1、Designation: D 6883 04Standard Practice forManual Sampling of Stationary Coal from Railroad Cars,Barges, Trucks, or Stockpiles1This standard is issued under the fixed designation D 6883; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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 covers procedures for obtaining a manualgross sample from beneath the surface of coal i
3、n railroad cars,barges, trucks, or stockpiles. These procedures are to be used toprovide gross samples for estimating the quality of the coal.The gross samples are to be crushed, divided, and furtherprepared for analysis in accordance with Practice D 2013.1.2 This practice provides instruction for s
4、ampling beneaththe exposed surface coal to a depth of approximately 61 cm (24in.). Collect samples at this depth to get below the surface ofthe material, since drying and oxidation may have occurred at,or near the surface. Changes in moisture, in particle size, andin other properties continue to occ
5、ur deeper in the coal and,although not as drastic as near the surface, will cause themethod to be biased. The user should review the conditions ofthe coal (weather conditions, prior transport, settling time, andso forth, see 8.1) so that the interested parties can agree thatpotential biases are not
6、overly great or that some adjustment inspecifications is warranted. Sample increments collected fromthe surface layer(s) of coal in railroad cars, barges, or stock-piles are classified condition “D” (see Practice D 2234, Incre-ment Collection Classification). It is a good practice to requirethat “de
7、tails of sampling procedure shall be agreed upon inadvance by all parties concerned” whenever collection ofsample increments falls under condition “D.” This practiceoffers a sampling procedure that parties may use to meetrequirements of Practice D 2234 for condition “D.” Thepractice does not produce
8、 samples that satisfy precision re-quirements of Practice D 2234 general-purpose sampling, orPractice D 2234 special-purpose sampling.1.3 The user is cautioned that samples of this type do notsatisfy the minimum requirements for probability sampling andas such cannot be used to draw statistical infe
9、rences such asprecision, standard error, or bias.1.4 This sampling method is intended for use only whensampling by more reliable methods that provide a probabilitysample is not possible.1.5 The quantities stated in either acceptable SI units or ininch-pound units are regarded separately as standard.
10、 Thequantities stated in each system may not be exact equivalents;therefore, each system must be used independently of the other,without combining quantities in any way.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility o
11、f 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 121 Terminology of Coal and CokeD 2013 Practice for Preparing Coal Samples for AnalysisD 2234 Practic
12、e for Collection of a Gross Sample of CoalD 4749 Test Method for Performing Sieve Analysis of Coaland Designating Coal SizeD 4916 Practice for Mechanical Auger SamplingE 105 Practice for Probability Sampling of MaterialsE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456
13、Terminology for Relating to Quality and Statistics3. Terminology3.1 Definitions:3.1.1 consignment, na discrete amount of coal, such as ashipment, a carload, a unit train, or a days production. Aconsignment may include more than one lot of coal and maycorrespond to a specific period of time such as s
14、ampling periodor billing period.3.1.2 particle segregation, nthe segregation of sized par-ticles to specific areas as a result of the particles rolling, falling,or sliding down the sides of a pile or a result of the peculiaritiesof a coal handling system used to build the pile. Particlesegregation i
15、s a process of separation, not exclusively by size,but by size, shape, and density.1This practice is under the jurisdiction of ASTM Committee D05 on Coal andCoke and is the direct responsibility of Subcommittee D05.23 on Sampling.Current edition approved June 1, 2004. Published June 2004. Orginally
16、approvedin 2003. Last previous edition approved in 2003 as D688303a.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 w
17、ebsite.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.3 stockpile, nmaterial stored or reserved in a stackedpile or heap.4. Summary of Practice4.1 Use of this practice is limited to manual collection ofsample increments from ben
18、eath the surface layer(s) of station-ary coal from railroad cars, barges, trucks, or stockpiles for thepurpose of acquiring a gross sample.5. Significance and Use5.1 These guidelines provide procedures for manually col-lecting gross samples from beneath the exposed surface of coalin railroad cars, b
