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Scope1.1 This test method covers two procedures for determiningthe bulk density of crushed coal less than 37.5 mm [1.5 in.] insize, such as is charged into coke ovens, as follows:1.1.1 P
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee Designation: D291/D291M − 20 Standard Test Method for Bulk Density of Crushed Bituminous Coal1 This standard is issued under the fixed designation D291/D291M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last reapproval A superscript epsilon (´) indicates an editorial change since the last revision or reapproval 1 Scope 2 Referenced Documents 2.1 ASTM Standards:2 1.1 This test method covers two procedures for determining D440 Test Method of Drop Shatter Test for Coal the bulk density of crushed coal less than 37.5 mm [1.5 in.] in D2234/D2234M Practice for Collection of a Gross Sample size, such as is charged into coke ovens, as follows: of Coal D3038 Test Method for Drop Shatter Test for Coke 1.1.1 Procedure A—The cone procedure for determining an D3302/D3302M Test Method for Total Moisture in Coal uncompacted bulk density D4749 Test Method for Performing the Sieve Analysis of Coal and Designating Coal Size 1.1.1.1 Standard Method—Procedure employs the use of a 115 mm [4.5 in.] chute opening and a measuring box having 3 Significance and Use dimensions of 305 mm x 305 mm x 305 mm [12.0 in x 12.0 in x 12.0 in.] 3.1 This test method concerns the compaction of crushed coal to determine either its compacted or uncompacted bulk 1.1.1.2 Alternate Method—Procedure employs the use of a density, for purposes such as charging coke ovens 203 mm [8.0 in.] chute opening and a measuring box having dimensions of 203 mm x 203 mm x 305 mm [8.0 in x 8.0 in x PROCEDURE A—CONE PROCEDURE FOR 12.0 in.] for coals with a total moisture greater than 7 % UNCOMPACTED BULK DENSITY 1.1.2 Procedure B—The dropped-coal procedure for deter- 4 Apparatus mining a compacted bulk density, comparable to actual bulk densities attained in coke ovens 4.1 Measuring Box: 4.1.1 Standard Method, of rigid construction, having inside 1.2 This test method is not applicable to the testing of dimensions of 305 mm x 305 mm x 305 mm [12.0 in x 12.0 in powdered coal as used in boiler plants, nor to the determination x 12.0 in.], and a volume of 0.02873 m3 6 0.00008 m3 of the bulk density of coal in storage piles [1.000 ft3 6 003 ft3] The exact volume of the box shall be determined by water calibration 1.3 Units—The values stated in either SI units or inch- 4.1.2 Alternate Method, of rigid construction, having the pound units are to be regarded separately as standard The inside dimensions of 203 mm x 203 mm x 305 mm [8.0 in x values stated in each system are not necessarily exact equiva- 8.0 in x 12.0 in.], and a volume of 0.01257 m3 6 00003 m3 lents; therefore, to ensure conformance with the standard, each [0.4444 ft 3 6 0.0012 ft3] The exact volume of the box shall be system shall be used independently of the other, and values determined by water calibration from the two systems shall not be combined 4.2 Cone: 1.4 This standard does not purport to address all of the 4.2.1 Standard Method, conforming to Fig 1 for filling the safety concerns, if any, associated with its use It is the measuring box This cone shall be 610 mm [24.0 in.] high and responsibility of the user of this standard to establish appro- 510 mm [20.0 in.] in inside diameter at the top, with a circular priate safety, health, and environmental practices and deter- opening 115 mm [4.5 in.] in diameter at the bottom A slide mine the applicability of regulatory limitations prior to use valve consisting of a sliding-plate shutter and its supports shall be welded to the bottom of the cone in such a manner that the 1.5 This international standard was developed in accor- valve may be opened and closed with ease by removing or dance with internationally recognized principles on standard- inserting the shutter in its supporting slides The cone shall be ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or mendations issued by the World Trade Organization Technical contact ASTM Customer Service at service@astm.org For Annual Book of ASTM Barriers to Trade (TBT) Committee Standards volume information, refer to the standard’s Document Summary page on the ASTM website 1 This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.15 on Metallurgical Properties of Coal and Coke Current edition approved Nov 1, 2020 Published January 2021 Originally approved in 1927 Last previous edition approved in 2012 as D291 – 07(2012) DOI: 10.1520/D0291_D0291M-20 Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 United States 1 D291/D291M − 20 FIG 1 Example of Apparatus for Cone Procedure: Standard Method supported in a tripod frame having a circular opening at the top 4.2.2 Alternate Method, 3 conforming to Fig 2 for filling the of 457 mm [18.0 in.] in diameter This frame shall support the measuring box This cone shall