1、Designation: C471M 171Standard Test Methods forChemical Analysis of Gypsum and Gypsum Products(Metric)1This standard is issued under the fixed designation C471M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTECorrected equation reference in 9.6 and restored item (6) to list in 16.1 editorially in August 2017.1. Scope*1.1 These test methods c
3、over the chemical analysis ofgypsum and gypsum panel products, including gypsum ready-mixed plaster, gypsum wood-fibered plaster, and gypsumconcrete.1.2 The test methods appear in the following order:SectionsPreparation of Sample 4Complete Procedure 516Alternative Procedure for Analysis of Free Wate
4、r in 17Gypsum Using a Moisture BalanceAlternative Procedure for Analysis of Combined Water in 18Gypsum Using a Moisture BalanceAlternative Procedure for Analysis for Calcium Sulfate by 19Ammonium Acetate MethodAlternative Procedure for Analysis for Sodium Chloride by 20the Coulometric MethodDetermin
5、ation of Sand in Set Plaster 21Wood-Fiber Content in Wood-Fiber Gypsum Plaster 22Optional Procedure for Analysis for Sodium by the Atomic 23Absorption MethodOptional Procedure for Analysis for Sodium by Flame 24PhotometryDetermination of Orthorhombic Cyclooctasulfur (S8)in 25Ggypsum Panel ProductsGe
6、neral ProvisionsDetermination of Orthorhombic Cyclooctasulfur (S8)in 26Gypsum Panel Products by Gas ChromatographEquipped with a Mass Spectrometer (GS/MS)Determination of Orthorhombic Cyclooctasulfur (S8)in 27Gypsum Panel Products by Gas ChromatographEquipped with an Electron Capture Detector (GC/EC
7、D)Determination of Orthorhombic Cyclooctasulfur (S8)in 28Gypsum Panel Products by High-performance LiquidChromatograph Equipped with and Ultraviolet Detector(HPLC UV)1.3 The text of this standard references notes and footnotesthat provide explanatory material. These notes and footnotes(excluding tho
8、se in tables and figures) shall not be consideredas requirements of the standard.1.4 The values stated in SI units are to be regarded as thestandard.1.5 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 s
9、tandard to establish appro-priate safety, health and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision
10、 on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsC22/C22M
11、Specification for GypsumC28/C28M Specification for Gypsum PlastersC59 Specification for Gypsum Casting Plaster and GypsumMolding PlasterC61 Specification for Gypsum Keenes CementC317/C317M Specification for Gypsum ConcreteC778 Specification for Standard SandC842 Specification for Application of Inte
12、rior Gypsum Plas-terD1193 Specification for Reagent WaterD1428 Test Method for Test for Sodium and Potassium InWater and Water-Formed Deposits by Flame Photometry(Withdrawn 1989)3D2013 Practice for Preparing Coal Samples for AnalysisE11 Specification for Woven Wire Test Sieve Cloth and TestSieves1Th
13、ese test methods are under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and are the direct responsi-bility of Subcommittee C11.01 on Specifications and Test Methods for GypsumProducts.Current edition approved June 1, 2017. Published July 2017. Originally
14、 approvedin 1961. Last previous edition approved in 2016 as C471M 16A. DOI: 10.1520/C0471M-17E01.2For 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 Docum
15、ent Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesTh
16、is international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (
17、TBT) Committee.1E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsDefinitions shall be in accordance withTerminology C11.3.2 Definitions:3.2.1 calibrati
18、on standard, na chemical mixture contain-ing a known quantity of the analyte used to relate the measuredanalytical signal to the concentration of the analyte.3.2.2 dried sample, na sample devoid of free water.3.2.3 internal standard, na chemical used in the quantifi-cation of S8by monitoring and adj
19、usting for minor variances ininstrument performance.3.2.4 riffle, na hand feed sample divider device thatdivides the sample into parts of approximately the sameweight. (D2013)3.2.5 sample as received, na representative portion of rawgypsum or gypsum product in the state received by the testinglabora
20、tory, including aggregates, impurities and water content.3.2.6 surrogate standard, na chemical used to account forextraction efficiency of S8.4. Preparation of Sample4.1 General ProceduresDetails of sample preparation willvary according to the type of material being tested.4.1.1 Sample As ReceivedUs
