1、Designation: D1245 11Standard Practice forExamination of Water-Formed Deposits by ChemicalMicroscopy1This standard is issued under the fixed designation D1245; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes a procedure for the examinationof water-formed deposits by means of chemical microscopy.This practice may
3、 be used to complement other methods ofexamination of water-formed deposits as recommended inPractices D2331 or it may be used alone when no otherinstrumentation is available or when the sample size is verysmall.1.2 The values stated in SI units are to be regarded asstandard. No other units of measu
4、rement are included in thisstandard.1.3 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 limi
5、tations prior to use.2. Referenced Documents2.1 ASTM Standards:2D887 Practices for Sampling Water-Formed DepositsD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2331 Practices for Preparation and Preliminary Testing ofWater-Formed DepositsD2332 Practice for Analysis of Water
6、-Formed Deposits byWavelength-Dispersive X-Ray FluorescenceD3483 Test Methods for Accumulated Deposition in aSteam Generator Tube3. Terminology3.1 DefinitionsFor definitions of terms in this practicerelating specifically to water and water-formed deposits, referto Terminology D1129.3.2 Descriptions
7、of Terms Specific to This StandardCertain terms in this practice that relate specifically to chemicalmicroscopy are described as follows:3.2.1 anisotropic, adjhaving different optical properties indifferent optical planes.3.2.1.1 DiscussionThese planes are referred to as thealpha, beta, and omega ax
8、es.3.2.2 Becke line, na faint, halo-like line that surrounds acrystal when the crystal is mounted in an oil of differentrefractive index.3.2.2.1 DiscussionThe Becke line increases in intensity asthe difference in the refractive index between the crystal andthe oil increases.3.2.3 dispersion, nthe va
9、riation of index of refractionwith wavelength.3.2.4 dispersion staining, nthe color effects producedwhen a transparent object, immersed in a liquid having arefractive index near that of the object, is viewed under themicroscope by transmitted white light and precise aperturecontrol.3.2.5 extinction
10、angle, nthe angle between the extinctionposition and some plane, edge, or line in a crystal.3.2.6 extinction position, nthe position in which an aniso-tropic crystal, between crossed polars, exhibits complete dark-ness.3.2.7 index of refraction, nthe numerical expression of theratio of the velocity
11、of light in a vacuum to the velocity of lightin a substance.3.2.8 isotropic, adjhaving the same optical properties inall directions.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposit
12、s, Analysis of Water for Power Generation and Process Use,On-Line Water Analysis, and Surveillance of Water.Current edition approved May 1, 2011. Published May 2011. Originallyapproved in 1952. Last previous edition approved in 2008 as D1245 08. DOI:10.1520/D1245-11.2For referenced ASTM standards, v
13、isit 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
14、-2959, United States.3.2.9 petrographic, adjpertaining to the description ofrocks or rocklike substances.3.2.9.1 DiscussionSuch description is usually in terms ofmorphology and optical properties.3.2.10 solid solution, na homogeneous mixture of two ormore components, in the solid state, retaining su
15、bstantially thestructure of one of the components.4. Summary of Practice4.1 The practice is essentially chemical microscopical,supplemented by optical data obtained by the petrographicmethod. The identification of compounds is made by observ-ing, under the microscope, characteristic reactions and pr
16、ecipi-tates resulting from the action of specific reagents on the solidsample or solutions thereof, and by measuring the opticalproperties.5. Significance and Use5.1 Chemical composition of water-formed deposits is amajor indicator of proper or improper chemical treatment ofprocess water, and is oft
17、en an indicator of operational param-eters as well, for example, temperature control. This practiceallows for rapid determination of constituents present in thesedeposits, particularly those indications of improper watertreatment, since they usually have very distinctive and easilyrecognized optical
18、 properties.5.2 This practice, where applicable, eliminates the need fordetailed chemical analysis, which is time-consuming, andwhich does not always reveal how cations and anions aremutually bound.5.3 Qualitative use of this practice should be limited tothose deposits whose control is generally kno
