自动电位滴定法测定冷轧薄板酸洗液中总酸度

自动电位滴定法测定酸液中总酸度具有简单、快捷、不受其他元素干扰等优点。用硫代硫酸钠掩蔽铁离子,利用自动电位滴定仪测定冷轧薄板酸洗液的总酸度(以盐酸量计)。当电位突变达30mV以上时,仪器自动判定滴定终点。自动电位滴定法测定冷轧薄板酸洗液中总酸度结果与酸碱中和滴定方法具有较好的一致性。相对标准偏差小于0.6%,能够满足生产检验的要求。

Determination of Total Acidity of Acidic Washing Solution for Cold-Rolled Thin Sheet by Automatic Potentiometric Titration Method

The automatic potentiometric titration method has the advantages of simplicity, speediness and no interference by other elements, etc. Iron ion was masked with Na2S2O3. The total acidity of the acidic washing solution for cold-rolled thin sheet was determined （calculated according to the hydrochloric acid quantity）. When a potential jump was bigger than 30 mV, the instrument automatically judged the titra tion end-point. The total acidity of the acidic washing solution for cold-rolled thin sheet which was determined by the automatic potentiometric titration method was in accordance with that by acid-base neutralization titration, with RSD smaller than 0.6%. The method can meet the requirement for accurately determining the total acidity of the washing solution in manufacturing process.