The determination of metallic iron and ferrous oxide in furnace slag was studied.The leaching effect of five weak acid salt solutions (which could react with metallic iron but not react with ferrous oxide,including lead acetate,copper acetate,ferric chloride-sodium acetate-acetic acid,iodinepotassium iodide and ferric trichloride) and non-aqueous solution (iodine-ethanol solution) on metallic iron were investigated.The iodine-ethanol solution was selected as the leaching agent for metallic iron in furnace slag.0.200 0 g of furnace slag sample was leached with 50 mL of iodine-ethanol solution for 40 min,then the content of iron in leaching solution and ferrous in residue was determined by potassium dichromate titration,respectively,to obtain the content of metallic iron and ferrous oxide in furnace slag.The experimental method showed that,leaching rate of metallic iron was higher than 97％,while ferrous oxide was not leached.Compared with the classical ferric chloride leaching reagent,iodine-ethanol system showed better leaching effect of metallic iron.The metallic iron could be totally separated from ferrous oxide and avoided the acid dissolution interference while using ferric trichloride as leaching agent.The steel slag and dephosphorization slag were leached with iodine-ethanol solution and then determined by potassium dichromate titration.The relative standard deviation (RSD) of metallic iron was 4.2％ and 4.6 ％,respectively.The RSD of ferrous oxide was 0.72 ％ and 0.62 ％,respectively.%对炉渣中的金属铁与氧化亚铁的测定进行了研究.通过考察与金属铁反应而不与氧化亚铁反应的5种弱酸盐溶液(醋酸铅溶液、醋酸铜溶液、三氯化铁-醋酸钠-醋酸溶液、碘-碘化钾溶液、三氯化铁溶液)和非水溶液(碘-乙醇溶液)对金属铁的浸取效果,选取了碘-乙醇溶液作为炉渣中金属铁的浸取剂.实验结果表明,0.200 0 g炉渣样品用50 mL碘-乙醇溶液浸取40min,采用重铬酸钾滴定法分别测定浸取液中铁量和浸取后残渣中的亚铁量,得到炉渣中金属铁和氧化亚铁量,金属铁的浸取率在97％以上,而氧化亚铁不被浸出.与经典的三氯化铁浸取剂相比,本浸取剂对金属铁的浸取效果好,金属铁与氧化亚铁分离完全,避免了用三氯化铁溶液作浸取剂时亚铁与金属铁的酸溶干扰.以碘-乙醇溶液浸取钢渣和脱磷渣后采用重铬酸钾滴定法测定,金属铁的测定结果的相对标准偏差(RSD)分别为4.2％和4.6％,氧化亚铁测定结果的相对标准偏差(RSD)分别为0.72％和0.62％.
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