1、Designation: D 874 07Designation: 163/96An American National StandardBritish Standard 4716Standard Test Method forSulfated Ash from Lubricating Oils and Additives1This standard is issued under the fixed designation D 874; 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.This standard has been approved for use by agencies of the Department of Defen
3、se.1. Scope*1.1 This test method covers the determination of the sul-fated ash from unused lubricating oils containing additives andfrom additive concentrates used in compounding. These addi-tives usually contain one or more of the following metals:barium, calcium, magnesium, zinc, potassium, sodium
4、, and tin.The elements sulfur, phosphorus, and chlorine can also bepresent in combined form.1.2 Application of this test method to sulfated ash levelsbelow 0.02 mass % is restricted to oils containing ashlessadditives. The lower limit of the test method is 0.005 mass %sulfated ash.NOTE 1This test me
5、thod is not intended for the analysis of usedengine oils or oils containing lead. Neither is it recommended for theanalysis of nonadditive lubricating oils, for which Test Method D 482 canbe used.NOTE 2There is evidence that magnesium does not react the same asother alkali metals in this test. If ma
6、gnesium additives are present, the datais interpreted with caution.NOTE 3There is evidence that samples containing molybdenum cangive low results because molybdenum compounds are not fully recoveredat the temperature of ashing.1.3 The values stated in SI units are to be regarded asstandard. No other
7、 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 standard to establish appro-priate safety and health practices and determine the applica-bility of
8、regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 482 Test Method for Ash from Petroleum ProductsD 1193 Specification for Reagent WaterD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum
9、 ProductsD 6299 Practice for Applying Statistical Quality AssuranceTechniques to Evaluate Analytical Measurement SystemPerformance3. Terminology3.1 Definitions:3.1.1 sulfated ashthe residue remaining after the samplehas been carbonized, and the residue subsequently treated withsulfuric acid and heat
10、ed to constant weight.4. Summary of Test Method4.1 The sample is ignited and burned until only ash andcarbon remain. After cooling, the residue is treated withsulfuric acid and heated at 775C until oxidation of carbon iscomplete. The ash is then cooled, re-treated with sulfuric acid,and heated at 77
11、5C to constant weight.5. Significance and Use5.1 The sulfated ash can be used to indicate the concentra-tion of known metal-containing additives in new oils. Whenphosphorus is absent, barium, calcium, magnesium, sodiumand potassium are converted to their sulfates and tin (stannic)and zinc to their o
12、xides (Note 5). Sulfur and chlorine do notinterfere, but when phosphorus is present with metals, itremains partially or wholly in the sulfated ash as metalphosphates.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility
13、 of SubcommitteeD02.03 on Elemental Analysis.Current edition approved Nov. 1, 2007. Published November 2007. Originallyapproved in 1946. Last previous edition approved in 2006 as D 87406.In the IP, this test method is under the jurisdiction of the StandardizationCommittee. This test method has been
14、approved by the sponsoring committees andaccepted by the cooperating societies in accordance with established procedures.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
15、r to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 4Since zinc sulfate slowly decomposes to its oxide at
16、theignition temperature specified in the test method, samples containing zinccan give variable results unless the zinc sulfate is completely converted tothe oxide.5.2 Because of above inter-element interferences, experi-mentally obtained sulfated ash values may differ from sulfatedash values calcula
17、ted from elemental analysis. The formationof such non-sulfated species is dependent on the temperature ofashing, time ashed, and the composition of metal compoundspresent in oils. Hence, sulfated ash requirement generallyshould not be used in product specifications without a clearunderstanding betwe
18、en a buyer and a seller of the unreliabilityof an ash value as an indicator of the total metallic compoundcontent.36. Apparatus6.1 Evaporating Dish or Crucible; 50 to 100-mL forsamples containing more than 0.02 mass % sulfated ash, or 120to 150-mL for samples containing less than 0.02 mass %sulfated
