1、Designation: C25 112C25 17Standard Test Methods forChemical Analysis of Limestone, Quicklime, and HydratedLime1This standard is issued under the fixed designation C25; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of las
2、t revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1 NOTERevised 28.3.5 editorially for clarity in May
3、 2016.1. Scope1.1 These test methods cover the chemical analysis of high-calcium and dolomitic limestone, quicklime, and hydrated lime.These test methods are classified as either standard (preferred) or alternative (optional).1.2 The standard test methods are those that employ classical gravimetric
4、or volumetric analytical procedures and are typicallythose required for referee analyses where chemical specification requirements are an essential part of contractual agreementbetween buyer and seller.1.3 Alternative or optional test methods are provided for those who wish to use procedures shorter
5、 or more convenient than thestandard methods for the routine determinations of certain constituents. Optional test methods may sometimes be preferred to thestandard test methods, but frequently the use of modern and expensive instrumentation is indicated which may not be accessibleto everyone. There
6、fore, the use of these test methods must be left to the discretion of each laboratory.1.4 The analytical procedures appear in the following order:SectionAluminum Oxide 15Aluminum Oxide 15Available Lime Index 28Available Lime Index 28Calcium and Magnesium Oxide:Calcium and Magnesium Oxide:Alternative
7、 EDTA Titration Method 31Alternative EDTA Titration Method 31Calcium Carbonate Equivalent 33Calcium Carbonate Equivalent 33Calcium Oxide:Calcium Oxide:Gravimetric Method 16Gravimetric Method 16Volumetric Method 17Volumetric Method 17Carbon Dioxide by Standard Method 22Carbon Dioxide by Standard Meth
8、od 22Combined Oxides of Iron and Aluminum 12Combined Oxides of Iron and Aluminum 12Ferrous Iron Appendix X5Ferrous Iron Appendix X5Free Calcium Oxide Appendix X6Free Calcium Oxide Appendix X6Free Moisture in Hydrated Lime 21Free Moisture in Hydrated Lime 21Free Moisture in Limestone 20Free Moisture
9、in Limestone 20Free Silica 29Free Silica 291 These test methods are under the jurisdiction of ASTM Committee C07 on Lime and Limestone and are the direct responsibility of Subcommittee C07.05 on ChemicalTests.Current edition approved June 1, 2011Dec. 1, 2017. Published May 2016January 2018. Original
10、ly approved in 1919. Last previous edition approved in 2011 asC25 1112. DOI: 10.1520/C0025-11E02.10.1520/C0025-17.This document is not an ASTM standard 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
11、 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 by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Dr
12、ive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Insoluble Matter Including Silicon Dioxide:Insoluble Matter Including Silicon Dioxide:Standard Method 8Standard Method 8Optional Perchloric Acid Method 9Optional Perchloric Acid Method 9Insoluble Matter Other Than Silicon Dioxide 11In
13、soluble Matter Other Than Silicon Dioxide 11Loss on Ignition 19Loss on Ignition 19Magnesium Oxide 18Magnesium Oxide 18Manganese:Manganese:Bismuthate Method Appendix X4Bismuthate Method Appendix X4Periodate (Photometric) Method 27Periodate (Photometric) Method 27pH Determination of Alkaline Earth Sol
14、utions 34pH Determination of Alkaline Earth Solutions 34Phosphorus:Phosphorus:Titrimetric Method Appendix X3Titrimetric Method Appendix X3Molybdovanadate Method 26Molybdovanadate Method 26Silicon Dioxide 10Silicon Dioxide 10Strontium Oxide Appendix X2Strontium Oxide Appendix X2Sulfur Trioxide 23Sulf
15、ur Trioxide 23Total Carbon:Total Carbon:Direct Combustion-Thermal Conductivity CellMethod32Direct Combustion-Thermal Conductivity CellMethod32Total Carbon and Sulfur:Total Carbon and Sulfur:Combustion/Infrared Detection Method 35Combustion Infrared Detection Method 35Total Iron:Total Iron:Standard M
16、ethod, Potassium DichromateTitration13Standard Method, Potassium DichromateTitration13Potassium Permanganate Titration Method Appendix X1Potassium Permanganate Titration Method Appendix X1Ortho-Phenanthroline, Photometric Method 14Ortho-Phenanthroline, Photometric Method 14Total Sulfur:Total Sulfur:
