Overview
ISO 10086-2:2004 - "Coal - Methods for evaluating flocculants for use in coal preparation - Part 2" defines a laboratory method for the comparative evaluation of flocculants as filter aids in rotary vacuum filtration systems. The standard specifies how to prepare flocculant solutions, dose a representative coal slurry, run a bench-scale rotary vacuum filter-leaf test and quantify performance using cake yield, cake moisture and filtrate clarity. It is intended to simulate plant rotary vacuum filter conditions for meaningful comparison of flocculant performance.
Key topics and requirements
- Principle: Performance is assessed by adding flocculant to a slurry aliquot, forming a cake on a filter leaf, and measuring wet and dry cake mass to derive yield and moisture.
- Apparatus: ordinary lab equipment plus vacuum pump/gauge, Buchner flask, filter-leaf assembly, vacuum tubing, motorized stirrers and syringes.
- Materials & sampling: slurry and water collection and sub-sampling follow ISO 10086-1 procedures.
- Flocculant preparation: powder or liquid flocculants prepared per ISO 10086-1.
- Test procedure:
- Homogenize 500 ml subsample, dose flocculant, record conditioning time.
- Recommended default times (if plant times unknown): immersion 1 min 10 s, drying 2 min.
- Measure cake thickness (three points), weigh wet cake, dry at 105 °C to constant mass for dry cake.
- Evaluate filtrate clarity visually or by turbidity instrument.
- Dosage calculation: method and worked example provided; dosage expressed as g flocculant per kg dry solids (or kg/tonne).
- Repeatability: duplicate tests should agree within ±1.0% cake moisture and ±1 mm cake thickness.
- Reporting: test date, flocculant description, slurry details, cake yield, filtrate clarity, cake moisture, dosage and vacuum parameters, filter cloth, stirring, immersion and drying times. Annexes include a worked example and data recording sheet.
Practical applications and users
ISO 10086-2:2004 is used for:
- Comparing flocculant performance for coal preparation and dewatering trials.
- Selecting filter aid chemistries for rotary vacuum drum and disc filters.
- Optimizing dosage rates to meet cake dryness and filtrate clarity targets.
- Supporting procurement, quality assurance and R&D on flocculants and filtration equipment.
Typical users:
- Coal process engineers and plant operators
- Laboratory technicians and analytical chemists
- Flocculant suppliers and formulators
- Filtration equipment manufacturers
- Process optimization and environmental compliance teams
Related standards
- ISO 10086-1:2000 - Coal - Methods for evaluating flocculants - Part 1: Basic parameters (referenced for sampling, water and flocculant solution preparation, and filtrate clarity evaluation).