21、e a sufficient amount ofsample such that, after sieving, not less than 50 g of samplewill remain for testing. Weigh the entire sample immediatelyafter opening the container in which the material was received.This will become the weight of the sample as received.4.1.2 DryingDry the sample in accordan
22、ce with Section 7.This will be the weight of the dried sample.4.1.3 Crushing and GrindingCrush and grind the sampleby hand with a mortar and pestle or by mechanical crushingand grinding equipment to pass a 250-m (No. 60) sieve. Takecare, particularly with mechanical equipment, not to expose thesampl
23、e to temperatures of more than 52C. Clean the equip-ment thoroughly between samples. Thoroughly remix theground sample and store it in an airtight container to avoidcontamination.4.1.4 RehydratingThoroughly blend and rehydratesamples which contain calcium sulfate in forms other thanCaSO42H2O and nat
24、ural anhydrite. Place the sample indistilled water and keep it wet for not less than 48 h. Dry thehydrated sample in an oven at 45 6 3C to constant weight andrecrush or grind it in accordance with 4.1.3.4.1.5 Sample ReductionThoroughly mix and reduce largesamples as required by quartering or by the
25、use of a riffle toobtain a specimen of approximately 50 g.4.2 Gypsum (Specification C22/C22M)Gypsum sampleswill be received in the form of rocks or powder, or both. Ifnecessary crush and reduce the entire dried sample in accor-dance with 4.1.3 and 4.1.5.4.3 Gypsum Plaster, (Specification C28/C28M).4
26、.3.1 Gypsum Ready-Mixed Plaster or Gypsum WoodFi-bered PlasterScreen the dried sample through a 150-m(No. 100) sieve4and discard the residue retained on the sieve.Reweigh the remaining sample and calculate the percentage ofthe dried sample. Reduce the sample in accordance with 4.1.5.Thoroughly blend
27、 and rehydrate the specimen in accordancewith 4.1.44.3.2 Gypsum Neat Plaster or Gypsum Gauging PlasterReduce the dried sample in accordance with 4.1.5. Thoroughlyblend and rehydrate the specimen in accordance with 4.1.4.4.4 Gypsum Casting and Molding Plaster, (SpecificationC59)Reduce the dried sampl
28、e in accordance with 4.1.5.Thoroughly blend and rehydrate the specimen in accordancewith 4.1.4.4.5 Gypsum Keenes Cement, (Specification C61)Reducethe dried sample in accordance with 4.1.5. Blend in no morethan 1 % molding plaster or K2SO4and rehydrate the specimenin accordance with 4.1.4.4.6 Gypsum
29、Concrete, (Specification C317/C317M)Screen the dried sample through a 150-m (No. 100) sieve4and discard the residue retained on the sieve. Reweigh theremaining sample and calculate the percentage of the driedsample. Reduce the sample in accordance with 4.1.5. Thor-oughly blend and rehydrate the spec
30、imen in accordance with4.1.44.7 Gypsum Panel ProductsCut or break the dried sampleinto small pieces. Using a mortar and pestle, strike the piecesof the sample to loosen the paper face. Remove the pieces ofpaper by hand as they are separated from the core of thegypsum board. Carefully scrape any rema
31、ining powder fromthe paper. When all the paper has been removed from thepieces of the sample, reduce the sample in accordance with4.1.5.COMPLETE PROCEDURE5. Apparatus5.1 Analytical BalanceCapable of weighing the weighingbottles, lids and samples.5.2 BalanceCapable of weighing not less than 100 g at
32、aprecision of 0.001 g.5.3 Drying OvenA mechanical convection oven set at 456 3C.5.4 DesiccatorCapable of being tightly sealed and con-taining calcium chloride or equivalent desiccant.5.5 Calcining Oven or FurnaceCapable of achieving andmaintaining temperatures to not less than 1000C.5.6 Weighing Bot
33、tlesBorosilicate glass or ceramic con-tainers with tightly sealable lids.5.7 Hot PlateA controllable hot plate capable of heatingcasseroles to approximately 120C.4Detailed requirements for this sieve are given in Specification E11.C471M 17125.8 Porcelain CasserolesWith a capacity of 50 to 100 mL.5.9
34、 Filtering Funnels.5.10 Filter Paper.5.11 Porcelain Crucibles.5.12 Mortar and Pestle.5.13 Mechanical Jaw CrusherCapable of crushing gyp-sum rocks up to 50 mm diameter.5.14 Mechanical GrinderBurr mill or equivalent capableof grinding the granular output of the jaw crusher specified in5.13.6. Reagents
