1、Designation: D 686 93 (Reapproved 2002)An American National StandardStandard Test Methods ofQualitative Examination of Mineral Filler and MineralCoating of Paper1This standard is issued under the fixed designation D 686; the number immediately following the designation indicates the year oforiginal
2、adoption or, 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 These test methods cover two procedures for the quali-tative determ
3、ination and identification of the mineral constitu-ents of filled and coated papers.1.2 Due to the similarity in chemical composition andphysical size and shape of some of the various possibleconstituents contained in a given paper specimen, more pre-cise, quantitative methods may at times be requir
4、ed for positiveidentification.1.3 It is recommended that one become thoroughly familiarwith these test methods by analyzing paper samples of knownmineral component content.1.4 The test methods appear as follows:SectionsMethod AChemical Analysis 4 to 11Method BMicroscopical Identification 2 to 191.5
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 prior to use.NOTE 1These test me
6、thods are technically equivalent to TAPPI T421 83.2. Referenced Documents2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper, Paperboard, Fiberboard, and Related Products2D 586 Test Method for Ash in Pulp, Paper, and PaperProducts2D 921 Test Method for Titanium Dioxide
7、in Paper3D 1030 Test Method for Fiber Analysis of Paper andPaperboard22.2 TAPPI Standards:T 401 Fiber analysis of paper and paperboard4T 438 Zinc and cadmium in paper and pigments4Test Method AQualitative Chemical Analysis3. Significance and Use3.1 Qualitative chemical analyses of the mineral compon
8、entof a paper specimen, Test Method A, serve to identify the ionsof any such minerals. The results may then be interpreted interms of the minerals themselves. Direct identification of someof these minerals or their ions is frequently possible usingoptical microscopical examination, Test Method B. Fo
9、r addi-tional information, see the annex.3.2 The analysis can be considerably simplified if it isdesired only to establish the presence or absence of a particularfiller.3.3 A microscopical examination of the ash usually provesto be a useful adjunct to chemical analysis, and if possibleshould be atte
10、mpted (see Sections 12 to 18).4. Apparatus4.1 Crucible, platinum, with lid, for use in 9.7.1 and inashing the sample that is being examined. Porcelain or silicacrucibles may be used if their weight does not change under theignition conditions.4.2 Muffle Furnace, electric, controlled to maintain a te
11、m-perature of 525 6 25C.4.3 Laboratory Oven, electric, controlled to maintain atemperature of 150 6 3C.4.4 Blowpipe.4.5 Wire Loop, platinum.4.6 Spot Plate, black, glazed.1These test methods are under the jurisdiction of ASTM Committee D06 onPaper and Paper Products and are the direct responsibility
12、of Subcommittee D06.92on Test Methods.Current edition approved Sept. 15, 1993. Published November 1993. Originallypublished as D 686 42T. Last previous edition D 686 88.2Annual Book of ASTM Standards, Vol 15.09.3Discontinued, see 1981 Annual Book of ASTM Standards, Part 20.4Available from the Techni
13、cal Association of the Pulp and Paper Industry,Technology Park/Atlanta, P.O. Box 105113, Atlanta, GA 30348.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.7 Other ApparatusBeakers, 250-mL; watch glass; volu-metric flasks, 100-mL; f
14、ilter funnels and fairly rapid, low-ashfilter paper,5and Bunsen burner.5. Reagents5.1 Acetic Acid, (Glacial, 99.7 % CH3-COOH, sp gr 1.05),approximately 1 N solution. Add approximately 11.5 mLglacial acetic acid to 50 mL water in a volumetric flask anddilute to 100-mL mark.5.2 Ammonium Chloride Solut
15、ion (NH4OH, 10 %).5.3 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).5.4 Ammonium Oxalate Solution (NH4)2-C2O4H2O,3.5 %).5.5 Ammonium Sulfate, (NH4)2SO4.5.6 Barium Chloride Solution (BaCl2,10%).5.7 Charcoal Black.5.8 Cobalt Nitrate SolutionDissolve8gofcobalt nitrate(Co(NO3)2
16、6H2O) in 100 mL of water.5.9 Diphenylthiocarbazone (Dithizone) SolutionDissolve10 mg dithizone in 100 mL carbon tetrachloride, (CCl4).5.10 Hydrochloric Acid (2 N, sp gr 1.19)Concentratedhydrochloric acid (HCl). Add 15 mL of concentrated HCl toapproximately 75 mL water in a 100-mL volumetric flask, c
17、ool,and dilute to 100-mL mark.5.11 Hydrogen Peroxide (30 % H2O2), or a solution of 3 %H2O2used in proportionately greater quantities. Extremecaution should be used when handling 30 % H2O2solution asit is very active when in contact with skin. Eye protectionshould be worn.5.12 Iodine Solution (0.1 N)
18、.5.13 Lead Acetate PaperImmerse strips of filter paper ina saturated solution of lead acetate (Pb(C2H3O2)23H2O);withdraw from solution and allow to air dry.5.14 Lime Water, saturated solution. Dissolve about 0.2 g ofcalcium hydroxide (Ca(OH)2) in 100 mL of water and filter.5.15 Magnesium ReagentDiss
19、olve 0.5 g of para-nitrobenzeneazoresorcinol in 100 mL of sodium hydroxide(NaOH) solution (1 %).5.16 Microcosmic Salt SolutionDissolve5gofsodiumammonium phosphate (NaNH4HPO44H2O) in water anddilute to 100 mL.5.17 Morin (3,5,7,28,48-pentahydroxyflavanone)Saturated solution of morin in methyl alcohol.
