熔融制样-X射线荧光光谱法测定钛铁中钛磷硅锰铝

采用传统的化学湿法测定钛铁中主次元素含量时操作繁琐,分析时间长且不易掌握。为开拓X射线荧光光谱仪测定钛铁的应用,实验采用硫酸(1+10)溶解试样,低温加热蒸干、冒硫酸烟、高温加热预氧化技术,解决了钛铁合金高温熔融时单质合金元素易与铂形成低温共熔体而损坏铂黄坩埚的难题,并对硫酸浓度及用量、试样溶解条件、稀释比及熔融温度和时间对检测结果的影响进行了研究,得出了使用10 mL硫酸(1+10)溶解试样、加热冒尽硫酸烟、以1∶40的稀释比在1 100 ℃温度下熔融15 min的最佳试验条件,并以此条件建立了熔融制样-X射线荧光光谱法测定钛铁中钛、磷、硅、锰、铝的校准曲线,校准曲线的线性相关系数均大于0.993。选用钛铁样品平行制备12个玻璃样片,以进行精密度考察,5种元素测定结果的相对标准偏差(RSD,n=12)在0.15%～5.0%范围内。采用实验方法测定钛铁标准样品中钛、磷、硅、锰、铝,测定值与认定值基本一致。对于钛铁样品,实验方法与国家或行业标准方法检测结果相符,能满足钛铁合金的日常检测需求。

Determination of titanium,phosphorus, silicon,manganese and aluminum in ferrotitanium by X-ray fluorescence spectrometry with fusion sample preparation

During the determination of major and minor elements in ferrotitanium by the traditional chemical wet analysis method, the operation was time-consuming and difficult to master. The application of X-ray fluorescence spectrometry(XRF) for determination of ferrotitanium was explored. The sample was dissolved with sulfuric acid (1+10). The pre-oxidation technology of low temperature heating evaporation, fuming sulfuric acid and high temperature heating were adopted to solve the problem that the platinum-gold crucible was easily damaged due to the formation of low temperature eutectic between alloying element and platinum during high-temperature fusion of ferrotitanium alloy. The effects of concentration and dosage of sulfuric acid, sample dissolution conditions, dilution ratio, fusion temperature and fusion time on the determnaiton results were investigated. The optimal conditions were obtained as follows: 10 mL of sulfuric acid (1+10) was used to dissolve the sample; the solution was heated to exhaust sulfuric acid smoke; the dilution ratio was 1∶40; the fusion temperature and time was 1 100 ℃ and 15 min, respectively. Consequently, the calibration curves for determination of titanium, phosphorus, silicon, manganese, and aluminum in ferrotitanium by X-ray fluorescence spectrometry with fusion sample preparation were established. The correlation coefficients of calibration curves were all greater than 0.993. The ferrotitanium sample was selected to prepared twelve parallel glass sheet for precision test. The relative standard deviations (RSD, n=12) of the determination results for five elements were between 0.15% and 5.0%. The proposed method was applied to determination of titanium, phosphorus, silicon, manganese, and aluminum in ferrotitanium certified reference materials. The results were consistent with the certified values. For ferrotitanium samples, the determination results of the proposed method were consistent with those obtained by national or industry standard methods. The proposed method could meet the daily testing requirements of ferrotitanium alloy.