铬铁合金中铁的测定  

Determination of Iron in Ferrochrome Alloy

作　　者：姚应锋 方彦霞 牛永胜 孙帅楠 李秀花 YAO Yingfeng;FANG Yanxia;NIU Yongsheng;SUN Shuainan;LI Xiuhua(Northwest Research Institute of Mining and Metallurgy,Baiyin 730900,China)

机构地区：[1]西北矿冶研究院,甘肃白银730900

出　　处：《甘肃冶金》2025年第1期81-84,共4页Gansu Metallurgy

摘　　要：铬铁矿石中的铬无论是高价还是低价,均因其带色而干扰许多组分的测定。采用氯化铬酰挥发法除去铬,试样用高氯酸分解,铬被氧化到高价,通过滴加盐酸或氯化钠,六价铬以氯化铬酰气体挥发,部分六价铬又被还原到三价,需要用高氯酸反复氧化,在用盐酸或氯化钠除铬。加入硫酸使高氯酸蒸发完全,继续加热至硫酸烟冒尽。加入盐酸溶解,加热用二氯化锡热还原,冷却后加入氯化汞除去过量的二氯化锡,加入硫磷混酸,以二苯胺磺酸钠为指示剂,用重铬酸钾标准溶液滴定至溶液呈蓝紫色即为终点,进而得出铁的含量。这种通过重复滴加盐酸或氯化钠使铬形成氯化铬酰挥发掉,提高铬铁合金中铁的检测的准确性和时效性。Chromium in ferrochrome ore,whether high or low,interferes with the determination of many components because of its color.In this paper,chromic chloride volatilization method is used to remove chromium,the sample is decomposed with perchloric acid,chromium is oxidized to high price,by dropping hydrochloric acid or sodium chloride,hexavalent chromium is volatilized with chromic chloride gas.Part of the hexavalent chromium is reduced to trivalent,requiring repeated oxidation with perchloric acid,and removal of chromium with hydrochloric acid or sodium chloride.Sulfuric acid is added to evaporate the perchloric acid completely,and the heat is continued until the sulfuric acid smoke is exhausted.After cooling,mercury chloride was added to remove excess tin dichloride,and thiophosphoric acid was added.Titrations of potassium dichromate standard solution with sodium diphenylilinesulfonic acid as an indicator were made until the solution turned blue and purple,which was the end point,and then the iron content was obtained.By repeated drops of hydrochloric acid or sodium chloride,chromium forms chromioyl chloride to volatilize,improving the accuracy and timeliness of the detection of iron in ferrochrome alloy.

关 键 词：铬铁合金 重铬酸钾容量法 氯化铬酰 二氯化锡 氯化汞 

分 类 号：TF641[冶金工程—钢铁冶金] O655.2[理学—分析化学]