1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA CG 2-2004Powdered GraphiteNEMA Standards Publication CG 2-2004 Powdered Graphite Published by: National Electrical Manufacturers Association 1300 North 17th Street, Suite 1847 Rosslyn, Virginia 22209 www.nema.org Copyright 2
2、004 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions. NO
3、TICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person particip
4、ating in the development of this document. The National Electrical Manufacturers Association (NEMA) standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers
5、and/or seeks out the views of persons who have an interest in the topic covered by this publication. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify th
6、e accuracy or completeness of any information or the soundness of any judgments contained in its standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, dir
7、ectly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, expressed or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the informat
8、ion in this document will fulfill any of your particular purposes or needs. NEMA does not undertake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaki
9、ng to render professional or other services for or on behalf of any person or entity, nor is NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a compe
10、tent professional in determining the exercise of reasonable care in any given circumstances. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this public
11、ation. NEMA has no power, nor does it undertake to police or enforce compliance with the contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safetyr
12、elated information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement.CG 2-2004 Page i Copyright 2004 by the National Electrical Manufacturers Association. CONTENTS Page Foreword iv Section 1 GENERAL 1.1 Scope.1 1.2 Normativ
13、e References 1 1.3 Definitions2 1.3.1 Definitions for Graphite.2 1.3.2 Other Definitions .2 Section 2 TEST METHODS 2.1 Proximate Graphite Analysis 4 2.1.1 Scope 4 2.1.2 Interferences .4 2.1.3 Apparatus4 2.1.4 Procedure for Testing Percent Moisture4 2.1.5 Procedure for Testing Percent Volatile 4 2.1.
14、6 Procedure for Testing Percent Ash4 2.1.7 Procedure for Testing Percent Loss on Ignition 4 2.1.8 Calculations.5 2.1.9 Report5 2.2 Bulk Density.5 2.2.1 Scope 5 2.2.2 Interferences .5 2.2.3 Apparatus6 2.2.4 Procedure6 2.2.5 Calculation.6 2.2.6 Report6 2.3 Compressed Density.8 2.3.1 Scope 8 2.3.2 Inte
15、rference .8 2.3.3 Apparatus8 2.3.4 Procedure8 2.3.5 Calculation.8 2.3.6 Report8 2.4 Tap Density .8 2.4.1 Scope 8 2.4.2 Interference .8 CG 2-2004 Page ii Copyright 2004 by the National Electrical Manufacturers Association. 2.4.3 Apparatus9 2.4.4 Procedure10 2.4.5 Calculation.10 2.4.6 Report10 2.5 Par
16、ticle Size Analysis by Light Scattering Method 10 2.5.1 Scope 10 2.5.2 Interference .10 2.5.3 Apparatus10 2.5.4 Procedure10 2.5.5 Calculations.11 2.5.6 Report11 2.6 Particle Size Analysis by Vacuum Sieve Method 11 2.6.1 Scope 11 2.6.2 Interferences .11 2.6.3 Apparatus11 2.6.4 Procedure11 2.6.5 Calcu
17、lations.11 2.6.6 Report12 2.7 Impurities by X-Ray Fluorescence Method12 2.7.1 Scope 12 2.7.2 Interference .12 2.7.3 Apparatus12 2.7.4 Procedure12 2.7.5 Calculations.13 2.7.6 Report13 2.8 Real Density by Gas Pycnometry Method.13 2.8.1 Scope 13 2.8.2 Interferences .13 2.8.3 Apparatus13 2.8.4 Procedure
18、13 2.8.5 Calculations.15 2.8.6 Report15 2.9 Surface Area15 2.9.1 Scope 15 2.9.2 Interferences .15 2.9.3 Apparatus15 2.9.4 Procedure16 CG 2-2004 Page iii Copyright 2004 by the National Electrical Manufacturers Association. 2.9.5 Calculations.16 2.9.6 Report16 2.10 pH.16 2.10.1 Scope 16 2.10.2 Interfe
19、rence .16 2.10.3 Apparatus16 2.10.4 Procedure17 2.10.5 Calculations.17 2.10.6 Report17 2.11 Resiliency 17 2.11.1 Scope 17 2.11.2 Interferences .17 2.11.3 Apparatus17 2.11.4 Procedure17 2.11.5 Calculations.18 2.11.6 Report18 2.12 Electrical Resistivity.18 2.12.1 Scope 18 2.12.2 Interferences .18 2.12
20、.3 Apparatus18 2.12.4 Procedure18 2.12.5 Calculations.19 2.12.6 Report19 FIGURES Figure 2-1 Volumeter for Bulk Density Test.7 Figure 2-2 Mechanical Tapping Device .9 Figure 2-3 Typical Gas Pycnometer.14 Figure 2-4 Mold Assembly for Electrical Resistivity Test.20 CG 2-2004 Page iv Copyright 2004 by t
