Powder or Granular: What an Export Buyer Specifies for Sodium Metasilicate
Powder and granular sodium metasilicate differ in wet-out, dust at the port, and automatic dosing versus a small batch. The RFQ has to name the form.
Short answer
Choose powder or granular sodium metasilicate by how the plant uses it. A finer powder typically wets faster in an agitated tank and makes more dust when a bag is opened or split. A granular or beaded solid is the usual fit for automatic dosing, because it flows and drops as particles rather than as a dust cloud. A small batch charged by hand often specifies powder for that faster wet-out.
Write the form on the RFQ. Zhongzhi Chemical (Shandong Zhongzhi Chemical Technology Co., Ltd.) quotes the form you name. The notes below are the industry-typical difference between a fine solid and a coarser free-flowing solid. They do not describe a Zhongzhi Chemical granulation method.
Powder is not another word for anhydrous
Importers mix up two choices. Hydrate is anhydrous or pentahydrate: that is crystal water and the active content on the specification. Form is powder or granular: that is particle size and how the solid behaves in a hopper, a feeder, a tank, and a torn bag. Both hydrates are published as powder and as granular.
Published floors sit close, and they are separate lines. Anhydrous beaded granules are SiO₂ ≥ 45.0% and Na₂O ≥ 50.0%. Anhydrous powder is SiO₂ ≥ 44.5% (45.5 ± 1.0) and Na₂O ≥ 49.5% (50.5 ± 1.0), iron ≤ 0.010%. Pentahydrate on the Superior tier is Na₂O ≥ 28.7% and SiO₂ ≥ 27.8%, with iron ≤ 0.008% on the granular form and ≤ 0.010% on the powder. The active-content comparison between hydrates is a different note. This page is only the form.
What changes for an export buyer
The table is how plants and receiving warehouses usually talk about the two forms. It is industry-typical particle behaviour. It is not a measured dissolve time from Zhongzhi Chemical, and it is not a description of how a granule is made.
| What the plant is deciding | Powder | Granular or beaded |
|---|---|---|
| Wet-out in an agitated tank | More surface meets the water, so the solid typically wets faster. Confirm on a plant trial. | Slower and more even. The same trial is what confirms the make-up. |
| Dust at the bag dump, the hopper, and a split bag at the port | The usual complaint is airborne dust. Closed transfer or extraction is what the warehouse plans for. | The solid drops as particles. It is still alkaline. The SDS controls still apply. |
| Automatic dosing | A screw feeder or a loss-in-weight feeder can see bridging, flushing, or dust. | The usual export choice for a dry-blend line that meters the solid. |
| Small batch, charged by hand | Often the specified form, because wet-out is the reason for the finer particle. | Used when that buyer also runs an automatic line and wants one form in the warehouse. |
The mesh windows already on the specification
If your dosing equipment has a mesh window, write that window. If it does not, the quotation is checked against the published window for the grade. These are the windows on the specification of record.
| Published grade | Form | Particle-size window |
|---|---|---|
| Anhydrous, beaded granules, Superior and Standard | Granular | 18–60 mesh ≥ 93.0% |
| Anhydrous powder, single grade | Powder | Pass 60 mesh ≥ 90.0% |
| Pentahydrate, Superior | Granular | 14–60 mesh ≥ 80.0% |
| Pentahydrate, Superior | Powder | Pass 30 mesh ≥ 90.0% |
| Pentahydrate, Standard | Granular | 14–60 mesh ≥ 95.0% |
| Pentahydrate, Standard | Powder | Pass 30 mesh ≥ 90.0% |
The line the RFQ has to carry
Name powder or granular on the line you want priced. Beaded, on the anhydrous sheet, is the granular form. Add the hydrate when you know it. Add a mesh window when the feeder or the sieve requires one. Describe the dosing in one phrase: automatic dry-blend, or hand-charged small batch. That phrase is what makes an open choice decidable.
Quantity, packing, destination port, buyer type, and documents sit on the inquiry checklist. They are commercial facts. They do not replace the form. A single quotation is written for one form. If you need both, ask for two lines.
FAQ
Do I have to write powder or granular on a sodium metasilicate RFQ?
Is powder the same thing as anhydrous sodium metasilicate?
Does choosing powder or granular change the transport class?
Name the form on the RFQ
Write powder or granular, the hydrate if you have chosen one, and how the plant doses the material. Zhongzhi Chemical quotes the form you name. There is no public price list.
- Grade
- Monthly quantity (MT)
- Packing
- Destination port
- Documents needed
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