1、Designation: D1918/D1918M 95 (Reapproved 2017)Standard Test Method forAsbestos Content of Asbestos Textiles1This standard is issued under the fixed designation D1918/D1918M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year
2、of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the asbes-tos content of untreated chrysotile asbestos textile materia
3、lswhich are usually blends of asbestos and organic fibers. Thistest method is also applicable to treated asbestos textilematerials provided the treatment can be completely removedprior to testing.1.2 This test method is limited to those asbestos textilematerials in which asbestos is the only inorgan
4、ic fiber present,or in which any other inorganic fiber or wire used as reinforce-ment can be removed prior to testing.1.3 If carbonates are present, a correction is made for theloss on ignition in the calculation for asbestos content.1.4 The values stated in either SI units or inch-pound unitsare to
5、 be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 WarningBreathing of asbestos dust is hazardous.As
6、bestos and asbestos products present demonstrated healthrisks for users and for those with whom they come into contact.In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For informa-tion on the safe use of chrysoltile asbestos, refer to “Saf
7、e Useof Chrysotile Asbestos: A Manual on Preventive and ControlMeasures.”21.6 This standard does not purport 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
8、 the applica-bility of regulatory limitations prior to use. For specific safetyhazard, see 1.5.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Sta
9、ndards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D123 Terminology Relating to TextilesD1193 Specification for Reagent WaterD2946 Terminology for Asbestos and AsbestosCementProducts3. Termi
10、nology3.1 For definitions of other textile terms used in this testmethod, refer to Terminology D123. For asbestos terms, referto Terminology D2946.3.2 Definitions:3.2.1 asbestos, n1. generala group of impure silicateminerals occurring in fibrous form. 2. textilethe hydrousmagnesium silicate serpenti
11、ne mineral designated as chrysotileand having the general empirical formula Mg3Si2O5(OH)4.3.2.2 Small amounts of carbonates, which may be present,are calculated as asbestos.4. Summary of Test Method4.1 When carbonates are not present in the fibers, a speci-men is dried to constant mass, heated to 80
12、0 to 840C 1470 to1540F for 1 h and the loss in mass determined. The mass ofthe ignited specimen divided by 0.86 (see 5.2) is assumed toequal the mass of asbestos fiber originally present. Thiscorrected mass is calculated as a percentage of the weight ofthe original specimen.4.2 When carbonates are p
13、resent they are included in theamount of asbestos reported. While carbonates are not deter-mined and reported separately, the amount of carbon dioxideincluded in the carbonates is measured and used to determine1This test method is under the jurisdiction of ASTM Committee C17 onFiber-Reinforced Cemen
14、t Products and is the direct responsibility of SubcommitteeC17.03 on Asbestos - Cement Sheet Products and Accessories.Current edition approved June 1, 2017. Published July 2017. Originally approvedin 1962. Last previous edition approved in 2009 as D1918/D1918M 95(2009)1.DOI: 10.1520/D1918_D1918M-95R
15、17.2Available from The Asbestos Institute, Online, http:/ referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyrigh
16、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International
17、 Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1the correct residue from ignition of the asbestos when calcu-lating asbestos in presence of carbonates.4.3 Both of the alternate procedures (4.1 and 4.2) areapplicable in the pr
18、esence of organic fiberous material.5. Significance and Use5.1 The asbestos content of asbestos textile materials is ofmajor significance, since the percentage of asbestos presentdefines the grade of the textile and the approximate service-ability temperature for such materials.5.2 This test method
19、is considered satisfactory for accep-tance testing of commercial shipments because: (1) currentestimates of between-laboratory reproducibility are acceptable,(2) the test method has been used extensively in the trade foracceptance testing. In cases of dispute, the statistical bias, ifany, between th
