光度法EDTA滴定法联合测定铌铁合金中铌和铝  

Combined Determination of Niobium and Aluminum in Ferro-Niobium Alloy by Spectrophotometry and EDTA Titration Method

作　　者：王际祥 魏恩双 马芳 王俊秀 薛明浩 

机构地区：[1]品质保证部 [2]山东鲁丽钢铁有限公司

出　　处：《莱钢科技》2016年第2期54-56,共3页Laigang Science & Technology

摘　　要：建立了一种快速测定铌铁合金中铌和铝的分析方法。以硝酸、氢氟酸、硫酸溶解试样,加速蒸发至硫酸冒烟以除去硅和氟,当用水稀释溶解盐类后,铌离子极易水解形成沉淀,但在稀氢氟酸存在下,铌与氟形成可溶性络合物（H_2NbF_7）。该方法用此特性,使铌保持于滤液中,用二甲酚橙光度法测定铌铁合金中铌量。经过用氢氧化钠沉淀分离试液中铁、铌、钛等干扰元素后,在p H=4.5~5.5缓冲体系中,以氟盐置换EDTA滴定法测定铝量。该方法用于实际铌铁合金标样中铌和铝的分析,测定值与标准值相符,铌和铝相对标准偏差分别为0.14%和5.30%。One rapid analysis method for determination of niobium and aluminum in ferro-niobium alloy was set up. The sample was dissolved with nitric acid,hydrofluoric acid and sulfuric acid,and the silicon and fluorine were removed by accelerating the evaporation until sulfuric acid smoking. After the salts were diluted and dissolved with water,the niobium ion was easily hydrolyzed to form precipitation,while in the presence of dilute hydrofluoric acid,the niobium and fluorine could formed into a soluble complex（ H_2NbF_7）. By using this characteristic,the niobium could be kept in the filtrate,and the content of niobium in the alloy was determined by xylenol orange spectrophotometry. Then after the sodium hydroxide was added to precipitate and separate the interference elements such as iron,niobium and titanium in solution,in pH = 4. 5 ~ 5. 5 buffer system,the content of aluminium was determined by fluoride salt replacement EDTA titration method. The measured value obtained by this method used in the analysis on niobium and aluminium in actual ferro-niobium alloy standard sample was in conformity with the standard value,the relative standard deviation of niobium and aluminum were respectively 0. 14% and 5. 30%.

关 键 词：铌铁合金 光度法 络合滴定法 铌 

分 类 号：TQ153.2[化学工程—电化学工业]