AS 1038.25:2002 pdf free download.Coal and coke—Analysis and testing Part 25: Coal—Durham cone handleability test.
8 PROCEDURE
8.1 Sample preparation
The procedure shall be as follows:
(a) Subdivide the sample by either incremental sampling or fractional shovelling as described in AS 4264. 1. This operation shall be performed rapidly to minimize loss of moisture.
NOTE: Separate subsampies are extracted for total moisture and size analysis.
(b) Rapidly screen the coal sample at 37.5 mm and discard any oversize fraction. Sieving procedures are given in AS 3881.
8.2 Testing
The procedure shall be as follows:
(a) Record the weight of the —37.5 mm sample (in) using the weighing device (6.5) to the nearest 0.001 kg.
(b) Transfer the sample into the Durham cone (6.1).
(c) Vibrate the sample for 10 s. then open the trap door. Record the time required for the sample to pass through the cone in seconds (tf), using the stop watch (6.6).
Continue vibration until the entire test sample has passed through the cone.
(d) Transfer the sample onto the tray (6.2) and rapidly but thoroughly mix with the mixing scoop (6.3), taking care to minimize coal breakage.
(e) Transfer the sample back into the cone with the mixing scoop (6.3) and repeat Steps (c) to (e) at least twice, to obtain a minimum of 3 readings. After 3 test runs, i1 the range between the lowest and highest Specific Flow Time results differ by more than 5%, repeat Steps (c) to (e) two more times and discard the lowest and highest value from the set.
(f) Concurrently to the testing performed on the Durham cone apparatus. the total moisture of the test sample shall be determined in accordance with AS 1038.1.
NOTE: For product coal the difference in total moisture between the entire sample and the —37.5 mm size fraction used for the determination of specific how time, is generally not
significant. In some cases, a comparison of total moisture in the product coal and that in the —37.5 mm fraction may be of interest.AS 1038.25 pdf download.