1、Designation: D 1245 84 (Reapproved 2003)An American National StandardStandard Practice forExamination of Water-Formed Deposits by ChemicalMicroscopy1This standard is issued under the fixed designation D 1245; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes a procedure for the examinationof water-formed deposits
3、 by means of chemical microscopy.This practice may be used to complement other methods ofexamination of water-formed deposits as recommended inPractices D 2331 or it may be used alone when no otherinstrumentation is available or when the sample size is verysmall.1.2 This standard does not purport to
4、 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 prior to use.2. Referenced Documents2.1 ASTM Standards:2D 887 Pra
5、ctices for Sampling Water-Formed DepositsD 1129 Terminology Relating to WaterD 1193 Specification for Reagent WaterD 2331 Practices for Preparation and Preliminary Testing ofWater-Formed DepositsD 2332 Practice for Analysis of Water-Formed Deposits byWavelength-Dispersive X-Ray FluorescenceD 3483 Te
6、st 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 D 1129.3.2 Descriptions of Terms Specific to This StandardCertain terms in this practice t
7、hat relate specifically tochemical microscopy are described as follows:3.2.1 anisotropichaving different optical properties indifferent optical planes. These planes are referred to as thealpha, beta, and omega axes.3.2.2 Becke linea faint, halo-like line that surrounds acrystal when the crystal is m
8、ounted in an oil of differentrefractive index. It increases in intensity as the difference in therefractive index between the crystal and the oil increases.3.2.3 dispersionthe variation of index of refraction withwavelength.3.2.4 dispersion stainingthe color effects produced whena transparent object
9、, immersed in a liquid having a refractiveindex near that of the object is viewed under the microscope bytransmitted white light and precise aperture control.3.2.5 extinction anglethe angle between the extinctionposition and some plane, edge, or line in a crystal.3.2.6 extinction positionthe positio
10、n in which an aniso-tropic crystal, between crossed polars, exhibits complete dark-ness.3.2.7 index of refractionthe numerical expression of theratio of the velocity of light in a vacuum to the velocity of lightin a substance.3.2.8 isotropichaving the same optical properties in alldirections.3.2.9 p
11、etrographicpertaining to the description of rocksor rocklike substances. Such description is usually in terms ofmorphology and optical properties.3.2.10 solid solutiona homogeneous mixture of two ormore components, in the solid state, retaining substantially thestructure of one of the components.1Th
12、is practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.03 on Sampling of Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use,On-Line Water Analysis, and Surveillance of Water.Current edition approved
13、 Oct. 26, 1984. Published February 1985. Originallyapproved in 1952. Last previous approved in 1984 as edition D 1245 84.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refe
14、r to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Practice4.1 The practice is essentially chemical microscopical,supplemented by optical data obtained by the pet
15、rographicmethod. The identification of compounds is made by observ-ing, under the microscope, characteristic reactions and precipi-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
16、composition of water-formed deposits is amajor indicator of proper or improper chemical treatment ofprocess water, and is often an indicator of operational param-eters as well, for example, temperature control. This practiceallows for rapid determination of constituents present in thesedeposits, par
17、ticularly those indications of improper watertreatment, since they usually have very distinctive and easilyrecognized optical 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 an
18、ions aremutually bound.5.3 Qualitative use of this practice should be limited tothose deposits whose control is generally known or predictable,based on treatment and feedwater mineral content, and whoseconstituents are crystalline, or in other ways optically ormorphologically distinctive. If these c
19、riteria are not met, othertechniques of analysis should be used, such as Practice D 2332or Test Methods D 3483, or both.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 m
20、aterial may interfere with both the petro-graphic and the chemical procedures. Organics can usually beremoved by solvent extraction as recommended in PracticeD 2331.6.2 Deposits containing solid solutions present a complica-tion in that optical data vary throughout such a system, andunless the prese
21、nce of this complication is known, the data maybe misinterpreted.6.3 Extremely fine material and opaque material are difficultto identify. When present in appreciable amounts they maycloud over and obscure details of otherwise recognizableparticles.6.4 Interference with the chemical tests will be di
22、scussed inthe procedures.7. Apparatus7.1 Beakers, 30-mL, borosilicate glass.7.2 Cover Glasses, No. 1 or No. 112 thickness, 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 Source
