1、Designation: D7626 10Standard Test Methods forDetermining the Organic Treat Loading of OrganophilicClay1This standard is issued under the fixed designation D7626; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. 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 standard covers two index test methods that can beused in the evaluation of the amount of organic compoundchemically bond
3、ed to the base clay portion of a representativesample of organophilic clay.1.2 The values stated in SI units are to be regarded as thestandard. No other units of measurement are included in thisstandard.1.3 All observed and calculated values shall conform to theguidelines for significant digits and
4、rounding established inPractice D6026.1.3.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that generally should be retained. The proce-dures used do not
5、 consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or reduce significant digits of the reported data to becommensurate with these considerations. It is beyond the scopeof this sta
6、ndard to consider significant digits used in analysismethods for engineering design.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
7、 determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering
8、Design and ConstructionD4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD6026 Practice for Using Significant Digits in GeotechnicalDataE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3. Ter
9、minology3.1 DefinitionsFor common definitions of terms in thisstandard, refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 base clay, nan untreated naturally occurring clay(e.g., bentonite, kaolinite).3.2.2 organic treat loading, nthe amount of organiccompound chemica
10、lly bonded to the base clay portion of anorganophilic clay.3.2.3 organophilic, adjhaving a strong affinity for oil andother insoluble organic compounds.3.2.4 organophilic clay, na manufactured oleophilic ma-terial consisting of base clay to which an organic compoundhas been chemically bonded to the
11、clay surface.4. Summary of Test Methods4.1 Test Method AMoisture content is determined bydrying an organophilic clay specimen at 160 C in an oven ormuffle furnace. The moisture content is expressed as a percent-age of the as-received mass. The ash content of the organo-philic clay specimen is determ
12、ined by igniting the driedspecimen from the moisture content determination in a mufflefurnace at 750 C.4.2 Test Method BAn organophilic clay specimen isheated at a controlled rate in a thermal gravimetric analyzer.Percent moisture content and ash are taken from thermalgravimetric analyzer report.4.3
13、 Some volatile structural matter within the base clay willbe lost during the last stage of heating. Organic treat loading isdetermined on a dry weight basis by a calculation that accounts1These test methods are under the jurisdiction ofASTM Committee D18 on Soiland Rock and are the direct responsibi
14、lity of Subcommittee D18.21 on GroundWater and Vadose Zone Investigations.Current edition approved May 1, 2010. Published June 2010.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inform
15、ation, refer 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.for the moisture content, ash, and a nominal percent of volatilestructural matter within the base clay.NOTE 1The s
16、upplier of the organophilic clay must be able to verifywith historical data the nominal percent mass of the base clay (on a dryweight basis) remaining after similar heating. This value is typically in therange of 94 to 96 %.5. Significance and Use5.1 This standard test method is intended as an index
17、 test todetermine the organic treat loading of organophilic clay. Thisstandard test method can be used for manufacturing qualitycontrol and construction quality assurance material evaluation.5.2 The percent organic treat loading of organophilic clay isa relative indicator of its adsorptive capacity.
18、 Organophilic clayis used for remediation of contaminated sediment, soil, andgroundwater.5.3 The two test methods denote different devices, a mufflefurnace and a thermal gravimetric analyzer. The thermalgravimetric analyzer may be programmed to reach a highertemperature than the muffle furnace, but
19、the organic matter willbe burnt off at 750 C.NOTE 2The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capa
20、ble of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.6. Apparatus6.
