以准确测定高碱性烟气脱硫灰中亚硫酸钙含量,重复性好,同时可有效避免Fe3＋干扰。

Since there is no national or industrial standard for determination of calcium sulfite content in flue gas desulfurization ash,in referred to different measuring methods of sulphite in various standards,the iodometry method for determination of calcium sulfite content in the flue gas desulfurization ash was studied.Results showed that high alkaline desulfurization ash before titration should be treated with iodized first then followed by adding hydrochloric acid or phosphoric acid.By using phosphoric acid as acidulant and controlling pH of solution from 1.40 to 2.49,content of calcium sulfite in high alkaline flue gas desulfurization ash can be determined accurately.The method has good repeatability and could avoid the interruption from Fe3＋ effectively.