1、Designation: D 6347/D 6347M 05Standard Test Method forDetermination of Bulk Density of Coal Using NuclearBackscatter Depth Density Methods1This standard is issued under the fixed designation D 6347/D 6347M; the number immediately following the designation indicates theyear of original adoption or, i
2、n the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONData obtained from the density of coal stockpiles is combined with volume determi
3、nations per TestMethod D 6172 to complete the physical inventory of total tons. The book inventory is compared tothe physical inventory for determining the accumulation of measurement difference that have occurredsince the last physical inventory.Since the physical inventory is the reference value u
4、sed to compare and adjust the book inventory,it is important that the standard methods for conducting the density and volume measurementsintroduce the least possible error. Close adherence to the details of the procedures described in thisstandard is a prerequisite to the objective of this test meth
5、od.This standard test method for determination of bulk density of stockpiled coal is used for all ranksof coal. Proper density determination involves an understanding of the physical characteristics of thecoal types and the stockpiling facilities.1. Scope1.1 This test method covers procedures for de
6、termining thebulk density of coal using instrumentation that measures therelative backscatter of nuclear gamma radiation throughout thedepth of the stockpile under test.1.2 This procedure is applicable to all ranks of coal.1.3 The values stated in either SI units or inch-pound unitsare to be regarde
7、d separately as standard. The values stated ineach system are not exact equivalents: therefore, each systemmust be used independent of the other. Within the text, SI unitsare shown in brackets.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I
8、t is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. The equipment usesradioactive materials, which may be hazardous to the health ofusers, unless proper precautions are take
9、n.2. Referenced Documents2.1 ASTM Standards:2D 1586 Test Method for Penetration Test and Split-BarrelSampling of SoilsD 6172 Test Method Determining the Volume of BulkMaterials Using Contours of Cross Sections Created byDirect Operator Compilation Using Photogrammetric Pro-cedures2.2 NIST Standard:N
10、ational Institute for Standards and Technology Handbook44, Specifications, Tolerances, and Other Technical Re-quirements for Weighing and Measuring Devices32.3 ASME Standard:ASME Pipe Codes42.4 Code of Federal Regulations:Title 10, Parts 19 and 205Title 4951This test method is under the jurisdiction
11、 of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D 05.07 on PhysicalCharacteristics of Coal.Current edition approved June 1, 2005. Published July 2005. Originally approvedin 1998. Last previous edition approved in 1999 as D 6347/D 6347M 99.2For referenced ASTM
12、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.3Available from National Institute of Standards and Technology (NIST),Gaithersburg
13、, MD 20899.4Available from American Society of Mechanical Engineers, 345 E. 47th St.,New York, NY 10017.5Available from the U.S. Government Printing Office, Superintendent ofDocuments, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
14、-2959, United States.3. Terminology3.1 Definitions of Terms:3.1.1 counting periodthe period of time, set using thescaler time switch, during which the readout device accumu-lates pulses.3.1.2 test countsthe recording of pulses accumulated bythe readout device during a counting period. The test count
15、 isinitiated by pushing a start button located on the scaler, whichresets the accumulator and starts a new counting period.3.1.3 standard counta test count taken with the probepositioned inside the shield and standard assembly.3.1.4 reference standard counta series of 30 consecutivestandard counts,
16、taken on the occasions specified in 9.1.5.3.1.5 stability check standard counta series of five con-secutive standard counts, taken on the occasions specified in9.1.6.3.1.6 access holeused loosely in this standard to denotethe opening made into the stockpile for insertion of the probeaccess tube.3.1.