21、1 Oven, meeting the requirements of Specification E145and capable of being regulated to a constant temperature of 1606 5 C.6.2 Muffle Furnace, capable of producing constant tempera-ture of 750 C.6.3 TGA, thermal gravimetric analyzer capable of reachinga minimum 750 C with a balance having 0.001 mg r
22、eadability.6.4 Balance or Scale, a balance or scale for determining themass of organophilic clay having a minimum capacity of 100g and meeting the requirements of Guide D4753 for a balanceor scale of 0.01 g readability.6.5 Porcelain Container and Cover.6.6 Desiccator.6.7 Mortar and Pestle.6.8 Sieve,
23、 0.075 mm sieve opening.6.9 Gloves, Tongs or Other Suitable Equipment or Combi-nations Thereof, to safely handle porcelain containers to andfrom furnace.7. Sample7.1 Collect a representative maximum 50 g sample oforganophilic clay.7.2 Crush organophilic clay sample with mortar and pestleand then scr
24、een through 0.075 mm sieve. Retain finer fractionof sample.8. Procedures8.1 Test Method AOven or Muffle Furnace or Combina-tions Thereof:8.1.1 Moisture Content Determination:8.1.1.1 Record to the nearest 0.01 g the mass of a clean, dryporcelain container and cover.8.1.1.2 Place a test specimen of at
25、 least 10 g and no morethan 50 g in the porcelain container and record mass to thenearest 0.01 g.8.1.1.3 Dry uncovered in an oven or muffle furnace for atleast 16 h at 160 C or until there is no change in mass of thespecimen after further drying in periods in excess of 1 h.8.1.1.4 Remove from the ov
26、en, cover tightly, cool in adesiccator and record the mass (mdry) to the nearest 0.01 g.8.1.1.5 Calculate the moisture content as percent of as-received mass as follows:M 5 mi mdry! 3 100#/mi(1)where:M = moisture content, as percent of as-received mass,mi= mass of the as-received test specimen, g, a
27、ndmdry= mass of the dried specimen, g.8.1.2 Organic Treat Loading Determination:8.1.2.1 Place the entire oven-dried specimen and porcelaincontainer from the moisture content determination in a mufflefurnace. Raise the temperature in the furnace to 750 C.8.1.2.2 Heat at 750 C for a minimum of 1 h. Re
28、move thecontainer, cool in a desiccator, and weigh and record the mass.8.1.2.3 Replace into furnace and repeat step 8.1.2.2 untilweight loss is less than 0.05 % over at least1hofheating.8.1.2.4 Remove the container, cool in a desiccator, andweigh and record the mass of dried ash (mash) to the neares
29、t0.01 g.8.1.2.5 Determination of the Organic Treat Loading requiresseveral computation steps:Calculate the percent dry weight ash content as follows:% ashdry5 mash3 100!/mdry(2)where:% ashdry= ash content as percent on a dry weight basis,mash= mass of ash, g, andmdry= mass of the dried test specimen
30、, g.Calculate percent dry base clay as follows:% base claydry5% ashdry% ashdryof base clay3 100 % (3)where:% ashdryof base clay = nominal percent of mass of baseclay remaining as ash (on a dryweight basis) after similar heatingas above, as reported by manufac-turer (see 4.3, Note 1), and% base clayd
31、ry= percent of mass attributable tobase clay on a dry weight basis.Calculate the Organic Treat loading as follows:% organic treat loading 5 100%base claydry(4)where:% organic treat load-ing= percent of organic treat loadingon a dry weight basis.8.2 Test Method BThermal Gravimetric Analyzer (TGA):D76
32、26 1028.2.1 Use compressed air as the gas source. Check that airpump is connected and on. Check the gas flow rate ensuringflow is in accordance with manufacturers standard operatingprocedure.8.2.2 Tare a clean, dry porcelain container in the TGAdevice.8.2.3 Remove the container from the TGA device a
33、nd inserta test specimen of at least 50 mg in the container.8.2.4 Place the container and specimen into the TGA deviceand allow the balance to stabilize.8.2.5 Heat at a rate of 20 C per minute to 160 C and holduntil no further loss of mass and record percent mass loss dataas M.8.2.6 Heat at rate of
34、20 C per minute to between 750 Cand 1000 C.8.2.7 Hold at final temperature until weight loss is less than0.05 % over at least 3 min and record data as % ashwet.8.2.8 Organic Treat Loading Determination:8.2.8.1 Determination of the Organic Treat Loading requiresseveral computation steps:Determine the
