Overview
ISO 1017:2006 specifies a laboratory method for determining the mass fraction of acetone‑soluble material (termed “resinous substance”) in the benzene‑soluble extract obtained from brown coals and lignites. The method defines sample preparation, extraction conditions, drying and calculation rules so results are comparable between laboratories. Note: the acetone extract can also dissolve some waxes in addition to the resinous fraction.
Key topics and technical requirements
- Scope: Quantifies acetone‑soluble material in the benzene‑soluble fraction of brown coal/lignite extracts (reference to ISO 975 for obtaining the benzene extract).
- Reagents & safety: Uses analytical‑grade acetone (flammable - follow appropriate laboratory safety and ventilation).
- Apparatus: Centrifuge (capable of ~1 600 r/min), 15 ml glass centrifuge vessels with stoppers, 20 mm × 50 mm evaporating dish, vacuum drying oven (80 ± 2 °C at ≈50 kPa), air oven (100–110 °C), infrared lamp, and a 100 µm wire‑cloth sieve.
- Sample prep: Benzene‑soluble extract residue must pass a 100 µm sieve; viscous residues are cooled (solid CO2 to −80 °C) and crushed.
- Controlled extraction: Extract with acetone at 18–22 °C. Solvent and room temperatures at the start and end of the test must be within 0.5 °C of each other to ensure selectivity. Typical test: ~0.5 g sample, 7 ml acetone, shake 2 min; repeat (up to 4 times) until extract is colourless; decant/centrifuge/filter into evaporating dish.
- Drying & weighing: Evaporate acetone (vacuum oven or IR lamp), then dry to constant mass (air oven at 105 ± 3 °C) and weigh residue.
- Calculation: The mass fraction is calculated from the mass of acetone‑soluble residue and the mass of benzene‑soluble extract taken, using the temperature correction factor K as specified in the Standard.
- Precision: Repeatability and reproducibility limits are provided (e.g., for mass fraction