be 470 mm [18.5 in.] high and cone so that the top-side of the shutter shall be 560 mm [22.0 in.] from the inside bottom surface of the box An 3 Supporting data have been filed at ASTM International Headquarters and may example of the apparatus for the standard cone procedure is be obtained by requesting Research Report RR:D05-2001 Contact ASTM Customer shown in Fig 1 Service at service@astm.org 2 D291/D291M − 20 FIG 2 Example of Apparatus for Cone Procedure: Alternate Method 510 mm [20.0 in.] in inside diameter at the top, with a circular supported in a tripod frame having a circular opening at the top opening of 203 mm [8.0 in.] in diameter at the bottom A slide of 457 mm [18.0 in.] in diameter This frame shall support the valve consisting of a sliding-plate shutter and its supports shall cone so that the top-side of the shutter shall be 560 mm be welded to the bottom of the cone in such a manner that the [22.0 in.] from the inside bottom surface of the box An valve may be opened and closed with ease by removing or example of the apparatus for the alternate cone procedure is inserting the shutter in its supporting slides The cone shall be shown in Fig 2 3 D291/D291M − 20 4.3 Leveling Bar, a steel strip 760 mm [30 in.] long by the determination of the bulk density (see Section 5) The 37.5 mm [1.5 in.] wide and approximately 5 mm [3⁄16 in.] thick minimum gross sample masses required by Test Methods D3302/D3302M and D4749 will not apply 4.4 Scales, platform, capable of weighing up to 100 kg [220 lb] and sensitive to 0.05 kg [0.1 lb] 6.5 For the purpose of simplifying communication between concerned parties in the reporting of the size distribution of the 5 Sampling actual bulk density sample, it is recommended to employ the standard series of sieves identified in 6.1.2 of Test Method 5.1 Gross Sample—For collecting gross samples of crushed D4749 covering from within the actual topsize of the coal bituminous coal, the procedures described in Practice D2234/ down to 6.3 mm (1⁄4 in.) Other sieve sizes may be used D2234M shall apply During the period of collecting the gross sample, the increments of the sample shall be stored in a 7 Calculation waterproof container with a tightly fitting cover in order to prevent the loss of moisture The minimum number and mass 7.1 Calculate the uncompacted bulk density, BDuncomp, to of increments collected shall be in accordance with Table 2 of the nearest 0.05 kg/m3 [0.1 lb/ft3] as follows: Practice D2234/D2234M The minimum gross mass of the sample shall be 140 kg [300 lb] BDuncomp,kg⁄m3@lb ⁄ ft3# 5 ~W2 2 W1!⁄V1 (1) 5.2 Laboratory Sample—The gross sample of coal shall be where: the mass of the empty measuring box, kg [lb]; thoroughly mixed and subdivided, without crushing, into four W1 = the mass of the filled measuring box after leveling as 34 kg [75 lb] portions This operation shall be done as quickly W2 = as possible to avoid loss of moisture, and the bulk density shall described in 6.3, kg [lb]; and be determined immediately If this determination cannot be V1 = the measured volume of the measuring box as deter- made immediately, the samples shall be kept in waterproof mined by water calibration as described in 4.1, m3 containers with tightly fitting covers until the time for making [ft3] the determination 8 Report 6 Procedure 8.1 Report the uncompacted bulk density, BDuncomp, as 6.1 Before filling the cone hopper, level it in its tripod on a calculated in Section 7 to the nearest 0.05 kg/m3 [0.1 lb/ft3] solid floor Pour the prepared sample into a pile on the floor and carefully flatten it to about 100 mm [4 in.] in thickness using a 8.2 Report the method, either the Standard Method or rake or shovel Avoid pounding of the pile with the back of the Alternate Method, used to determine the BDuncomp shovel Take successive shovelfuls from uniformly distributed points in the pile and allow them to slide gently from the shovel 9 Precision and Bias into the hopper at different peripheral points This will prevent segregation and packing while the hopper is being filled Place 9.1 Repeatability: about 34 kg [75 lb] of coal in the hopper 9.1.1 Duplicate results by the same operator in a given laboratory on consecutive tests determined within a minimum 6.2 Weigh the empty measuring box to the nearest 0.05 kg interval of time shall be considered suspect if they differ by [0.1 lb] Center the previously weighed measuring box under more than 9.6 kg/m3 [0.6 lb/ft3] the valve of the cone Remove the valve shutter completely, 9.1.2 When two results are obtained that differ by more than allowing all of the coal to flow into the box and overflow the this value, two additional tests shall be made If the second pair edges Loosen wet coal, not flowing freely from the hopper, by of results differs by less than the repeatability, the first pair gently thrusting downward (or poke) through the coal to the shall be discarded and the mean of the second pair shall be valve with the leveling bar