35、 percent dry weight ash content:% ashdry5% ashwet100%M3 100 % (5)where:M = percent of initial mass loss determined at 160C as reported by TGA,% ashwet= percent of initial mass remaining as ash afterheating to between 750 C and 1000 C asreported by TGA, and% ashdry= percent of mass on a dry weight ba
36、sis remain-ing as ash after heating to between 750 C and1000 C as reported by TGA.NOTE 3M is the moisture content as a percent of as-received mass.The moisture content analysis method with oven as described in 8.2.1could be used to determine this value if it is difficult to obtain it from theTGA rep
37、ort.Determine the percent dry base clay:% base claydry5% ashdry% ashdryof base clay3 100 % (6)where:% ashdryof base clay = nominal percent of mass of baseclay remaining as ash (on a dryweight basis) after similar heatingas above, as reported by manufac-turer (see 4.3, Note 1), and% base claydry= per
38、cent of mass attributable tobase clay on a dry weight basis.Calculate the Organic Treat loading as follows:% organic treat loading 5 100%base claydry(7)where:% organictreat= percent of organic treat loading on a dryweight basis.9. Report9.1 ReportTest Data Sheet:9.1.1 The methodology used to specify
39、 how data are re-corded as given below, is covered in 1.3.9.1.1.1 Record as a minimum the following general infor-mation (data):(1) Sample/specimen identifying information such as num-ber, location, project, or feature.(2) A description of the organophilic clay used in theevaluation including source
40、, and manufacturers codes ofproduct identification, such as type and lot number.9.1.1.2 Record as minimum the following test specimendata (see example test data sheet in Appendix X1):(1) Specimen masses to 0.01 g (four significant digits).(2) The results for moisture content and organic treatloading
41、 of the organophilic clay to the nearest 0.1 % (threesignificant digits).9.1.2 Types of oven, furnace or TGA and representativetemperatures used, and9.1.3 Other reporting information not listed here, but as maybe required by the referenced ASTM test methods.10. Precision and Bias10.1 PrecisionTest d
42、ata on precision is not presented dueto the nature of the organophilic clay materials tested by thistest method. It is either not feasible or too costly at this time tohave ten or more laboratories participate in a round-robintesting program. In addition, it is either not feasible or toocostly to pr
43、oduce multiple specimens that have uniform physi-cal properties. Any variation observed in the data is just aslikely to be due to specimen variation as to operator orlaboratory testing variation.10.1.1 Subcommittee D18.21 is seeking any data from theusers of this test method that might be used to ma
44、ke a limitedstatement on precision.10.2 BiasThere is no accepted reference value for this testmethod, therefore, bias cannot be determined.11. Keywords11.1 ground water remediation; organic treat loading; orga-nophilic clayD7626 103APPENDIX(Nonmandatory Information)X1. EXAMPLE DATA SHEETORGANIC TREA
45、T LOADING OF ORGANOPHILIC CLAY TESTSample No.: Project: Test Device:Tested by: Computed by: Checked by:Date: Date: Date:Specimen No.:Moisture Content Determination Method A, Oven and/or Muffle Furnace(1) Container No.(2) Oven or muffle furnace drying temperature (C)(3) Mass of container, cover and o
46、rganophilic clay (g)(4) Mass of container, cover and dry organophilic clay (g)(5) Mass of container and cover (g)(6) Mass of organophilic clay, mi=(3)(5) (g)(7) Mass of dry organophilic clay, mdry=(4)(5) (g)(8) Moisture content as % of as-received mass, M =(67)(6) 3 100 (%)Organic Treat Loading Dete
47、rmination(9) Muffle furnace ash temperature (C)(10) Mass of container, cover and ash (g)(11) Mass of container and cover = (5) (g)(12) Mass of ash, mash=(10)(11) (g)(13) Ash content, % dry weight =(12)(7) 3 100 (%)(14) Nominal % ash for base clay* (%)(15) Organic Treat Loading =(13)(14) 3 100 (%)*Re
48、marks (as reported by manufacturer):D7626 104ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, an
49、d the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend.
