电位滴定法测定铬矿石中三氧化二铬的微波溶样法研究

来源期刊：冶金分析2011年第2期

论文作者：胡德新 马德起 潘宏伟 王振坤 王虹 姚传刚 魏红兵

文章页码：63 - 66

关键词：微波消解； 电位滴定； 铬矿石； 三氧化二铬； 消解功率

Key words：microwave digestion； potentiometric titration； chrome ore； chromium sesquioxide； digestion power

摘    要：详细探讨、优化了超高压条件下微波消解铬矿石的条件,并对来自各国的大部分铬矿石进行消解试验。结果表明,在称样量为0.20 g,加入7 mL硫酸、5 mL磷酸和1 mL氟硼酸及在1 200 W的超高压输出功率下消解40 min,能很好的溶解铬矿石样品。在此消解条件下消解样品,并利用电位滴定法对2个不同三氧化二铬含量的铬矿石国家一级标准物质测定10次,测定结果的平均值与认定值的相对误差为0.018%~0.024%,相对标准偏差为0.11%~0.14%;用相同的方法对来自不同国家的铬矿石进行消解和测定,三氧化二铬测定结果在实验室允许误差范围内。

Abstract: The conditions of high-pressure microwave digestion in closed vessels are discussed in detail and optimized.Most of chrome ores from main business countries were tested by this method.The results showed that chrome ores could be digested completely under such conditions as: 0.20 g of sample weight,7 mL of H₂SO₄,5 mL of H₃PO₄,1 mL of HBF₄,high-pressure digestion power at 1200 W and digestion time of 40 min.Using this digestion conditions,two national primary reference ores of chromium containing different content of chromium sesquioxide were determined for 10 times by potentiometric titration.The average value of the determination results were consistent with the certified values with a relative error of 0.018%-0.024% and relative standard deviation of 0.11%-0.14%.The proposed method has also been applied to the digestion and determination of chromium ores from different countries.The results of chromium sesquioxide were all within the allowable error.