ISO 1018:2023

Overview

ISO 1018:2023 - Coal - Determination of moisture-holding capacity defines a reference method for measuring the moisture-holding capacity of coal. The document references ASTM D1412 and specifies the principle, sampling references and reporting format rather than repeating the full ASTM procedure. The standard clarifies that full moisture-holding capacity relates to coal in equilibrium with a saturated water-vapour atmosphere; practically, the determination is carried out at 96–97% relative humidity and 30 °C.

Key topics and technical requirements

• Referenced method: Uses ASTM D1412 (Equilibrium Moisture of Coal at 96–97% RH and 30 °C) as the test method to be followed for details of apparatus, conditioning and calculation.
• Sampling: Samples must be collected in accordance with the ISO sampling standards applicable to the situation (see Related standards).
• Sample conditioning:
  • Determination is performed on wetted and unwetted coal; wetted coal is prepared by immersion in water and removal of excess surface water.
  • Coal is brought to equilibrium over a saturated potassium sulfate solution (K2SO4) at 30 °C to obtain the target relative humidity.
  • Conditioning is carried out under reduced pressure to assist equilibration.
• Drying and reporting:
  • After conditioning, samples are dried to constant mass at 105 °C.
  • Moisture-holding capacity is reported as a percent mass fraction of the conditioned moist coal.
• Scope note: The 2023 third edition broadened the title and scope to explicitly cover coal in line with the referenced ASTM method.

Applications

• Correcting calorific value and energy content to a moist mineral matter-free basis for fuel evaluation and commercial transactions.
• Coal classification and rank assessment by laboratories and quality-control units.
• Comparative testing for fuel procurement, blending decisions and combustion performance modelling.
• Research into coal sorption behaviour and storage/transport moisture management.

Who uses this standard

• Analytical and commercial coal testing laboratories
• Power generation and utility fuel analysts
• Coal producers, traders and procurement teams
• Industrial users managing fuel quality, storage and handling
• Researchers studying coal moisture sorption and fuel properties

Related standards

• ASTM D1412 - Standard Test Method for Equilibrium Moisture of Coal at 96 to 97 Percent Relative Humidity and 30 °C (referenced for test details)
• ISO 13909 - Coal and coke - Mechanical sampling
• ISO 14180 - Coal - Guidance on the sampling of coal seams
• ISO 18283 - Coal and coke - Manual sampling

ISO 1018:2023 is a concise ISO reference that ensures consistency in reporting coal moisture-holding capacity by directing users to the established ASTM method and recognized ISO sampling practices.