氟盐取代络合滴定法测定铝锰合金中铝含量

来源期刊：冶金分析2011年第2期

论文作者：钟国秀 黄清华 晏高华

文章页码：71 - 73

关键词：铝锰合金； 铝； 氟盐取代络合滴定法； EDTA

Key words：aluminium-mangamese alloy； aluminium； furoride replacement complexometric titration； EDTA

摘    要：采用一种无需预先分离铁、锰,直接用氟盐取代络合滴定法测定铝锰合金中铝含量。试样经盐酸和H₂O₂溶解后,在一定量的铜离子存在下,加入过量的EDTA溶液,使其与溶液中铁、锰、铜等金属离子络合,煮沸溶液使铝也全部形成络合物,以PAN为指示剂,用铅的标准溶液回滴过量EDTA,加入氟化物使Al-EDTA络合物解蔽,释放出与铝等量EDTA,再用铅的标准溶液滴定,由此计算铝的质量分数。试验并确定了测定过程中的最佳分析条件。方法用于分析铝锰合金中铝含量,其相对标准偏差小于0.2%,结果与经典的碱分离EDTA滴定法相符。该方法可用于测定铝锰合金中铝质量分数为15%~30%的样品。

Abstract: The content of aluminum in aluminum-manganese alloy was directly determined by fluoride replacement complexometric titration without pre-separation of iron and manganese.The samples were dissolved in hydrochloric acid and H₂O₂.Excessive EDTA solution was added in the presence of copper ion to complex with metals ions such as iron,manganese and copper.The solution was boiled to make aluminum completely form complex.The excessive EDTA was back-titrated with lead standard solution using PAN as indicator.Fluoride was added to demask Al-EDTA complex,and equivalent EDTA to aluminum was released.Then,it was titrated with standard lead solution to calculate the mass fraction of aluminum.The optimal analytical conditions were tested and obtained.This method was applied to determine aluminum in aluminum-manganese alloy,and the relative standard deviation (RSD) was smaller than 0.2%.The results were consistent with those obtained by classic alkali separation EDTA titration method.This method was used to determine the aluminum-manganese alloy sample containing 15%-30% aluminum in mass fraction.