1、Designation: E359 10Standard Test Methods forAnalysis of Soda Ash (Sodium Carbonate)1This standard is issued under the fixed designation E359; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in p
2、arentheses indicates the year of last reapproval. Asuperscript epsilon () 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. Scope*1.1 These test methods cover the analyses usually requiredon commerc
3、ial 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 31-35Sodium Chloride, Titrimetric 36-42Sodium Sulfate, Gravimetric 43
4、-49Iron, Photometric 50-58Sieve Analysis 59-651.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 Review the current Materials Safety Data Sheets(MSDS) for detailed information concerning toxicity, first aidprocedures, handl
5、ing 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 practices and determine the applica-bility of regulatory limitations p
6、rior to use. Specific hazardsstatements are given in Section 6.2. Referenced Documents2.1 ASTM Standards:2C429 Test Method for Sieve Analysis of Raw Materials forGlass ManufactureD1193 Specification for Reagent WaterE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE60 Practice for Ana
7、lysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE70 Test Method for pH of Aqueous Solutions With theGlass ElectrodeE145 Specification for Gravity-Convection and Forced-Ventilation OvensE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing
8、 of Industrial and Spe-cialty Chemicals3E200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical AnalysisE300 Practice for Sampling Industrial Chemicals3. Significance and Use3.1 Soda ash is used in a number of manufacturing pro-cesses. The procedures
9、 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 Practice E60.4.2 pH MeterspH meters and their use shall conform
10、 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 and a50-mL stem below may be used.5. Purity of Reagents and Wat
11、er5.1 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 Reagents of the American Chemical Society,1These test methods are under the jurisdiction of ASTM
12、Committee E15 onIndustrial and Specialty Chemicals and are the direct responsibility of Subcommit-tee E15.02 on Product Standards.Current edition approved March 1, 2010. Published April 2010. Originallyapproved in 1968. Last previous edition approved in 2005 as E359 00(05)1. DOI:10.1520/E0359-10.2Fo
13、r 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.3Withdrawn. The last approved version of this historical standar
14、d is referencedon www.astm.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.where such specifications are available.4Other grades may beused, provided it is first a
15、scertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 Unless otherwise indicated, references to water shall beunderstood to mean Type II or Type III reagent water conform-ing to Specification D1193.6. Hazards6.1 Soda ash is
16、 a primary skin irritant. Dusts or mists aremoderately irritating to the mucous membrane of the nose andeyes. The irritation is temporary and symptoms usually disap-pear shortly after contact is ended.7. Sampling7.1 The general principles for sampling solids are coveredin Practice E300. The followin
17、g aspects of soda ash samplingmust be considered:7.2 General:7.2.1 The selection of a representative sample is a necessaryprerequisite for any accurate analysis, and this is particularlyimportant with the alkalies, since they are susceptible to rapidcontamination by moisture and carbon dioxide upon
18、exposureto air. Also, some of them are not uniform in particle size andtend to segregate on handling.7.2.2 The characteristics 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 gen
19、erally shipped, and the susceptibil-ity of dense ash in bulk to segregate in relation to particle sizeas the result of normal 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 as
20、h; and (3) the type ofanalysis desired, whether chemical or physical.7.3 Bulk Shipments:7.3.1 Although bulk shipments are 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
21、 are to be included, it isparticularly important to avoid segregation that occurs onsurface areas.7.3.2 To sample boxcar shipments, 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 thie
22、f.7.3.3 Hopper cars and trucks are more difficult to sampleadequately. Samples can be taken through the hatches with asample 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.
