SIST ISO 12900:2020 PDF

Overview

ISO 12900:2018 - Hard coal - Determination of abrasiveness - defines a laboratory method to quantify the abrasiveness of hard coal. The standard measures metal loss from four standardized steel blades rotated in a prepared coal charge under controlled conditions, producing a reproducible abrasiveness index expressed in milligrams of metal lost per kilogram of coal. The method is intended for ranking coals and providing initial empirical estimates of wear in various coal-handling and pulverizing systems.

Key topics and requirements

• Test principle: abrasion is determined from the mass loss of four steel blades after a defined number of revolutions with a 2 kg test portion of coal.
• Apparatus and components:
  • Standard reference blades with Vickers hardness 160 ± 15 (ISO 6507-1 referenced).
  • Mill mortar and removable quadrant assembly, with specified clearances and dimensions.
  • Drive system with controlled speed and automatic cut-off (test run to 12 000 revolutions at the prescribed quadrant speed).
  • Precision balances for blade (0.1 mg) and test portion weighing.
• Sample preparation:
  • Nominal top size: 6.7 mm (minus 6.7 mm fraction used).
  • Fines content: not more than 30 %