GB/T 4632-2008 in English

《GB/T 4632-2008煤的最高内在水分测定方法》由TC42（全国煤炭标准化技术委员会）归口，TC42SC1（全国煤炭标准化技术委员会煤炭检测分会）执行，主管部门为中国煤炭工业协会。
本标准代替GB 4632-1997《煤的最高内在水分测定方法》。
本标准规定了煤的最高内在水分充氮常压法的方法提要、试剂和材料、仪器设备、煤样的采制、测定步骤、结果计算及方法精密度。
本标准适用于褐煤、烟煤和无烟煤。
本标准与GB 4632-1997相比主要变化如下：
―――在规范性引用文件中，增加了GB/T 483（本版第2章）；
―――在“方法提要”中，强调了“充氮常压”的概念（本版第3章）；
―――增加了“试验报告”一章（本版第10章）。

1 Scope

This standard specifies nitrogen-filling atmospheric pressure method for determination of the moisture-holding capacity in coal, including the method summary, reagents and materials, instruments and apparatus, preparation of coal sample, determination procedures, expression of results and method precision.

This standard is applicable to lignite, bituminite and anthracite.

2 Normative References

The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However parties to agreements based on this standard 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 referred to applies.

GB/T 212 Proximate Analysis of Coal (GB/T 212-2008, ISO 11722: 1999, ISO 1171: 1997, ISO 562: 1998, NEQ)
GB 474 Method for Preparation of Coal Sample (GB 474-2008, ISO 18283: 2006, Hard Coal and Coke - Manual Sampling, MOD)
GB/T 483 General Rules for Analytical and Testing Methods of Coal
GB/T 6003.1 Test Sieves of Metal Wire Cloth
GB/T 16496 Chemical Reagent - Potassium Sulfate

3 Method Summary

After the coal sample reaches water saturation, remove most of external moisture with constant-humidity paper, the coal is brought to moisture equilibrium with an nitrogen-filling atmospheric pressure, relative humidity of 96% at 30℃ and then dried under nitrogen flow at 105~110℃. The moisture-holding capacity is expressed by the fraction of mass loss.

4 Reagents and Materials

4.1 Pulp mixing potassium sulfate crystal with its saturated solution: add 10g chemically pure potassium sulfate (GB/T 16496) to 3mL water to form a pulp.

Foreword i
1 Scope
2 Normative References
3 Method Summary
4 Reagents and Materials
5 Instruments and Apparatus
6 Preparation of Coal Sample
7 Determination Procedures
8 Expression of Results
9 Method Precision
10 Test Report
Annex A (Informative) Corresponding Numbering Equivalent Clauses between This Standard and ISO 1018:
Annex B (Informative) Technical Deviations between This Standard and ISO 1018:1975 and Their Justifications