硝酸银电位滴定法测定铁矿石中水溶氯

以2g/L硫酸钾为溶解试剂,硝酸银为滴定剂,电位滴定法测定铁矿石中的水溶氯,通过电极电位-浓度二次微商滴定曲线,计算二次微商等于零时对应的V为滴定终点,可省去绘制E-V曲线或ΔE/ΔV-V一次微商曲线作图带来的麻烦。试验比较了温度、酸度、搅拌方式等对测定结果的影响,对干扰元素及活度与浓度的关系进行了分析。方法的相对标准偏差小于2.12%,用于实际样品分析加标回收率在90.0%~108.0%之间。

Determination of water soluble chloride content in iron ore by potentiometric titration with silver nitrate

A method for the determination of water soluble chloride content in iron ore by potentiometric titration was studied. The 2 g/L solution of potassium sulfate was employed for the dissolving of sample, and silver nitrate was used as titrant. The titration terminal point was decided by the calculation of the second order derivative.The method is simple since there is no need to draw the E-V curve or the first order derivative curve.The effects of temperature,time,acidity and stirring method were investigated.The influences of interfering elements were discussed and eliminated.The recoveries were in the range of 90.0%-108.0% and relative standard deviation was below 2.12%.The method was sensitive,accurate and simple.Good results were achieved for the analysis of water soluble chloride content in iron ores.