钒触媒中五氧化二钒分析方法的改进

Improved Methods of Vanadium Pentoxide Analysis in Vanadium Catalyst

将钒触媒样品放入聚四氟塑料杯中,加入高氯酸和氢氟酸进行分解,分解后直接转移于烧杯中,加水溶解盐类,在保证溶液酸度的情况下,直接加入试剂分析滴定。试验讨论了用高锰酸钾滴定过量的亚铁时,酸度和温度的影响,结果发现高锰酸钾滴定过量的亚铁时酸度必须控制在2mol/L之间,滴定的起始温度在60~80℃,近滴定终点温度宜在55~75℃。方法的样品适应性强,与旧方法测定结果一致,试验方法的相对标准偏差(n=12)在1. 5%~2. 87%,加标回收率在99%~100. 5%。

The vanadium catalyst sample is put into a polytetrafluorinated plastic cup and added to perchloric acid and hydrofluoric acid for decomposition. After decomposition,it is directly transferred to the beaker,and the salt is dissolved with water. Under the condition of ensuring the acidity of the solution,the reagent is directly added for analysis titration. The effects of acidity and temperature on the titration of excess ferrous with potassium permanganate were discussed. It was found that the acidity of potassium permanganate when titrating excess ferrous must be controlled between 2 mol/L,and the starting temperature of titration was 60 ~ 80 ℃,The near titration end temperature should be 55 ~ 75 ° C. The sample of the method has strong adaptability and is consistent with the results of the old method. The relative standard deviation( n = 12) of the experimental method is 1. 5% ~ 2. 87%,and the standard recovery rate is 99% ~ 100. 5%. It is a easy and fast method to analyze vanadium pentoxide content in vanadium catalyst.