23、Microscope lamp with concentrated fila-ment bulb and a focusing lens.7.6 Micro Gas Burner.7.7 Micro Spatula.7.8 Microscope Slides, of selected grade, 25.4 by 76.2 or25.4 by 50.8 mm (1 by 3 or 1 by 2 in.).7.9 Mortar and Pestle, of tool steel, mullite, or aluminumoxide.7.10 Petrographic MicroscopeA mi
24、croscope equippedwith a circular rotating stage, graduated in degrees. The opticalsystem shall include two polarizing devices, one mountedbelow 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 micro
25、scope shall beadjustable so that it can be brought into coincidence with thecenter of rotation of the revolving stage.ABertrand-Amici 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
26、 necessary externalaccessories. Aperture stops are necessary for observing thecolor effects of dispersion, that is, dispersion staining. 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 Porce
27、lain Crucibles, No. 0.7.12 Reagent Bottles for Immersion LiquidsGlass drop-ping bottles of 30-mL capacity. These bottles shall be equippedwith groundglass stoppers with dropping rods integral with thestoppers. Inert plastic bulbs and caps may be used, butdropping bottles with rubber bulbs are unsati
28、sfactory becauseof the effect of some of the immersion liquids on the rubber. Itis essential that the bottles be marked with the refractive indexof the contained liquid. Commercially available liquids comein dropping bottles which are acceptable.7.13 Refractometer, for measuring the refractive index
29、 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 ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-te
30、e 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 determination.8.1.1 Unless otherwise indi
31、cated, references to water shallbe understood to mean reagent water conforming to Specifi-cation D 1193, Type II.8.2 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For sug
32、gestions 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 Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.D 1245 84 (2003)28.3 Ammoni
33、um Molybdate Solution (100 g/L)Dissolve 1g of ammonium molybdate (NH4)6Mo7O244H2O) in water,add 35 mL of nitric acid HNO3(sp gr 1.42) and dilute to 1 Lwith water.8.4 Ammonium Persulfate (NH4)2S2O8), crystalline.8.5 Barium Chloride Solution (100 g/L)Dissolve 100 g ofbarium chloride (BaCl22H2O) in wat
34、er and dilute to 1 L.8.6 Cesium SulfateCs2SO4crystals, 10 to 20-mesh.8.7 Chloroform.8.8 Chloroplatinic Acid SolutionDissolve1gofchloro-platinic acid 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)2H
35、PO4in water anddilute to 1 L.8.10 Dimethylglyoxime, crystalline.8.11 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).8.12 Hydrochloric Acid (1+4)Mix 1 volume of HCl (sp gr1.19) with 4 volumes of water.8.13 Lead Acetate Test Paper.8.14 Nitric Acid (sp gr 1.42)Concentrated nitric a
36、cid(HNO3).8.15 Nitric Acid (1+19)Mix 1 volume of HNO3(sp gr1.42) with 10 volumes of water.8.16 Phenolphthalein Indicator Solution.8.17 Potassium Ferricyanide K3Fe(CN)6, crystalline.8.18 Potassium Iodide (KI), crystalline.8.19 Potassium Mercuric Thiocyanate Solution (100 g/L)Prepare freshly precipita
37、ted mercuric thiocyanate Hg(CNS)2by adding a concentrated 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.
38、Collect the first crop oftabular crystals of potassium 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 ran
39、ge from 1.45 to 1.65, it is desirable to have liquidsavailable 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 ofref
40、raction of these liquids must be checked prior to 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 mL of HNO3(sp gr 1.42),and dilute to 1 L with water.8.22 Sodium BismuthatePowdered NaBiO3.8.
41、23 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric 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
42、 acetic acidin 5 mL of water. Dissolve3gofzinc acetateZn(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.
43、1 Collect the sample in accordance with Practice D 887.10. Laboratory Preparation of Samples10.1 Prepare the sample in accordance with PracticeD 2331.10.2 Place a portion of the ground sample (approximately0.1 g or less) in a porcelain crucible, add 4 drops of HNO3(spgr 1.42), and evaporate to dryne
44、ss over the microburner. Add 1mL of water, warm, and stir with a glass rod. Allow theinsoluble material to settle. Withdraw portions of the superna-tant liquid, henceforth referred to as the test solution, on theend of a glass rod and transfer to a slide for carrying out certainof the tests describe
45、d in Section 11.11. Chemical Procedures11.1 The 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 constituen
46、t present based on the amount of sample usedand 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 Evolut
47、ion of Gas with Dilute AcidPlace a portion ofthe 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. Effereve-scens
48、e due to carbonates is usually violent and of shortduration. The gas evolution due to sulfites, nitrites, and sulfidesis usually 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 t
49、histest. 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 the magnet under the slide. As the magnetmoves under the slide, any magnetic material in the samplewill respond to the magnetic field.NOTE 1A coating of magnetite on nonmagnetic particles may give anerroneous indication of the total amount of magnetic materi