20、e laboratory of the purchaser and the laboratoryof the seller should be determined with each comparison beingbased on testing randomized specimens from one sample ofmaterial.5.3 The factor of 0.86 is based upon a measured average of14 % for the loss of water of crystallization on heatingchrysotile a
21、sbestos to a temperature of at least 800C 1470F.The calculated asbestos content may be in error if the actualmass loss differs from the 14 % average.5.4 If the specimen includes calcium carbonate (CaCO3),this compound is decomposed at 800C 1470F and highertemperatures. No other carbonates are presen
22、t in appreciableamounts.5.5 If the textile specimen includes carbonates, the loss ofmass observed during ignition will include the water ofcrystallization of the asbestos and carbon dioxide from thecarbonates. If the specimen includes both carbonates andorganic fiber the loss of mass will include wa
23、ter of crystalli-zation of the asbestos, carbon dioxide from the carbonates, andthe combustible part of the organic fibers. Failure to takeproper account of these losses will result in lower grading ofthe material.5.6 Asbestos textiles as used in normal applications are notsubjected to a temperature
24、 where CaCO3will decompose. AnyCaCO3contained will remain unchanged and as such offersexcellent thermal insulation. It is therefore included in thecalculation as part of the asbestos content.5.7 The mass of the original carbonate and the residualoxide formed on ignition of the carbonate in any speci
25、men canbe calculated from the amount of carbon dioxide evolved froma known mass of the specimen. The calculated values are usedin the determination of the asbestos content of specimenswhich include carbonate.6. Apparatus6.1 Knorr Alkalimeter, for determining carbon dioxide asshown in Fig. X1.1 and F
26、ig. X1.2 and described in AppendixX1.6.2 Muffle Furnace, capable of maintaining a temperaturerange from 800 to 840C 1470 to 1540C.6.3 Crucibles, 50-cm3glazed porcelain or equivalent.7. Reagents and Materials7.1 Purity:7.1.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless
27、otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.4Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity
28、to permit its use without lessening the accuracy ofthe determination.7.1.2 Purity of WaterUnless otherwise indicated, refer-ences to water shall be understood to mean reagent water asdefined by Type IV of Specification D1193.7.2 Reagents:7.2.1 Hydrochloric Acid, HCl, concentrated sp gr 1.19.7.2.2 Hy
29、drochloric Acid, HCl, solution (one volume of sp gr1.19 concentrated acid added to one volume of reagent water).7.2.3 Silver Sulphate, Ag2SO4, solution (5 to 10 masspercent in hydrochloric acid, HCl, concentrated sp gr 1.19).7.3 Materials:7.3.1 Calcium Sulphate, CaSO4, anhydrous, desiccant,8-mesh so
30、lid, indicating. See Note 1.NOTE 1Drierite has been found suitable for this purpose.7.3.2 Copper Sulphate, CuSO4, anhydrous, absorbent forhydrogen sulfide, H2S; or penahydrate, CuSO4H2O.7.3.3 Soda-Asbestos Absorbent (such as ascarite).8. Hazards8.1 Warningsee 1.5.8.2 When handling sulfuric acid, wea
31、r protective goggles,gloves, and clothing to protect against corrosion.8.3 The reagents and materials in 7.2 to 7.3.3 may be toxicin sufficient doses.9. Sampling and Test Specimens9.1 Take a laboratory sample from each lot and from thissample take the number of specimens prescribed in theapplicable
32、material specification. In the absence of applicablematerial specification, take two specimens, believed to berepresentative of the lot to be tested.9.2 Remove all treatments and all inorganic or wirereinforcements, or both, from the specimen before testing.10. Conditioning10.1 Preconditioning and c
33、onditioning of the test specimensare not necessary.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Po
34、ole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D1918/D1918M 95 (2017)211. Procedure11.1 Procedure for Determining Presence of Carbonates:11.1.1 Place a specimen of approximately 0.5 g in a testtube. Wet the specim
35、en thoroughly with 10 cm3of distilledwater by stirring and tamping with a glass rod, so that no airbubbles are visible in the wet specimen. Add 5 cm3of HCl (spgr 1.19) and again stir and tamp gently with a glass rod, takingcare not to introduce any air bubbles. Warm gently.11.1.2 If no gas bubbles a
