1、Designation: C471M 16aC471M 17Standard 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 l
2、ast revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods cover the chemical analysis of gypsum and gypsum panel products, including gypsum ready-mixedplaste
3、r, gypsum wood-fibered plaster, and gypsum concrete.1.2 The test methods appear in the following order:SectionsPreparation of Sample 4Complete Procedure 5 16Alternative Procedure for Analysis of Free Water in 17Gypsum Using a Moisture BalanceAlternative Procedure for Analysis of Combined Water in 18
4、Gypsum Using a Moisture BalanceAlternative Procedure for Analysis for Calcium Sulfate by 19Ammonium Acetate MethodAlternative Procedure for Analysis for Sodium Chloride by 20the Coulometric MethodDetermination of Sand in Set Plaster 21Wood-Fiber Content in Wood-Fiber Gypsum Plaster 22Optional Proced
5、ure for Analysis for Sodium by the Atomic 23Absorption MethodOptional Procedure for Analysis for Sodium by Flame 24PhotometryDetermination of Orthorhombic Cyclooctasulfur (S8) in 25Ggypsum Panel ProductsGeneral ProvisionsDetermination of Orthorhombic Cyclooctasulfur (S8) in 26Gypsum Panel Products b
6、y 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/ECD)Determination of Orthorhombic Cyclooctasulfur (S8) in 28Gypsum Panel Products by High-perfo
7、rmance LiquidChromatograph Equipped with and Ultraviolet Detector(HPLC UV)1.3 The text of this standard references notes and footnotes that provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be considered as requirements of the standard.1.4 The v
8、alues stated in SI units are to be regarded as the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabi
9、lity of regulatorylimitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World
10、Trade Organization Technical Barriers to Trade (TBT) Committee.1 These test methods are under the jurisdiction of ASTM Committee C11 on Gypsum and Related Building Materials and Systems and are the direct responsibility ofSubcommittee C11.01 on Specifications and Test Methods for Gypsum Products.Cur
11、rent edition approved June 15, 2016June 1, 2017. Published July 2016July 2017. Originally approved in 1961. Last previous edition approved in 2016 asC471M 16.C471M 16A. DOI: 10.1520/C0471M-16A.10.1520/C0471M-17.This document is not an ASTM standard and is intended only to provide the user of an ASTM
12、 standard an indication of what changes have been made to the previous version. Becauseit may 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 b
13、y ASTM is to be considered the official document.*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 States12. Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to G
14、ypsum and Related Building Materials and SystemsC22/C22M Specification for GypsumC28/C28M Specification for Gypsum PlastersC59 Specification for Gypsum Casting Plaster and Gypsum Molding PlasterC61 Specification for Gypsum Keenes CementC317/C317M Specification for Gypsum ConcreteC778 Specification f
15、or Standard SandC842 Specification for Application of Interior Gypsum PlasterD1193 Specification for Reagent WaterD1428 Test Method for Test for Sodium and Potassium In Water and Water-Formed Deposits by Flame Photometry (Withdrawn1989)3D2013 Practice for Preparing Coal Samples for AnalysisE11 Speci
16、fication for Woven Wire Test Sieve Cloth and Test SievesE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 DefinitionsDefinitions shall be in accordance with Term
17、inology C11.3.2 Definitions:3.2.1 calibration standard, na chemical mixture containing 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
18、quantification of S8 by monitoring and adjusting for minor variances ininstrument performance.3.2.4 riffle, na hand feed sample divider device that divides the sample into parts of approximately the same weight. (D2013)3.2.5 sample as received, na representative portion of raw gypsum or gypsum produ
19、ct in the state received by the testinglaboratory, including aggregates, impurities and water content.3.2.6 surrogate standard, na chemical used to account for extraction efficiency of S8.4. Preparation of Sample4.1 General ProceduresDetails of sample preparation will vary according to the type of m
