基于探针气体吸附等温线的矿物岩石表征技术IV:比表面积的测定和应用

矿物的比表面积是决定矿物表面反应能力和吸附容量的重要参数,但因其测定方法多样、分析结果受多种因素影响,致使分析结果有时会偏离实际值.为全面认识和更好地利用比表面积数据,本文在对比表征矿物材料比表面积的几种常用技术的基础上,重点介绍了基于探针气体吸附等温线的比表面积测定方法.以方解石粉体、石英粉体、蒙脱石等常见矿物材料和铁锰结壳为例,根据各类材料的比表面积测定数据,研究了探针气体种类、脱气温度和吸附平衡时问等测试条件的影响.并从表面能量非均质性和孔隙结构的角度,提出了在应用测定结果时需要注意的问题.

The Technique of Surface Characteristics of Mineral Material Based on Probe Gas Adsorption Isotherm IV:Measurement and Application of Specific Surface Area

The specific surface area is a key parameter characterizing the surface reactivity and adsorption capacity. But the measured values of specific surface area of many minerals and materials are sometimes deviated from the re al ones due to the influence of many factors, including structure properties and selection of measuring parameters, and the difference of measuring methods. In order to comprehensively understand better utilize the data of specific surface area of minerals and materials, this paper has made comparison among several normal techniques for measuring specific surface area of minerals and materials, and especially introduced the method based on probe gas adsorption isotherm. In this study, a set of parallel measurements of the specific surface area of calcite, quartz, smectites and marine hydrogenous ferromanganese crusts has been carried out. Then, the influences on the analysis by the analytical conditions including probe gas types,degassing temperature and equilibrium duration have been discussed in details by comparing with the above measured data. Furthermore, several aspects for applying the measured data of the specific surface area have been addressed in the view of surface energy heterogeneity and porous structure.