36、re detected, proceed as directed in11.2.11.1.3 If gas bubbles form on the surface of the submergedspecimen, proceed as directed in 11.3 and 11.4.11.2 Procedure for Asbestos Content by Ignition (Carbon-ates Absent):11.2.1 Take two test specimens, each weighing not less than5 g, both representative of
37、 each lot or unit samples. Place thespecimens in tared crucibles that have been previously heatedto 800 to 840C 1470 to 1540F for 1 h, cool in a desiccator,and weigh to the nearest 0.001 g. Dry each specimen toconstant mass at 105 to 110C 220 to 230F and record themass to the nearest 0.001 g. Subtra
38、ct the mass of the crucibleto obtain the weight of the oven-dry specimen and record asmass M.11.2.2 Place the crucibles containing the specimens in themuffle furnace and heat for not less than1hat800to840C1470 to 1540F. Remove the specimen and crucible from thefurnace, and cool in a desiccator to ro
39、om temperature. Weigh tothe nearest 0.001 g and subtract the tared mass of the crucibleto obtain the mass of the residue (ash). Record this mass as A.11.2.3 CalculationsWhen carbonates are not present, cal-culate the asbestos content to the nearest 0.1 % by Eq 1 asfollows:Asbestos content, % 5 A/0.8
40、6 M! 3100 (1)where:M = mass of specimen after drying but prior to ignition, g,A = mass of residue (ash) from the specimen afterignition, g, and0.86 = factor to correct for 14 % water of crystallization lostwhen heating.11.3 Procedure for Quantitative Test for Carbon Dioxide:11.3.1 Check the Knorr al
41、kalimeter (Fig. X1.1) to ensurefreedom from leaks. Aspirate a current of air through thesystem at the rate of about two bubbles per minute for a periodof 10 min. Stop the air current and remove the absorption tube.Place the absorption tube G in the balance case and allow it tostand for several minut
42、es. Just before weighing, open thestopcocks momentarily and then close them. Weigh the tubeand repeat the above procedure. The second mass should agreewith the first within 0.05 g. If it does not, repeat this processuntil the two successive weighings agree. When a constantmass is reached, replace th
43、e absorption tube in the gas train.11.3.2 Place a specimen of approximately 1 g weighed tothe nearest 0.001 g in the distillation flask. Wash down anyadhering particles on the inside neck of the flask with distilledwater. Add enough distilled water to the flask to that when theapparatus is reconnect
44、ed the tip of the dropping funnel will be5 to 10 mm below the surface of the liquid. Place 50 cm3ofdilute HCl (1 + 1) in the dropping funnel and replace the guardgas-absorption tube at the top of the funnel. Start the flow ofwater in the condenser and open all stopcocks fully except theone in the dr
45、opping funnel. Turn on the aspirator for mediumsuction. Adjust the stopcock on the dropping funnel so that thesuction will draw the acid slowly into the flask. When all theacid is in the flask, open the funnel stopcock fully and adjustthe aspirator to pull air through the system at a rate of two ort
46、hree bubbles per second. After the reaction in the flask hassubsided, heat the contents slowly to boiling. When condensa-tion appears in the condenser, turn off the heat. Continue todraw air through the apparatus for 30 to 35 min. Reweigh theabsorption tube G as before. The gain in mass represents t
47、hecarbon dioxide in the specimen. Record this mass as D.11.3.3 Calculate the mass of carbon dioxide recovered pergram of specimen by Eq 2 as follows:E 5 D/F (2)where:F = mass of the specimen used for the Knorr alkalimetertest, g,D = gain in mass of the absorption tube G, g, andE = mass of carbon dio
48、xide released per gram of specimen,g.11.3.4 Repeat the procedure on another specimen of similarsize and calculate the average value of E in the two determi-nations. If desired, use the mass of the absorption tube G afterthe first determination as the starting point for the seconddetermination withou
49、t repeating the initial process of obtainingconstant mass of the tube G.11.4 Procedure for Asbestos Content by Ignition (Carbon-ates Present):11.4.1 Proceed as directed in 11.2.1 and 11.2.2.11.4.2 Calculation for Asbestos ContentUse the values forcarbon dioxide content as determined in 11.3.3 and calculatethe asbestos content using Eq 3 or Eq 4 as follows: Asbestoscontent, %5A 2 1.27 ME0.8612.27 MEM3100 (3)5A10.68 ME0.86 M3100 (4)where:M = mass of specimen after drying but prior to ignition, g,A
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