20、aterial being tested.4.1.1 Sample As ReceivedUse a sufficient amount of sample such that, after sieving, not less than 50 g of sample will remainfor testing. Weigh the entire sample immediately after opening the container in which the material was received. This will becomethe weight of the sample a
21、s received.4.1.2 DryingDry the sample in accordance with Section 7. This will be the weight of the dried sample.4.1.3 Crushing and GrindingCrush and grind the sample by hand with a mortar and pestle or by mechanical crushing andgrinding equipment to pass a 250-m (No. 60) sieve. Take care, particular
22、ly with mechanical equipment, not to expose the sampleto temperatures of more than 52C. Clean the equipment thoroughly between samples. Thoroughly remix the ground sample andstore it in an airtight container to avoid contamination.4.1.4 RehydratingThoroughly blend and rehydrate samples which contain
23、 calcium sulfate in forms other than CaSO4 2H2Oand natural anhydrite. Place the sample in distilled water and keep it wet for not less than 48 h. Dry the hydrated sample in anoven at 45 6 3C to constant weight and recrush or grind it in accordance with 4.1.3.4.1.5 Sample ReductionThoroughly mix and
24、reduce large samples as required by quartering or by the use of a riffle to obtaina specimen of approximately 50 g.4.2 Gypsum (Specification C22/C22M)Gypsum samples will be received in the form of rocks or powder, or both. Ifnecessary crush and reduce the entire dried sample in accordance with 4.1.3
25、 and 4.1.5.4.3 Gypsum Plaster, (Specification C28/C28M).4.3.1 Gypsum Ready-Mixed Plaster or Gypsum WoodFibered PlasterScreen the dried sample through a 150-m (No. 100)sieve4 and discard the residue retained on the sieve. Reweigh the remaining sample and calculate the percentage of the driedsample. R
26、educe the sample in accordance with 4.1.5. Thoroughly blend and rehydrate the specimen in accordance with 4.1.42 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the st
27、andards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.4 Detailed requirements for this sieve are given in Specification E11.C471M 1724.3.2 Gypsum Neat Plaster or Gypsum Gauging PlasterReduce the dried sample in accorda
28、nce with 4.1.5. Thoroughly blendand rehydrate the specimen in accordance with 4.1.4.4.4 Gypsum Casting and Molding Plaster, (Specification C59)Reduce the dried sample in accordance with 4.1.5. Thoroughlyblend and rehydrate the specimen in accordance with 4.1.4.4.5 Gypsum Keenes Cement, (Specificatio
29、n C61)Reduce the dried sample in accordance with 4.1.5. Blend in no more than1 % molding plaster or K2SO4 and rehydrate the specimen in accordance with 4.1.4.4.6 Gypsum Concrete, (Specification C317/C317M)Screen the dried sample through a 150-m (No. 100) sieve4 and discardthe residue retained on the
30、 sieve. Reweigh the remaining sample and calculate the percentage of the dried sample. Reduce thesample in accordance with 4.1.5. Thoroughly blend and rehydrate the specimen in accordance with 4.1.44.7 Gypsum Panel ProductsCut or break the dried sample into small pieces. Using a mortar and pestle, s
31、trike the pieces ofthe sample to loosen the paper face. Remove the pieces of paper by hand as they are separated from the core of the gypsum board.Carefully scrape any remaining powder from the paper. When all the paper has been removed from the pieces of the sample, reducethe sample in accordance w
32、ith 4.1.5.COMPLETE PROCEDURE5. Apparatus5.1 Analytical BalanceCapable of weighing the weighing bottles, lids and samples.5.2 BalanceCapable of weighing not less than 100 g at a precision of 0.001 g.5.3 Drying OvenA mechanical convection oven set at 45 6 3C.5.4 DesiccatorCapable of being tightly seal
33、ed and containing calcium chloride or equivalent desiccant.5.5 Calcining Oven or FurnaceCapable of achieving and maintaining temperatures to not less than 1000C.5.6 Weighing BottlesBorosilicate glass or ceramic containers with tightly sealable lids.5.7 Hot PlateA controllable hot plate capable of he
34、ating casseroles to approximately 120C.5.8 Porcelain CasserolesWith a capacity of 50 to 100 mL.5.9 Filtering Funnels.5.10 Filter Paper.5.11 Porcelain Crucibles.5.12 Mortar and Pestle.5.13 Mechanical Jaw CrusherCapable of crushing gypsum rocks up to 50 mm diameter.5.14 Mechanical GrinderBurr mill or
