1、Designation: C146 94a (Reapproved 2014)Standard Test Methods forChemical Analysis of Glass Sand1This standard is issued under the fixed designation C146; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the chemical analysis of glasssands. They are useful for either high-silica sands(99 % + silica (SiO2) or for
3、high-alumina sands containing asmuch as 12 to 13 % alumina (Al2O3). Generally nonclassical,the test methods are rapid and accurate. They include thedetermination of silica and of total R2O3(see 11.2.4), and theseparate determination of total iron as iron oxide (Fe2O3),titania (TiO2), chromium oxide
4、(Cr2O3), zirconia (ZrO2), andignition loss. Included are procedures for the alkaline earthsand alkalies. High-alumina sands may contain as much as 5 to6 % total alkalies and alkaline earths. It is recommended thatthe alkalies be determined by flame photometry and thealkaline earths by absorption spe
5、ctrophotometry.1.2 These test methods, if followed in detail, will provideinterlaboratory agreement of results.NOTE 1For additional information, see Test Methods C169 andPractices E50.1.3 The test methods appear in the following order:Procedures for Referee Analysis: SectionSilica (SiO2)Double Dehyd
6、ration 10Total R2O3Gravimetric 11Fe2O3,TiO2,ZrO2,Cr2O3, by Photometric Methods andAl2O3by Complexiometric Titration1217Preparation of the Sample for Determination of IronOxide, Titania, Alumina, and Zirconia12Iron Oxide (as Fe2O3) by 1,10-Phenanthroline Method 13Titania (TiO2) by the Tiron Method 14
7、Alumina (Al2O3) by the CDTA Titration Method 15Zirconia (ZrO2) by the Pyrocatechol Violet Method 16Chromium Oxide (Cr2O3) by the 1,5-Diphenylcarbo-hydrazide Method17Procedures for Routine Analysis:Silica (SiO2)Single Dehydration 19Al2O3, CaO, and MgOAtomic Absorption Spec-trophotometry2025Na2O and K
8、2OFlame Emission Spectrophotometry 26-27Loss on Ignition (LOI) 281.4 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 appl
9、ica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C169 Test Methods for Chemical Analysis of Soda-Limeand Borosilicate GlassC429 Test Method for Sieve Analysis of Raw Materials forGlass ManufactureD1193 Specification for Reagent WaterE11 Specification for W
10、oven Wire Test Sieve Cloth and TestSievesE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Spectrophotometry2.2 Other Documents:NIST Special Publication 26033
11、. Significance and Use3.1 These test methods can be used to ensure that thechemical composition of the glass sand meets the composi-tional specification required for this raw material.3.2 These test methods do not preclude the use of othermethods that yield results within permissible variations. In
12、anycase, the analyst should verify the procedure and techniqueused by means of a National Institute of Standards andTechnology (NIST) standard reference material or other similarmaterial of known composition having a component compa-rable with that of the material under test. A list of standardrefer
13、ence materials is given in the NIST Special Publication260, current edition.1These test methods are under the jurisdiction of ASTM Committee C14 onGlass and Glass Products and are the direct responsibility of Subcommittee C14.02on Chemical Properties and Analysis.Current edition approved Oct. 1, 201
14、4. Published October 2014. Originallyapproved in 1939. Last previous edition approved in 2009 as C146 94a (2009).DOI: 10.1520/C0146-94AR14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
15、 information, refer to the standards Document Summary page onthe ASTM website.3Standard samples available from the National Institute of Standards andTechnology are listed in U.S. Dept. of Commerce, NIST, Special Publication 260(current edition), Washington, DC 20234.Copyright ASTM International, 10
16、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Photometers and Photometric Practice4.1 Photometers and photometric practice prescribed inthese test methods shall conform to Practice E60.5. Purity of Reagents5.1 Reagent grade chemicals shall be used throughout.Un
17、less otherwise indicated, it is intended that reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhi
18、gh purity to permit its use without lessening the accuracy ofthe determination.5.2 Unless otherwise indicated, references to water shall beunderstood to mean reagent water as defined by Type I, II, orIII of Specification D1193.6. Concentration of Acids and Ammonium Hydroxide(NH4OH)6.1 When acids and
