ASTM E359-2000(2005)e1 Standard Test Methods for Analysis of Soda Ash (Sodium Carbonate)《苏打灰(纯碱)分析的标准试验方法》.pdf

1、Designation: E 359 00 (Reapproved 2005)e1Standard Test Methods forAnalysis of Soda Ash (Sodium Carbonate)1This standard is issued under the fixed designation E 359; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r

2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (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.e1NOTEEditorial changes were made in June 2005.1. Scop

3、e1.1 These test methods cover the analyses usually requiredon commercial soda ash (sodium carbonate).1.2 The analytical procedures appear in the following sec-tions:SectionsTotal Alkalinity, Titrimetric 8-15Sodium Bicarbonate, Titrimetric 16-23Loss on Heating, Gravimetric 24-30Moisture, Calculation

4、31-35Sodium Chloride, Titrimetric 36-42Sodium Sulfate, Gravimetric 43-49Iron, Photometric 50-58Sieve Analysis 59-651.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 Review the current Materials Safety Data Sheets(MSDS) fo

5、r detailed information concerning toxicity, first aidprocedures, handling and safety precautions.1.5 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

6、practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardsstatements are given in Section 6.2. Referenced Documents2.1 ASTM Standards:2C 429 Test Method for Sieve Analysis of Raw Materials forGlass ManufactureD 1193 Specification for Reagent WaterE11 Specific

7、ation for Wire-Cloth Sieves for Testing Pur-posesE60 Practice for Photometric and SpectrophotometricMethods for Chemical Analysis of MetalsE70 Test Method for pH of Aqueous Solutions with theGlass ElectrodeE 145 Specification for Gravity-Convection and Forced-Ventilation OvensE 180 Practice for Dete

8、rmining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty ChemicalsE 200 Practice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysisE 300 Practice for Sampling Industrial Chemicals3. Significance and Use3.1 Soda ash

9、is used in a number of manufacturing pro-cesses. The procedures listed in 1.2 are suitable for specifica-tion acceptance and manufacturing control of commercial sodaash.4. Apparatus4.1 Photometers and Photometric PracticePhotometersand photometric practice used in these test methods shallconform to

10、Practice E60.4.2 pH MeterspH meters and their use shall conform toTest Method E70.4.3 BuretA calibrated 50-mL buret, or any standard50-mL buret calibrated by either the National Institute ofStandards and Technology or by the user. Alternatively, a100-mL calibrated buret with a 50-mL bulb at the top

11、and a50-mL stem below may be used.1These test methods are under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and are the direct responsibility of Subcommit-tee E15.02 on Product Standards.Current edition approved March 1, 2005. Published April 2005. Originallyapproved

12、in 1968. Last previous edition approved in 2000 as E 359 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1

13、Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Purity of Reagents and Water5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the s

14、pecifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determinati

15、on.5.2 Unless otherwise indicated, references to water shall beunderstood to mean Type II or Type III reagent water conform-ing to Specification D 1193.6. Hazards6.1 Soda ash is a primary skin irritant. Dusts or mists aremoderately irritating to the mucous membrane of the nose andeyes. The irritatio

16、n is temporary and symptoms usually disap-pear shortly after contact is ended.7. Sampling7.1 The general principles for sampling solids are coveredin Practice E 300. The following aspects of soda ash samplingmust be considered:7.2 General:7.2.1 The selection of a representative sample is a necessary

17、prerequisite for any accurate analysis, and this is particularlyimportant with the alkalies, since they are susceptible to rapidcontamination by moisture and carbon dioxide upon exposureto air. Also, some of them are not uniform in particle size andtend to segregate on handling.7.2.2 The characteris

18、tics of soda ash that make propersampling difficult at times are its tendency to absorb moistureand carbon dioxide from the air through any commercialcontainer in which it is generally shipped, and the susceptibil-ity of dense ash in bulk to segregate in relation to particle sizeas the result of nor

19、mal transit vibrations.7.2.3 Details of good sampling depend on: (1) the type ofshipment, whether in containers or in bulk; (2) the type ofproduct, whether light or dense soda ash; and (3) the type ofanalysis desired, whether chemical or physical.7.3 Bulk Shipments:7.3.1 Although bulk shipments are

20、normally in transit arelatively short time, there is likely to be some absorption ofmoisture and carbon dioxide in exposed surface areas. Ifphysical tests such as screen analysis are to be included, it isparticularly important to avoid segregation that occurs onsurface areas.7.3.2 To sample boxcar s