35、equivalent capable of grinding the granular output of the jaw crusher specified in 5.13.6. Reagents6.1 Purity of ReagentsUse reagent grade chemicals in all tests. Unless otherwise indicated, use reagents that conform to thespecifications of the Committee on Analytical Reagents of the American Chemic
36、al Society, where such specifications areavailable.5 If it is necessary to use other grades, first ascertain that the reagent is of sufficiently high purity so that its use will notlessen the accuracy of the determination.6.1.1 Ammonium Chloride (NH4Cl).6.1.2 Ammonium Hydroxide (sp gr 0.90)Concentra
37、ted ammonium hydroxide (NH4OH).6.1.3 Ammonium Nitrate (25 g/L)Dissolve 25 g of ammonium nitrate (NH4NO3) 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 barium chloride (BaCl22H2O) in water and dilute to 1 L.6.1.6 Calcium Chloride (CaCl2
38、)Anhydrous Calcium Chloride with a combined water of not more than 5 %.6.1.7 Hydrochloric Acid (sp gr 1.19)Concentrated hydrochloric acid (HCl).6.1.8 Hydrochloric Acid (1 + 4)Mix 1one volume of HCl (sp gr 1.19) with 4four volumes of water.6.1.9 Hydrochloric Acid (1 + 5)Mix 1one volume of HCl (sp gr
39、1.19) with 5five volumes of water.6.1.10 Nitric Acid (sp gr 1.42)Concentrated nitric acid (HNO3).5 Reagent Chemicals, American Chemical Society Specifications , American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Anala
40、r Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.C471M 1736.1.11 Potassium Chromate Solution (100 g/L)Dissolve 5 g of potassium chromate (K2CrO4) in 50 mL of water,
41、 mix, add10ten drops of 0.05 N silver nitrate (AgNO3) solution, allow to stand for 5 min, and filter.6.1.12 Potassium Permanganate (5.6339 g/L)Dissolve 5.6339 g of potassium permanganate (KMnO4) in water and dilute to1 L.6.1.13 Silver Nitrate, Standard Solution (0.05 N)Prepare and standardize a 0.05
42、 N silver nitrate (AgNO3) solution.6.1.14 Sodium Ammonium Phosphate(NaNH4HPO4).6.1.15 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid (H2SO4).6.1.16 Sulfuric Acid (1 + 6)Carefully mix 1one volume of H2SO4 (sp gr 1.84) with 6six volumes of water.6.1.17 Nitric Acid (0.1 N)Mix 1.4 mL of HNO3 (sp g
43、r 1.42) with 200 mL of water.6.1.18 Phenolphthalein Indicator SolutionDissolve 0.25 g of phenolphthalein in 30 mL of methanol and dilute to 50 mL withwater.6.1.19 Sodium Hydroxide Solution (0.1 N)Dissolve 1 g of sodium hydroxide (NaOH) in 250 mL of water.6.1.20 WaterReagent water shall be in accorda
44、nce with Specification D1193, type II. Specification D1193 gives the followingvalues 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 carbon (TOC), max, g/L 50.0Sodium, max, g/L 5.0Chlorides max, g/L 5.0To
45、tal silica, max, g/L 5.07. Free Water7.1 Significance and UseThe free water analysis determines the amount of free water contained in the sample as opposed tochemically combined water, and prepares the sample for further analysis.7.2 Procedure:7.2.1 Weigh a sample of the material as received of not
46、less than 50 g to a precision of 0.001 g and spread it out in a thin layerin a suitable vessel. Place in an oven and dry at 45 6 3C for 2 h, then cool in a desiccator and weigh again. The loss of weightcorresponds to the free water.7.2.2 Retain the sample in a sealed container or in the desiccator f
47、or further analysis.7.3 Calculation and ReportCalculate and report loss in weight as a percentage of the sample as received or of the dried sampleas required.7.4 Precision and BiasBias: Neither the precision nor the bias for the free water analysis has been determined.7.4.1 The precision of this tes
48、t method is based on an interlaboratory study of ASTM C471M, Standard Test Methods forChemical Analysis of Gypsum and Gypsum Products, conducted in 2016. Each of 17 laboratories analyzed two different gypsumsample types. Every “test result” represents an individual determination, and all participant
49、s reported five test results per material.Practice E691 was followed for the design and analysis of the data; the details are given in ASTM Research Report No.C11-XXXX.67.4.1.1 Repeatability (r)The difference between repetitive results obtained by the same operator in a given laboratory applyingthe same test method with the same apparatus under constant operating conditions on identical test material within short intervalsof time would in the long run, in the normal and correct operation of the