21、he National Electrical Manufacturers Association. Foreword User needs and safety considerations were addressed during the preparation of this Standard, which was reviewed and approved for publication by both the Graphite Technical Committee and the Refractory, Metallurgical, and Chemical Group of th
22、e Carbon and Manufactured Graphite Section. SI units for weights and measures are used wherever possible; U.S. customary units are used only where it is necessary to agree with common U.S. laboratory equipment and practices. All clausesi.e., scope, normative references, definitions, and test methods
23、are considered normative (equivalent to the designation of “NEMA Standard“). Matter considered informative (equivalent to the designation of “NEMA Authorized Engineering Information“) appears under notes in these clauses. The Carbon and Manufactured Graphite Section will periodically review this Sta
24、ndards Publication and revise it as necessary to reflect advancing technology. Proposed or recommended revisions, as well as questions concerning the availability of generically described test equipment, should be submitted to: Vice President, Engineering Department National Electrical Manufacturers
25、 Association 1300 North 17th Street Rosslyn, Virginia 22209 This Standards Publication was developed by the Powdered Graphite Working Group of the NEMA Carbon and Manufactured Graphite Section. Section approval of the standard does not necessarily imply that all section members voted for its approva
26、l or participated in its development. At the time it was approved, the Powdered Graphite Working Group was composed of the following members: Graftech International Limited SGL Carbon Corporation, LLC Showa Denko Carbon, Inc. Superior Graphite Company CG 2-2004 Page 1 Copyright 2004 by the National
27、Electrical Manufacturers Association. Section 1 GENERAL 1.1 SCOPE This standard covers terminology and test methods for those physical and chemical properties relevant to the material characterization of powdered graphite, generally less than 75 microns, used in the electrical industry. The test met
28、hods specified assume adherence to good laboratory practice. No attempt has been made to determine the precision and bias of these test methods. This standard does not contain any application performance requirements relative to powdered graphite. 1.2 NORMATIVE REFERENCES The following standards con
29、tain provisions which, through reference in this text, constitute provisions of this Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and investigation of applying the most recent editions of the standards indicated below is encouraged.
30、American Society for Testing and Materials 100 Barr Harbor Drive West Consochocken, PA 19428 ASTM C 561-91 Standard Test Method for Ash in a Graphite Sample ASTM C 562-91 Standard Test Method for Moisture in a Graphite Sample ASTM C 709-91 Standard Terminology for Manufactured Carbon and Graphite AS
31、TM C 816-92 Standard Test Method for Sulfur in Graphite by Combustion-Iodometric Titration ASTM D 2638-91 Standard Test Method for Real Density of Calcined Petroleum Coke by Helium Pycnometry ASTM D 3175-89 Standard Test Method for Volatile Matter in the Analysis Sample of Coal and Coke ASTM D 3177-
32、89 Standard Test Method for Total Sulfur in the Analysis Sample of Coal and Coke ASTM D 4326-90 Standard Test Method for Major and Minor Elements in Coal and Coke Ash by X-Ray Fluorescence ASTM D 5004-89 Standard Test Method for Real Density of Calcined Petroleum Coke by Xylene Displacement ASTM D 5
33、187-91 Standard Test Method for Determination of Crystallite Size (Lc) of Calcined Petroleum Coke by X-Ray Diffraction ASTM E 305-89 Standard Practice for Establishing and Controlling Spectrochemical Analytical Curves ASTM E 1617-94 Standard Practice for Reporting Particle Size Characterization Data
34、 CG 2-2004 Page 2 Copyright 2004 by the National Electrical Manufacturers Association. Metal Powder Industries Federation 105 College Road East Princeton, NJ 05840 MPIF 46-92 Determination of Tap Density of Metal Powders NOTEFurther informative material relating to this standard can be found in ASTM
35、 volumes 5.05 and 15.01. 1.3 DEFINITIONS For the purposes of this standard, the following definitions apply: 1.3.1 Definitions for Graphite graphite: Occurring either in synthetic or natural form, a material composed predominantly of carbon with extensive long range order (per ASTM C709 and ASTM D51
