1、Designation: C604 02 (Reapproved 2012)C604 18Standard Test Method forTrue Specific Gravity of Refractory Materials by Gas-Comparison Pycnometer1This standard is issued under the fixed designation C604; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the true specific gravity of solid materia
3、ls, and is particularly useful formaterials that easily hydrate which are not suitable for test with Test Method C135. This test method may be used as an alternatefor Test MethodMethods C135, Test Method C128, and Test Method C188 for determining true specific gravity.1.2 UnitsThe values stated in S
4、I units are to be regarded as standard. No other units of measurement are included in thisstandard.1.2.1 ExceptionIn 7.3, the equivalent SI unit is expressed in parenthesis.parentheses.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is th
5、e responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles
6、on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C128 Test Method for Relative Density (S
7、pecific Gravity) and Absorption of Fine AggregateC135 Test Method for True Specific Gravity of Refractory Materials by Water ImmersionC188 Test Method for Density of Hydraulic CementE11 Specification for Woven Wire Test Sieve Cloth and Test SievesE177 Practice for Use of the Terms Precision and Bias
8、 in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Summary of Test Method3.1 The sample is powdered to ensure permeation of gas into all pores. For practical purposes, this is assumed to be true whenthe sample passes a No. 325 (45
9、-m) sieve. U.S. sieve as specified in Specification E11. The volume of a carefully weighedpowdered sample, which has first been heated to drive off moisture and undesired combined water, is measured by thegas-comparison pycnometer. Density is calculated from the sample weight in grams divided by its
10、 volume in cubic centimetres.This is also the specific gravity of the sample at room temperature compared to water at 4C.4 C.3.2 The principle of the gas-comparison pycnometer is as follows: There are two chambers and two pistons as sketched in Fig.1. For purposes of illustration, the chambers are a
11、ssumed to be equal in volume, and there is no sample in either cylinder. Underthese conditions, with the coupling valve closed, any change in the position of one piston must be duplicated by an identical strokein the other in order to maintain the same pressure on each side of the differential press
12、ure indicator.3.3 If a sample, Vx, is inserted into chamber B, the coupling valve closed and both pistons advanced the same amount fromposition 1 to position 2, the pressures will not remain the same. However, the pressures can be maintained equal if piston B insteadis moved only to position 3. Then
13、 the remaining displacement dx, from position 3 to position 2, is equal to the volume of the1 This test method is under the jurisdiction of ASTM Committee C08 on Refractories and is the direct responsibility of Subcommittee C08.03 on Physical Properties.Current edition approved Oct. 1, 2012Oct. 1, 2
14、018. Published November 2012October 2018. Originally approved in 1967. Last previous edition approved in 20072012as C604 02 (2012).(2007). DOI: 10.1520/C0604-02R12.10.1520/C0604-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org
15、. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit m
16、ay not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Har
17、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1sample, Vx. If piston A always is advanced exactly the same distance each time a measurement is made, the distance that pistonB differs from position 2, when the pressures in both cylinders are equal, will always be proportional
18、 to the volume, Vx. Thedistance (dx) between positions 2 and 3 can be calibrated and made to read directly in terms of cubic centimetres, employing adigital counter.4. Significance and Use4.1 The true specific gravity of a material is the ratio of its true density, determined at a specific temperatu
19、re, to the true densityof water, determined at a specific temperature. Thus, the true specific gravity of a material is a primary property which is relatedto chemical and mineralogical composition.4.2 This test method is particularly useful for hydratable materials whichthat are not suitable for tes
20、t with Test Method C135.4.3 For refractory raw materials and products, the true specific gravity is a useful value for: classification, detecting differencesin chemical composition between supposedly like samples, indicating mineralogical phases or phase changes, calculating totalporosity when the b
21、ulk density is known, and for any other test method that requires this value for the calculation of results.4.4 This test method is a primary standard method which is suitable for use in specifications, quality control, and research anddevelopment. It can also serve as a referee test method in purch
22、asing contracts or agreements.4.5 Fundamental assumptions inherent in this test method are the following:4.5.1 The sample is representative of the material in general,4.5.2 The total sample has been reduced to the particle size specified,4.5.3 No contamination has been introduced during processing o
23、f the sample,4.5.4 The ignition of the sample has eliminated all free or combined water without inducing sintering or alteration,4.5.5 An inert gas (helium) has been used in the test, and4.5.6 The test method has been conducted in a meticulous manner.4.5.7 Deviation from any of these assumptions neg
24、ates the usefulness of the results.4.6 In interpreting the results of this test method, it must be recognized that the specified sample particle size is significantlyfiner than specified forTest Method C135. Even this finer particle size for the sample does not preclude the presence of some closedpo
