EDTA配位滴定法在野外检测多金属矿石中锌量的应用

Application of EDTA Coordination Titration Method in Field Detection of Zinc in Polymetallic Ores

多金属矿石中锌量检测的准确性和速度直接影响到野外锌量勘查的准确性和效率。目前,将多金属矿石样品运输到实验室检测的方式存在采加化周期偏长、检测高含量锌稳定性和准确性不足的问题。本文对比了不同方式去除多金属矿石样品中有机质和硫、不同氧化剂、样品溶液是否离心、不同除氨方式对多金属矿石样品中锌量检测速度、稳定性和准确性的影响,建立了一种能在野外现场快速检测多金属矿石样品中锌量的EDTA配位滴定法。采用该方法对低、中、高锌含量的4个多金属国家标准物质分别进行6次平行分析,锌量的相对偏差为0.00%~2.11%,相对误差为0.00%~2.41%。结果表明,采用高温灼烧多金属矿石样品去除有机质和硫,将多金属矿石样品溶液离心后过滤可显著提升样品前处理速度;采用较为温和的氧化剂、滴加盐酸除氨,可提升检测方法的稳定性和准确度。

The accuracy and speed of zinc detection in polymetallic ores directly affect the accuracy and efficiency of field zinc exploration.At present,the transportation of polymetallic ore samples to the laboratory for testing has problems such as long addition cycles,insufficient stability and accuracy in detecting high levels of zinc.The effects of different methods of removing organic matter and sulfur from polymetallic ore samples,different oxidants,whether the sample solution was centrifuged,and different ammonia removal methods on the detection speed,stability,and accuracy of zinc in polymetallic ore samples were compared.A EDTA coordination titration method that can quickly detect zinc in polymetallic ore samples in the field was developed.Using this method,six parallel analyses were conducted on four polymetallic national standard materials with low,medium,and high zinc content.The relative deviation and relative error of zinc content were 0.00%to 2.11%and 0.00%to 2.41%,respectively.The research results indicate that using high-temperature calcination to remove organic matter and sulfur from polymetallic ore samples,and centrifuging and filtering the polymetallic ore sample solution can greatly improve the sample pretreatment speed.The use of milder oxidants and dropwise addition of hydrochloric acid for ammonia removal can improve the stability and accuracy of the detection method.