ASTM_C_25-17.pdf

C25-17C50 Practice for Sampling,Sample Preparation,Packaging,be capable of reproducing weighings within 0.0002 g with anand Marking of Lime and Limestone Productsaccuracy of+0.0002 g.Rapid weighing devices that may beC51 Terminology Relating to Lime and Limestone(as usedprovided such as a chain,damper,or heavy riders shall notby the Industry)increase the basic inaccuracy by more than 0.0001 g at anyC911 Specification for Quicklime,Hydrated Lime,andreading and with any load within the rated capacity of theLimestone for Selected Chemical and Industrial Usesbalance.D1193 Specification for Reagent Water5.1.2 Weights-Weights used for analysis shall conform toE29 Practice for Using Significant Digits in Test Data toClass S-1 requirements of the National Institute of StandardsDetermine Conformance with Specificationsand Technology as described in NIST Circular 547.They shallE50 Practices for Apparatus,Reagents,and Safety Consid-be checked at least once a year or when questioned,anderations for Chemical Analysis of Metals,Ores,andadjusted to within allowable tolerances for Class S-1 weights.Related MaterialsAll new sets of weights purchased shall have the weights of I gE70 Test Method for pH of Aqueous Solutions With theand larger made of stainless steel or other corrosion-resistantGlass Electrodealloy not requiring protective coating and shall meet theE173 Practice for Conducting Interlaboratory Studies ofdensity requirements for Class S.Methods for Chemical Analysis of Metals(Withdrawn5.1.3 Glassware and Laboratory Containers-Standard1998)3volumetric flasks,burets,pipets,dispensers,and so forth,shallE177 Practice for Use of the Terms Precision and Bias inbe carefully selected precision grade or better and shall beASTM Test Methodscalibrated,if necessary,to meet the requirements of eachE200 Practice for Preparation,Standardization,and Storageoperation.Standard-type interchangeable ground glass or TFE-of Standard and Reagent Solutions for Chemical Analysisfluorocarbon joints are recommended for all volumetric glass-E691 Practice for Conducting an Interlaboratory Study toware.Polyethylene containers are recommended for all aque-Determine the Precision of a Test Methodous solutions of alkalies and for standard solutions where theE832 Specification for Laboratory Filter Paperspresence of dissolved silica or alkali from the glass would beobjectionable.3.Terminology5.1.4 Desiccators-Desiccators shall be provided with a3.1 Definitions:Definitions-Unless otherwise specified,forgood desiccant such as anhydrous magnesium perchloratedefinitions of terms used in these test methods refer toactivated alumina,sulfuric acid,or phosphoric anhydrideTerminology C51.Anhydrous calcium sulfate may also be used provided it hasbeen treated with a color-changing indicator to show when the4.Significance and Usedesiccant has lost its effectiveness.Calcium chloride and silica4.1 These test methods provide accurate and reliable ana-gel are not satisfactory desiccants for this type of analysis.lytical procedures to determine the chemical constituents of5.1.5 Filter Paper-Filter paper shall conform to the re-limestone,quicklime,and hydrated lime(see Note 1).Thequirements of Specification E832,Type II(quantitative).Classpercentages of specific constituents which determine a materi-E shall be used for coarse and gelatinous precipitates.Whenals quality or fitness for use are of significance dependingmedium-textured paper is required,Class F filter paper shall beupon the purpose or end use of the material.Results obtainedused.When a retentive paper is needed,Class G shall be used.may be used in relation to specification requirements.Recommendations:ClassFilter Pore Size(um)Filter Speed4.2 Because quicklime and hydrated lime quickly absorb20to25fast speedwater and carbon dioxide from the air,precision and bias are8medium speedextremely dependent upon precautions taken during sample2.5slow speedpreparation and analysis to minimize excessive exposure to5.1.6 Crucibles-Platinum crucibles and tight fitting lidsambient conditions.should preferably be made of pure unalloyed platinum and beof 25 to 35-mL capacity.Where alloyed platinum is used forNorE 1-These test methods can be applied to other calcareousmaterials if provisions are made to compensate for known interferences.greater stiffness or to obviate sticking of fused material tocrucible or lid,the alloyed platinum should not decrease in5.General Apparatus and Materials and Reagentsweight by more than 0.2 mg when heated at 1200C for 1 h.5.1 General Apparatus and Materials:5.1.7 Mufle Furnace-The electric muffle furnace should be5.1.1 Balance-The balance shall be of an analytical typecapable of continuous operation up to 1000C and be capablewith a capacity not to exceed 200 g.It may be of conventionalof intermittent operation at higher temperatures if required.Itdesign or it may be a constant-load,direct-reading type.It shallshould have an indicating pyrometer accurate to+25C.3The last approved version of this historical standard is referenced on4 Available from National Institute of Standards and Technology(NIST),100www.astm.orgBureau Dr.Stop 3460.Gaithersburg,MD 20899-3460.2C25-175.2 Reagents:6.2 Tared or Weighed Crucibles-The tare weight of cru-5.2.1 Purity of Reagents-Reagent grade chemicals shall becibles shall be determined by preheating the empty crucible toused in all tests.Unless otherwise indicated,it is intended thatconstant weight at the same temperature and under the sameall reagents shall conform to the specifications of the Commit-conditions as shall be used