普碳钢轧钢氧化铁粉中全铁的测定

Determination of Total Iron in Iron Oxide Powder from Plain Carbon Steel Rolling

试样以盐酸溶解后,在酸性介质中,先以氯化亚锡将三价铁大部分还原为二价,然后在钨酸钠指示下,再以三氯化钛将剩余的三价铁还原为二价,过量的三氯化钛以重铬酸钾氧化消除干扰,在硫磷混合酸存在下,以二苯胺磺酸钠为指示剂,用重铬酸钾标准溶液滴定全铁量。实验结果表明,该分析方法操作简便易行,数据准确可靠,能够满足氧化铁粉对全铁含量指标化验的要求。

After the sample was dissolved in acidic medium, stannous chloride was used to reduce large parts of trivalent iron into bivalent, under the indication of sodium tungstate, titanium trichloride was used to reduce the remaining trivalent iron into bivalent, and then totassium dichromate was used to oxidize excessive titanium trichloride to eliminate its interference. In the presence of the combination of sulphuric and phosphoric acid, with sodium diphenylamine sulfonate as the indicator, standard solution of potassium dichromate was used to titrate total iron value. The test results show the method ,which is simple to operate, data being accurate and reliable, can meet the requirements in examining total iron value indexes in iron oxide powder.