高频加热-红外线吸收法测定石灰石样品中硫含量

High frequency heating-infrared absorption method for determination of sulfur content in limestone samples

石灰石样品熔融时分解产生的氧化钙对硫有很强的吸附能力,而且极容易吸水。分析用坩埚主要成分是二氧化硅和三氧化二铝,而且表面有粗糙的微孔容易吸附空气中的二氧化碳和水汽。本文采用高频加热方式燃烧石灰石样品,红外线吸收法测定硫含量,确定了仪器分析的最佳条件、坩埚与样品的预处理方法、合理的称样质量、适宜的助熔剂与加入方式。通过对不同石灰石标准样品分别进行测定,测定结果与标准值基本一致,相对标准偏差(RSD,n=10)小于3.50%,实验结果表明,本方法测定结果准确可靠,有效解决了样品和坩埚因为吸附作用影响硫含量分析结果不稳定的问题。

The calcium oxide produced by the decomposition of limestone samples has a strong adsorption capacity for sulfur and is extremely easy to absorb water.The main components of the crucible are silica and alumina,and the surface is with rough micropore to absorb carbon dioxide and water vapor in the air.The high frequency heating mode was used for burning the limestone samples,and the infrared absorption method for determination of sulfur content was established.The optimum conditions of instrument analysis,the pretreatment method of the crucible and samples,the reasonable amount of samples,appropriate flux and addition method were determined.Different standard limestone samples were measured respectively,and the determination results were in agreement with the standard values while the relative standard deviation（RSD,n = 10）was below 3.50%.This method was accurate and reliable,by which the problem that the analytic results of sulfur may be unstable due to the adsorption effect of the samples and the crucible was effectively solved.