Establish technical equivalence first
Two quotations for anionic or cationic PAM may describe materially different grades. Check the proposed code, form, specification and preparation requirements. Where samples have not been qualified, describe price comparisons as provisional rather than treating the products as proven substitutes.
Do not assume a higher reported molecular weight or charge value means better performance. The relevant question is whether the material achieves the agreed separation result under realistic operating conditions.
Normalize consumption without double counting
For a commercial-product dose, multiply kilograms consumed per treatment unit by delivered cost per kilogram. If dose is stated as active polymer, divide active dose by the documented active mass fraction before multiplying by commercial-product price. Do not divide again when the measured dose already represents commercial product.
Illustrative arithmetic: 2 kg of active polymer per tonne of dry solids at a 0.40 active mass fraction corresponds to 5 kg of commercial product. This is a calculation example, not a recommended dose, product specification or price. Liquid volume also requires density for a mass conversion.
Keep the operating result in the comparison
A lower polymer line item can be offset by poorer capture, greater sludge volume or constrained throughput. Record relevant downstream effects, but do not assign invented savings to unmeasured outcomes. Preparation water, energy, labor and waste handling may also matter.
Use a common observation period and stable feed where possible. Report uncertainty if one candidate was tested under significantly different conditions. A precise spreadsheet does not repair an inconsistent trial.
Align the commercial terms
Confirm quantity, currency, packaging, named delivery place, included freight or handling and quotation validity. Identify destination-side costs and tax treatment with the appropriate logistics or finance team. Do not compare an ex-factory figure with a delivered figure as though they include the same obligations.
Connect the selected offer to export order planning and the grade document set. Keep the approved specification attached to the order so a price agreement does not obscure a product change.