36、87, a lattice spacing of 3.354 angstroms is optimal). natural graphite: Non-synthetic graphite. synthetic graphite: a. Artificial graphite b. Manufactured graphite c. Electrographite d. Thermally processed carbon containing a significant graphitic matrix 1.3.2 Other Definitions ash content: The amou
37、nt of residue remaining in a powder after ignition of combustible substances determined by definite prescribed methods. blinding: The reduction in the number of clear openings in a sieve due to mechanically trapped particles caught in the openings. bound moisture: Water that is chemically combined w
38、ith a powder. bulk density: Apparent density. The mass, under specified conditions, of a unit volume of a powder including its pore volume and inter-particle voids. compressed density: The mass, under specified conditions, of a unit volume of a powder while being subjected to a specified pressure. d
39、ensity: The mass per unit volume. electrical resistivity: The longitudinal electrical resistance of a uniform volume of powder. fixed carbon: That portion of a powder not attributable to moisture, volatile matter, and ash contents, and made up principally of carbon but may contain appreciable amount
40、s of sulfur, hydrogen, nitrogen, oxygen, etc. CG 2-2004 Page 3 Copyright 2004 by the National Electrical Manufacturers Association. flooding: A reduction in sieving efficiency due to overloading a sieve with an excessive amount of powder. free moisture: Non-bound water. impurity: Material other than
41、 an allotropic form of carbon. loss on ignition: That portion of a powder not attributable to ash content, and made up principally of carbon but may contain appreciable amounts of moisture, volatile matter, sulfur, hydrogen, nitrogen, oxygen, etc. moisture content: The amount of water in a powder as
42、 measured under specified conditions. particle size analysis: The particle size expressed as weight or by a count of fractions into which a powder sample has been separated. pH: The acidity, basicity, or neutrality of a powder under specified conditions. powder: A quantity of particles of various si
43、zes and shapes, generally less than 75 microns. proximate graphite analysis: A method to assess the moisture content, ash content, volatile content, loss on ignition, and fixed carbon of a powder. real density: Absolute density. The mass, under specified conditions, of a unit volume of a powder excl
44、uding its pores and voids. resiliency: Springback. The increase in vertical dimension of a powder compact after the release of pressure relative to the compressed height under specified conditions. sulfur content: The amount of sulfur in a powder as measured under specified conditions. surface area:
45、 The area, per unit mass of a powder, of surfaces that are accessible to a penetrating gas. tapped density: The density of a powder obtained when confined and tapped during loading under specified conditions. thermal conductivity: The ability to transfer heat. volatile content: The loss of weight, e
46、xcluding moisture, after heating under specified conditions. CG 2-2004 Page 4 Copyright 2004 by the National Electrical Manufacturers Association. Section 2 TEST METHODS 2.1 PROXIMATE GRAPHITE ANALYSIS 2.1.1 Scope This test method provides a means to estimate the moisture, volatile matter, and ash c
47、ontent in a powder. 2.1.2 Interferences a. Base material of the crucible b. Bound moisture c. Incomplete drying d. Incomplete oxidation 2.1.3 Apparatus a. Metallic or quartz crucible with tight-fitting cover b. Ceramic crucible c. Drying oven capable of 110C 5C d. Muffle furnace capable of 950C 25C
48、e. Balance readable to 0.001 g 2.1.4 Procedure for Testing Percent Moisture a. Record weight of ceramic crucible. b. Weigh 1.000 g to 10.000 g of the powder and record as start weight (w1). c. Place ceramic crucible in the drying oven and leave for a minimum of 2 hours. Remove ceramic crucible from
49、oven and allow to cool to room temperature. Weigh and record weight of powder (w2). 2.1.5 Procedure for Testing Percent Volatile a. Weigh at least 1.000 g of the dried powder in the metallic or quartz crucible and record weight (w1). b. Cover crucible securely with matching cover and place it in 950C 25C furnace for 7 minutes. Remove from furnace and allow to cool to room temperature. Weigh and record weight of powder (w2). Cover must have remained in place for the duration of
