1、Designation: D283 13Standard Test Methods forChemical Analysis of Cuprous Oxide and Copper Pigments1This standard is issued under the fixed designation D283; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. 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 These test methods cover procedures for the chemicalanalysis of cuprous oxide and copper pigments.1.2 The analytical procedures app
3、ear in the following order:SectionsTotal Copper 7Total Reducing Power as Cuprous Oxide 8 and 9Metallic Copper 10 and 11Cuprous Oxide 12Cupric Oxide 13Metals Other than Copper 1416Chlorides and Sulfates 17 and 18Acetone-Soluble Matter 19Water 20Stability 21Coarse Particles 22Coarse Particles Insolubl
4、e in Nitric Acid 231.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 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 standar
5、d 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:2D185 Test Methods for Coarse Particles in PigmentsD1193 Specification for Reagent WaterD1208 Test Methods for Common Properties o
6、f CertainPigments3. Significance and Use3.1 This collection of test methods is used by pigmentproducers and paint manufacturers for process control, productacceptance, and research and development.4. Treatment of Sample4.1 Grind dry pigments, if lumpy or not finely ground, to afine powder and thorou
7、ghly mix (Note 1). Large samples maybe thoroughly mixed and a representative portion taken andpowdered if lumpy or not finely ground. In all cases thoroughlymix the sample before taking portions for analysis. Preserve allsamples in dry, dark, airtight and completely filled bottles orcontainers to pr
8、event oxidation. Some commercial copperoxides appear to segregate or oxidize rather easily. Therefore,the thorough mixing of the sample to ensure homogeneity andthe rapid handling of the sample, when exposed to light and air,are extremely important factors in obtaining accurate resultsNOTE 1It is ve
9、ry important that the sample be thoroughly mixed.Some samples of cuprous oxide are not homogeneous so are likely to givetrouble when an attempt is made to obtain concordant results. By placinga few grams of a sample on a sheet of white paper and drawing it out witha spatula, it is frequently found t
10、hat the sample contains coarse particlesof black scale, along with small balls of bright red cuprous oxide. Thus,it may be necessary to pass the pigment through a No. 60 (250-m) sieve,break up any lumps of ground pigment by gentle pressure, and grind anycoarse particles failing to pass through the s
11、ieve. Since oxidation of slightor even considerable magnitude may take place, these operations shouldbe performed quickly, avoiding prolonged grinding and exposure to lightand air.5. Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is in
12、tended 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 be1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materia
13、ls, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Nov. 1, 2013. Published December 2013. Originallyapproved in 1928. Last previous edition approved in 1999 as D283 84 (1999)which was withdrawn January 2008 and reinstated i
14、n November 2013. DOI:10.1520/D0283-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, Ame
15、rican Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions 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 Formular
16、y, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1used, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening thea
17、ccuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type II of Specification D1193.5.3 Ammonium Sulfate(NH4)2SO4).5.4 Nitric Acid (sp gr 1.42)Concentration nitric acid(HNO3).5.5 Perchloric Acid (70 %)Co
18、ncentrated perchloric acid(HClO4).6. Hazards6.1 WarningConcentrated mineral acids cause burns ofthe skin and eyes. Concentrated bases are also hazardous.Avoid contact with skin or eyes. In case of contact immediatelyflush skin or eyes with plenty of water. See appropriate MCASafety Data Sheets for f
19、urther information before handlingdangerous chemicals.6.2 Chemicals that have been declared toxic should bedisposed of as hazardous chemicals and not discharged into asink.TOTAL COPPER7. Procedure7.1 Weigh accurately 1.0 g of the sample and transfer to a300-mL electrolytic beaker. Add 10 mL of conce
20、ntrated nitricacid (HNO3) and boil several minutes. Add 10 mL of HClO4(70 %) and fume for 5 min. Cool, dilute to a volume ofapproximately 150 mL, and add 1 mL of HNO3and1gof(NH4)2SO4.7.2 Carefully weigh the platinum electrode to 0.1 mg.Electroplate the copper on a rotating platinum electrode at acur
