Identify the stream within the coal circuit
A coal-washing plant can have different polymer requirements for clarification, thickening and dewatering. Name the point of use, feed source and required result. State whether the trial treats dilute wash water, thickener feed or solids entering filtration. One industry label cannot define all three duties.
Anionic polyacrylamide flocculant is a common candidate for mineral fines, but clay and recycled-water chemistry can change its response. Provide solids, pH and particle information along with other reagents. Describe variation between coal sources instead of assuming the easiest sample represents normal operation.
Compare clarification and solids behaviour together
Measure overflow quality at a defined observation time. Inspect the settled bed and the solids that must be pumped or filtered. Fast settlement may leave a loose bed, while compaction may come with slower water release. Specify the combination the circuit needs before choosing a winner.
Keep actual process water in the comparison. A test in clean water may rank candidates differently from a circuit with accumulated salts or reagents. The controlled sample method preserves the dose, mixing and sampling basis while the product range is screened.
Account for feedwell and transfer conditions
Describe available dilution, injection and contact conditions. A thickener feedwell and downstream filter impose different stresses from a settling cylinder. Take promising candidates into a stable plant comparison and record flow, solids, water quality and underflow behaviour together.
When slurry changes suddenly, review coal source, loading, withdrawal and preparation before increasing polymer indefinitely. Base the quotation on a grade that works across the agreed range. An unusually favourable feed producing spectacular floc cannot establish reliable routine consumption.
Request a coded anionic sample proposal
Send the baseline material and limitation to the Xinqi mineral-process polymer team. Request identified candidates and instructions for each. An unexplained high molecular-weight value cannot establish which product will improve the coal circuit.
The anionic PAM reference and local anionic product page support the discussion. Link the supplier proposal to the trial code so purchasing can identify the intended material after technical acceptance.
Forecast supply from accepted plant consumption
Use measured consumption, operating hours and expected feed variability to estimate demand. Include packaging, unloading constraints and destination in the RFQ. Ask the supplier to confirm availability and order-specific timing rather than assigning a generic delivery promise.
The receiving and quality requirements should preserve the accepted grade and lot identity. State how coal-source or water-condition changes will be reported to operators. Product approval follows circuit performance; a low price per bag does not compensate for unsuitable overflow or difficult downstream solids.
Check a new coal source before repeating the order
Suppose a grade works well on the usual feed but clarity deteriorates after the coal source changes. Collect the changed fines and recycled water, record loading and withdrawal, and repeat a short reference comparison. A higher consumption forecast should remain provisional until the plant understands whether the grade, preparation or circuit condition changed.
Send the changed-feed evidence with the repeat-order discussion. Ask whether the accepted grade can cover the new range or whether another candidate needs testing. Keep the two duties or feed sources identifiable in the purchasing record if their requirements differ; combining them into a single generic coal-washing consumption figure may conceal the need for separate approval.
| Review point | Evidence to retain |
|---|---|
| Water | Actual recycled-water condition |
| Solids | Coal fines and clay variability |
| Circuit | Overflow and underflow remain manageable |