19、arges, trucks, or stockpiles taking intoaccount the wide variety of conditions that may be encoun-tered. The samples are further processed for the laboratory toprovide estimations of the coal quality. The use of this practiceis conditional upon agreement among all interested partiesconcerning all re
20、levant details of sample collection beforesampling begins. These include, but are not limited to: lot size;number and mass of increments; the size, shape, and manipu-lation of the increment collection devices; location of incre-ment collection site or sites; circumstances under whichincrements are n
21、ot to be collected or suspended; and safetyprecautions. It is preferable that such agreements be in writing.The user is cautioned that samples so obtained do not representmaterial below the point of penetration.6. Hazards6.1 WarningStockpile sampling involves exposure tohazardous operations, conditi
22、ons, and equipment. Awareness topersonnel safety cannot be overemphasized. Personnel mayrequire approved federal and/or state safety training beforetaking part in field sampling. Site-specific safety regulationsmust be observed. This includes personnel wearing all speci-fied personal protection equi
23、pment. The general safety precau-tions necessary when working around moving equipment mustbe observed. Sampling technicians must never work in coalthat is piled or in railroad cars over hoppers and/or feeders orwhere there is the possibility of the coal being eroded frombeneath them. Sampling should
24、 never be performed near a faceof a stockpile where the face extends upward at an anglegreater than the angle of repose of the coal.7. Procedure7.1 ObservationsBefore sampling a lot of coal using thismethod, perform a visual inspection for particle distributionand possible particle segregation withi
25、n the stockpile. Notesshould be made on the sampling log to reflect these observa-tions. These notes could be useful in understanding differencesof analytical test results or in identifying changes in stockpilingcharacteristics. The approximate top size of the coal on thesurface layer should be esti
26、mated in this step.7.2 Lot SizeAll interested parties should agree to the sizeof the lot to be represented by one gross sample beforesampling begins.7.3 Weight of IncrementsIncrement weights are to beequal to, or in excess of, those contained in Table 2 of PracticeD 2234. All increments should be of
27、 approximately equalmass.7.4 Number of IncrementsMeaningful levels of precisioncannot be obtained with the methods described herein. Deter-mine the number of increments to be collected for one grosssample using Eq 1. Fewer increments are permissible if agreedupon in advance. Since meaningful levels
28、of precision cannotbe obtained for these samples, any multiplier can be consideredvalid in place of the number 35 in Eq 1 if agreed upon by theparties concerned.N 5 35total lot size Mg or tons!908 Mg or 1000 tons(1)where:N = number of increments.7.5 Increment CollectionCollect increments from a dept
29、hof approximately 61 cm (24 in.), on top of conveyances,around the base of the stockpile, and up the slopes of the pile.The angles of the sides of the holes should be less than theangle of repose. Place the coal that is removed from the holesaway from the sampling area. Remove the increment from the
30、bottom of the hole and place it into the container. Avoid anyspillage.7.5.1 The pattern of increment placement can be dependentupon the size and number of conveyances or height and shapeof the stockpile. Space the increments over the surface of thecoal so that each increment will represent equally s
31、ized areas.This will require different spacing of increments as the size andnumber of conveyances or the profile of the pile changes. TheAppendix contains a discussion of pattern selection for collec-tion of increments from coal in conveyances.7.5.2 As increments are collected, protect them from con
32、-tamination and moisture change. Place the increments inplastic-lined canvas bags, metal drums with plastic liners,plastic buckets with airtight lids, or other moisture imperviouscontainers. Each sample must be clearly identified. Place amoisture-proof identification tag inside the sample containera
33、nd attach another securely on the outside of the samplecontainer. Sample identification shall include the samplingtechnicians initials, the date, the location, weather conditions,the number of increments, and the sampling method used. Thisinformation will become part of the analytical report. Othern
34、otes or pertinent information can be recorded in the samplinglog (see Section 8). This information may or may not be in thereport, but it shall be retained as a part of the laboratory record.7.6 Collection DevicesThe estimated top size of the coalascertained in 7.1 should be used to determine the op