19、wn or predictable,based on treatment and feedwater mineral content, and whoseconstituents are crystalline, or in other ways optically orD1245 112morphologically distinctive. If these criteria are not met, othertechniques of analysis should be used, such as Practice D2332or Test Methods D3483, or bot
20、h.5.4 Quantitative use of this practice should be limited toestimates only. For more precise quantitative results, othermethods should be used (see 5.3).6. Interferences6.1 Organic material may interfere with both the petro-graphic and the chemical procedures. Organics can usually beremoved by solve
21、nt extraction as recommended in PracticesD2331.6.2 Deposits containing solid solutions present a complica-tion in that optical data vary throughout such a system, andunless the presence of this complication is known, the data maybe misinterpreted.6.3 Extremely fine material and opaque material are d
22、ifficultto identify. When present in appreciable amounts they maycloud over and obscure details of otherwise recognizableparticles.6.4 Interference with the chemical tests will be discussed inthe procedures.7. Apparatus7.1 Beakers, of borosilicate glass, 30-mL.7.2 Cover Glasses, No. 1 or No. 112 thi
23、ckness, round orsquare cover glasses.7.3 Glass Rods, 150 by 5-mm, for transferring drops, and 75by 1-mm, for stirring and leading reagent drops on the slides.7.4 Hotplate.7.5 Light SourceMicroscope lamp with concentrated fila-ment bulb and a focusing lens.7.6 Micro Gas Burner.7.7 Micro Spatula.7.8 M
24、icroscope Slides, of selected grade, 25.4 by 76.2-mmor 25.4 by 50.8-mm.7.9 Mortar and Pestle, of tool steel, mullite, or aluminumoxide.7.10 Petrographic MicroscopeA microscope equippedwith a circular rotating stage, graduated in degrees. The opticalsystem shall include two polarizing devices, one mo
25、untedbelow the condenser and the other just above the objective;43,103, and 453 objectives; and 53 and 103 eyepiecesfitted with crosshairs. The optic axis of the microscope shall beadjustable so that it can be brought into coincidence with thecenter of rotation of the revolving stage.ABertrand-Amici
26、 lensequipped with an iris diaphragm, or a sliding stop ocular, shallbe used for viewing interference figures. A quartz wedge,gypsum plate, and standard mica plate are necessary externalaccessories. Aperture stops are necessary for observing thecolor effects of dispersion, that is, dispersion staini
27、ng. Acardboard “washer” in the objective and a cover glass with acentered dried drop of India ink are sufficient; however, adevice is available commercially.7.11 Porcelain Crucibles, No. 0.7.12 Reagent Bottles for Immersion LiquidsGlass drop-ping bottles of 30-mL capacity. These bottles shall be equ
28、ippedwith groundglass stoppers with dropping rods integral with thestoppers. Inert plastic bulbs and caps may be used, butdropping bottles with rubber bulbs are unsatisfactory becauseof the effect of some of the immersion liquids on the rubber. Itis essential that the bottles be marked with the refr
29、active indexof the contained liquid. Commercially available liquids comein dropping bottles which are acceptable.7.13 Refractometer, for measuring the refractive index ofimmersion liquids.7.14 Sample Vials, 45 by 15-mm.7.15 Sieve, No. 100 (149 m).7.16 Small Alloy Magnet.8. Reagents8.1 Purity of Reag
30、entsReagent 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,where such specifications are available.3Other grades may beused, provided
31、it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.8.1.1 Purity of WaterReference to water that is used forreagent preparation, rinsing or dilution shall be understood tomean water that conforms to the quantitat
32、ive specifications ofType II reagent water of Specification D1193.8.2 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).8.3 Ammonium Molybdate Solution (100 g/L)Dissolve 1 gof ammonium molybdate (NH4)6Mo7O244H2O) in water, add35 mL of nitric acid HNO3(sp gr 1.42) and dilute to
33、1 L withwater.8.4 Ammonium Persulfate(NH4)2S2O8), crystalline.8.5 Barium Chloride Solution (100 g/L)Dissolve 100 g ofbarium chloride (BaCl22H2O) in water and dilute to 1 L.8.6 Cesium SulfateCs2SO4crystals, 10 to 20-mesh.8.7 Chloroform.8.8 Chloroplatinic Acid SolutionDissolve1gofchloro-platinic acid
34、H2PtCl66H2O in 5 mL of water and add 0.5 mLof HCl (sp gr 1.19).8.9 Diammonium Phosphate Solution (100 g/L)Dissolve100 g of diammonium phosphate (NH4)2HPO4in water anddilute to 1 L.8.10 Dimethylglyoxime, crystalline.8.11 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).8.12 Hydroch