35、6.1 Purity of ReagentsUse reagent grade chemicals in alltests. Unless otherwise indicated, use reagents that conform tothe specifications of the Committee on Analytical Reagents ofthe American Chemical Society, where such specifications areavailable.5If it is necessary to use other grades, first asc
36、ertainthat the reagent is of sufficiently high purity so that its use willnot lessen the accuracy of the determination.6.1.1 Ammonium Chloride (NH4Cl).6.1.2 Ammonium Hydroxide (sp gr 0.90)Concentratedammonium hydroxide (NH4OH).6.1.3 Ammonium Nitrate (25 g/L)Dissolve 25 g of ammo-nium nitrate (NH4NO3
37、) in water and dilute to 1 L.6.1.4 Ammonium Oxalate (NH4)2C2O4).6.1.5 Barium Chloride (100 g/L)Dissolve 100 g of bariumchloride (BaCl22H2O) in water and dilute to 1 L.6.1.6 Calcium Chloride (CaCl2)Anhydrous CalciumChloride with a combined water of not more than 5 %.6.1.7 Hydrochloric Acid (sp gr 1.1
38、9)Concentrated hydro-chloric acid (HCl).6.1.8 Hydrochloric Acid (1+4)Mix one volume of HCl(sp gr 1.19) with four volumes of water.6.1.9 Hydrochloric Acid (1+5)Mix one volume of HCl(sp gr 1.19) with five volumes of water.6.1.10 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).6.1.11 Potassium C
39、hromate Solution (100 g/L)Dissolve5 g of potassium chromate (K2CrO4) in 50 mL of water, mix,add ten drops of 0.05 N silver nitrate (AgNO3) solution, allowto stand for 5 min, and filter.6.1.12 Potassium Permanganate (5.6339 g/L)Dissolve5.6339 g of potassium permanganate (KMnO4) in water anddilute to
40、1 L.6.1.13 Silver Nitrate, Standard Solution (0.05 N)Prepareand standardize a 0.05 N silver nitrate (AgNO3) solution.6.1.14 Sodium Ammonium Phosphate(NaNH4HPO4).6.1.15 Sulfuric Acid (sp gr 1.84)Concentrated sulfuricacid (H2SO4).6.1.16 Sulfuric Acid (1+6)Carefully mix one volume ofH2SO4(sp gr 1.84) w
41、ith six volumes of water.6.1.17 Nitric Acid (0.1 N)Mix 1.4 mL of HNO3(sp gr1.42) with 200 mL of water.6.1.18 Phenolphthalein Indicator SolutionDissolve 0.25 gof phenolphthalein in 30 mL of methanol and dilute to 50 mLwith water.6.1.19 Sodium Hydroxide Solution (0.1 N)Dissolve1gofsodium hydroxide (Na
42、OH) in 250 mL of water.6.1.20 WaterReagent water shall be in accordance withSpecification D1193, type II. Specification D1193 gives thefollowing values for type II grade water.Electrical conductivity, max, S/cm at 298 K (25-C) 1.0Electrical resistivity, min, Mcm at 298 K (25-C) 1.0Total organic carb
43、on (TOC), max, g/L 50.0Sodium, max, g/L 50.0 5.0Chlorides max, g/L 50.0 5.0Total silica, max, g/L 50.0 5.07. Free Water7.1 Significance and UseThe free water analysis deter-mines the amount of free water contained in the sample asopposed to chemically combined water, and prepares thesample for furth
44、er analysis.7.2 Procedure:7.2.1 Weigh a sample of the material as received of not lessthan 50 g to a precision of 0.001 g and spread it out in a thinlayer in a suitable vessel. Place in an oven and dry at 45 6 3Cfor 2 h, then cool in a desiccator and weigh again. The loss ofweight corresponds to the
45、 free water.7.2.2 Retain the sample in a sealed container or in thedesiccator for further analysis.7.3 Calculation and ReportCalculate and report loss inweight as a percentage of the sample as received or of the driedsample as required.7.4 Precision and Bias:7.4.1 The precision of this test method i
46、s based on aninterlaboratory study ofASTM C471M, Standard Test Methodsfor Chemical Analysis of Gypsum and Gypsum Products,conducted in 2016. Each of 17 laboratories analyzed twodifferent gypsum sample types. Every “test result” representsan individual determination, and all participants reported fiv
47、etest results per material. Practice E691 was followed for thedesign and analysis of the data; the details are given in ASTMResearch Report No. C11-100367.4.1.1 Repeatability (r)The difference between repetitiveresults obtained by the same operator in a given laboratoryapplying the same test method
48、with the same apparatus underconstant operating conditions on identical test material withinshort intervals of time would in the long run, in the normal andcorrect operation of the test method, exceed the followingvalues only in one case in 20.(1) Repeatability can be interpreted as maximum differen
49、cebetween two results, obtained under repeatability conditions,5Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.6Supporting data have been filed at ASTM International Headqua