20、5.18 Potassium Dichromate Solution (K2Cr2O7, 4%).5.19 Potassium Ferrocyanide SolutionDissolve 15 g of(K4Fe(CN)63H2O) in 1000 mL of water.5.20 Potassium Hydroxide Solution (2N)Dissolve 11.2 gof potassium hydroxide (KOH) in 75 mL water; cool and diluteto 100 mL.5.21 Sodium CarbonatePowdered sodium car
21、bonate(Na2CO3).5.22 Sodium Hydroxide Solution (2N). Dissolve 8 g(NaOH) in 75 mL water; cool and dilute to 100 mL.5.23 Sulfuric Acid (5 %, sp gr 1.84)Concentrated sulfuricacid (H2SO4). Add 3 mL of concentrated H2SO4to 75 mL ofwater, cool, dilute to 100 mL.6. Purity of Reagents6.1 Reagent grade chemic
22、als shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.6Other grades may be used, pro-vided it is first ascertained
23、that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.Test Method AQualitative Chemical Analysis7. Sampling7.1 Obtain a sample of the paper to be tested in accordancewith Methods D 585.8. Test Specimens8.1 From each test unit, for each co
24、mplete determination,cut test specimens of sufficient size to yield at least 0.15 g ofash.8.2 An additional specimen of each test unit should beavailable for testing without previous ashing.9. Procedure9.1 An outline scheme of the qualitative procedure is givenin Fig. 1.9.2 Sulfite, Sulfide, and Car
25、bonate (Unignited Coating orPaper Sample):9.2.1 Treat a portion of the unignited coating or papersample in a small beaker or test tube with 2 N HCl. Notewhether effervescence takes place and the odor of any escapinggas. Liberation of SO2and H2S indicates the presence ofsulfites and sulfides, respect
26、ively. Warm the contents of thebeaker and test the vapor with moistened lead acetate paper.The development of a metallic gray or black color confirms thepresence of sulfide. In the absence of sulfides, add either asmall crystal of potassium dichromate or a few drops of a 4 %dichromate solution to a
27、small portion of the HCl solution ofthe sample. A green coloration indicates the presence of areducing agent, in this case probably a sulfite.NOTE 2Mixtures of sulfites and sulfides are not known to be used inloading or coating paper.9.2.2 If sulfites and sulfides are absent, effervescence aloneis a
28、 good indication of the presence of a carbonate, which maybe confirmed by holding a glass rod with a drop of saturatedlime water just above the solution. Cloudiness (milky) appear-ance of the supported drop indicates the presence of CO2. Thisprecipitate may later dissolve. A confirmatory test of CO2
29、in5Whatman No. 40, available from A. H. Thomas Co., P. O. Box 779,Philadelphia, PA 19105, or its equivalent, has been found satisfactory for these testmethods.6“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-cal Soc., Washington, DC. For suggestions on the testing of reagent
30、s not listed bythe American Chemical Society, see “Reagent Chemicals and Standards,” by JosephRosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPharmacopeia.”D 686 93 (2002)2FIG. 1 Qualitative Analysis of Mineral Filler and Mineral Coating of PaperD 686 93 (2002)3the presence of
31、sulfites is to oxidize the sulfites to sulfates byadding to the contents of the beaker, a weak solution of iodine(about 0.1 N), drop by drop, until the entire liquid is coloredyellow. Then test with lime water on a glass rod as describedpreviously in this paragraph.9.3 Ashing:9.3.1 Ash the specimen
32、at a temperature of 525C (lowerthan the 925C temperature used in Test Method D 586 (seealso 9.3.2). This lower temperature is used to prevent orminimize the alteration of the composition of various coatingor filling components.9.3.2 For coated paper where separate analyses of fillingmaterial and coa
33、ting minerals are desired, remove the coatingby an enzymatic stripping procedure. Evaporate to dryness theaqueous mixture containing the coating minerals and ash thisresidue as well as the base stock in accordance with 9.3.1.NOTE 3If synthetic coating adhesives have been used in place ofstarch or ca
34、sein, enzymatic stripping will not be effective. In this case,scrape the coating from the surface with a razor blade.9.4 Aluminum Hydrate: Sodium Silicoaluminate; Al, Ca, orMg Silicates; Ca or Ba Sulfates; TiO2:9.4.1 To approximately 0.05 g of ash add 10 g of (NH4)2SO4and 20 mL of concentrated H2SO4
35、. Cover with a watch glassand boil vigorously for at least 3 min.9.4.2 Considerable undissolved matter indicates the pres-ence of one or more of the following: sodium silicoaluminate;Ca, Al, or Mg silicate; aluminum hydrate or diatomaceousearth. If this strongly acidic, hot solution is clear, the ab
