1、Designation: C 288 87 (Reapproved 2002)Standard Test Method forDisintegration of Refractories in an Atmosphere of CarbonMonoxide1This standard is issued under the fixed designation C 288; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the comparative behavior ofrefractories under the disintegrating action of c
3、arbon monox-ide(CO). The test method is an accelerated exposure to CO todetermine potential material behavior in a relatively short time.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.3 This standard does not pur
4、port to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 This test method i
5、s used to determine the relativeresistance of various refractories to disintegration caused byexposure to a CO atmosphere. The results obtained by thismethod can be used to select refractories that are resistant toCO disintegration.2.2 This test method is suitable for research and develop-ment and f
6、or establishing CO disintegration criteria for speci-fication acceptance.2.3 The disintegration of test specimens is accelerated byproviding a higher concentration of CO than anticipated inmost service environments. The effects on the test specimensmay be different than those found for refractories
7、in actualservice conditions.3. Apparatus3.1 Heated Chamber The chamber shall be gastight andof a suitable size, made of stainless steel, brass, aluminum, orunoxidized Monel metal. A suggested size is 18 in. (460 mm)in diameter and 36 in. (914 mm) long. The unit may be heatedby resistance wire or oth
8、er means, provided that at thetemperature of operation the difference in temperature betweenany two points within the chamber shall not be greater than20F (11C). The chamber may be provided with a thermo-couple well and shall have a gas inlet and outlet, with aprovision for gas sampling at the outle
9、t.3.2 Temperature-Control InstrumentThe temperature ofthe test chamber shall be controlled and recorded by a suitableinstrument having the required accuracy.3.3 Atmosphere ControlThe CO shall be supplied from atank, or of the gas, or manufactured by the conversion ofcarbon dioxide(CO2). The pressure
10、 from a tank supply (Cau-tion, see Note 1) shall be reduced by a regulator made for thatpurpose, and the flow of gas adjusted by means of a sensitiveneedle or regulating valve. A flowmeter shall be used in the lineas an aid for regulating the flow. When CO is used from a tank,iron carbonyl is presen
11、t in the gas and may cause clogging ofthe inlet tube, in which case the carbonyl may be removedbefore the gas enters the chamber. A soda-asbestos (theAscarite) tower in the inlet line will remove the carbonyl, butthis should be preceded by a drying tower to prevent moisturefrom getting into the soda
12、-asbestos.NOTE 1Caution: As a precaution against the possibility of tankexplosions, the tanks should be stored and used outdoors or in a separatebuilding designed to reduce the explosion hazard.3.4 Furnace Pressure ControlThe unit shall be equippedwith a bubbling bottle or a sensitive gage to contro
13、l thepressure of the exhaust gas. A positive pressure shall bemaintained throughout the test.3.5 Gas Analyzer Any conventional gas analyzer can beused to periodically determine the CO content of the exhaustgas.4. Test Specimens4.1 Ten specimens shall constitute a specimen set.4.2 The specimens shall
14、 be 9 in. (228 mm) long and 2 or3 in. (64 or 76 mm) square in cross section. Only one specimenshall be cut from a shape so that as many original surfaces aspossible remain intact. The specimen shall be cut lengthwisefrom the original shape.5. Unfired Samples5.1 Unfired refractories shall be prepared
15、 for testing byfiring for 5 h under oxidizing conditions at one of the followingtemperatures:1This test method is under the jurisdiction of ASTM Committee C-8 onRefractories and is the direct responsibility of Subcommittee C08.04 on ChemicalBehaviors.Current edition approved Jan. 30, 1987. Published
16、 April 1987. Originallypublished as C 288 52 T. Last previous edition C 288 78 (1984)e1.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.1 1000F (540C), to remove combined water.5.1.2 2000F (1095C), to remove combined water andcom
17、pounds that inhibit the deposition of carbon.6. Procedure6.1 Bring the heating chamber containing the dried speci-mens to an operating temperature of 925 to 940F (495 to505C) in a nitrogen atmosphere. After the specimens haveattained test temperature, change the atmosphere of the cham-ber so that it
18、 shall contain at least 95 % (CO).NOTE 2This may be done in one of the following ways: A vacuumpump may be used to evacuate the nitrogen from the chamber to a pressureof about 100 mm Hg. Then introduce the CO, and repeat the evacuationprocess three times. Time the test from the last evacuation. A se
19、condmethod consists of flushing the nitrogen from the system with a fast flowof CO.NOTE 3Carbon Dioxide AbsorbentA sufficient quantity of burnedlime or calcium oxide (CaO) may be placed in the furnace or in thecirculating system of the CO to absorb the CO2as it is produced. Acommercial CO2absorbent
20、can be used outside the test chamber for theabsorption of CO2from the circulating gas. This granular material,probably calcium hydroxide, is very efficient, but does have the advantageof giving water vapor, which must be taken out of the circulating gas witha calcium chloride tower. (Five pounds (2.
21、3 kg) of CaO theoretically willabsorb the CO2from a gas mixture containing 1 % CO2, flowing at therate of ft3(14.2 dm3)/h for 7000 h.)6.2 Regulate the CO to a flow of not less than 2 in.3/hin.3(32.8 cm3/h16.4 cm3) of specimen volume. Analyzethe chamber atmosphere at least twice a day and maintain th
22、eCO content of the exit gas above 95 %. If a recirculatingsystem is used, the CO flow may be greater.6.3 Inspect the specimens at the end of each selected timeperiod. Before each inspection, pass a fast flow of nitrogenthrough the furnace to flush out the CO, and then maintain aslow flow of nitrogen
23、 during cooling. If half the specimens inany set of ten show complete disintegration at the end of anytest period, consider the test for that specimen set complete.7. Report7.1 Report any prefiring temperature of the specimens andthe condition of each specimen at each inspection by photo-graphing th
24、e most affected face(s), and by describing the extentof any spotting and the degree of disintegration, according tothe following classifications (see Fig. 1).7.1.1 Unaffected, when no particles spall and no crackingoccurs.7.1.2 AffectedSurface Popouts, when destructive action isconfined to spalls or
25、 surface popouts of in. (13 mm) or lessin diameter.7.1.3 AffectedCracked, when destructive action producesspalls or popouts greater than in. (13 mm) in diameter, orcracking, or both.7.1.4 Destructive Condition, when the specimen breaks intotwo or more pieces, or when hand pressure can cause breaking
26、.NOTE 4Spalls or popouts that have not separated from the specimenare to be considered as if separation had occurred.8. Precision and Bias8.1 PrecisionNo justifiable statement of precision is pos-sible since the results of the test are word descriptions ratherthan numerical values.8.2 BiasNo justifi
27、able statement of accuracy is possiblesince a true value of refractory disintegration by carbonmonoxide cannot be established by an accepted referencesample.9. Keywords9.1 carbon monoxide; CO atmosphere; disintegration; re-fractoriesC 288 87 (2002)2ASTM International takes no position respecting the
28、 validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is
29、 subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Hea
30、dquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This st
31、andard 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 the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).FIG. 1 Guide to Degrees of DisintegrationC 288 87 (2002)3
