黑钨精矿、黑钨中矿标准物质样品的制备

Preparation of Reference Material for Wolframite Concentrate and Middling Wolframite Concentrate

钨标准物质在钨的测定、分析仪器校准、分析方法的评价等方面发挥非常重要的作用。黑钨精矿、黑钨中矿在标准物质样品制备过程中产生严重的热团聚现象,样品制备非常困难,至今国内没有相关标准物质。研究发现通过降低转速、延长磨样间隔时间可以降低磨样产生的大量热量以减小热团聚现象,再结合过筛完成制样。实验采用间歇正反转干磨,过0.074mm湿筛,筛上3kg小瓷球磨机湿磨,再球磨机混样,最后人工8次梅花堆锥混样。经均匀度检验样品粒度小于0.074mm超过98%,稳定性检验合格。制备的样品满足标准物质要求。

Reference material of tungsten plays important role in quality control of the determination of tungsten in wolframite,calibration of analytical instrument and assessment of analytical method.The preparation of wolframite concentrate,middling wolframite concentrate is very difficult,so there is no standard tungsten concentrate in China.It is mainly problem that there exists seriously hot reunion phenomenon in sample preparation and sample is hard to be powdered.The hot reunion phenomenon is caused by heat liberation.This problem was solved through reducing rotate speed of ball grinding mill and prolonging interval of mill.The optimized procedure was as follows：intermittent dry grinding in negative and positive direction,wet screening of 0.074mm,screenings wet grinding with 3kg porcelain ball mill,sample mixing with ball mill,artificial sample mixing by heaping up for 8 times.The concentrate were tested for homogeneity,and the results showed that more than 98% of the concentrate were less than 0.074mm in size.The concentrate were up to standard.