1、Designation: C 25 06Standard Test Methods forChemical Analysis of Limestone, Quicklime, and HydratedLime1This standard is issued under the fixed designation C 25; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the chemical analys
3、is ofhigh-calcium and dolomitic limestone, quicklime, and hy-drated lime. These test methods are classified as either standard(preferred) or alternative (optional).1.2 The standard test methods are those that employ classi-cal gravimetric or volumetric analytical procedures and aretypically those re
4、quired for referee analyses where chemicalspecification requirements are an essential part of contractualagreement between buyer and seller.1.3 Alternative or optional test methods are provided forthose who wish to use procedures shorter or more convenientthan the standard methods for the routine de
5、terminations ofcertain constituents. Optional test methods may sometimes bepreferred to the standard test methods, but frequently the use ofmodern and expensive instrumentation is indicated which maynot be accessible to everyone. Therefore, the use of these testmethods must be left to the discretion
6、 of each laboratory.1.4 The analytical procedures appear in the following order:SectionAluminum Oxide 15Available Lime Index 28Calcium and Magnesium Oxide:Alternative EDTA Titration Method 31Calcium Carbonate Equivalent 33Calcium Oxide:Gravimetric Method 16Volumetric Method 17Carbon Dioxide by Stand
7、ard Method 22Combined Oxides of Iron and Aluminum 12Ferrous Iron Appendix X5Free Calcium Oxide Appendix X6Free Moisture in Hydrated Lime 21Free Moisture in Limestone 20Free Silica 29Insoluble Matter Including Silicon Dioxide:Standard Method 8Optional Perchloric Acid Method 9Insoluble Matter Other Th
8、an Silicon Diox-ide11Loss on Ignition 19Magnesium Oxide 18Manganese:Bismuthate Method Appendix X4Periodate (Photometric) Method 27pH Determination of Alkaline Earth Solu-tions34Phosphorus:Titrimetric Method Appendix X3Molybdovanadate Method 26Silicon Dioxide 10Strontium Oxide Appendix X2Sulfur Triox
9、ide 23Total Carbon:Direct Combustion-Thermal Conductiv-ity Cell Method32Total Carbon and Sulfur:Combustion/Infrared Detection Method 35Total Iron:Standard Method, Potassium Dichro-mate Titration13Potassium Permanganate TitrationMethodAppendix X1Ortho-Phenanthroline, PhotometricMethod14Total Sulfur:S
10、odium Carbonate Fusion 24Combustion-Iodate Titration Method 25Unhydrated Oxides 301.5 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 standard to establish appro-priate safety and health practices and d
11、etermine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see 9.3, 10.2.1, 18.4.3, 31.6.4.2,X2.3.1, and X5.4.1.1.2. Referenced Documents2.1 ASTM Standards:2C50 Practice for Sampling, Sample Preparation, Packag-ing, and Marking of Lime and Limestone Pro
12、ductsC51 Terminology Relating to Lime and Limestone (as usedby the Industry)C911 Specification for Quicklime, Hydrated Lime, andLimestone for Chemical and Industrial Uses1These test methods are under the jurisdiction of ASTM Committee C07 onLime and are the direct responsibility of Subcommittee C07.
