Overview
ISO 10086-1:2019 - "Coal - Methods for evaluating flocculants for use in coal preparation - Part 1: Basic parameters" defines a laboratory method for the comparative evaluation of flocculants used in coal preparation. The standard specifies how to test flocculant performance on a given slurry by measuring initial settling velocity, sediment volume after compaction/consolidation, and clarity of the supernatant liquid. This second edition (2019) is a minor revision of the original 2000 edition and is intended for use by laboratories and process engineers in coal preparation plants.
Key topics and technical requirements
- Scope and principle
- Comparative evaluation of flocculants for clarification, thickening and sedimentation.
- Performance determined from relative settling rates and supernatant clarity.
- Sampling and materials
- Slurry sampling: at least 10 increments over ≥2 hours to yield ≥50 L; store at 20 °C ± 2 °C and use within 24 h.
- Determine solids concentration (drying at 105 °C), particle size and ash content per referenced methods.
- Apparatus
- Typical lab equipment: variable-speed stirrers, 500 ml graduated cylinders (plastic or glass), syringes, timer and a clarity wedge.
- Flocculant preparation
- Procedures for powder and liquid flocculants, preparation of stock solutions and recommended storage/use windows (use within 24 h).
- Test procedures
- Preparation and homogenization of test subsamples (500 ml).
- Addition of flocculant, mixing (avoid overmixing), and measurement of settling:
- Free settling rate: time for interface to fall from 450 ml to 250 ml; convert to m/h.
- Full settling curve: monitor interface at each 25 ml subdivision to derive maximum average settling rate.
- After 30 minutes measure settled sediment volume and evaluate supernatant clarity with a clarity wedge.
- Calculations and reporting
- Flocculant concentration and dosage rate calculations, repeatability guidance and test report requirements are included.
Applications and users
- Who uses it:
- Coal preparation plant operators, process engineers, laboratory analysts, product development teams and suppliers of flocculants.
- Practical uses:
- Select and dose flocculants for improved clarification, thickening and tailings handling.
- Compare alternative polymers/emulsions/solids for sedimentation performance.
- Support process optimization, environmental control (clarity of discharged water) and product selection.
Related standards
- ISO 1171 - Solid mineral fuels - Determination of ash
- ISO 1953 - Hard coal - Size analysis by sieving
Keywords: ISO 10086-1:2019, flocculants, coal preparation, settling rate, sedimentation, clarification, thickening, slurry testing, flocculant evaluation.