FOB Unit Price Is Not the Effective Use Cost of Sodium Metasilicate

Short answer

Rank sodium metasilicate offers on effective use cost, not on the FOB unit price alone. The unit price buys a physical tonne. The formula consumes active alkali and silicate. Water of crystallization and the freight paid on that water sit between the two.

Nothing in this article is a price. Zhongzhi Chemical does not publish a price list. Any index below is marked illustrative.

Three different tonnes

Importers usually receive a single number: FOB Qingdao per metric ton. That number is real only for the physical goods on the invoice. Three different “tonnes” get mixed together in the same spreadsheet.

The physical tonne is what you pay the supplier for and what the carrier weighs. The active tonne is the Na₂O and SiO₂ the formula doses. The freight tonne is the physical weight ocean freight is charged on, including crystal water.

On Zhongzhi Chemical’s published specification, anhydrous powder is Na₂O ≥49.5% and SiO₂ ≥44.5%. Pentahydrate on the Standard tier is Na₂O ≥28.5% and SiO₂ ≥27.5% as shipped, because about 42% of its mass is water of crystallization (about 42.5% by the theoretical hydrate: 90.08 of 212.14 g/mol). Dividing through shows the same chemistry on a water-free basis. The published teaching check is that roughly 1.74 tonnes of pentahydrate carry the active content of one tonne of anhydrous. That 1.74 is arithmetic from the published specification. It is not a quotation.

An illustrative index, not a quote

Use the offers you actually hold. The table only shows the arithmetic, with made-up indexes so no real price appears here.

What the index still leaves out

Row 3 is not a landed cost. Ocean freight, duty and destination handling are paid on physical tonnes, so the hydrate’s extra mass can widen the gap after the goods leave Qingdao. Palletizing changes how many tonnes share one container’s freight; the published planning range is about 22–27 MT in a 20-foot container depending on packing. Those effects are why two FOB numbers with no packing line cannot be ranked.

The plant’s own dose still matters. A formula built and qualified on one hydrate does not switch on the index alone: dissolution, heat of solution and feeder behaviour are trial results. This page does not estimate a formula saving and does not recommend a form.

When you are ready, send one basis — application, quantity, packing, destination port, buyer type. Grade is optional. The quotation will name that basis. It will not be a number copied from this table.

FAQ