reported as the result of the test 9.1.3 When both pairs of results exceed the repeatability, the 6.3 After filling the box, carefully level off the excess coal mean of the four results shall be reported, provided that the two above the box edge by means of the leveling bar, and place the most divergent results differ by less than 13 kg/m3 [0.8 lb/ft3] box on the platform scale and weigh it to the nearest 0.05 kg Otherwise, all results shall be discarded and the apparatus, [0.1 lb] Avoid jarring or shifting of the filled box until all procedure, and sample shall be examined for noncompliance excess coal is leveled off Record the mass of the filled causes, which should be corrected before redetermining new measuring box to the nearest 0.05 kg [0.1 lb] pairs of values 6.4 Moisture and size distribution of the coal are the two 9.2 Reproducibility—It is not possible to specify the preci- main factors which affect the bulk density It is recommended sion (reproducibility) of the procedure in Test Method D291/ for proper interpretation that a moisture determination and D291M for measuring the uncompacted bulk density because sieve analysis of the coal be reported along with the bulk of the impracticality of obtaining, transporting, and handling density result For directions for determination of the total representative splits of the materials in the quantities that moisture, see Test Method D3302/D3302M For directions for would be needed to establish the precision statement the determination of size distribution, see Test Method D4749 For the purposes of reporting both total moisture and size 9.3 Bias—No information can be presented on the bias of distribution associated with the bulk density results, the repre- the procedure in Test Method D291/D291M for measuring the sentative sample is taken to be the actual sample employed for uncompacted bulk density because the method is empirical and no material having an accepted reference value is available 4 D291/D291M − 20 FIG 3 Example of Apparatus for Dropped Coal Procedure The use of the 203 mm x 203 mm x 305 mm [8.0 in x 8.0 in been shown to produce results 1 kg ⁄m3 [0.06 lb ⁄ft3] higher x 12.0 in.] measuring box specified in the Alternate Method has 5 D291/D291M − 20 than when using the 305 mm x 305 mm x 305 mm [12.0 in x floor of the dropping apparatus and center it directly under the 12.0 in x 12.0 in.] measuring box of the standard method hopper with the long axis of the box parallel to the long axis of the hopper Mark the floor of the dropping apparatus so that the PROCEDURE B—DROPPED-COAL PROCEDURE measuring box will always be positioned exactly the same each FOR COMPACTED BULK DENSITY4 time 10 Apparatus 12.2 Pour the prepared coal sample into a pile on the floor and carefully flatten it to about 100 mm [4 in.] in thickness 10.1 Measuring Box, specially constructed, externally using a rake or shovel Avoid pounding of the pile with the braced to ensure rigidity, having inside dimensions of 457 mm back of the shovel Take successive shovelfuls from uniformly x 610 mm x 203 mm [18.0 in x 24.0 in x 8.0 in.] and a volume distributed points in the pile and carefully place them into the of 0.05659 m3 6 0.00016 m3 [2.000 ft3 6 0.006 ft3] The exact hopper to avoid segregation Place each shovelful to one side volume of the box shall be determined by water calibration of the preceding one until 82 kg to 90 kg [180 lb to 200 lb] are contained in the hopper, avoiding any heaping up of the coal at 10.2 Dropping Apparatus, consisting of the shatter test any one point as well as any compacting of the coal with the machine described and illustrated in Test Method D3038 and shovel Test Method D440 It shall consist of a box 457 mm [18.0 in.] in width, 710 mm [28 in.] in length, and approximately 12.3 Raise the hopper containing the coal and allow the coal 380 mm [15 in.] in depth, supported above a rigidly mounted to drop into the measuring box from the 1.8 m [6 ft] height cast iron or steel plate, not less than 13 mm [0.5 in.] in Carefully level the excess coal even with the top edge of the thickness, 970 mm [38 in.] in width, and 1220 mm [48 in.] in box by means of the leveling bar Avoid jarring or shifting of length The inside of the bottom of the box shall be 1800 mm the filled box until all excess coal is leveled Fill any voids left [72 in.] above the plate The bottom of the box shall consist of in the corners of the box below the top edge by gently raking two doors hinged lengthwise and latched so that they will the excess coal across the corner Place the box, or its contents, swing open freely and not impede the fall of the coal In order on the platform scale and weigh it to the nearest 0.05 kg to facilitate filling the box with coal, the box shall be [0.1 lb] constructed so that it can be lowered to a convenient level An example of the dropping apparatus is shown in Fig 3 12.4 Moisture and size distribution of the coal are the two main factors which affect the bulk density