for the final ignition of a residue andtee on Analytical Reagents of the American Chemical Society5cooling in a desiccator for the same period of time used for thewhere such specifications are available.Other grades may becrucible containing the residue.used provided it is first ascertained that the reagent is of6.3 Constancy of Weight of Ignited Residue-To definitelysufficiently high purity to permit its use without lessening theestablish the constancy of weight of the ignited residue,theaccuracy of the determination.In addition to this,it is desirableresidue and container shall be ignited at the specified tempera-in many cases for the analyst to ensure the accuracy of histure and time,cooled to room temperature in a desiccator,andresults by running blanks or checking against a comparableweighed.The residue and container shall then be reheated forsample of known composition.at least 30 min at the same temperature,cooled in a desiccator5.2.2 Purity of Water-Unless otherwise indicated,refer-for the same period of time,and reweighed.Additional ignitionences to water are understood to mean distilled water or otherperiods may be required until two consecutive weights do notwater of equivalent purity.Water conforming to Specificationdiffer by more than 0.2 mg,at which time it shall be consideredD1193 meets these requirementsthat constant weight has been attained.For ignition loss,each5.2.3 Concentration of Reagents:5.2.3.1 Concentrated Acids and Ammonium Hydroxide-reheating period shall be 5 min.When acids and ammonium hydroxide are specified by name6.4 Calculation:or chemical formula only,it shall be understood that concen-6.4.1 The calculations included in the individual procedurestrated reagents approximating the following specific gravitiessometimes assume that the exact weight specified has beenor concentrations are intended:used.Accurately weighed samples which are approximatelyAcetic acid(HC2HgO2)99.5%but not exactly equal to the weight specified may be usedHydrochloric acid(HCI)sp gr 1.19provided appropriate corrections are made in the calculation.Hydrofluoric acid(HF)48%Unless otherwise stated,weights of all samples and residuesNitric acid(HNO)sp9r1.42Perchloric acid(HCIO)70%should be recorded to the nearest 0.0001 g.Phosphoric acid(HaPO)85%6.4.2 In all mathematical operations on a set of observedSulfuric acid(H2SO)sp gr 1.84values,the equivalent of two more places of figures than in theAmmonium hydroxide(NH OH)sp gr 0.905.2.3.2 Dilute Reagents-The concentration of dilute acidssingle observed values shall be retained.For example,ifobserved values are read or determined to the nearest 0.1 mg,and NHOH except when standardized,are specified as a ratiocarry numbers to the nearest 0.001 mg in calculation.stating the number of measured volumes of the concentratedreagent to be diluted with a given number of measured volumes6.5 Rounding Figures-Rounding figures to the nearestof water.In conformance with international practice,new andsignificant place required in the report should be done after therevised methods will use the plusdesignation instead of thecalculations are completed,in order to keep the final resultsratio(symbol as the specified designation of dilution;forfree from calculation errors.The rounding procedure shouldexample,H2SO(5+95)means 5 volumes of concentratedfollow the principle outlined in Practice E29.H2SO(sp gr 1.84)diluted with 95 volumes of water.5.2.3.3 Standard Solutions-Concentrations of standard so-7.Performance Requirements for Test Methodslutions shall be expressed as normalities(N)or as equivalents7.1 Referee Analyses-The reference test methods that apin grams per millilitre of the component to be determined,forpear in Sections 8 through 32,or any other test methodsexample:0.1 N K2Cr207 solution(1 mL=0.004 g Fe203).Thequalified in accordance with 7.3,are required for refereeaverage of at least three determinations shall be used for allanalysis in those cases where conformance to the requirementsstandardizations.The standardization used to determine theof a chemical specification are questioned.In these cases astrength of the standard solutions is described in the text underlimestone,quicklime,or hydrated lime shall not be rejected foreach of the appropriate procedures.failure to conform to chemical requirements unless all samplepreparation and analysis of any one constituent is made entirely6.General Proceduresby reference test methods prescribed in the appropriate sections6.1 Sampling-Samples of lime and limestone for chemicalof this test method or by other qualified test methods.Excep-analysis shall be taken and prepared in accordance with thetion can be made when specific test methods are prescribed inrequirements of Practice C50 applicable to the material to bethe standard specification for the limestone,quicklime,ortested.hydrated lime in question.The test methods actually used forthe analysis shall be designated.7.1.1 When there is a question regarding acceptance,referee5 Reagent Chemicals,American Chemical Society Specifications,Americananalyses shall be made in duplicate.If the two results do notChemical Society,Washington,DC.For suggestions on the testing of reagents notagree within the permissible variation given in Table 1,thelisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.and the United States Pharmacopeiadetermination including sample preparation shall be repeatedand National Formulary.U.S.Pharmacopeia Convention.Inc.(USPC).Rockville,in duplicate until the results agree within the permissibleMD.variation.When the results agree within the permissible