13、05 on Chemical Tests.Current edition approved Feb. 15, 2006. Published March 2006. Originallyapproved in 1919. Last previous edition approved in 1999 as C 2599.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
14、 ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D 1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Tes
15、t Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE70 Test Method for pH of Aqueous Solutions With theGlass ElectrodeE 173 Practice for Conducting Interlaboratory Studies ofMe
16、thods for Chemical Analysis of Metals3E 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysisE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 832 Specification for Laboratory Filter Papers3
17、. Terminology3.1 DefinitionsUnless otherwise specified, for definitionsof terms used in these test methods refer to Terminology C51.4. Significance and Use4.1 These test methods provide accurate and reliable ana-lytical procedures to determine the chemical constituents oflimestone, quicklime, and hy
18、drated lime (See Note 1). Thepercentages of specific constituents which determine a materi-als quality or fitness for use are of significance dependingupon the purpose or end use of the material. Results obtainedmay be used in relation to specification requirements.4.2 Because quicklime and hydrated
19、 lime quickly absorbwater and carbon dioxide from the air, precision and bias areextremely dependent upon precautions taken during samplepreparation and analysis to minimize excessive exposure toambient conditions.NOTE 1These test methods can be applied to other calcareousmaterials if provisions are
20、 made to compensate for known interferences.5. General Apparatus and Materials and Reagents5.1 General Apparatus and Materials:5.1.1 BalanceThe balance shall be of an analytical typewith a capacity not to exceed 200 g. It may be of conventionaldesign or it may be a constant-load, direct-reading type
21、. It shallbe capable of reproducing weighings within 0.0002 g with anaccuracy of 6 0.0002 g. Rapid weighing devices that may beprovided such as a chain, damper, or heavy riders shall notincrease the basic inaccuracy by more than 0.0001 g at anyreading and with any load within the rated capacity of t
22、hebalance.5.1.2 WeightsWeights used for analysis shall conform toClass S-1 requirements of the National Institute of Standardsand Technology as described in NIST Circular 547.4They shallbe checked at least once a year or when questioned, andadjusted to within allowable tolerances for Class S-1 weigh
23、ts.All new sets of weights purchased shall have the weights of 1g and larger made of stainless steel or other corrosion-resistantalloy not requiring protective coating and shall meet thedensity requirements for Class S.5.1.3 Glassware and Laboratory ContainersStandardvolumetric flasks, burets, pipet
24、s, dispensers, etc., shall becarefully selected precision grade or better and shall becalibrated, if necessary, to meet the requirements of eachoperation. Standard-type interchangeable ground glass or TFE-fluorocarbon joints are recommended for all volumetric glass-ware. Polyethylene containers are
25、recommended for all aque-ous solutions of alkalies and for standard solutions where thepresence of dissolved silica or alkali from the glass would beobjectionable.5.1.4 DesiccatorsDesiccators shall be provided with agood desiccant such as anhydrous magnesium perchlorate,activated alumina, sulfuric a
26、cid, or phosphoric anhydride.Anhydrous calcium sulfate may also be used provided it hasbeen treated with a color-changing indicator to show when thedesiccant has lost its effectiveness. Calcium chloride and silicagel are not satisfactory desiccants for this type of analysis.5.1.5 Filter PaperFilter
27、paper shall conform to the re-quirements of Specification E 832, Type II (quantitative). ClassE shall be used for coarse and gelatinous precipitates. Whenmedium-textured paper is required, Class F filter paper shall beused. When a retentive paper is needed, Class G shall be used.Recommendations:Clas
28、sFilter Pore Size(microns)Filter SpeedE 20 to 25 fast speedF 8 medium speedG 2.5 slow speed5.1.6 CruciblesPlatinum crucibles and tight fitting lidsshould preferably be made of pure unalloyed platinum and beof 25 to 35-mL capacity. Where alloyed platinum is used forgreater stiffness or to obviate sti
29、cking of fused material tocrucible or lid, the alloyed platinum should not decrease inweight by more than 0.2 mg when heated at 1200 C for 1 h.5.1.7 Muffle FurnaceThe electric muffle furnace shouldbe capable of continuous operation up to 1000 C and becapable of intermittent operation at higher tempe
30、ratures ifrequired. It should have an indicating pyrometer accurate to6 25 C.5.2 Reagents:5.2.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagent
31、s of the American Chemical Society5where such specifications are available. Other grades may beused provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination. In addition to this, it is desirablein many cases
32、for the analyst to ensure the accuracy of hisresults by running blanks or checking against a comparablesample of known composition.3Withdrawn.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.5Reagent Chemicals, American Chem