17、7 penetrationinserting the probe access tube in aselected position for collecting test count readings.3.1.8 vertical positionthe position of the probe where atest count reading is taken, measured from a reference eleva-tion.3.1.9 vertical intervalthe vertical interval moved by thetest probe when rep
18、ositioned from one vertical position to thenext test vertical position in the same access hole. For this testmethod, a vertical interval is equal to 30 in. 76 cm.4. Summary of Test Method4.1 The area of the stockpile accessible for stockpile pen-etration is first identified. An access (sampling) pla
19、n for theaccessible area is determined, and the depth of the stockpile isaccessed at locations within the area according to plan. Theprobe is used to obtain test count readings at vertical intervalswithin each access hole. Test count readings of compacted coalin field calibration vessels are taken u
20、sing coal from thestockpile so as to convert stockpile test count readings to bulkdensity using a calibration curve. The mean bulk density of thestockpile is estimated using the test count reading and calibra-tion data.4.2 The procedures appear in the following order:Procedures SectionPreparation of
21、 Sampling Plan 8Standardization of the Nuclear Depth Density Gauge 9Field standardization 9.1Stockpile Penetration and Access Procedures 10Standardize the nuclear depth probe 10.1Penetrate the stockpile 10.2Measure and record depth 10.3Place access stabilization and sample collection device 10.4Taki
22、ng replicate test counts 10.5Procedure Asplit-barrel sampler/larger auger 10.6Procedure Bsmall auger procedure 10.7Procedure Chydraulic access procedure 10.8Field Calibration of the Nuclear Gauge 11Influence of elemental composition on nuclear depth density probe 11.1Perform calibration procedures o
23、n-site 11.2Minimum eight calibration vessels 11.3Weight and record empty calibration vessel weight 11.4Compact coal in calibration vessel 11.5Weigh and record compacted coal in calibration vessel 11.6Penetrate compacted coal in calibration vessel 11.7Minimum number of replicate test counts 11.8Condu
24、ct a uniform compaction check 11.9Data for establishing calibration curve (Annex A3) 11.10Develop calibration curve (Annex A3) 11.11Separate calibration curve for each access method 11.12Interpretation of Results 12Report 135. Significance and Use5.1 The measured mean bulk density of a coal stockpil
25、e isused with a measurement of the stockpile volume per TestMethod D 6172. Procedures to determine the quantity ofstockpiled coal. This measure of quantity is often used as areference value for adjusting inventory records.6. Apparatus6.1 Field-test location preparation equipment consisting of:6.1.1
26、Drilling Rigmobile equipment capable of boring,driving, or hydraulically forcing, on its own power, accessholes through the entire depth of the stockpile.6.1.2 Access Tubehollow tubing with an inside diameterallowing clearance between 0.035 in. 0.90 mm and 0.060 in.1.50 mm for the nuclear depth prob
27、e to be positioned atspecified vertical intervals. The tubing shall be sufficientlydurable to withstand the applied forces of insertion into theaccess hole. The inside diameter of the access tube shallprovide a smooth path with an annular space and wall thicknesssufficient that there is no deformati
28、on of shape under normaluse. ASME Schedule 80 thickness PVC pipe is the mostcommonly used access tube material. Other materials may beused, but their use may require a different tube wall thicknessor a different counting period, or both, to obtain an equivalenttest count.6.1.3 Small Augera boring ap
29、paratus with connectingsections used to provide an access hole the entire depth of thestockpile. The outside diameter of the auger is sized to producean access hole with a diameter equal to the outside diameter ofthe access tube. To obtain reliable test count readings, it isessential that the access
30、 tube fit snugly into the access hole withno empty spaces at the junction between the coal and the accesstube.6.1.4 Split-Barrel Samplera hollow device with a cuttingedge, which, when driven into coal, can be extracted and leavean access hole. Drill rod extensions provide for sampling theentire dept
31、h of the stockpile.6.1.5 Hollow Stem Augeran auger with a hollow centralshaft having an inside diameter larger than the access tube.This auger is used in the split-barrel access technique tocontinue the access hole through previously tested depths ofthe stockpile.6.1.6 Nuclear Depth Density ProbeThe
32、 device requiredfor collecting the test count readings from the stockpile. It isequipped with the following components:6.1.7 Gamma Sourcean encapsulated and sealed radioac-tive source that meets the specific form requirements of Title49 of the Code of Federal Regulations.ACesium 137, nominal8-milli-
33、curie source is used.6.1.8 Gamma Detectora Geiger-Mueller tube housed inthe probe is an unlimited life, metal wall gamma detector. AD 6347/D 6347M 052preamplifer is included to amplify and send the electrical signalto the readout device or scaler.6.1.9 Shield and Standardan assembly, which protects
