快速测定铬铁矿中铬的溶样方法研究

Study on the Sample Dissolution Method for Rapid Determination of Chrominum in Chromite

根据对硫酸高温(～330℃)湿烧铬铁矿反应过程原理的应用研究,改进了测定铬铁矿中铬的溶样方法。试样与硫酸共热(2000W电炉)至冒三氧化硫浓烟,并腾空>6min,然后与磷酸共热,再腾空至杯壁近2/3处时冷却、稀释、氧化、常法测定铬量。所推荐的测定铬铁矿中铬的改进型的溶样方法模式,经标准物质和管理样验证(RSD=0.31%～0.40%,n=10)以及生产样品测试数据对比等,均获满意结果。

Through the application research on the reaction principle for the wet ablating chromite by sulfuric acid at high temperature（-330 ℃）, the sample dissolution method for determination of chromium in chromite was improved. The sample was heated （in a 2000 W electric furnace） with sulfuric acid until thick sulfur trioxide smoke appeared and then soared for 〉6 min. Then the sample was heated again with phosphoric acid until thick smoke appeared and soared to the level of about 2/3 height of the beaker wall. After the sample was cooled properly, diluted and oxidized, the chromium contents were determined by normal method. By comparing the analytical results of the production samples with the standards and the verification experiments （RSD=0.31%～0.40%,n=10）, it concluded that the improved sample dissolution method can give satisfactory results.