33、ical 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. Ph
34、armacopeia Convention, Inc. (USPC), Rockville,MD.C250625.2.2 Purity of WaterUnless otherwise indicated, refer-ences to water are understood to mean distilled water or otherwater of equivalent purity. Water conforming to SpecificationD 1193 meets these requirements.5.2.3 Concentration of Reagents:5.2
35、.3.1 Concentrated Acids and Ammonium HydroxideWhen acids and ammonium hydroxide are specified by nameor chemical formula only, it shall be understood that concen-trated reagents approximating the following specific gravitiesor concentrations are intended:Acetic acid (HC2H3O2) 99.5 %Hydrochloric acid
36、 (HCl) sp gr 1.19Hydrofluoric acid (HF) 48 %Nitric acid (HNO3) sp gr 1.42Perchloric acid (HClO4)70Phosphoric acid (H3PO4)85Sulfuric acid (H2SO4) sp gr 1.84Ammonium hydroxide (NH4OH) sp gr 0.905.2.3.2 Dilute ReagentsThe concentration of dilute acidsand NH4OH except when standardized, are specified as
37、 a ratiostating the number of measured volumes of the concentratedreagent to be diluted with a given number of measured volumesof water. In conformance with international practice, new andrevised methods will use the “plus” designation instead of theratio (:) symbol as the specified designation of d
38、ilution; forexample, H2SO4(5 + 95) means 5 volumes of concentratedH2SO4(sp gr 1.84) diluted with 95 volumes of water.5.2.3.3 Standard SolutionsConcentrations of standard so-lutions shall be expressed as normalities (N) or as equivalentsin grams per millilitre of the component to be determined, forex
39、ample: 0.1 N K2Cr2O7solution (1 mL = 0.004 g Fe2O3). Theaverage of at least three determinations shall be used for allstandardizations. The standardization used to determine thestrength of the standard solutions is described in the text undereach of the appropriate procedures.6. General Procedures6.
40、1 SamplingSamples of lime and limestone for chemicalanalysis shall be taken and prepared in accordance with therequirements of Practice C50applicable to the material to betested.6.2 Tared or Weighed CruciblesThe tare weight of cru-cibles shall be determined by preheating the empty crucible toconstan
41、t weight at the same temperature and under the sameconditions as shall be used for the final ignition of a residue andcooling in a desiccator for the same period of time used for thecrucible containing the residue.6.3 Constancy of Weight of Ignited ResidueTo definitelyestablish the constancy of weig
42、ht of the ignited residue, theresidue and container shall be ignited at the specified tempera-ture and time, cooled to room temperature in a desiccator, andweighed. The residue and container shall then be reheated forat least 30 min at the same temperature, cooled in a desiccatorfor the same period
43、of time, and reweighed.Additional ignitionperiods may be required until two consecutive weights do notdiffer by more than 0.2 mg, at which time it shall be consideredthat constant weight has been attained. For ignition loss, eachreheating period shall be 5 min.6.4 Calculation:6.4.1 The calculations
44、included in the individual proceduressometimes assume that the exact weight specified has beenused. Accurately weighed samples which are approximatelybut not exactly equal to the weight specified may be usedprovided appropriate corrections are made in the calculation.Unless otherwise stated, weights
45、 of all samples and residuesshould be recorded to the nearest 0.0001 g.6.4.2 In all mathematical operations on a set of observedvalues, the equivalent of two more places of figures than in thesingle observed values shall be retained. For example, ifobserved values are read or determined to the neare
46、st 0.1 mg,carry numbers to the nearest 0.001 mg in calculation.6.5 Rounding FiguresRounding figures to the nearestsignificant place required in the report should be done after thecalculations are completed, in order to keep the final resultsfree from calculation errors. The rounding procedure should
47、follow the principle outlined in Practice E29.7. Performance Requirements for Test Methods7.1 Referee AnalysesThe reference test methods that ap-pear in Sections 8 through 32, or any other test methodsqualified in accordance with 7.3, are required for refereeanalysis in those cases where conformance
48、 to the requirementsof a chemical specification are questioned. In these cases alimestone, quicklime, or hydrated lime shall not be rejected forfailure to conform to chemical requirements unless all samplepreparation and analysis of any one constituent is made entirelyby reference test methods presc
49、ribed in the appropriate sectionsof this test method or by other qualified test methods. Excep-tion can be made when specific test methods are prescribed inthe standard specification for the limestone, quicklime, orhydrated lime in question. The test methods actually used forthe analysis shall be designated.7.1.1 When there is a question regarding acceptance, refereeanalyses shall be made in duplicate. If the two results do notagree within the permissible variation given in Table 1, thedetermination including sample preparation shall be repeatedTABLE 1 Maximum Pe
