碱熔乙醇分离法测定铝锰合金中铝的含量

The Ethanol-alkali Extraction Method for the Determination of the Content of Aluminum in Aluminum-manganese Alloy

铝锰合金样品用过氧化钠熔融，使样品完全分解后，加乙醇煮沸使高价锰还原，消除高价锰的干扰，再利用铝是两性元素的特性，使铁、锰、钛生成碱性氧化物沉淀，过滤与铝分离。然后采用EDTA容量法可测得铝锰合金中铝量。该方法一次分离，简便、快速、准确，可适用于测定铝锰合金中10％～50％的铝量。其相对标准偏差（RSD，n=5）小于0．5％，加标回收率98．5％～101％。

The aluminum manganese alloy sample is melted in sodium peroxide. When the sample completely decomposed, ethanol is added and boiled to reduce the high valence of manganese. Thus the interference of high valence manganese is eliminated. Because A1 is amphoteric, the Fe, Mn and Ti in the sample can generate alkaline oxide precipitation and are separated with A1 by filtration. A portion of filtrate is acidified i and EDTA is added to generates coordination complex with A1. Zinc acetate standard solution is used to back- titrated the excess EDTA. KF is added and quantitative coordinated with A1. Zinc acetate standard solution is then used to titrate the substituted EDTA and get the content of aluminum. The proposed method has only one separation process. It is simple, rapid and accurate, and can be applied to the determination of the aluminum which amount is 10%-50% in the alloy of aluminum and 5 ） is less than 0.5% and the recovery is 98.5%-101%. manganese. The relative standard deviation （ RSD,n=