25、res, and the amount of residual closed pores may vary between materials or even between samples of the same or like materials.The values generated by this test method may, therefore, be very close approximations rather than accurate representations of truespecific gravities. Thus, comparisons of res
26、ults should only be judiciously made between like materials tested by this test methodor with full recognition of potentially inherent differences between the materials being compared or the test method used.5. Apparatus5.1 Analytical Balance, 200-g capacity, minimum sensitivity 10 mg.5.2 Desiccator
27、, charged with magnesium perchlorate.FIG. 1 Simplified Schematic DiagramC604 1825.3 Muffle Furnace, capable of heating to 1000C.1000 C.5.4 Cylinder of Dry Helium Gas, with regulator and gage.5.5 Equipment for Grinding Sample, to pass a No. 325 (45-m) sieve without contamination.5.6 Gas-Comparison Py
28、cnometer, equipped with external purge manifold.6. Sample Preparation6.1 Grind a sufficient representative sample for three determinations to pass a No. 325 (45-m) sieve. With the BeckmaninstrumentUsing a gas-comparison pycnometer, the quantity needed is approximately 150 cm3.6.2 After grinding, ign
29、ite the total sample at a temperature sufficient to drive off free moisture and any undesired combinedwater, organic matter, etc., without inducing sintering of the powder. In the case of refractory materials that hydrate, the ignitiontemperature is a minimum of 600C600 C for 3 h.6.3 After ignition,
30、 place the powdered sample in a desiccator charged with magnesium perchlorate and allow to cool to roomtemperature.7. Procedure7.1 Check the gas-comparison pycnometer for zero measurement and calibration as specified in the instruction manual for theinstrument.7.2 Take the cooled sample from the des
31、iccator and rapidly fill the previously tared sample cup nearly full. Weigh to 10 mg.10 mg. The sample and sample cup must be within 6 2C 62 C of instrument temperature. With materials that hydrate, once thesample is removed from the desiccator the succeeding steps must be taken as rapidly as possib
32、le to prevent hydration.7.3 Place the sample cup with sample in the pycnometer sample compartment and lock firmly into place. Purge the pycnometersystem with dry helium gas at pressures not exceeding 2 psi (13.8 kPa).7.4 Measure the sample volume by the standard procedure given in the instruction ma
33、nual for purge atmosphere volumemeasurement, except that the wait period for temperature equilibration is increased to 60 s.7.5 Repeat the volume measurement for the same sample, and take the sample volume as the average of the two measurements,which must agree to within 0.05 cm3.8. Calculation8.1 C
34、alculate the true specific gravity of the sample at room temperature as compared to water at 4C4 C as follows:S 5 W/Vwhere:S = true specific gravity,W = sample weight, g, andV = sample volume, cm3 (average of two measurements).9. Report9.1 Report the true specific gravity to twothree decimal places
35、as the average of the values determined on three separate samplesof the material, which individual values must agree to within 0.01.10. Precision and Bias10.1 An interlaboratory study was run in which randomly drawn test specimens of two materials (tabular alumina and Mulcoa47) were tested for true
36、specific gravity by gas-comparison pycnometer. Both materials were tested in 4four labs. Replicates perlab in the tabular alumina testing ranged from 3three to 9nine, averaging 6.six. Replicates per lab in the Mulcoa 47 testing rangedfrom 3three to 6six, averaging 4.75. Number of operators ranged fr
37、om 1one to 3three for both materials. Instruments used in thestudy were Beckman Air Comparison Pycnometers at 2two labs and a Micromeritics AccuPyc 1330 at 1one lab. The instrumentfor the 4thfourth lab was not identified. Except for the lack of uniformity in number of replicate tests and the use of
38、only twomaterials, Practice E691 was followed for the design and analysis of the data,data; the details are given inASTM Research ReportNo. RR:C08-1013.310.2 Test ResultThe precision information given below in the unit of measurement (g/cc) is for the comparison of the two testresults. If the differ
39、ence in the two test results is greater than or equal to the applicable 95 % limit, there is a 95 % probability that3 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:C08-1013. Contact ASTM CustomerService at serviceastm.org.C604
40、 183the materials are measurably different. If the difference in results are less than the applicable 95 % limit, it cannot be said withcertainty that the materials are measurably different.Tabular Alumina Mulcoa 47Average Test Value 3.952 2.79095 % repeatability limit (within laboratory) 0.026 0.01
41、695 % reproducibility limit (between laboratories) 0.053 0.048The above terms (repeatability limit and reproducibility limit)“repeatability limit” and “reproducibility limit” are used asspecified in Practice E177. The respective standard deviations among test results may be obtained by dividing the
42、above limitvalues by 2.8.10.3 BiasNo justifiable statement can be made on the bias of the procedure in this test method for measuring true specificgravity because no reference material was readily available.11. Keywords11.1 gas comparison pycnometer; hydratable materials; refractory materials; true
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46、he ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at th
47、e aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ A suitable instrument is the Beckman Air Comparison Pycnometer manufactured by Beckman Instruments, Inc., 2500 Harbor Blvd., Fullerton, CA 92634.C604 184