23、7.4 Bag Shipments:7.4.1 Packaged soda ash that has been in storage for sometime can be sampled satisfactorily only by emptying 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 who
24、le. The reason is thata bag or other container taken from an outer layer of the storagepile is subject to more air contact 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
25、 the usual practice to take the sample from somewhere nearthe center of the package. This may be done by removing thetop 6 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 foundrepr
26、esentative except in cases of long storage or unusuallydamp storage conditions.7.5 Sample Preparation:7.5.1 Thoroughly mix 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
27、sample for analysis in a glass or othersuitable container that will not contaminate the sample and thatcan be sealed to prevent 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. Th
28、is alkalinity is normallyexpressed as percent sodium oxide (Na2O).9. Summary of Test Method9.1 Total alkalinity is determined by titration with standardhydrochloric (or sulfuric) acid using methyl orange or modifiedmethyl orange indicator solution.10. Interferences10.1 Alkalies other than soda ash (
29、sodium carbonate) andcompounds that consume acid will affect the accuracy of thistest method.11. Reagents11.1 Hydrochloric (or Sulfuric) Acid (1.0 meq/mL)Prepare in accordance with Practice E200 (record temperatureof solution when standardized).11.2 Modified Methyl Orange Indicator Solution or Methy
30、lOrange Indicator SolutionSee Practice E200.11.3 Water, carbon dioxide-free (freshly boiled and cooled).12. 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
31、weight of sample requires a 100-mL buretfor titration and is recommended. If a 50-mL buret is used, the sampleweight should be halved.4Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the A
32、merican Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.E359 10212.2 Add 3 drops of modified methyl orange indicatorsolution (Note 2). Tit
33、rate this solution with standard 1.0meq/mL acid to a gray end point (Note 3). Record the volumeto the nearest 0.02 mL and temperature of the acid used.Correct the acid normality for any difference from the stan-dardization temperature by use of the factor DN/C = 0.00035between 20 and 30C.Add the cor
34、rection when the temperatureof use is below and subtract when above the temperature ofstandardization (see Practice E200).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 stan
35、dardization of the acid.13. Calculation13.1 Calculate the total alkalinity as percent sodium oxide(Na2O) as follows:sodium oxide, % mass m/m!5A 3 B 3 0.030990! 3 100W(1)where:A = acid required for titration of the sample, mL,B = corrected meq/mL of the acid, andW = sample used, g.13.2 Alternatively,
36、 calculate the alkalinity as sodium car-bonate as follows:sodium carbonate, % mass m/m!51.7101 3 Na2O, wt % (2)13.3 If actual sodium 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
37、.6308! (3)where:A =Na2CO3, % (see 13.2), andB = NaHCO3, % (see 21.1).14. Report14.1 Report the percentage of sodium oxide to the 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 Analy
38、st)The standard devia-tion for a single determination has been estimated to be0.032 % absolute at 52 DF. The 95 % limit for the differencebetween two such runs is 0.09 % absolute.15.1.2 Laboratory Precision (Within-Laboratory, Between-Days Variability)The standard deviation of results (each theavera
39、ge of duplicates), obtained by the same analyst ondifferent days, has been estimated to be 0.038 % absolute at 26DF. The 95 % limit 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 duplicate
40、s), obtained byanalysts in different laboratories, has been estimated to be0.154 % absolute at 8 DF. The 95 % limit for the differencebetween 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 so
41、da ashcovering the range from 58.190 to 58.385 % sodium oxide. Ten labora-tories analyzed the three samples, with one analyst in each laboratoryperforming duplicate determinations and repeating 1 day later.5PracticeE180 was used for developing these precision estimates.15.2 BiasThe bias of this test
42、 method has not beendetermined because of the lack of acceptable reference mate-rial.SODIUM BICARBONATE16. Scope16.1 This test 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.
43、1 Bicarbonate is determined titrimetrically by adding asample to an excess of standard sodium hydroxide solution(thus converting bicarbonate to carbonate), precipitating thecarbonate with barium chloride solutions and back-titrating theexcess sodium hydroxide with standard acid solution using apH me
44、ter to determine the end point.17.2 Aprimary standard is run simultaneously to correct thetitration for adsorption or occlusion 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 buffer
45、solution.18.2 Magnetic Stirrer, with TFE-fluorocarbon-covered stir-ring bar.19. Reagents19.1 Barium Chloride Solution (120 g/L)See PracticeE200.19.2 Hydrochloric Acid, Standard (0.1 meq/mL)See Prac-tice E200.19.3 Sodium Carbonate, Primary Standard Na2CO3Dryabout 10 g of anhydrous primary standard so
46、dium carbonate(Na2CO3) in a platinum dish or low-form weighing bottle(70-mm diameter) for4hat250C (minimum) but do notexceed 300C. Cool in a desiccator. Prepare fresh for use.19.4 Sodium Hydroxide, Standard Solution (0.1 meq/mL)See Practice E200.19.5 Water, carbon dioxide-free (freshly boiled and co
47、oled).20. Procedure20.1 Perform the following steps of the procedure on equalmass 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
48、 standard Na2CO3as ablank is required.5Supporting data are available from ASTM Headquarters. Request RR:E15-0046.E359 10320.2 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 meq/mL NaOH solution (or HCl) as required.20.3 Into a 600-m
49、L beaker place 150 mL of CO2-free water.Add by pipet 5.0 mL of 0.1 meq/mL NaOH solution.NOTE 6If, in 20.6, the pH of the sample solution is below 8.8 beforetitrating with 0.1 meq/mL HCl, repeat the test adding by pipet 10.0 mL of0.1 meq/mL NaOH solution to the beakers being prepared for both thesample and the primary 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 7
