Detail of GB/T 21650.1-2008

Introduction of GB/T 21650.1-2008

Pore size distribution and porosity of solid materials by mercury porosimetry and gas adsorption - Part 1: Mercury porosimetry WARNING - The use of this International Standard may involve hazardous materials, operations and equipment. This part does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this part to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1 Scope This part describes a method for the evaluation of the pore size distribution and the specific surface in pores of solids by mercury porosimetry according to the method of Ritter and Drake[1], [2]. It is a comparative test, usually destructive due to mercury contamination, in which the volume of mercury penetrating a pore or void is determined as a function of an applied hydrostatic pressure, which can be related to a pore diameter. Practical considerations presently limit the maximum applied absolute pressure to about 400 MPa (60000 psia) corresponding to a minimum equivalent pore diameter of approximately 0.003 μm. The maximum diameter will be limited for samples having a significant depth due to the difference in hydrostatic head of mercury from the top to the bottom of the sample. For the most purposes, this limit can be regarded as 400 μm. The measurements cover interparticle and intraparticle porosity. In general, it cannot distinguish between these porosities where they co-exist. The method is suitable for the study of most non-wettable, by mercury, porous materials. Samples that amalgamate with mercury, such as certain metals, e.g. gold, aluminium, reduced copper, reduced nickel and silver, can be unsuitable for this technique or can require a preliminary passivation. Under the applied pressure, some materials are deformed, compacted or destroyed, whereby open pores can be collapsed and closed pores opened. In some cases, it is possible to apply sample compressibility corrections and useful comparative data can still be obtained. For these reasons, the mercury porosimetry technique is considered to be comparative. 2 Normative references The following normative documents contain provisions which, through reference of GB/T 21650.1, constitute provisions of this part. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document applies. GB/T 3723 Sampling of chemical products for industrial use - Safety in sampling (GB/T 3723-1999, IDT ISO 3165:1976) ISO 8213 Chemical products for industrial use - Sampling techniques - Solid chemical products in the form of particles varying from powders to coarse lumps M 024 4/85 Quecksilber und seine Verbindungen. Merkblatt der Berufsgenossenschaft der chemischen Industrie, Postfach 101480, D-69004 Heidelberg, Germany 3 Terms and definitions For the purposes of this part, the following terms and definitions apply. 3.1 bulk density powder density under defined conditions 3.2 blind pore dead-end-pore open pore having a single connection with an external surface 3.3 closed pore cavity not connected to the external surface Note: Closed pores are not covered in this International standard. 3.4 contact angle angle that a non-wetting liquid makes with a solid material

Contents of GB/T 21650.1-2008

Foreword I Introduction II 1 Scope 2 Normative references 3 Terms and definitions 4 Symbols 5 Principles 6 Apparatus and material 6.1 Sample holder 6.2 Porosimeter 6.3 Mercury 7 Procedures for calibration and performance 7.1 General 7.2 Pressure signal calibration 7.3 Volume signal calibration 7.4 Vacuum transducer calibration 7.5 Verification of porosimeter performance 8 Procedures 8.1 Sampling 8.1.1 Obtaining a test sample 8.1.2 Quantity of test sample 8.2 Method 8.2.1 Sample pretreatment 8.2.2 Filling of the sample holder 8.2.3 Evacuation 8.2.4 Filling the sample holder with mercury 8.2.5 Measurement 8.2.6 Completion of test 8.2.7 Blank and sample compression correction 9 Evaluation 9.1 Calculation of the pore size distribution 9.2 Calculation of the specific pore volume 9.3 Calculation of the specific surface area 10 Reporting Annex A (Informative) Mercury porosimetry analysis results for alumina reference sample Bibliography