1、Designation: C471M 01 (Reapproved 2012)C471M 13Standard 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 revisi
2、on, 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 These test methods cover the chemical analysis of gypsum and gypsum panel products, including gypsum r
3、eady-mixedplaster, gypsum wood-fibered plaster, and gypsum concrete.1.2 The test methods appear in the following order:colwidth=“127.98pt“/COLSPEC SectionsPreparation of Sample 4Complete Procedure 5 16Alternative Procedure for Analysis for Calcium Sulfate by Ammonium Acetate Method17 22Alternative P
4、rocedure for Analysis for Sodium Chloride by the Coulometric Method23 29Complete Procedure 5 16Determination of Sand in Set Plaster 30 36Optional Procedure for Analysis for Sodium by Flame Photometry 47 54Wood-Fiber Content in Wood-Fiber Gypsum Plaster 37 39Optional Procedure for Analysis for Sodium
5、 by the Atomic Absorption Method40 46Preparation of Sample 4Optional Procedure for Analysis for Sodium by Flame Photometry 47 54Wood-Fiber Content in Wood-Fiber Gypsum Plaster 37 39Determination of Sulfur (S8) in Gypsum Panel Products by Liquid Extraction for Analysis by Liquid or Gas Chromatography
6、 55651.3 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 values stated in SI units are to be regarded as the standard.1.5 This
7、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 applicability of regulatorylimitations prior to use.2. Referenced Documents2.1
8、 ASTM Standards:2C11 Terminology Relating to Gypsum 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 Specifi
9、cation for Gypsum ConcreteC778 Specification for SandC842 Specification for Application of Interior Gypsum PlasterD1193 Specification for Reagent Water1 These test methods are under the jurisdiction of ASTM Committee C11 on Gypsum and Related Building Materials and Systems and are the direct respons
10、ibility ofSubcommittee C11.01 on Specifications and Test Methods for Gypsum Products.Current edition approved June 1, 2012Dec. 1, 2013. Published July 2012January 2014. Originally approved in 1961. Last previous edition approved in 20062012 as C471 01 (2006)(Reapproved1. 2012). DOI: 10.1520/C0471M-0
11、1R12.10.1520/C0471M-13.2 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 standards Document Summary page on the ASTM website.This document is not an ASTM standard
12、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 may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases onl
13、y the current versionof the standard as published by 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 States1D1428 Test Method for
14、 Test for Sodium and Potassium In Water and Water-Formed Deposits by Flame Photometry (Withdrawn1989)3D2013 Practice for Preparing Coal Samples for AnalysisE11 Specification for Woven Wire Test Sieve Cloth and Test Sieves3. Terminology3.1 DefinitionsDefinitions shall be in accordance with Terminolog
15、y C11.3.2 Definitions of Terms Specific to This Standard: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 stand
16、ard, na chemical used in the 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
17、of raw gypsum or gypsum product in the state received by the testinglaboratory, including aggregates, impurities and water content.3.2.6 dried sample,surrogate standard, na sample devoid of free chemical used to account for extraction efficiency ofS8water3.2.3 riffle, na hand feed sample divider dev
18、ice that divides the sample into parts of approximately the same weight. (D2013)4. Preparation of Sample4.1 General ProceduresDetails of sample preparation will vary according to the type of material being tested.4.1.1 Sample As ReceivedUse a sufficient amount of sample such that, after sieving, not
19、 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 as received.4.1.2 DryingDry the sample in accordance with Section 7. This will be the weight of the dried sam
20、ple.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, particularly with mechanical equipment, not to expose the sampleto temperatures of more than 52 C. Clean the equipment
21、 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 calcium sulfate in forms other than CaSO42H2Oand natural anhydrite. Place the sample in distilled water an
22、d keep it wet for not less than 48 h. Dry the hydrated sample in anoven at 45 6 3 C to constant weight and recrush or grind it in accordance with 4.1.3.4.1.5 Sample ReductionThoroughly mix and reduce large samples as required by quartering or by the use of a riffle to obtaina specimen of approximate
23、ly 50 g.4.2 Gypsum (C22/C22M)Gypsum samples will be received in the form of rocks, powder or both. If necessary crush andreduce the entire dried sample in accordance with 4.1.3 and 4.1.5.4.3 Gypsum Plaster, (C28/C28M).4.3.1 Gypsum Ready-Mixed Plaster or Gypsum WoodFibered PlasterScreen the dried sam
24、ple 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. Reduce the sample in accordance with 4.1.5. Thoroughly blend and rehydrate the specimen in accordance with 4.1.4.4.3.2 Gypsum Neat Plaster
25、or Gypsum Gauging PlasterReduce the dried sample in accordance with 4.1.5. Thoroughly blendand rehydrate the specimen in accordance with 4.1.4.4.4 Gypsum Casting and Molding Plaster , (C59)Reduce the dried sample in accordance with 4.1.5. Thoroughly blend andrehydrate the specimen in accordance with
