1、Designation: D4596 09 (Reapproved 2015)Standard Practice forCollection of Channel Samples of Coal in a Mine1This standard is issued under the fixed designation D4596; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. 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 practice describes procedures for collecting a coalsample from a channel extending from top to bottom in the faceof a
3、 coal seam in a mine.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 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 stand
4、ard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary information, see Note 2.2. Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD388 Classification of Coals by RankD2234/D
5、2234M Practice for Collection of a Gross Sampleof CoalD2796 Terminology for Megascopic Description of Coaland Coal Seams and Microscopical Description andAnalysis of Coal (Withdrawn 1995)3D4371 Test Method for Determining the Washability Char-acteristics of Coal3. Summary of Practice3.1 At selected
6、sites in the mine the face of the seam iscleaned of weathered coal and debris and the face is evened. Achannel of uniform horizontal cross section is cut from the coalseam and the coal therefrom is collected for analysis andtesting.4. Significance and Use4.1 A properly collected face channel sample
7、that includesthe total coal bed interval provides a sample that is a repre-sentative cross section of the coal bed at the point of sampling.Channel samples are taken for subsequent testing needed forevaluation of coal quality and characterization for commercialevaluations, for planning of mining ope
8、rations to maintain coalquality, for the determination of coal rank in accordance withClassification D388, and for geologic coal resource studies.NOTE 1Because of the potential for lateral variability, a sample maynot represent the quality of the coal bed at another sample point. Thereliability of t
9、he data generated from channel samples is dependent on thenumber and spacing of the sample points and the variability of the coalcharacteristics in a given area.NOTE 2Sampling of the mine product for these purposes is unsatis-factory because of contamination of the product with out-of-seammaterial,
10、selective mining of parts of a seam, inability to obtain samplesfrom one or more specific locations in the mine, or other incompatibilityof the purpose of sampling with the mining practice. Conversely, channelsamples should not be used for evaluation of the quality of commercialshipments of the mine
11、 product, which should be sampled in accordancewith Methods D2234/D2234M.5. Apparatus5.1 Steel Measuring Tape, not less than3m(8ft)long.5.2 Miners Pick or Similar Tool, with file for sharpening.Other devices may be used such as a pneumatically operatedchain saw with tungsten carbide teeth.5.3 Brush
12、or Broom, for removing loose particles on thecoal face.5.4 Chalk.5.5 Sample Containers With ClosuresIf the sample is to beused for determination of inherent moisture, the container shallbe such that less than 0.05 % of the sample weight is lostbetween the time of sealing the container with sample an
13、d thetime of opening for preparation of the sample for analysis.Steel airtight containers with polyethylene bag liners have been1This practice is under the jurisdiction of ASTM Committee D05 on Coal andCoke and is the direct responsibility of Subcommittee D05.18 on Classification ofCoals.Current edi
14、tion approved Sept. 1, 2015. Published September 2015. Originallypublished approved in 1986. Last previous edition approved in 2009 as D4596 09.DOI: 10.1520/D4596-09R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annua
15、l Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United S
16、tates1found to be satisfactory for this purpose. For other purposes,bags made of a strong cloth and lined with a polyethylene bagmay be suitable.5.6 Ground ClothCanvas tarpaulin or heavy-duty plasticsheet about 3 by 3 m (10 by 10 ft). If the purpose of samplingincludes the determination of inherent
17、moisture, the sheet shallbe of low water solubility and permeability, such as polyeth-ylene or oilcloth.5.7 Tags and Pen, for sample identification and for marking.5.8 Shovel.5.9 Notebook and Pencil, or other means for record keeping.6. Planning of Sampling6.1 Considerations regarding weathered coal
18、 and inherentmoisture:Weathered coal is unsuitable for inclusion in channel samplescollected to secure fresh and unaltered material. Weatheredcoal typically contains anomalously low total moisture, yieldslow calorific value (dry and moisture-and-ash-free basis), andalso produces atypical results for
19、 other tests. It does not reflectunaltered in-situ coal properties, cannot be used for classifica-tion according to rank, and does not give accurate estimates oftypical as-mined moisture.6.1.1 Obvious indications of weathering include, but are notlimited to: (1) any discoloration of broken coal surf
20、aces orcleats, (2) presence of sulfate minerals resulting from oxidationof pyrite, (3) presence of gypsum (calcium sulfate) crystals,and (4) presence of dust, cracked and crazed coal surfaces, ora fragmented condition of the coal blocks resulting from loss ofinherent moisture.6.1.2 It is often usefu
21、l to collect samples containing theirfull complement of inherent moisture, but that condition maynot always be readily discernable. A simple field test can beused to qualitatively identify seemingly fresh coal that has lostsome inherent moisture but has not yet obviously weathered. Alight coating of
22、 water is sprayed or wiped onto the surface ofthe coal, and the rate at which it disappears is observed. Rapiddisappearance (typically within a few seconds) indicates ab-sorption and demonstrates that the coal contains less than itsfull compliment of inherent moisture. Slower disappearance(taking pe