35、loric Acid (1+4)Mix one volume of HCl (spgr 1.19) with four volumes of water.8.13 Lead Acetate Test Paper.8.14 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).8.15 Nitric Acid (1+19)Mix one volume of HNO3(sp gr1.42) with ten volumes of water.8.16 Phenolphthalein Indicator Solution.3Reagent Ch
36、emicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand Natio
37、nal Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D1245 1138.17 Potassium Ferricyanide K3Fe(CN)6, crystalline.8.18 Potassium Iodide (KI), crystalline.8.19 Potassium Mercuric Thiocyanate Solution (100 g/L)Prepare freshly precipitated mercuric thiocyanate Hg(CNS)2by adding a conc
38、entrated solution of mercuric nitrateHg(NO3)2to a concentrated solution of potassium thiocyanateKCNS. Filter and air-dry the precipitate. To one part Hg(CNS)2add three parts KCNS, dissolve in a minimum quantity ofwater, and evaporate in a desiccator. Collect the first crop oftabular crystals of pota
39、ssium mercuric thiocyanateK2Hg(CNS)4, wash with alcohol, and dry. Dissolve 10 g of thecrystals in water and dilute to 100 mL.8.20 Refractive Index StandardsA set of liquids havingrefractive indices ranging from 1.40 to 1.74 in steps of 0.01. Inthe range from 1.45 to 1.65, it is desirable to have liq
40、uidsavailable in steps of 0.005. Commercially available liquids arerecommended; however directions for the preparation of suit-able liquids are given in U. S. Geological Survey Bulletin No.848 (1)4or Elements of Optical Mineralogy (2). The index ofrefraction of these liquids must be checked prior to
41、 their use, asthey may change from loss of more volatile constituents.8.21 Silver Nitrate Solution (50 g/L)Dissolve 50 g ofsilver nitrateAgNO3in water, add 20 mLof HNO3(sp gr 1.42),and dilute to 1 L with water.8.22 Sodium BismuthatePowdered NaBiO3.8.23 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric
42、 acid(H2SO4).8.24 Sulfuric Acid (1+19)Add 1 volume of H2SO4(sp gr1.84) slowly and with stirring to 19 volumes of water.8.25 Zinc DustPowdered zinc metal.8.26 Zinc Uranyl Acetate SolutionDissolve1gofuranylacetate UO2(C2H3O2)22H2O and 0.1 mL of glacial acetic acidin 5 mL of water. Dissolve3gofzinc ace
43、tateZn(C2H3O2)22H2O and 0.1 mL of glacial acetic acid in 5 mLof water. Warm if necessary to complete solution. Mix the twosolutions and store in a chemically resistant glass bottle. Ifprecipitation occurs, filter the solution before use.9. Sampling9.1 Collect the sample in accordance with Practices
44、D887.10. Laboratory Preparation of Samples10.1 Prepare the sample in accordance with PracticesD2331.10.2 Place a portion of the ground sample (approximately0.1 g or less) in a porcelain crucible, add four drops ofHNO3(sp gr 1.42), and evaporate to dryness over the micro-burner. Add 1 mL of water, wa
45、rm, and stir with a glass rod.Allow the insoluble material to settle. Withdraw portions of thesupernatant liquid, henceforth referred to as the test solution,on the end of a glass rod and transfer to a slide for carrying outcertain of the tests described in Section 11.11. Chemical Procedures11.1 The
46、 tests in this section are intended as an aid to thepetrographic section of this practice. The sensitivity of thesetests varies so that the operator should become familiar witheach test to be able to judge semiquantitatively the amount ofeach constituent present based on the amount of sample usedand
47、 the strength of the reaction observed. Some of these testsmay not be necessary if spectrographic or X-ray diffractionequipment or both are available. For a more detailed discussionof these tests refer to Chamot and Mason (3) or to Feigl (6).11.2 Evolution of Gas with Dilute AcidPlace a portion ofth
48、e ground deposit on a slide and allow a drop of HCl (1+4) toflow into it. Observe macroscopically or under the 43 objec-tive for evolution of gas bubbles which indicates that presenceof carbonates, sulfites, sulfides, nitrites, or metals. Efferves-cence due to carbonates is usually violent and of sh
49、ort duration.The gas evolution due to sulfites, nitrites, and sulfides isusually less vigorous and there is a characteristic odor of thegas. Evolution of hydrogen gas from a metal is usually ofconsiderable duration. Dry and examine the slide used for thistest. If sodium salts are present, cubic crystals of sodiumchloride will be formed. If appreciable amounts of calcium andsulfate ions were present, characteristic clumps ofCaSO42H2O needles will be formed.11.3 Magnetic MaterialPlace some of the ground sampleon a slide and bring
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