21、rent of 2 A for 2 h. Dilute with water and continue theelectrolysis for 15 min. When the deposition is complete,remove the electrode, wash with water and acetone, dry, andweigh to 0.1 mg. Save the electrolyte for the determination ofmetals other than copper (Section 15).7.3 Calculate the percent of
22、total copper, Cu.TOTAL REDUCING POWER AS CUPROUS OXIDE8. Reagents8.1 Ceric Ammonium Nitrate, Standard Solution (0.1 N)Mix 54.826 g of ceric ammonium nitrate (Ce(NH4)2(NO3)6)(either reagent grade or reference standard purity) with 56 mLof sulfuric acid (H2SO4) (1+1). Dissolve the salt and acid inwate
23、r, cool to room temperature, and dilute to 1 L. Standardizethis solution against analyzed bright copper foil that has beenfreed from all oxide coating.8.2 Ferric Chloride SolutionDissolve 75 g of ferric chlo-ride (FeCI36H2O) in a mixture of 150 mL of hydrochloricacid (HCl) (sp gr 1.19) and 400 mL of
24、 distilled water. Add 5mL of hydrogen peroxide (H2O2) (30 %) and boil to removethe excess.8.3 Ferrous Ammonium Sulfate, Standard Solution (0.03N)Dissolve 12 g of ferrous ammonium sulfate(Fe(NH4)2(SO4)26H2O) in 200 to 300 mL of water and add40 mL of H2SO4(sp gr 1.84), while stirring constantly. Dilut
25、eto 1 L in a volumetric flask. A few pieces of mossy aluminummay be added to stabilize the solution. The solution should berestandardized frequently against 0.1 N ceric ammonium ni-trate solution.8.4 Orthophenanthroline Indicator Solution (0.5 % inwater)Orthophenanthroline ferrous complex (ferroin)
26、shallbe used as the indicator.9. Procedure9.1 Weigh accurately (Note 2) 0.15 g of the sample andplace in a 250-mL, vented, glass-stoppered Erlenmeyer flaskpreviously filled with carbon dioxide (CO2) or other inert gas.Add a few small glass beads and 10 mLof FeCI3solution. Heatgently for 15 min, stir
27、ring occasionally and maintaining at alltimes an atmosphere of CO2or other inert gas.NOTE 2The use of a 0.4-mL micro beaker for weighing the specimenis advised. The beaker is weighed first and the sample introduced into thebeaker, the correct weight obtained, and the entire beaker and its contentsdr
28、opped into the flask. This eliminates errors in weighing caused bybrushing the sample from glass balance pans.9.2 After the specimen has been dissolved, cool, add 50 mLof distilled water, and titrate at once with 0.1 N ceric ammo-nium nitrate solution until near the end point. Add 2 drops oforthophe
29、nanthroline indicator solution and complete the titra-tion. A sharp, distinct color change from orange to pale greenoccurs at the end point. Back-titrate with 0.03 N ferrousammonium sulfate solution to the orange color.9.3 CalculationCalculate the percent of total reducingpower, A, as cuprous oxide
30、(Cu2O) as follows:A 5V1N12 V2N23 0.07154S13 100 (1)where:V1= Ce(NH4)2(No3)6solution required to titrate thespecimen, mL,N1= normality of the Ce(NH4)2(No3)6solution,V2= Fe(NH4)2(SO4)2solution required for back-titration, mL,N2= normality of the Fe(NH4)2(SO4)2solution,S1= specimen weight, g, and0.0715
31、4 = equivalent weight of Cu2O/1000.METALLIC COPPER410. Reagents10.1 Ceric Ammonium Nitrate, Standard Solution (0.1 N)See 8.1.10.2 Denatured Alcohol (Formula No. 2B).4This test method is based on the procedure described by Irvin Baker and R.Stevens Gibbs, “Determination of Metallic Copper in Cuprous
32、OxideCupricOxide Mixtures,” Industrial and Engineering Chemistry,Analytical Edition, Vol 13,February 15, 1946, p. 124.D283 13210.3 Extraction SolutionAdd 40 mL of HCl (sp gr 1.19) to1 Lof denatured alcohol. Mix thoroughly.Add 40 g of stannouschloride (SnCI22H2O) and stir until completely dissolved.1
33、0.4 Ferric Chloride SolutionSee 8.2.10.5 Orthophenanthroline IndicatiorSee 8.4.11. Procedure11.1 Add approximately 20 mL of 4-mm diameter glassbeads to a 250-mL Phillips beaker (assay flask). Weighaccurately 0.15 g of sample on a tared, glazed paper approxi-mately 13 mm square or a small watch glass
34、 that will fit intothe Phillips beaker, and transfer the specimen and paper orwatch glass to the beaker.11.2 Add 25 mL of denatured alcohol and swirl vigorouslyfor approximately 1 min to remove any surface coating andbreak up lumps. While swirling the flask, slowly add 100 mLof the extraction soluti
35、on.11.3 After the addition of the extraction solution, swirl theflask vigorously for 5 min, adding lumps of dry ice (solidcarbon dioxide) (Note 3) continuously during this time to lowerthe temperature of the solution to approximately 10C. Breakup any lumps in the solution with a glass rod or policem