23、rhaps a minute or more) is characteristic of evapo-ration and suggests that the pores are filled with moisture. Toaccount for variations in field conditions such as temperature,humidity, different absorption rates by different coals, and soforth, the test is applied to a number of coal pieces both b
24、eforeand during the sample collection process.6.2 Sampling Plan for Classification According to Rank:6.2.1 Refer to Section 7 of Classification D388 for informa-tion on the required number and location of samples.6.2.2 The channel size shall be at least 8 cm (3 in.) deep and10 cm (4 in.) wide, and s
25、hall yield at least 3 kg (6 lb) of coalfor each foot of thickness of coal seam.6.2.3 All roof and floor rock, mineral partings more than 1cm (38 in.) thick, and mineralized lenses or concretions (suchas sulfur balls) more than 114 cm (12 in.) thick and 5 cm (2 in.)wide shall be excluded from the sam
26、ple.6.3 Sampling for Other PurposesVariations in the purposeof sampling and in conditions encountered in the field precludethe establishment of rigid procedures covering every samplingsituation. In each case, formulate a plan taking into account themining operation, the purpose of the sampling, and
27、the knowncharacteristics of the coal seam. Characteristics include lateralor vertical variations in coal quality, occurrences of persistentmineral partings or concretions within the seam, and the extentof oxidation or weathering of coal. Take these considerationsinto account in planning sample site
28、selection and whetherlithotypes, partings, and layers above and below the seamshould be described.4,5Also establish a method of preparingthe coal face, and determining the size of sample.6.3.1 Obtain information for identification of suitable loca-tions for sampling. Choose sites that will best sati
29、sfy thepurpose of sampling.6.3.2 A channel at least 8 cm (3 in.) deep (into the face ofthe seam) and 10 cm (4 in.) wide yields a sufficient sample formost purposes. The channel may be enlarged to minimize theeffect of channel size variability when a coal characteristic ofinterest, such as ash conten
30、t, varies greatly from layer to layerin the seam, or when the coal breaks unevenly. Also, thechannel cross-section may be enlarged to obtain sufficientsample for tests requiring large amounts. The size of channelfor the required amount of coal may be estimated from thedensity of coalapproximately 1.
31、3 g/cm3(0.05 lb/in.3). Forinformation on determining washability, see Test MethodD4371 and the report by Wizzard.66.3.3 Practice with respect to weathering of the coal de-pends on a number of factors. Some characteristics of coal,such as total sulfur content, do not change appreciably withweathering
32、 if the coal is not leached. The forms of sulfur, themoisture-holding capacity, and oxygen content of high volatileC bituminous and lower rank coals, and the rheologicalproperties of coking coals do change with weathering. Sam-pling to different depths and testing of such properties may berequired t
33、o establish the depth at which unweathered coal canbe obtained.7. Sampling Procedures7.1 At each sampling site, survey the condition of the coalface and the rock above the coal (if exposed).NOTE 3Warning: Beware of danger from rock falling from the roofof underground mines or from the highwall of su
34、rface mines. Take downany loose blocks as a safety precaution and to prevent extraneous materialfrom subsequently contaminating the sample.7.2 With a miners pick, remove weathered coal from theface area to be sampled, to the depth (but at least 3 cm (1 in.)required in the plan of sampling. True up t
35、o the face to leave astraight surface normal to the bedding and free of extraneousmatter.4Schopf, J. M., “ Field Description and Sampling of Coal Beds,” U.S.Geological Survey Bulletin No. 1111-B, 1960.5Field Description of Coal ASTM, 1978, pp. 333, 5868, ASTM STP 661, .6Wizzard, J. T., “The Reliabil
36、ity of Using Channel Samples to RepresentRun-of-Mine Coal Washability,” DOE/PETC/TR-82/3.D4596 09 (2015)27.3 Describe and record observations on the character oflayers in the coal seam (see Terminology D121 or DefinitionsD2796) to the extent required by the sampling plan.7.4 Mark the sides of the ch
37、annel with chalk and mark anymineral partings or other parts of the seam that are to bediscarded.7.5 Clear and smooth the floor adjacent to the sample areaand spread a ground cloth on the floor with one edge at the coalface.7.6 Cut away with a miners pick (or other tool) a channelfrom top to bottom
38、(or bottom to top) of the coal seam. If a sawis used at the sides of the channel, exercise care that finesgenerated by the saw do not become part of the sample. Ensurethat all material from the channel that is to be sampledaccording to the plan of sampling falls on the ground cloth andthat any miner
39、al matter to be discarded does not contaminatethe coal sample. Cut the channel to a uniform width and depthin a rectangular cross section, to ensure that representativevolumes of material are obtained from every part of the coalseam.7.7 As quickly as possible, if inherent moisture will bedetermined,
40、 transfer the material on the ground cloth to asample container and seal and then label the container. Ifsurface moisture is visible on the coal, or if there is any reasonto question the accuracy of inherent moisture content deter-mined from the sample, the description of the sample shallinclude the
41、 warning: “Moisture content questionable.”8. Keywords8.1 channel; coal; mine; rank; sample collection; samplingASTM 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 advise
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