GB/T 21650.1-2008 in English

《GB/T 21650.1-2008压汞法和气体吸附法测定固体材料孔径分布和孔隙度 第1部分：压汞法》由TC168（全国颗粒表征与分检及筛网标准化技术委员会）归口，主管部门为国家标准化管理委员会。
ＧＢ／Ｔ２１６５０《压汞法和气体吸附法测定固体材料孔径分布和孔隙度》分为３个部分,本部分为ＧＢ／Ｔ２１６５０的第１部分。本标准描述了压汞法来评价固体的孔径分布和孔中比表面的比较方法。本部分适用于研究大多数非润湿多孔材料。本部分不适合于汞齐化的材料，例如金、铝、还原铜、还原镍和银等某些金属，如果一定要用该方法，则需要对样品进行预钝化处理。在外压力下，有些材料会发生变形、挤压或破坏，并出现开孔坍塌、闭孔打开的现象。在某些情况下，可能需要引入样品压缩率修正因子以获得有用的可比较的数据。因此，压汞法具有可比较性。本部分等同采用ＩＳＯ１５９０１-１：２００５《压汞法和气体吸附法测定固体材料孔径分布和孔隙度　第１部分：压汞法》（英文版）。

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

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