ISO 10329:2025

Overview

ISO 10329:2025 - Hard coal - Determination of plastic properties - Constant-torque Gieseler plastometer method defines a laboratory procedure to obtain a relative measure of the plastic behaviour (fluidity) of hard coal when heated under prescribed conditions. The method uses a constant-torque Gieseler plastometer to record stirrer rotation (expressed as dd/min) against temperature and yields characteristic plasticity parameters used in carbonization and quality control of coals and blends.

Key topics and technical requirements

• Scope and purpose: Empirical test for relative plastic behaviour of hard coal; applicable to coals and blends important for carbonization.
• Apparatus: Detailed Gieseler plastometer retort design (e.g., crucible internal diameter 21.4 ± 0.1 mm, depth 35.0 ± 0.3 mm), steel stirrer geometry, plastometer head with constant torque drive and 100-division dial (or equivalent electronic readout).
• Constant torque: Brake/clutch adjusted to (101.6 ± 5.0) g·cm (note calibration requirement).
• Heating and bath: Electric furnace with molten solder bath, controlled heating rate (3.0 ± 0.1 °C/min) over ~300 °C to 550 °C; thermocouple placement specified.
• Sample preparation: Representative sampling per ISO 18283 / ISO 13909 series; laboratory sample crushed to pass 4.75 mm, subsampled and reduced to pass 425 µm; final test charge = 5.0 g. Drying limited (≤40 °C) and testing within 8 hours to limit oxidation effects.
• Calibration and quality assurance: Torque checked by string-and-pulley method (or validated transducer). Regular dimension checks on stirrer rabble arms and equipment maintenance emphasized.
• Measured results / terms: dd/min, initial softening temperature, maximum fluidity temperature, maximum fluidity, plastic range, solidification temperature, final fluidity temperature.
• Precision: Method includes sections on repeatability and reproducibility (laboratory comparison required for specific limits).

Practical applications

• Quality control in coke and carbonization plants to assess coal cokeability and blend performance.
• Coal testing and certification laboratories measuring coal fluidity for process optimization.
• Research and development on coal beneficiation, blend formulation, and thermal behaviour.
• Regulatory and procurement specifications where plastic properties influence downstream processing.

Who should use ISO 10329:2025

• Coal and coke producers, carbonization engineers, laboratory managers, QA/QC teams, research institutes, and standards bodies involved in coal testing and material characterization.

Related standards

• ISO 18283 (Manual sampling)
• ISO 13909 series (Coal and coke - Mechanical sampling) These referenced standards govern sampling and sample preparation practices required by ISO 10329:2025.

Keywords: ISO 10329:2025, Gieseler plastometer, hard coal, plastic properties, coal fluidity, constant-torque plastometer, coal testing, carbonization.