19、 ammonium hydroxide are specified byname or chemical formula only, concentrated reagents of thefollowing percent concentrations are intended:Sp Gr %Hydrochloric acid (HCl) 1.2 36 to 38Hydrofluoric acid (HF) 1.2 48 to 51Nitric acid (HNO3) 1.4 69 to 71Perchloric acid (HClO4) 1.8 70 to 72Sulfuric acid
20、(H2SO4) 1.8 95 to 98Ammonium hydroxide (NH4OH) 0.9 28 to 306.2 Concentrations of diluted acids and NH4OH, exceptwhen standardized, are specified as a ratio stating the numberof volumes of the concentrated reagent to be added to a givennumber of volumes of water, as in the following example: HCl(1 +
21、99) means 1 volume of concentrated HCl (sp gr 1.19)added to 99 volumes of water.7. Filter Papers7.1 Throughout these test methods, filter papers will bedesignated as “coarse,” “medium,” or “fine” without namingbrands or manufacturers. All filter papers are of the double-acid-washed ashless type. “Co
22、arse” filter paper refers to theporosity commonly used for the filtration of aluminum hydrox-ide. “Medium” filter paper refers to that used for filtration ofcalcium oxalate, and “fine” filter paper to that used for bariumsulfate.8. Preparation of Sample8.1 General ConsiderationsThe acquisition and p
23、repara-tion of the sample shall follow the principles stated in TestMethod C429.8.2 The laboratory sample is reduced for analysis to 10 to 20g by use of a small riffle with openings preferably of 6.4-mm(14-in.) size. The analytical sample is then ground in an agatemortar to pass a 150-m (No. 100) si
24、eve.5If the laboratorysample as received contains any large particles that are retainedon a 850-m (No. 20) sieve, these shall be sieved out, crushed(without contamination) so as to pass the sieve, and then mixedback into the laboratory sample before riffling.9. Precision and Bias9.1 PrecisionThe pro
25、bable precision of results that can beexpected by the use of procedures described in these testmethods is shown in the following tabulation. Precision isgiven as absolute error and is dependent on the quantity of theconstituent present as well as the procedure used.Probable Precision of Results, Wei
26、ght %Constituent Referee Analysis Routine AnalysisSiO2(99 %) 0.1 0.25SiO2(8590 %) 0.1 0.25R2O3(1 %) 0.05 0.10R2O3(1015 %) 0.1 0.15Al2O3(1 %) 0.05 0.10Al2O3(1015 %) 0.1 0.1Fe2O30.003 .TiO20.005 .ZrO20.001 to 0.005 .Cr2O30.0001 to 0.001 .CaO . 0.001MgO . 0.001Na2O . 0.001K2O . 0.0019.2 BiasStandard re
27、ference materials or other similarmaterials of known composition should be analyzed wheneverpossible to determine the bias of the results.PROCEDURES FOR REFEREE ANALYSIS10. Silica (SiO2) by the Double Dehydration Method10.1 Weigh 1.000 g of the powdered sample and 2.0 g ofanhydrous sodium carbonate
28、(Na2CO3) into a clean 75-mLplatinum dish (Note 2); mix well with a platinum or Nichrome6wire. Tap the charge so it lies evenly in the bottom of the dish.Cover evenly with an additional 1.0 g of Na2CO3. Cover withthe platinum lid and heat first at a dull red heat over a cleanoxidizing flame; graduall
29、y raise the temperature until a clearmelt is obtained. Properly carried out, little or no spatteringshould occur, and the fusion can be performed in 3 to 4 min.When melted, rotate the melt to spread it evenly over thebottom and lower sides of the dish, gradually withdrawingfrom the flame. Cover and
30、cool to room temperature. Duringfusion, the dish should be handled at all times with platinum-tipped tongs and the fusion performed with a platinum (pref-erably 90 % platinum and 10 % rhodium alloy) or silicatriangle.NOTE 2To obtain accurate repeat weighings, platinum ware must bekept scrupulously c
31、lean on the outside of the vessel as well as on theinside. It should be polished brightly with fine, round grain sand and4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemic
32、al 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.5Requirements for sieves are given in ASTM Specification E11.6Nichrome is a registered trademark
33、 of the Driver-Harris Co., 308 Middlesex St.,Harrison, NJ 07029.C146 94a (2014)2protected from dirty surfaces. It is recommended that porcelain plates beused for cooling fusions, and that platinum be set on paper towels or otherclean material during filtration.10.2 Add 20 to 25 mL of HCl (1 + 1) und
34、er the platinumcover and digest on a steam bath or hot plate until the melt hascompletely disintegrated; it is also possible to digest the melt inthe cold HCl overnight. Police and rinse the lid with a fine jetof water; rinse down the sides of the dish and evaporate todryness on a steam bath or unde
35、r an infrared lamp. Keep thedish covered with a raised cover glass during evaporation.When evaporation is complete (absence of HCl), cool, drenchthe residue with 5 mLof HCl, and then add 20 mLof hot water.Digest for 5 min and filter through a 9-cm medium filter paper.Catch the filtrate in a 250-mL p