19、 ash, and made of porcelain, fused silica, or platinum.(WarningDo not use platinum when the sample is likely tocontain elements such as phosphorus, which attack platinumunder the conditions of the test.)NOTE 5For best results on samples containing less than 0.1 mass %sulfated ash, platinum dishes ar
20、e used. The precision values shown inSection 13 for this type of sample were so obtained.6.2 Electric Muffle FurnaceThe furnace shall be capableof maintaining a temperature of 775 6 25C and preferablyhave apertures at the front and rear to allow a slow natural draftof air to pass through the furnace
21、.6.3 Balance, capable of weighing to 0.1 mg.7. Reagents7.1 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-tee on Analytical Reagents of the American Chemical Society,wh
22、ere such specifications are available, or to other recognizedstandards for reagent chemicals.4Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Purity of WaterUnless otherw
23、ise indicated, referencesto water shall be understood to mean reagent water defined byTypes II or III of Specification D 1193.7.3 Low-Ash Mineral OilWhite oil having a sulfated ashlower than the limit capable of being determined by this testmethod.NOTE 6Determine the sulfated ash of this oil by the
24、procedure givenin 9.1-9.11 below using 100 g of white oil weighed to the nearest 0.5 g ina 120 to 150-mL platinum dish. Deduct the sulfuric acid blank asdescribed in 9.11.7.4 Sulfuric Acid (relative density 1.84)Concentrated sul-furic acid (H2SO4). (WarningPoison. Corrosive. Strongoxidizer.)7.5 Sulf
25、uric Acid (1 + 1)Prepare by slowly adding 1volume of concentrated sulfuric acid (relative density 1.84) to1 volume of water with vigorous stirring. (WarningMixingthis acid into water generates considerable heat. When neces-sary, cool the solution before adding more acid. Do not allowthe solution to
26、boil.)7.6 Propan-2-ol.(WarningFlammable, can be explosivewhen evaporated to or near dryness.)7.7 Toluene.(WarningFlammable, toxic.)7.8 Quality Control (QC) Samples, preferably are portionsof one or more liquid petroleum materials that are stable andrepresentative of the samples of interest. These QC
27、 samplescan be used to check the validity of the testing process asdescribed in Section 12.8. Sampling8.1 Obtain samples in accordance with the instructions inPractice D 4057 or D 4177. The sample shall be thoroughlymixed before removal of the laboratory test portion.9. Procedure9.1 Select the size
28、of the evaporating dish or crucibleaccording to the quantity of sample necessary (see 9.3).9.2 Heat the evaporating dish or crucible that is used for thetest at 775 6 25C for a minimum of 10 min. Cool to roomtemperature in a suitable container and weigh to the nearest 0.1mg.NOTE 7The container in wh
29、ich the dish is cooled does not contain adesiccating agent.9.3 Weigh into the dish a quantity of sample given asfollows:W 5 10/a (1)where:W = mass of test specimen, g, anda = expected sulfated ash, mass %.However, do not take a quantity in excess of 80 g. In the caseof lubricating oil additives yiel
30、ding a sulfated ash of 2 mass %or more, dilute the weighed sample in the dish with approxi-mately 10 times its weight of low-ash mineral oil.NOTE 8If the amount of sulfated ash found differs from the expectedamount by more than a factor of two, repeat the analysis with a differentweight of sample ca
31、lculated from the first analysis.9.4 Heat the dish or crucible and sample carefully until thecontents can be ignited with a flame. Maintain at such atemperature that the sample continues to burn at a uniform andmoderate rate. When burning ceases, continue to heat gentlyuntil no further smoke or fume
32、s are evolved.9.4.1 If the sample contains sufficient moisture to causefoaming and loss of material from the dish, discard the sampleand to an additional sample add 1 to 2 mL of 99 % propan-2-ol3Further discussion of these interferences can be found in Nadkarni, R. A.,Ledesma, R. R., and Via, G. H.,
33、 “Sulfated Ash TM: Limitations of Reliability andReproducibility,” SAE Technical Paper No. 952548, available from SAE, 400Commonwealth Drive, Warrendale, PA 15096-0001, U.S.A.4Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on t
34、he 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. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D874072(WarningFlammable) before heating.