It is recommended 10.3 Leveling Bar, a steel strip 760 mm [30 in.] long by for proper interpretation that a moisture determination and 37.5 mm [1.5 in.] wide and approximately 5 mm [3⁄16 in.] thick sieve analysis of the coal be reported along with the bulk density result For directions for determination of the total 10.4 Scales, platform, capable of weighing up to 100 kg moisture, see Test Method D3302/D3302M For directions for [220 lb] and sensitive to 0.05 kg [0.1 lb] the determination of size distribution, see Test Method D4749 For the purposes of reporting both total moisture and size 11 Sampling distribution associated with the bulk density results, the repre- sentative sample is taken to be the actual sample employed for 11.1 Gross Sample—For collecting gross samples of the determination of the bulk density (see Section 5) The crushed bituminous coal, the procedures described in Practice minimum gross sample masses required by Test Methods D2234/D2234M shall apply During the period of collecting D3302/D3302M and D4749 will not apply the gross sample, the increments of the sample shall be stored in a waterproof container with a tightly fitting cover in order to 12.5 For the purpose of simplifying communication be- prevent the loss of moisture The minimum number and mass tween concerned parties in the reporting of the size distribution of increments collected shall be in accordance with Table 2 of of the actual bulk density sample, it is recommended to employ Practice D2234/D2234M The minimum gross mass of the the standard series of sieves identified in 6.1.2 of Test Method sample shall be 360 kg [800 lb] D4749 covering from within the actual topsize of the coal down to 6.3 mm (1⁄4 in.) Other sieve sizes may be used 11.2 Laboratory Sample—The gross sample of coal shall be thoroughly mixed and subdivided, without crushing, into four 13 Calculation 90 kg [200 lb] portions This operation shall be done as quickly as possible to avoid loss of moisture, and the bulk density shall 13.1 Calculate the compacted bulk density, BDcomp, to the be determined immediately If this determination cannot be nearest 0.05 kg ⁄m3 [0.1 lb ⁄ft3] as follows: made immediately, the samples shall be kept in waterproof containers with tightly fitting covers until the time for making BDcomp,kg⁄m3@lb ⁄ ft3# 5 ~W4 2 W3!⁄V2 (2) the determination where: the mass of the empty measuring box, kg [lb]; 12 Procedure W3 = the mass of the filled measuring box after leveling as W4 = 12.1 Weigh the empty measuring box to the nearest 0.05 kg described in 12.3, kg [lb]; [0.1 lb] Place the previously weighed measuring box on the V2 = the measured volume of the measuring box as deter- mined by water calibration as described in 10.1, m3 4 Auvi, H S., Schmidt, L D., and Graham, H G., “Control of Bulk Densities in [ft3] Coke Ovens: Studies on Precision and Application of Various Testing Methods,” U S Bureau of Mines R.I 3935, 1946 6 D291/D291M − 20 14 Report [1.3 lb ⁄ft3] Otherwise, all results shall be discarded and the apparatus, procedure, and sample shall be examined for non- 14.1 Report the compacted bulk density, BDcomp, as calcu- compliance causes, which should be corrected before redeter- lated in Section 13 to the nearest 0.05 kg ⁄m3 [0.1 lb ⁄ft3] mining new pairs of values 15 Precision and Bias 15.2 Reproducibility—It is not possible to specify the pre- cision (reproducibility) of the procedure in Test Method 15.1 Repeatability: D291/D291M for measuring the compacted bulk density be- 15.1.1 Duplicate results by the same operator in a given cause of the impracticality of obtaining, transporting, and laboratory on consecutive tests determined within a minimum handling representative splits of the materials in the quantities interval of time shall be considered suspect if they differ by that would be needed to establish the precision statement more than 16 kg ⁄m3 [1.0 lb ⁄ft3] 15.1.2 When two results are obtained that differ by more 15.3 Bias—No information can be presented on the bias of than this value, two additional tests shall be made If the second the procedure in Test Method D291/D291M for measuring the pair of results differs by less than the repeatability, the first pair compacted bulk density because the method is empirical and shall be discarded and the mean of the second pair shall be no material having an accepted reference value is available reported as the result of the test 15.1.3 When both pairs of results exceed the repeatability, 16 Keywords the mean of the four results shall be reported, provided that the two most divergent results differ by less than 21 kg ⁄m3 16.1 compacted bulk density; crushed coal; uncompacted bulk density ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of 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 and if not revised, either reapproved or withdrawn Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org) Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http://www.copyright.com/ 7