36、an.11.4 Filter off the metallic copper-cupric oxide residueusing a 125-mm close-texture paper, a filter cone to support thepaper, and suction (Note 4). Continue the addition of dry ice tothe flask and filter paper during the filtration to keep thesolution cold. Wash the flask and filter paper with 1
37、50 to 200mL of denatured alcohol, continuing the use of suction.NOTE 3During the 5-min swirling period approximately 25 to 30 g ofdry ice is added in approximately 5-g portions. The initial lumps of dry icevolatilize rapidly due to the temperature of the solution.Approximately 15g of dry ice is adde
38、d in the first 2 min with a subsequent temperature dropto 0C. The remaining 15 g volatilizes more slowly and gradually lowersthe temperature to the vicinity of 10C. These directions are not critical,but merely serve as a guide. The solution must be kept very cold in orderto obtain correct and reprod
39、ucible results. During the filtration period,additions of dry ice to the flask should be continued to keep the solutioncold until all of the extraction solution has been filtered.NOTE 4In the great majority of cases, the metallic copper-cupricoxide residue is completely retained by the use of a suit
40、able close-texturefilter paper. The filtration is rapid and can be readily completed in 5 minwith proper suction. The filtrate should be carefully examined for thepresence of finely divided particles of copper. In the event that extremelyfinely divided particles of copper are present and pass throug
41、h the filterpaper, as evidenced by the presence in the filtrate of a reddish color, whichmay be transient, the following method of filtration should be used: Placea 25-mm diameter, beveled-edge, perforated porcelain filter disk in a 60,75-mm diameter glass funnel. Using suction, prepare an asbestos
42、filter padon the porcelain disk of sufficient thickness and retentiveness to hold thefinely divided residue. Wash the asbestos pad several times with denaturedalcohol to remove all water from the pad. Filter the metallic copper-cupricoxide residue on this asbestos pad with the suction on at the star
43、t offiltration. Keep the solution cold by the addition of dry ice and proceedwith washing the residue, transferring it to the original extraction flask,and the subsequent titration as directed in Section 11.11.5 Transfer the entire residue, filter paper, and beads to theoriginal extraction flask and
44、 dissolve the residue in 25 mL ofFeCl3solution, keeping an atmosphere of CO2above thesample by addition of dry ice. Heat on a steam bath to dissolvethe copper. Add 50 mL of distilled water and 3 drops oforthophenanthroline indicator solution. Titrate with 0.1 N cericammonium nitrate solution until t
45、he color changes from orangeto pale green.11.6 CalculationCalculate the percent of metallic coppercontent, B, as follows:B 5V3CS23 100 (2)where:V3= ceric ammonium nitrate solution required for titrationof the sample, mL,C = copper equivalent of the ceric ammonium nitratesolution, g/mL, andS2= specim
46、en weight, g.CUPROUS OXIDE12. Calculation12.1 Calculate the percent of cuprous oxide (Cu2O), D,asfollows:D 5 A 2 2.252B (3)where:A = total reducing power as cuprous oxide (Section 9), %andB = metallic copper (Section 11), %.CUPRIC OXIDE13. Calculation13.1 Calculate the percent of cupric oxide (CuO),
47、 E,asfollows:E 5 1.252F 2 B! 2 1.112D (4)where:F = total copper (Section 7), %,B = metallic copper (Section 11), %, andD = cuprous oxide (Section 12), %.METALS OTHER THAN COPPER14. Reagents14.1 Ceric Ammonium Nitrate, Standard Solution (0.1 N)See 8.1.14.2 Diphenylamine IndicatorDissolve1gofdiphel-ny
48、lamine in 100 mL of H2SO4(sp gr 1.84).14.3 Potassium Ferricyanide Solution (50 g/L)Dissolve 5g of potassium ferricyanide (K3Fe(CN)6), in 100 mL ofdistilled water. Keep tightly stoppered in a dark bottle.14.4 Potassium Ferrocyanide, Standard Solution (1 mL =0.001 g Zn)Dissolve 5.0 g of potassium ferr
49、ocyanide(K4Fe(CN)63H2O) in distilled water and dilute to 1 L.Standardize with analyzed reagent grade zinc prior to use.15. Procedure15.1 Filter the electrolyte from the determination of totalcopper (Section 7).Add5mLofH2SO4(sp gr 1.84) andevaporate just to dryness to remove all HClO4and HNO3. AddD283 133approximately 150 mL of water and neutralize with NH4OH(sp gr 0.90), adding 5 mL in excess. Add 10 g of NH4Cl. Boilthe solution gently for several minutes and allow the precipitateto settle. Filter through a close-texture paper, and wash thepr
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