电导率法快捷高效测定生石灰活性度

Fast and efficient determination of quicklime activity by conductivity method

为了克服盐酸滴定法、温升速率法等测定生石灰活性度的方法试剂用量大、适用条件受限和操作复杂等缺点,提出一种试剂用量少、操作简便且适合不同活性度水平的生石灰活性度电导率测定方法。考察了搅拌时间、搅拌转速、溶液温度、生石灰与水的用量等因素对生石灰活性度与溶液电导率对应关系的影响,探究了生石灰活性度与电导率大小呈线性关系的最适宜条件。结果表明,生石灰活性度测定的最适宜条件为搅拌时间为12min、溶液温度为25℃、搅拌转速为200 r/min、生石灰与去离子水的加入量分别为1 g、1000 mL;生石灰活性度与溶液电导率之间的线性关系表达式为A=(σ-0.5657)/0.01246,拟合的线性相关系数R^(2)=0.9931,相较于现行标准YB/T105—2014《冶金石灰物理检验方法》规定的盐酸滴定法,该方法具有节省时间、节约药品、降低能耗、操作简便等优点,与盐酸滴定法测定值的最大相对偏差为0.366%,精密度完全可靠,可用于工业推广。

In order to overcome the shortcomings of the methods for determining the activity of quicklime by the titration method of hydrochloric acid and the temperature rise rate method,such as the large amount of reagents,restricted condi-tions and complicated operation,a method for the determination of the conductivity of quicklime activity with less reagents,simple operation and suitable for different activity levels was proposed.The effects of stirring time,stirring speed,solution temperature and the ratio of quicklime to water on the correspondence between the activity of quicklime and the conductiv-ity of the solution were investigated,and the most suitable conditions for the linear relationship between the activity of quicklime and the conductivity were investigated.The results showed that the optimum conditions for the determination of the lime activity were:stirring time of 12 min,solution temperature of 25℃,stirring speed of 200 r/min,and the dosage of lime and water of 1 g,1000 mL.The linear relationship between the lime activity and the solution conductivity was A=(σ-0.5657)/0.01246,and the fitted linear correlation coefficient was R^(2)=0.9931.Compared with the hydrochloric acid ti-tration method specified in the current standard(YB/T 105—2014),this method had the advantages of saving time,drugs,energy consumption and easy operation.The maximum relative deviation between this method and hydrochloric acid titration method was 0.366%,the precision was completely reliable and could be used for industrial promotion.