35、 If this is not satisfac-tory, add 10 mL of a mixture of equal volumes of toluene(WarningFlammable, Vapor harmful.) and propan-2-ol andmix thoroughly. Place several strips of ashless filter paper inthe mixture and heat; when the paper begins to burn, thegreater part of the water will have been remov
36、ed.9.5 Allow the dish to cool to room temperature, thencompletely moisten the residue by the dropwise addition ofsulfuric acid (relative density 1.84). Carefully heat the dish ata low temperature on a hot plate or over a gas burner, avoidingspattering, and continue heating until fumes are no longere
37、volved.9.6 Place the dish in the furnace at 775 6 25C and continueheating until oxidation of the carbon is complete or almostcomplete.9.7 Allow the dish to cool to room temperature.Add 3 dropsof water and 10 drops of sulfuric acid (1 + 1). Move the dish soas to moisten the entire residue. Again heat
38、 the dish inaccordance with 9.5.9.8 Again place the dish in the furnace at 775 6 25C andmaintain at that temperature for 30 min (see Note 9). Cool thedish to room temperature in a suitable container (see Note 7).NOTE 9A study conducted by two separate laboratories investigatingwhether heating sulfat
39、ed ash residues for extended periods of time (forexample, overnight) in a furnace at 775 6 25C as opposed to 30 min asrequired in 9.8 revealed that a significant difference in sulfated ash resultscan exist. The study indicated that lower sulfated ash results were obtainedon the samples left in the f
40、urnace overnight versus those that were heatedin 30min cycles. A thermogravimetric analysis also confirmed that thesamples evaluated continued to lose weight at 775C as a function of time.As such, it is essential that the 30min heating time requirement beadhered to in performing the test method. Det
41、ails concerning the study canbe found in ASTM Research Report RR: D02-1597.NOTE 10Zinc dialkyl or alkaryl dithiophosphates and blends contain-ing these additives can give a residue which is partially black at this stage.In this case, repeat 9.7 and 9.8 until a white residue is obtained.9.9 Weigh the
42、 dish and residue to the nearest 0.1 mg.9.10 Repeat 9.8 and 9.9 until two successive weighingsdiffer by no more than 1.0 mg.NOTE 11Normally one repeat will suffice, unless a high proportion ofzinc is present, when three or four heating periods can be required.9.11 For samples expected to contain 0.0
43、2 mass % or less ofsulfated ash, determine a sulfuric acid blank by adding 1 mL ofthe concentrated sulfuric acid to a tared platinum dish orcrucible, heating until fumes are no longer evolved and thenheating in the furnace at 775 6 25C for 30 min. Cool the dishor crucible to room temperature in a su
44、itable container (seeNote 7) and weigh to the nearest 0.1 mg. If any ash is found inthe sulfuric acid, make an adjustment to the weight of sulfatedash obtained by subtracting the weight of ash contributed bythe sulfuric acid, determined from the total volume of sulfuricacid used and the weight of as
45、h found for the 1-mL blank, fromthe total grams of sulfated ash for the sample. Use thiscorrected weight, w, in calculating the percent sulfated ash.10. Calculation10.1 Calculate the sulfated ash as a percentage of theoriginal sample as follows:Sulfated ash, mass % 5 w/W! 3 100 (2)where:w = grams of
46、 sulfated ash, andW = grams of sample used.11. Report11.1 Report the result to the nearest 0.001 mass % forsamples below 0.02 mass % and to the nearest 0.01 mass % forhigher levels as the sulfated ash, Test Method D 874.12. Quality Control12.1 Confirm the performance of the instrument or the testpro
47、cedure by analyzing a QC sample (see 7.8).12.1.1 When QC/Quality Assurance (QA) protocols arealready established in the testing facility, these may be used toconfirm the reliability of the test result.12.1.2 When there is no QC/QA protocol established in thetesting facility, Appendix X1 can be used
48、as the QC/QAsystem.13. Precision and Bias513.1 The precision of this test method as determined bystatistical examination of interlaboratory results is as follows:13.1.1 For sulfated ash levels between 0.005 and 0.10mass %.13.1.1.1 RepeatabilityThe difference between two testresults obtained by the s
49、ame operator with the same apparatusunder constant operating conditions on identical test materialswould, in the long run in the normal and correct operation ofthe test method, exceed the following values only in one casein twenty:r 5 0.047 X0.85(3)where X = average of two results.13.1.1.2 ReproducibilityThe difference between twosingle and independent results obtained by different operatorsworking in different laboratories on identical test materialwould, in the long run in the normal and correct operation ofthe test method, exceed the following