36、latinum dish. Transfer theprecipitated silica to the filter with the aid of a policeman anda bit of paper pulp, and wash the precipitate and paper twelvetimes with hot 2 % HCl. Transfer the paper and precipitate tothe dish used for fusion and dehydration and reserve forsubsequent ignition. Wipe the
37、stirring rod and the periphery ofthe funnel with a piece of damp filter paper, and add to the dishcontaining the precipitate for ignition.10.3 Evaporate the filtrate to dryness on the steam bath orunder an infrared lamp. When dry, cool, drench with 10 mL ofHCl (1 + 1), and again evaporate just to dr
38、yness; then bake ina drying oven at 105C for 30 min. Cool, drench with 5 mL ofHCl, and add 20 mL of hot water and a small bit of filter pulp.Digest hot for 5 min and filter through a 7-cm fine paper. Policethe dish with the aid of a bit of paper pulp and wash precipitateand paper eight times with ho
39、t 2 % HCl. Transfer the paper andprecipitate to the dish containing the initial precipitation. Wipethe stirring rod and the periphery of the funnel with a piece ofdamp filter paper, and add to the dish containing the precipitatefor ignition.10.4 Partially cover the dish with its platinum lid, but le
40、aveenough space so air can circulate during ignition. Place the dishin a cold muffle furnace, and bring the temperature to 1200Cfor 30 min. Carefully and completely cover the dish beforeremoving it from the furnace and transfer to a desiccator. Coolto room temperature and weigh the covered dish (W1)
41、. Moistenthe silica with 1 to 2 mL of water and add 4 to 5 mL of HF and0.5 g of oxalic acid crystals. Evaporate to dryness on a sandbath or under an infrared lamp. Carefully sublime any remain-ing oxalic acid, cover the dish with its platinum cover, heat to1000C for 2 min, cool, and weigh (W2) as be
42、fore.10.5 CalculationCalculate the percent of SiO2as follows:SiO2,%5W12 W2! 3100sample weight(1)11. Total R2O3by Ammonium Hydroxide (NH4OH)Precipitation11.1 General ConsiderationsThe weight of sample takenfor analysis is governed by the amount of Al2O3known orsuspected to be present. Sands low in Al
43、2O3(0.05 to 0.5 %)require a 5- to 10-g sample; sands with larger amounts ofAl2O3require a 0.5- to 1.0-g sample. Usually experience or priorinformation will indicate a satisfactory sample weight. Thetotal R2O3serves as a check on the sum of the R2O3oxidesdetermined separately. It also helps to identi
44、fy an unknownsand as a low- or high-alumina type.11.2 Procedure:11.2.1 Weigh a suitable weight of sample into an 80- to100-mL platinum dish, moisten, and add 10 mL of HF for eachgram of sample taken; add 4 mL of H2SO4(1 + 1) andevaporate to the first fuming of H2SO4(Note 3). Cool,carefully wash down
45、 the sides of the dish with a minimum ofwater, and evaporate to the cessation of H2SO4fumes. Cool,add 10 to 15 mL of HCl (1 + 1), 20 mL of hot water, and digesthot until the salts are in solution. If they do not dissolve readily,transfer to a beaker, police the dish, and boil the solution untilthe s
46、ulfates have dissolved (Note 4).NOTE 3Some sands may contain small amounts of organic matter asshown by the presence of carbon or carbonaceous material in theconcentrated H2SO4. If this is the case, add 2 to 3 mL of HNO3and 10 to15 drops of HClO4, and proceed.NOTE 4High-alumina sands are generally m
47、ixtures of quartz andaluminum silicates of the feldspar group. Some of these silicates cancontain barium. If a fine, white, insoluble precipitate persists, it isprobably barium sulfate. In this case, partially neutralize the HCl until thesolution is about 1 to 2 % acid, add about ten drops of H2SO4(
48、1 + 1) andboil gently for about 30 min. Cool, and after 1 to 2 h, filter the solutionthrough a fine paper. The precipitate may be ignited and weighed andsubsequently tested for barium. If the precipitate is not barium sulfate, itshould be tested for silica. If the precipitate is neither of these, it
49、 can beconsidered R2O3and added to the R2O3found by ammonia precipitation.11.2.2 If the expected R2O3is about 10 mg, dilute thesample to about 75 to 100 mL; if much larger, dilute to about200 to 250 mL. Add approximately2gofNH4Cl, heat toboiling, add three to four drops of methyl red indicator solutionand precipitate the R2O3with the addition of NH4OH (1 + 1).Add the NH4OH slowly, stirring to obtain a sharp end point;finally add about four drops in excess for small amounts ofprecipitate and up to eight drops for large amounts. Boil thes
