ISO 10329:2017

Overview

ISO 10329:2017 specifies the constant-torque Gieseler plastometer method for obtaining a relative measure of the plastic behaviour (plasticity) of coal when heated under defined conditions. The test produces fluidity and temperature parameters (e.g., initial softening temperature, maximum fluidity, solidification temperature) that are important for carbonization, coke production and any process where coal plastic properties affect performance. The method is empirical and requires careful equipment calibration and sample handling to give reliable fluidity results.

Key topics and technical requirements

• Apparatus and dimensions: Detailed specifications for the Gieseler plastometer retort, crucible, stirrer (rabble arm dimensions), barrel and plastometer head are specified to ensure consistent results.
• Constant torque setting: Torque is set to 101,6 g·cm (± 5,1) and verified using the prescribed string-and-pulley calibration or an alternative validated torque transducer.
• Heating and bath: Electric furnace with a molten solder bath (approx. 50% lead / 50% tin) and controlled heating rate (3,0 ± 0,1) °C/min over ~300–550 °C. Thermocouple placement and bath agitation are required to ensure accurate temperature measurement.
• Sample preparation: Representative sampling (per ISO 18283 and ISO 13909 series), ~4 kg coarse sample reduced to laboratory subsample, final test material to pass a 425 µm sieve, test charge 5.0 g, packed under a 10 kg loading device (9 kg static + 1 kg drop weight).
• Procedure and measurements: Stirrer rotation recorded in dial divisions per minute (dd/min) to determine initial softening temperature, maximum fluidity, plastic range and solidification temperature.
• Maintenance and precision: Regular checks on stirrer geometry, bearings, calibration frequency and documented repeatability/reproducibility statistics are part of the standard’s quality expectations.

Practical applications

• Assessment of coals and blends for coke manufacture and blast-furnace feedstock.
• Quality control for coal carbonization, metallurgical processes and research into coal plasticity.
• Screening of feedstocks for briquetting, coal blending and any thermal process where softening and flow behavior influence product quality.

Who uses this standard

• Coal testing laboratories and research institutions
• Coke and metallurgical producers assessing blend performance
• Quality control and process engineers in carbonization plants
• Standards bodies and instrument manufacturers producing Gieseler plastometers

Related standards

• ISO 18283 - Hard coal and coke - Manual sampling
• ISO 13909-1, -2, -3 - Hard coal and coke - Mechanical sampling (sampling guidance referenced by ISO 10329)

Keywords: ISO 10329, Gieseler plastometer, coal plastic properties, constant-torque, coal fluidity, initial softening temperature, maximum fluidity, coal carbonization, plastometer calibration.