Overview
ISO/TS 20362:2022 specifies a standardized method for determining plastometric indices of hard coal using an automated Sapozhnikov penetration plastometer. The standard defines two primary plastometric outputs: Y (maximum thickness of the plastic layer, in mm) and X (final contraction or plastometric shrinkage, in mm, defined as the height difference between 250 °C and 730 °C). ISO/TS 20362:2022 applies to hard coals with a determined ash content of less than 15 % (dry basis), referenced to ISO 11722 and ISO 1171.
Key Topics and Requirements
- Principle: Unidirectional heating from the base under constant pressure while an automated probe records displacement. Displacement curves are generated and processed by computer software using curve‑fitting (least squares) to extract upper/lower plastic layer profiles.
- Measured indices:
- Y - maximum perpendicular thickness between upper and lower plastic layers.
- X - plastometric contraction between sample height at 250 °C (zero line) and at 730 °C.
- Materials & consumables: cigarette rolling paper, filter paper, thin steel rod, refractory ceramic pads, abrasive cloth (e.g., Emery P80).
- Apparatus: full automated Sapozhnikov plastometer system (determinator + computer), electric furnace, thermocouples and wells, pressure lever assembly, displacement sensors, weighing device, sample preparation equipment (crusher, sieves).
- Procedure essentials: sample preparation, loading in steel retort with paper tube and pads, furnace temperature calibration, displacement calibration, automated measurement, and computerised analysis.
- Quality & reporting: calibration steps, determination of zero height, expression of results, and precision statements including repeatability and reproducibility limits are covered. Test report content is specified.
Applications and Users
ISO/TS 20362:2022 is intended for laboratories and organizations involved in coal testing and quality control, including:
- Coking coal testing labs assessing plastic properties for coke-making.
- Coal producers and traders specifying product quality and suitability for metallurgical use.
- Research institutes studying coal thermo-plastic behaviour.
- Industrial quality control in steel and coke plants where plastometric indices influence process performance.
Practical benefits include improved automation vs manual Sapozhnikov methods, reduced operator bias, consistent displacement curves, and automatic reporting - enhancing throughput and comparability of plastometric data.
Related Standards
Keywords: ISO/TS 20362:2022, plastometric indices, automated Sapozhnikov penetration plastometer, hard coal testing, Y and X indices, coal plastometry.