Price per tonne is the easiest thing to compare between suppliers and, on its own, the least reliable way to choose one. The real cost of a reagent supply relationship shows up in consistency of purity, reliability of lead times, and how a supplier responds when something needs to change on short notice — none of which appear on a price sheet.
A direct question worth asking any supplier: do you manufacture this reagent, or are you reselling it? A manufacturer that produces its own material — as GGI Chemicals does with lead oxide at our own facility in Hebei — controls its own quality and supply chain. A trading company reselling third-party product is one extra link away from that control, which can matter when something goes wrong upstream.
Ask how long the supplier has operated in the specific product category you need, not just as a general chemical trading business. Mining reagents — flotation collectors, assay flux, leaching reagents — have narrow technical specifications that matter to your process; general industrial chemical experience does not automatically transfer.
Ask about consistency across shipments, not just the specification on paper. A single certificate of analysis tells you about one batch; what matters for a production operation is whether shipment 40 matches shipment 4 as closely as shipment 2 matched shipment 1.
Finally, ask how the supplier communicates when there is a problem — a delayed shipment, a specification question, a change in your order. Eighteen years of supplying mining and metallurgical operations has taught us that the suppliers operations keep working with are the ones who pick up the phone when something needs to be fixed, not just when there is an order to close.