Abstract：Iron ore is one of the important raw materials in the metallurgical industry, and total iron is the most important pricing element. Therefore, it is of great significance to determine total iron content in iron ore. When the sample is treated with Na2CO3-H3BO3 fusion according to the standard method of GB/T 6730.65-2009, a large amount of acid is required to leach the melt, and the operation is relatively tedious. The sample was treated with Li2B4O7-LiBO2 fusion, and the melt could be peeled automatically by adding release agent. Only a small amount of acid was required to completely dissolve the melt, which not only simplified the operation, but also saved the reagents. The sample fusion conditions were optimized. The mass ratio of flux to sample was 5∶1. The sample was placed in a platinum crucible containing the mixed flux of Li2B4O7-LiBO2. After mixing, 0.5 mL of 300 g/L NH4I solution was added as the release agent. The platinum crucible was heated in high-temperature furnace at 1 000 ℃ for 10 min. After cooling, the melt was peeled automatically and then dissolved with HCl (1+10) solution. The SnCl2 solution was dripped to reduce Fe (Ⅲ) to Fe (Ⅱ). Consequently, a determination method of total iron content in all kinds of iron ores was established by potassium dichromate titration with sodium diphenylamine sulfonate as the indicator. The certified reference materials of magnetite and sinter were determined according to the proposed method. The relative standard deviations (RSD,n=9) of the determination results were all less than 0.3%. The contents of total ion in certified reference materials of iron ore were determined according to the proposed method and potassium dichromate titration with Na2CO3-H3BO3 fusion in the standard method of GB/T 6730.65-2009. The determination results of two methods were basically consistent. Moreover, the errors between the determination results by the above two methods and the certified values or reference values were both within the allowable range specified in the standard method of GB/T 6730.65-2009.
滕广清, 张改梅, 鲍希波. 四硼酸锂-偏硼酸锂熔融-重铬酸钾滴定法测定铁矿石中全铁[J]. 冶金分析, 2023, 43(9): 76-80.
TENG Guangqing, ZHANG Gaimei, BAO Xibo. Determination of total iron in iron ore by potassium dichromate titration with lithium tetraborate-lithium metaborate fusion. , 2023, 43(9): 76-80.
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