34、theprobe from mechanical damage, provides the necessary shield-ing of the radioactive source when not in use and provides ameans to obtain repeatable reference and stability checkstandard counts.6.1.10 Read-Out Devicea scaler with a resolution andrange to display counts over the density for which th
35、eapparatus will be used. The scaler contains other electroniccomponents and an electrical power supply. Units with amaximum error of timing 60.005 and 60.002 % stability.6.1.11 Electrical Cableto connect the probe to the readoutdevice. The cable shall be of sufficient length to allow testcounts to b
36、e taken the entire depth of coal being tested.6.1.12 Transport Casea sampling case used for storingand transporting the nuclear depth probe. The transport caseshall be constructed and labeled to meet the U.S. Departmentof Transportation requirements in Title 49 of the Code ofFederal Regulations.6.2
37、Field Calibration Equipment:6.2.1 Field Calibration Vessela vessel with a minimuminside diameter of 23 in. 58 cm and a minimum inside heightof 32 in. 81 cm. The volume of the vessel is measured andcertified semiannually using the temperature-corrected watermethod. A weighing device that has been cer
38、tified as accurateby a metrology laboratory determines certification weights. Acertificate of calibration is provided in accordance with13.1.12. The vessel can be made of metal or polymer material,provided the vessel retains constant volume during compactionand weighing. However, the coefficient of
39、thermal expansionfor polymer material, which can be eleven times greater thanfor steel over the same temperature ranges, can result incalibration error.6.2.2 Field Calibration Access Tubeis identical to thatused to access the stockpile and specified in 6.1.2.6.2.3 Field Calibration Coal Retrieval Au
40、geran auger,with a minimum outside diameter of 2.5 times of top size of thecoal, used to collect calibration coal from the stockpile.6.2.4 Field Compaction Hammer Assemblyan apparatusfor compacting the coal uniformly in the calibration vessel tothe required range of densities. Manual devices are not
41、recommended for compaction.6.2.5 Field Calibration Scalea weighing device meetingNational Institute for Standards and Technology Handbook 44,Type II requirements. The weighing device shall have thecapacity of weighing the calibration vessel empty or filled withcoal in a single weighment. The weighin
42、g device shall becertified accurate to 60.1 % of applied load and calibratedsemiannually. Provide a certificate of calibration in accordancewith 13.1.12.6.2.6 Access Stabilization/Sample Collection Deviceasample collection pan with an opening placed over the top ofthe calibration vessel to restrict
43、the lateral movement of theaccess equipment.7. Precautions7.1 Operators of the equipment shall obtain a license for theuse of the equipment from the U.S. Nuclear Regulatorycommission or state regulatory agencies, or both. The operatortakes proper precautions to ensure that the use of this equip-ment
44、 complies with applicable sections of Title 10, Code ofFederal Regulations, Parts 19 and 20.7.2 Backfill the access holes to lessen the risk of stockpilespontaneous combustion.8. Preparation of the Sampling Plan8.1 Use experienced personnel familiar with stockpiling andreclaiming procedures used at
45、the location. Determine thesurface area and the nominal depth of the stockpile to besampled. Prepare a drawing that clearly identifies areas that arenot accessible for penetration or else not intended for access,such as areas covering underground hoppers and reclaimingfacilities, or heavily compacte
46、d haul roads.8.1.1 It is good practice to use laboratory analysis fromsamples collected at each vertical test interval to identifyforeign material from the base of the stockpile and to convertbulk density to other than in-situ moisture basis.8.1.2 Determine the number (n) of test counts required tor
47、epresent the stockpile. For stockpiles with a prior history ofdensity testing, this data will prove helpful in making thisdetermination. If no prior history is available, it is recom-mended that a minimum of 100 test counts and a minimum of8 access holes be used to represent the stockpile.NOTE 1The
48、minimum test counts designated for stockpiles with nohistory available are based on a standard deviation taken from a Z table.Eight borings were designated to assure reasonable representation of thestockpile.8.1.3 Using the accessible surface area and the nominaldepth of the stockpile determine the
49、number of access holesrequired to provide the number (n) of test counts selected in8.1.2, allowing one vertical interval per test count. Divide theaccessible area into the same number of grid openings as thenumber of access holes. The grid openings should represent asnear equal volume as feasible. The openings need not beidentical in shape.8.1.4 Select one access hole site within each grid openingand mark the site locations on the plot plan. For the selectionprocess, use a random location in each grid.8.1.5 For penetration and access of the st