26、 4.1.4.4.5 Gypsum Keenes Cement, (C61)Reduce the dried sample in accordance with 4.1.5. Blend in no more than 1 % moldingplaster or K2SO4 and rehydrate the specimen in accordance with 4.1.4.4.6 Gypsum Concrete, (C317/C317M)Screen the dried sample through a 150-m (No. 100) sieve4 and discard the resi
27、dueretained on the sieve. Reweigh the remaining sample and calculate the percentage of the dried sample. Reduce the sample inaccordance with 4.1.5. Thoroughly blend and rehydrate the specimen in accordance with 4.1.4.4.7 Gypsum BoardPanel ProductsCut or break the dried sample into small pieces. Usin
28、g a mortar and pestle, strike thepieces of the sample to loosen the paper face. Remove the pieces of paper by hand as they are separated from the core of the3 The last approved version of this historical standard is referenced on www.astm.org.4 Detailed requirements for this sieve are given in Speci
29、fication E11.C471M 132gypsum board. Carefully scrape any remaining powder from the paper. When all the paper has been removed from the pieces ofthe sample, reduce the sample in accordance with 4.1.5. Thoroughly blend and rehydrate the specimen in accordance with 4.1.4.COMPLETE PROCEDURE5. Apparatus5
30、.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 3 C.5.4 DesiccatorCapable of being tightly sealed and containing calcium chloride or eq
31、uivalent desiccant.5.5 Calcining Oven or FurnaceCapable of achieving and maintaining temperatures to not less than 1000 C.5.6 Weighing BottlesBorosilicate glass or ceramic containers with tightly sealable lids.5.7 Hot PlateA controllable hot plate capable of heating casseroles to approximately 120 C
32、.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 equivalent capable of grinding the gra
33、nular 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 Chemical Society, where such specifications
34、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)Concentrated ammonium hydroxide (NH4OH).6.1.3 Am
35、monium 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)Anhydrous Calcium Chloride with a comb
36、ined 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 1 volume of HCl (sp gr 1.19) with 4 volumes of water.6.1.9 Hydrochloric Acid (1 + 5) Mix 1 volume of HCl (sp gr 1.19) with 5 volumes of water.6.1.10 Nitric Aci
37、d (sp gr 1.42)Concentrated nitric acid (HNO3).6.1.11 Potassium Chromate Solution (100 g/L)Dissolve 5 g of potassium chromate (K2CrO4) in 50 mL of water, mix, add 10drops 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
38、 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 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.
39、16 Sulfuric Acid (1 + 6) Carefully mix 1 volume of H2SO4 (sp gr 1.84) with 6 volumes of water.6.1.17 Nitric Acid (0.1 N)Mix 1.4 mL of HNO3 (sp gr 1.42) with 200 mL of water.6.1.18 Phenolphthalein Indicator Solution Dissolve 0.25 g of phenolphthalein in 30 mLof methanol and dilute to 50 mLwithwater.6
40、.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 accordance with Specification D1193, type II. Specification D1193 gives the followingvalues for type II grade water.5 Reagent Chemicals, American Chemical Society S
41、pecifications , American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial
42、 Convention, Inc. (USPC), Rockville, MD.C471M 133Electrical 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 5.0Total silica, max, g/L 5.07. Free Water7.1 Significance and Us
43、eThe 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 less than 50 g to a precision of 0.001 g and spread it out i
44、n a thin layerin a suitable vessel. Place in an oven and dry at 45 6 3 C 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 for further analysis.7.3 Calculation and ReportCalculate and
45、 report loss in weight as a percentage of the sample as received or of the dried sampleas required.7.4 Precision and BiasNeither the precision nor the bias for the free water analysis has been determined.8. Combined Water8.1 Significance and UseThe combined water analysis determines the percent of c
46、hemically combined water and is used tocalculate the purity of gypsum or the amount of gypsum or gypsum plaster in gypsum products.8.2 InterferencesSome materials, such as organic and hydrated compounds that decompose within the same temperature rangeas gypsum, will cause high results. When the maxi
47、mum temperature is exceeded, some carbonates undergo decomposition, whichwill result in high results.8.3 Procedure:8.3.1 For each sample, place three weighing bottles with lids in the preheated calcining oven or furnace and heat for 2 h at 215to 230 C. Place in the desiccator and allow to cool to ro
48、om temperature. Weigh the bottles and lids to the nearest 0.0001 g andrecord the tare weights.8.3.2 Weigh out three specimens of approximately 1 g each of the sample as prepared in Section 4 and dried in Section 7 toa precision of 0.0001 g in the previously tared weighing bottles and record the tota
49、l weight with lids.8.3.3 Place the specimens in the calcining oven with the lids placed loosely on each bottle or crucible for 2 h or until constantweight has been obtained.8.3.4 Place the lids tightly on the weighing bottles, remove from the oven, and place in the desiccator to cool to roomtemperature.8.3.5 Weigh each specimen to a precision of 0.0001 g and record the weights.8.3.6 Retain the residues for carbon dioxide analysis.8.4 Calculation and ReportCalculate and report the
