Sodium Metasilicate for Ceramic Slurry & Casting Bodies
Ceramic plants use sodium metasilicate in tile-body, casting and glaze slurry where controlled alkalinity and electrolyte behaviour support slip stability, including the ball mill and the slip that is spray-dried on a tile line. Grade selection follows water content, dosing method and iron level — not a generic ceramics catalogue name.
Updated
Short answer
Ceramic plants use sodium metasilicate in body and glaze slurry for controlled alkalinity and electrolyte behaviour. For ceramic tiles, the same addition supports slurry deflocculation in the ball mill and in the slip that is spray-dried. The grade depends on crystal water, dosing method and iron level: pentahydrate is the usual starting point for wet trials, anhydrous where crystal water must stay low, and granules where dust and hopper flow matter at the charging point. Anhydrous sodium metasilicate, granular and powder, is specified at Na₂O 50.0–51.5% and SiO₂ 45.0–48.0%. Pentahydrate, granular and powder, is specified at Na₂O 28–30% and SiO₂ 28–30%. Zhongzhi Chemical supplies anhydrous, pentahydrate and granule grades from Changyi, Shandong. Buyer documents are the approved documents on Downloads: TDS, SDS, stamped COA samples, certificates and UN3253 hazmat files.
Identity & supply
Zhongzhi Chemical sodium metasilicate. Grade is optional on the RFQ.
- Product
- Sodium metasilicate
- Manufacturer
- Zhongzhi Chemical
- Anhydrous CAS
- 6834-92-0
- Pentahydrate CAS
- 10213-79-3
- Transport (typical SDS)
- UN3253, Class 8, PG III — verify current SDS
- HS
- 2839.11 (CN 28391100 series)
- Forms
- Anhydrous granular, anhydrous powder, pentahydrate granular, pentahydrate powder
- Packing
- 25 kg PP woven bags with PE liner; 1,000 kg FIBC
- Export port
- Qingdao — FOB on a full container
Na₂O and SiO₂ on the current TDS
Specification rows from the current sodium metasilicate TDS. Anhydrous granules and powder share these Na₂O and SiO₂ bands. Pentahydrate granules and powder share the other band. Iron and water-insoluble matter stay typical values on those sheets and are not repeated here.
Anhydrous granular
- Sodium oxide (Na₂O)
- 50.0–51.5%
- Silicon dioxide (SiO₂)
- 45.0–48.0%
Anhydrous powder
- Sodium oxide (Na₂O)
- 50.0–51.5%
- Silicon dioxide (SiO₂)
- 45.0–48.0%
Pentahydrate granular
- Sodium oxide (Na₂O)
- 28–30%
- Silicon dioxide (SiO₂)
- 28–30%
Pentahydrate powder
- Sodium oxide (Na₂O)
- 28–30%
- Silicon dioxide (SiO₂)
- 28–30%
Particle size
Particle size is a separate specification on each TDS. Anhydrous granular is 250–1000 μm (60–18 mesh) ≥95.0%. Anhydrous powder is passing 425 μm (40 mesh) ≥90.0% and passing 250 μm (60 mesh) ≥90.0%. Pentahydrate granular is 250–1400 μm (60–14 mesh) ≥95.0%. Pentahydrate powder is passing 600 μm (30 mesh) ≥90.0% and passing 250 μm (60 mesh) ≥15.0%. Granules pass the coarse sieve and are retained on the fine sieve. Test sieves: ISO 3310-1:2016.
Typical starting points
Trial starts about 0.2–0.5% on dry body solids. A plant trial is required; clay and slip systems vary.
This range is illustrative, not a performance guarantee. Confirm the addition in the customer slip and ball mill before any scale-up.
Dosing is usually with wet milling or slip make-up: after the water, and before or with electrolytes per the plant SOP. Keep the solid sealed and dry, and avoid acid contact.
| Form | CAS | Typical role |
|---|---|---|
| Pentahydrate | 10213-79-3 | Usual wet-trial starting form |
| Anhydrous | 6834-92-0 | When crystal water must stay low |
| Granular | Same grade family (6834-92-0) | Lower dust / hopper flow |
Iron and water-insoluble matter are typical values on the product TDS, not specifications. The batch COA reports the specification rows.
The RFQ stays on this site for ceramic-grade sodium metasilicate. Grade is optional.
Body and clay slip
In a ceramic body or clay slip, sodium metasilicate is the electrolyte that holds alkalinity in a working band. Pentahydrate is the usual starting form for a wet trial. Anhydrous is the alternative where crystal water must stay low. Granules are the alternative where dust and hopper flow matter at the charging point.
