Anhydrous or Pentahydrate: The Factory Counts Effective Solids Before It Quotes

Zhongzhi Chemical (Shandong Zhongzhi Chemical Technology Co., Ltd.) runs a multi-product silicate plant in Changyi. Sodium metasilicate — anhydrous, pentahydrate, and pentahydrate granules — is one product line beside liquid and solid sodium silicate, potassium silicate, lithium silicate, sodium orthosilicate, and a silicon-based flame retardant. This note is how the factory chooses between the anhydrous solid and the pentahydrate on that one line: count effective solids before anyone talks price.

Illustrative industrial scenario (composite): Rewritten from factory training for education. A detergent plant asked for the anhydrous grade because the team hoped a drier solid would lower formula cost. The recipe actually running was pentahydrate. No customer is named. No price is stated.

What the public FAQ already states

The FAQ on this site already separates the two forms. Those bands are the only Na₂O figures used below. This article does not add a new specification.

Illustrative arithmetic only: divide the anhydrous FAQ figure (51) by points inside the pentahydrate band (28.7 to 30). The result sits around 1.7–1.8. Read that as “a pentahydrate formula needs on the order of 1.7–1.8 kilograms to carry the Na₂O of 1 kilogram of anhydrous.” It is a teaching ratio on published FAQ bands. It is not a price, not a dose to copy onto a batch sheet, and not a new Zhongzhi specification. CAS identity stays separate: anhydrous 6834-92-0, pentahydrate 10213-79-3.

Why the anhydrous request was the wrong first move

In the composite, the buyer’s lab had qualified pentahydrate. Switching the purchase name to anhydrous without resetting the dose changes three things at once: alkali delivered per kilogram, water the crystal used to bring into the mixer, and how fast the solid dissolves. A lower invoice per tonne on the anhydrous name does not answer any of those. The factory’s job is to show the solids account, then let the buyer’s lab decide.

The plant reply in that composite had two honest paths:

1. Keep the validated pentahydrate and quote that form, mesh, and packing.
2. Trial anhydrous only after the lab rewrites the dose on effective solids. Size the trial to one container. The tonne count is whatever the current supply plan can confirm when you write — this page does not publish a trial tonnage or a capacity figure.

What Zhongzhi asks before a grade quote

• Which form the running formula uses today (anhydrous, pentahydrate, or granules)
• The Na₂O the formula actually needs, and whether mesh or dissolving speed is locked
• Application (detergent, industrial cleaning, or another use on the contact form)
• Packing and destination port
• Monthly quantity, answered against the current supply plan

Grade language under HG/T 2568-2021 still applies once the form is chosen. Modulus and batch COA are the next check — see spec sheet versus batch COA. A lot-specific COA ships with the order. Brochure typicals are not that COA.

Primary CTA (this site only): /contact

Zhongzhi Chemical · Changyi silicate factory · effective solids · /contact