17、Sodium Carbonate Fusion 24Sodium Carbonate Fusion 24Combustion-Iodate Titration Method 25Combustion-Iodate Titration Method 25Unhydrated Oxides 30Unhydrated Oxides 301.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof
18、the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific precautionary statements, see 9.3, 10.2.1, 18.4.3, 31.6.4.2, X2.3.1, and X5.4.1.1.1.5 This standard does not purport to address all of th
19、e safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use. For specific precautionary statements, see 9.3, 10.2.1,
20、 18.4.3, 31.6.4.2, X2.3.1, and X5.4.1.1.1.6 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 Tra
21、de Organization Technical Barriers to Trade (TBT) Committee.C25 1722. Referenced Documents2.1 ASTM Standards:2C50 Practice for Sampling, Sample Preparation, Packaging, and Marking of Lime and Limestone ProductsC51 Terminology Relating to Lime and Limestone (as used by the Industry)C911 Specification
22、 for Quicklime, Hydrated Lime, and Limestone for Selected Chemical and Industrial UsesD1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE50 Practices forApparatus, Reagents, and Safety Considerations for ChemicalAn
23、alysis of Metals, Ores, and Related MaterialsE70 Test Method for pH of Aqueous Solutions With the Glass ElectrodeE173 Practice for Conducting Interlaboratory Studies of Methods for Chemical Analysis of Metals (Withdrawn 1998)3E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
24、E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical AnalysisE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE832 Specification for Laboratory Filter Papers3. Terminology3.1 Definitions:Definitions
25、Unless otherwise specified, for definitions of terms used in these test methods refer to TerminologyC51.4. Significance and Use4.1 These test methods provide accurate and reliable analytical procedures to determine the chemical constituents of limestone,quicklime, and hydrated lime (See(see Note 1).
26、 The percentages of specific constituents which determine a materials quality orfitness for use are of significance depending upon the purpose or end use of the material. Results obtained may be used in relationto specification requirements.4.2 Because quicklime and hydrated lime quickly absorb wate
27、r and carbon dioxide from the air, precision and bias are extremelydependent upon precautions taken during sample preparation and analysis to minimize excessive exposure to ambient conditions.NOTE 1These test methods can be applied to other calcareous materials if provisions are made to compensate f
28、or known interferences.5. General Apparatus and Materials and Reagents5.1 General Apparatus and Materials:5.1.1 BalanceThe balance shall be of an analytical type with a capacity not to exceed 200 g. It may be of conventional designor it may be a constant-load, direct-reading type. It shall be capabl
29、e of reproducing weighings within 0.0002 g with an accuracyof 6 0.000260.0002 g. Rapid weighing devices that may be provided such as a chain, damper, or heavy riders shall not increasethe basic inaccuracy by more than 0.0001 g at any reading and with any load within the rated capacity of the balance
30、.5.1.2 WeightsWeights used for analysis shall conform to Class S-1 requirements of the National Institute of Standards andTechnology as described in NIST Circular 547.4 They shall be checked at least once a year or when questioned, and adjusted towithin allowable tolerances for Class S-1 weights. Al
31、l new sets of weights purchased shall have the weights of 1 g 1 g and largermade of stainless steel or other corrosion-resistant alloy not requiring protective coating and shall meet the density requirementsfor Class S.5.1.3 Glassware and Laboratory ContainersStandard volumetric flasks, burets, pipe
32、ts, dispensers, etc., and so forth, shall becarefully selected precision grade or better and shall be calibrated, if necessary, to meet the requirements of each operation.Standard-type interchangeable ground glass or TFE-fluorocarbon joints are recommended for all volumetric glassware.Polyethylene c
33、ontainers are recommended for all aqueous solutions of alkalies and for standard solutions where the presence ofdissolved silica or alkali from the glass would be objectionable.5.1.4 DesiccatorsDesiccators shall be provided with a good desiccant such as anhydrous magnesium perchlorate, activatedalum
