二安替比林甲烷光度法测定高钛型高炉渣中钛

针对高炉渣反应活性差,熔样困难的特点,实验采用将炉渣粒度球磨至100目以下,硼酸-碳酸钠(2+1)作熔剂,900 ℃下熔融30 min,在瓷坩埚中铺垫石墨的方式来代替铂坩埚熔融样品,然后用硫酸(φ=10%)加热浸取熔块,抗坏血酸掩蔽Fe³⁺的干扰,最后用二安替比林甲烷分光光度法测定高钛型高炉渣中钛的含量。二安替比林甲烷与钛生成黄色络合物的最大吸收波长为390 nm,表观摩尔吸光系数为1.06×10⁴ L·mol^-1·cm^-1。钛含量在0.5～20 μg/mL范围内符合比尔定律,相关系数为0.999 8。方法用于高炉渣标准样品和实际样品中钛的测定,结果与认定值及硫酸高铁铵滴定法的测定值相吻合,相对标准偏差(RSD,n=5)为0.24%～0.57%,回收率为99%～101%。

Spectrophotometric determination of titanium in high-Ti-bearing blast-furnace slag with diantipyrylmethane

Due to low reactivity and difficult dissolution of blast-furnace slag, the furnace slag was ball-milled below 100-mesh. The sample was fused at 900 ℃ for 30 min with boric acid and sodium carbonate (2+1) as flux. The platinum crucible was replaced by porcelain crucible with laid graphite for the fusion of sample. Then, the melt was leached with sulfuric acid (φ=10%) under the condition of heating. The interference of Fe³⁺ was masked by ascorbic acid. Finally, the content of titanium in high-Ti-bearing blast-furnace slag was determined by diantipyrylmethane spectrophotometry. The yellow complex formed by diantipyrylmethane and titanium had maximum absorption wavelength at 390 nm. The apparent molar absorptivity was 1.06×10⁴ L·mol^-1·cm^-1. Beer’s law was obeyed for titanium in the range of 0.5-20 μg/mL with the correlation coefficient of0.999 8. The proposed method was applied to the determination of titanium in CRM and actual sample of blast-furnace slag . The results were consistent with the certified values and those obtained by high ferric ammonium sulfate titration. The relative standard deviation (RSD, n=5) was 0.24%-0.57%,and the recoveries were between 99 % and 101 %.