36、senceof these materials is confirmed. Calcium or barium sulfate, orboth, will be dissolved unless the specimen being tested weighsmore than 0.05 g; TiO2will be in the solution.9.4.3 Decant some of the supernatant liquid into a smallbeaker, cool, and cautiously dilute it with a portion (up to aboutfi
37、ve times its volume) of cold water. The formation of aprecipitate on dilution indicates the presence of barium sulfate,which is relatively soluble in hot concentrated H2SO4.9.4.4 Mix the diluted acidic mixture (9.4.3) with the remain-der of the undiluted strongly acidic mixture (9.4.2) from theconce
38、ntrated H2SO4treatment and add sufficient water to makethe ratio of H2OtoH2SO4about 5:1. If the original H2SO4solution (9.4.1) was clear, dilute it 5:1 by adding watercautiously after cooling. Filter and retain any residue forexamination under 9.4.5. To the cooled filtrate add 1 mL of30 % H2O2. A de
39、ep yellow or orange color indicates thepresence of titanium, the depth of color being proportional tothe amount of titanium present. If only a very light yellowcolor is produced, it may be caused by titanium from clay, orderived from dissolved titanium in the mill water.9.4.5 The presence of barium
40、or calcium in any insolubleresidue (9.4.4) can be determined by a flame test as follows:Dip a clean platinum wire into the moist residue, retained onthe filter paper, and hold it in a Bunsen flame. A green flameindicates the presence of barium, a red flame indicates calcium,and a yellow to colorless
41、 flame indicates aluminum or magne-sium silicates, or both, or aluminum hydrate.NOTE 4Calcium sulfate (CaSO4) is quite soluble in diluted H2SO4and may not be observed at this step.9.4.6 The flame test can be used to detect soluble calcium,barium, and sodium in the clear solution obtained in 9.4.3.Ca
42、utiously dilute a small portion of the solution with an equalvolume of water. Dip a clean platinum wire into the solutionand hold it in a Bunsen flame. A green flame indicates barium,a red flame indicates calcium, and a strong yellow flameindicates sodium.9.5 Sulfide, Sulfite, and Carbonate (Ash Sam
43、ple Ignited at525C):9.5.1 Treat 0.1 g of ash (9.3.1) with 10 mL of water and 5mL of concentrated HCl in a small-sized beaker. Efferves-cence, as in 9.2.1, indicates the presence of a carbonate orsulfite. Withdraw 1 or 2 mL of the solution and add 2 drops of4%K2Cr2O7solution. A green coloration indic
44、ates sulfite.9.5.2 Heat the contents of the beaker to boiling and test thefumes with moistened lead acetate paper; the development of ametallic gray or black color indicates the presence of sulfides.These tests should be checked by tests made on the originalspecimen of paper since carbonates may be
45、lost. Sulfates maybe reduced to sulfites or sulfides, or sulfites and sulfidesoxidized to sulfates, depending on the temperature and oxidiz-ing conditions during ignition.NOTE 5If the temperature of ashing is around 925C as specified inTest Method D 586, no carbonates are present and any sulfites pr
46、obablywould have been oxidized to sulfates.9.5.3 Boil the mixture for at least 5 min unless completesolution occurs sooner. Add 35 mL of water, and again heat toboiling. If this solution is not clear, filter through a fairly rapid,low-ash filter paper and wash twice with water, reserving thefiltrate
47、 for analysis of the acid-soluble portion. Wash theinsoluble residue thoroughly and discard the washings. Re-serve the acid-insoluble portion retained on the filter paper forlater treatments in accordance with 9.7.9.6 Sulfate, Zn, Mg, Al, Ba, Ca:9.6.1 To approximately one fifth of the acid-soluble p
48、ortionfrom 9.5.3 add 1 mL of CaCl2solution. A precipitate thatappears immediately or after heating for 10 min shows thepresence of sulfates. To another one-fifth portion add a fewmillilitres of potassium ferrocyanide solution. A heavy whiteprecipitate indicates the presence of zinc. The presence of
49、zincmay be confirmed by the red color produced in the followingdithizone test.9.6.2 Place 1 drop of the acid-soluble portion from 9.5.3 ona watch glass and add 1 drop of 2N NaOH and a few drops ofdithizone solution. The carbon tetrachloride (CCl4) is evapo-rated by gentle blowing while stirring with a glass rod. Araspberry-red solution confirms the presence of zinc. The colorof any precipitate can be disregarded.9.6.3 To a small portion of the remaining three fifths of thefiltered solution (9.5.3) (about one tenth of the total) add 1 or2 drops of the
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