21、hipments, brush aside the surfacelayer to a depth of 12 in. (305 mm) and take portionssystematically from the newly exposed area to the bottom ofthe car by means of a sample thief.7.3.3 Hopper cars and trucks are more difficult to sampleadequately. Samples can be taken through the hatches with asamp

22、le thief, as for boxcar sampling. Preferably, samplesshould be taken during the unloading operation at the point ofdischarge to the bin, or from any open section of the conveyor.7.4 Bag Shipments:7.4.1 Packaged soda ash that has been in storage for sometime can be sampled satisfactorily only by empt

23、ying the wholepackage and mixing thoroughly before taking the sample. Evensuch a portion is likely to represent only the package sampledrather than the stock of packages as a whole. The reason is thata bag or other container taken from an outer layer of the storagepile is subject to more air contact

24、 and consequently moremoisture and carbon dioxide absorption than are packagesburied farther back in the stock.7.4.2 To get an idea of the quality of the soda ash as packed,it is the usual practice to take the sample from somewhere nearthe center of the package. This may be done by removing thetop 6

25、 or 8 in. (150 or 200 mm) of soda ash from the package,then removing the sample from the center of the remainingportion. Such a sample carefully taken will generally be foundrepresentative except in cases of long storage or unusuallydamp storage conditions.7.5 Sample Preparation:7.5.1 Thoroughly mix

26、 the total sample taken. Then quarteror riffle the entire sample to obtain the required size sample foranalysis. Minimize exposure to moisture and carbon dioxide.7.5.2 Store the sample for analysis in a glass or othersuitable container that will not contaminate the sample and thatcan be sealed to pr

27、event exposure of the sample to moisture orcarbon dioxide.TOTAL ALKALINITY8. Scope8.1 This test method covers the titrimetric determination ofthe total alkalinity of soda ash. This alkalinity is normallyexpressed as percent sodium oxide (Na2O).9. Summary of Test Method9.1 Total alkalinity is determi

28、ned by titration with standardhydrochloric (or sulfuric) acid using methyl orange or modifiedmethyl orange indicator solution.10. Interferences10.1 Alkalies other than soda ash (sodium carbonate) andcompounds that consume acid will affect the accuracy of thistest method.11. Reagents11.1 Hydrochloric

29、 (or Sulfuric) Acid (1.0 N)Prepare inaccordance with Practice E 200 (record temperature of solutionwhen standardized).11.2 Modified Methyl Orange Indicator Solution or MethylOrange Indicator SolutionSee Practice E 200.11.3 Water, carbon dioxide-free (freshly boiled and cooled).3Reagent Chemicals, Am

30、erican Chemical 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 Formula

31、ry, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E 359 00 (2005)e1212. Procedure12.1 Weigh, to the nearest 0.1 mg, 4.4 6 0.1g(Note 1)ofthe sample and transfer to a 500-mL conical flask.Add 100 mLof water and swirl to dissolve the sample.NOTE 1Use of the specfied weight of sample requires

32、 a 100-mL buretfor titration and is recommended. If a 50-mL buret is used, the sampleweight should be halved.12.2 Add 3 drops of modified methyl orange indicatorsolution (Note 2). Titrate this solution with standard 1.0 N acidto a gray end point (Note 3). Record the volume to the nearest0.02 mL and

33、temperature of the acid used. Correct the acidnormality for any difference from the standardization tempera-ture by use of the factor DN/C = 0.00035 between 20 and30C. Add the correction when the temperature of use is belowand subtract when above the temperature of standardization(see Practice E 200

34、).NOTE 2If desired, 0.1 % methyl orange indicator solution may beused.NOTE 3The analyst should end the titration at the same shade of coloras was used for the end point in the standardization of the acid.13. Calculation13.1 Calculate the total alkalinity as percent sodium oxide(Na2O) as follows:sodi

35、um oxide, wt % 5A 3 B 3 0.030990! 3 100W(1)where:A = acid required for titration of the sample, mL,B = corrected normality of the acid, andW = sample used, g.13.2 Alternatively, calculate the alkalinity as sodium car-bonate as follows:sodium carbonate, wt % 5 1.7101 3 Na2O, wt % (2)13.3 If actual so

36、dium carbonate content is desired, thesodium bicarbonate content must be determined separately asdescribed in Sections 16 and 23. Then:sodium carbonate actual!,%5 A 2 B 3 0.6308! (3)where:A =Na2CO3, % (see 13.2), andB = NaHCO3, % (see 21.1).14. Report14.1 Report the percentage of sodium oxide to the

