碱熔除铁氟化物置换容量法测定铁矿石中的三氧化二铝

Determination of aluminum oxide in iron ore by alkali molten iron removal fluoride replacement volumetry

试样经氢氧化钠碱熔，过滤分离铁等元素，将滤液酸化、DETA络合、氟化钠置换，再用硫酸铜标准溶液回滴释放出来的EDTA,从而实现对铝的测定，通过本方法对铁矿石标准物质及样品的测定，结果的相对标准偏差在0.93%～2.95%之间，且铁矿石标准物质测定值与认定值相符。

The samples were melted by sodium hydroxide and sodium peroxide, and most of the interfering elements like Fe were separated through precipitation, the ifltrate was acidiifed, DETA complex, sodium lfuoride replacement, and released EDTA with copper sulfate standard solution back titration. Though this method for determination of standard material and sample of iron ore, it was found that the relative standard deviation （RSD） was in the range of 0.93%-2.95%, and estimated value of iron ore standard material results were consistent with the certiifed value.