34、ina, sulfuric acid, or phosphoric anhydride. Anhydrous calcium sulfate may also be used provided it has been treated with acolor-changing indicator to show when the desiccant has lost its effectiveness. Calcium chloride and silica gel are not satisfactorydesiccants for this type of analysis.5.1.5 Fi
35、lter PaperFilter paper shall conform to the requirements of Specification E832, Type II (quantitative). Class E shallbe used for coarse and gelatinous precipitates. When medium-textured paper is required, Class F filter paper shall be used. Whena retentive paper is needed, Class G shall be used.2 Fo
36、r 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.3 The last approved version of this historical standard is refere
37、nced on www.astm.org.4 Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.C25 173Recommendations:ClassFilter Pore Size(microns)Filter SpeedE 20 to 25 fast speedF 8 medium speedG 2.5 slow speedRecommendations:Class Filter Pore
38、Size (m) Filter SpeedE 20 to 25 fast speedF 8 medium speedG 2.5 slow speed5.1.6 CruciblesPlatinum crucibles and tight fitting lids should preferably be made of pure unalloyed platinum and be of 25to 35-mL capacity. Where alloyed platinum is used for greater stiffness or to obviate sticking of fused
39、material to crucible or lid,the alloyed platinum should not decrease in weight by more than 0.2 mg when heated at 1200 C 1200C for 1 h.5.1.7 Muffle FurnaceThe electric muffle furnace should be capable of continuous operation up to 1000 C 1000C and becapable of intermittent operation at higher temper
40、atures if required. It should have an indicating pyrometer accurate to 6 25 C.625C.5.2 Reagents:5.2.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents shall conform to the specifications of the Committee on Analytical R
41、eagents of the American Chemical Society5 wheresuch specifications are available. Other grades may be used provided it is first ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination. In addition to this, it is desirable in ma
42、ny cases forthe analyst to ensure the accuracy of his results by running blanks or checking against a comparable sample of known composition.5.2.2 Purity of WaterUnless otherwise indicated, references to water are understood to mean distilled water or other water ofequivalent purity. Water conformin
43、g to Specification D1193 meets these requirements.5.2.3 Concentration of Reagents:5.2.3.1 Concentrated Acids and Ammonium HydroxideWhen acids and ammonium hydroxide are specified by name orchemical formula only, it shall be understood that concentrated reagents approximating the following specific g
44、ravities orconcentrations are intended:Acetic acid (HC2H3O2) 99.5 %Hydrochloric acid (HCl) sp gr 1.19Hydrofluoric acid (HF) 48 %Nitric acid (HNO3) sp gr 1.42Perchloric acid (HClO4) 70 %Phosphoric acid (H3PO4) 85 %Sulfuric acid (H2SO4) sp gr 1.84Ammonium hydroxide (NH4OH) sp gr 0.90Acetic acid (HC2H3
45、O2) 99.5 %Hydrochloric acid (HCl) sp gr 1.19Hydrofluoric acid (HF) 48 %Nitric acid (HNO3) sp gr 1.42Perchloric acid (HClO4) 70 %Phosphoric acid (H3PO4) 85 %Sulfuric acid (H2SO4) sp gr 1.84Ammonium hydroxide (NH4OH) sp gr 0.905.2.3.2 Dilute ReagentsThe concentration of dilute acids and NH4OH except w
46、hen standardized, are specified as a ratiostating the number of measured volumes of the concentrated reagent to be diluted with a given number of measured volumes ofwater. In conformance with international practice, new and revised methods will use the “plus” designation instead of the ratio (:)symb
47、ol as the specified designation of dilution; for example, H2SO4 (5 + 95) means 5 volumes of concentrated H2SO4 (sp gr 1.84)diluted with 95 volumes of water.5.2.3.3 Standard SolutionsConcentrations of standard solutions shall be expressed as normalities (N) or as equivalents ingrams per millilitre of
48、 the component to be determined, for example: 0.1 N K2Cr2O7 solution (1 mL = 0.004 g Fe2O3). The averageof at least three determinations shall be used for all standardizations. The standardization used to determine the strength of thestandard solutions is described in the text under each of the appr
49、opriate procedures.6. General Procedures6.1 SamplingSamples of lime and limestone for chemical analysis shall be taken and prepared in accordance with therequirements of Practice C50 applicable to the material to be tested.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 Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S.