37、 nearest0.01 %.15. Precision and Bias15.1 PrecisionThe following criteria should be used forjudging the acceptability of results (Note 4):15.1.1 Repeatability (Single Analyst)The standard devia-tion for a single determination has been estimated to be0.032 % absolute at 52 DF. The 95 % limit for the

38、differencebetween two such runs is 0.09 % absolute.15.1.2 Laboratory Precision (Within-Laboratory, Between-Days Variability)The standard deviation of results (each theaverage of duplicates), obtained by the same analyst ondifferent days, has been estimated to be 0.038 % absolute at 26DF. The 95 % li

39、mit for the difference between two suchaverages is 0.11 % absolute.15.1.3 Reproducibility (Multilaboratory)The standard de-viation of results (each the average of duplicates), obtained byanalysts in different laboratories, has been estimated to be0.154 % absolute at 8 DF. The 95 % limit for the diff

40、erencebetween two such averages is 0.43 % absolute.NOTE 4These precision estimates are based on an interlaboratorystudy of analyses performed in 1967 on three samples of soda ashcovering the range from 58.190 to 58.385 % sodium oxide. Ten labora-tories analyzed the three samples, with one analyst in

41、 each laboratoryperforming duplicate determinations and repeating 1 day later.4PracticeE 180 was used for developing these precision estimates.15.2 BiasThe bias of this test method has not beendetermined because of the lack of acceptable reference mate-rial.SODIUM BICARBONATE16. Scope16.1 This test

42、method describes the titrimetric determinationof sodium bicarbonate in soda ash. The lower limit of deter-mination is 0.02 % sodium bicarbonate.17. Summary of Test Method17.1 Bicarbonate is determined titrimetrically by adding asample to an excess of standard sodium hydroxide solution(thus convertin

43、g bicarbonate to carbonate), precipitating thecarbonate with barium chloride solutions and back-titrating theexcess sodium hydroxide with standard acid solution using apH meter to determine the end point.17.2 Aprimary standard is run simultaneously to correct thetitration for adsorption or occlusion

44、 of sodium hydroxide onthe barium carbonate.18. Apparatus18.1 pH Meter, with glass and calomel electrodes. Standard-ize the pH meter with commercially available pH 10 buffersolution.18.2 Magnetic Stirrer, with TFE-fluorocarbon-covered stir-ring bar.19. Reagents19.1 Barium Chloride Solution (120 g/L)

45、See PracticeE 200.19.2 Hydrochloric Acid, Standard (0.1 N)See PracticeE 200.19.3 Sodium Carbonate, Primary Standard Na2CO3Dryabout 10 g of anhydrous primary standard sodium carbonate(Na2CO3) in a platinum dish or low-form weighing bottle(70-mm diameter) for4hat250C (minimum) but do notexceed 300C. C

46、ool in a desiccator. Prepare fresh for use.19.4 Sodium Hydroxide, Standard Solution (0.1 N)SeePractice E 200.4Supporting data are available from ASTM Headquarters. Request RR:E150046.E 359 00 (2005)e1319.5 Water, carbon dioxide-free (freshly boiled and cooled).20. Procedure20.1 Perform the following

47、 steps of the procedure on equalweights of both the sample and the primary standard sodiumcarbonate (Na2CO3)(Note 5). Make duplicate determinations.NOTE 5To compensate for the adsorption or occlusion of NaOH bythe precipitated BaCO3(20.5), the use of primary standard Na2CO3as ablank is required.20.2

48、 Place 200 mL of BaCl2solution in a 400-mL beaker.Using a pH meter, adjust the solution to pH 8.8 by addition of0.1 N NaOH solution (or HCl) as required.20.3 Into a 600-mL beaker place 150 mL of CO2-free water.Add by pipet 5.0 mL of 0.1 N NaOH solution.NOTE 6If, in 20.6, the pH of the sample solutio

49、n is below 8.8 beforetitrating with 0.1 N HCl, repeat the test adding by pipet 10.0 mL of 0.1 NNaOH solution to the beakers being prepared for both the sample and theprimary standard Na2CO3.20.4 Weigh, to the nearest 1 mg, 4.0 g of the sample (or ofthe primary standard) and transfer to the solution in the600-mL beaker. Place the beaker on a magnetic stirrer, insert astirring bar, and stir to dissolve.NOTE 7The subsequent operations should be completed within 5 minto minimize absorption of atmospheric CO2.20.5 While continuing to stir, add the 200 mL o