35、ening sizeof the increment collection device. It should be a minimum oftwo and one half times the top size of the coal. Types anddimensions of sampling implements should be agreed upon byall interested parties before commencement of sampling. Acommon flat, square shovel with the two sides and the ba
36、ckbuilt up with metal plates which are at least 10 cm (4 in.) highis a device that is commonly used to obtain manual samplesSee Fig. 1.7.6.1 There are occasions when the use of an unloadingdevice can expose multiple faces and increase the access tomaterial for sampling. One example is to use heavy e
37、quipment,such as an end loader, to remove outside material of a stockpilethus allowing increments to be taken from a freshly exposedD6883042face. A second example is to have the end loader bucketremove primary increments from a stockpile and then manuallysubsample each increment with a manual sampli
38、ng implement(see Fig. 1). A third example is to have a clamshell bucketremove primary increments from a barge and then manuallysubsample each increment.7.6.2 Use of mechanical equipment such as auger samplersand core drill rigs are not in the scope of this procedure and areaddressed by other guides
39、(Practice D 4916) or workingpapers.7.7 In extremely cold weather, coal can become frozen onthe surface as well as inside the stockpiles. It is preferable notto collect increments manually from frozen coal. Wait until itthaws. If sampling is necessary while coal is frozen, make noteof the coals condi
40、tion when it was sampled. It will beextremely difficult or even impossible to collect incrementsproperly.8. Sampling Log8.1 Sampling technicians should keep a written log. Asampling log contains sample identification and also notationsof conditions encountered during increment collection. Entriesto
41、be noted include, but are not limited to: size of stockpile,number of railroad cars, barges, trucks or size segregationpatterns, general configuration of stockpile, compaction ofstockpile, perimeter conditions of pile, degree of contamina-tion, the visual appearance of the material, date, and weathe
42、rconditions.8.2 Any modifications to a sampling plan should be dis-cussed with the interested parties, if possible. Any changes tothe agreed upon sampling plan are to be documented on thesampling log. If it is not possible or feasible to discussmodifications, both the fact that discussion was not po
43、ssible,and the actual modifications that were made, are to bedocumented on the sampling log.9. Personnel9.1 Sampling technicians using this practice should beinstructed in the particular manual sampling practice agreedupon.9.2 Field situations often dictate on-site modifications ofsampling plans. Mo
44、difications of a sampling plan should bemade only by personnel with an understanding of and a senseof responsibility for the potential effects that the deviations willhave on the sample being taken.10. Precision and Bias10.1 The samples obtained using this practice are non-probability samples and as
45、 such they cannot be used tocalculate meaningful statistical inferences such as the levels ofprecision and bias. The user of this practice is referred toPractice E 105 for further information concerning probabilitysampling of materials.11. Keywords11.1 barges; manual sampling; rail cars; railroad ca
46、rs;stockpilesFIG. 1 Commonly Used Manual Sampling ImplementsD6883043APPENDIXES(Nonmandatory Information)X1. SAMPLING PATTERN SELECTIONX1.1 Increment PositionsX1.1.1 Sampling pattern and increment placement shouldbe agreed upon by all concerned parties. To determine potentialpositions of increments,
47、use of one of the following options isrecommended:X1.1.2 Option 1Divide the conveyance length into asmany equal sections as the required number of increments anddivide the width into three or more equal sections, dependingon the required number of increments per lot. An imaginarygrid is formed divid
48、ing the surface of the coal into equalrectangular sections which are the potential positions for theremoval of increments.X1.1.3 ExampleFor a lot consisting of six 1362 Mg (1500tons) barges 18 increments per barge would be required.Therefore, the grids according to X1.1.2 for the barges couldbe:18 s
49、ections long by 3 sections wide18 sections long by 4 sections wide18 sections long by 5 sections wide18 sections long by 6 sections wideX1.1.4 Option 2Divide the conveyance width into two,three, four, five, or six equal sections, depending on whichnumber is divisible and desirable, into the required number ofincrements per conveyance. Divide the required number ofincrements by this number to determine the number of equallength sections that will be required. An imaginary grid isformed dividing the surface of the barge into equal rectangularsections which are the pote
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1