The trial addition for a body or clay slip is about 0.2–0.5% on dry body solids.
The Latin America ceramic plant scenario is an anonymized example of a ceramic works scoping pentahydrate for a body or glaze slurry trial. Yield and shade stay with that plant’s own trial.
Tile body: ball milling and spray drying
Sodium metasilicate for ceramic tiles is the electrolyte in the body slip. In the ball mill it raises alkalinity and deflocculates the clay fraction so the slurry stays fluid enough to grind and to pump. It supports the deflocculant package the plant already qualifies. It is not a tile glaze colour, and it is not a substitute recipe for that package.
After milling, the same slip is screened and spray-dried into press granules. Deflocculation is what keeps the slip pumpable into the dryer at the solids the body recipe already runs. A slip that is too thick or too thin changes how the granules form. That check stays on the plant trial.
A tile-body trial typically starts at about 0.2–0.5% on dry body solids. The mill and the spray dryer confirm their own addition. Pentahydrate is the usual wet-mill form. Anhydrous is the alternative where crystal water must stay low. Granules are the alternative where dust and hopper flow matter at the mill charge. Iron is read from the grade COA, because specking on a fired tile is a reject the plant defines.
Sanitaryware slip casting
On a sanitaryware casting line, sodium metasilicate supports deflocculation beside the plant’s own deflocculant system. The plant qualifies that package.
Casting yield, green strength and scrap rate are plant-trial results. The 0.2–0.5% dry-body-solids figure is the body-slip trial start, and the casting line confirms its own addition in a plant trial.
Glaze slip
In a glaze slip, sodium metasilicate is an alkalinity aid where a silicate electrolyte is already in the recipe. Iron is taken from the grade specification and the batch COA, not from a ceramics label, because shade and specking are reject causes the plant defines.
Form follows the same rule as the body: pentahydrate for many wet trials, anhydrous where crystal water must stay low, granules where dust and hopper flow dominate at charging.
Benefits for This Industry
- Three physical forms — pentahydrate, anhydrous and granules — quoted against the same RFQ
- Iron and water-insoluble matter controlled by grade, reported on the batch COA
- Export packing in 25 kg bags and FIBC jumbo bags, confirmed before quotation
- Grade optional — send application, monthly quantity, packing, destination port and buyer type with the quotation request
How Our Sodium Metasilicate Supports This Application
| Formulation need | Product feature | Value to your line |
|---|---|---|
| Stable slurry alkalinity | Na₂O 50.0–51.5% and SiO₂ 45.0–48.0% (anhydrous); Na₂O 28–30% and SiO₂ 28–30% (pentahydrate) | Electrolyte level can be matched to the hydrate and form you dose |
| Low discoloration in body or glaze | Iron limited by grade specification | Fe is controlled on the grade COA rather than assumed from a ceramics label |
| Flexible dosing at the mill or tank | Pentahydrate, anhydrous and granule forms | Form follows water content, dissolution and dust — not a single powder SKU |
| A tile-body slip that stays fluid in the ball mill and into the spray dryer | Alkaline electrolyte for slurry deflocculation | The mill and the dryer keep the solids the body recipe already runs; the plant trial sets the addition |
| Buyer audit of incoming lots | Approved documents on Downloads | TDS, SDS, stamped COA samples, certificates and UN3253 hazmat files on Downloads; shipment COA is issued per lot. |
What We Need to Confirm Before Recommending a Grade
Grade selection for this application depends on your process, not on a catalogue number. Send these conditions with your enquiry and the recommendation comes back with the reasoning attached.
- Body vs glaze
- Whether the addition is for a body slurry, a casting slip, a glaze, or more than one stage.
- Target pH / package
- The working pH or alkalinity band, and whether metasilicate is the primary electrolyte or a support salt.
- Iron limit
- Your incoming Fe limit and whether shade or specking is a reject cause on the fired ware.
- Addition point
- Where it is charged — mill, make-up tank, or dry blend — which decides hydrate and granule vs powder.
- Monthly quantity and packing
- Expected monthly MT, and 25 kg bags or FIBC for plant handling.
- Destination port
- Discharge port so packing, loading and freight basis can be checked before price.
Scope and limits
Performance in your formulation is established by your own trial. These are the limits we hold to.
- We do not warrant casting yield, green strength, fired shade or scrap rate — those are plant-trial results.
- This is not a full deflocculant-system design. Sodium metasilicate may support electrolyte behaviour; the deflocculant package remains yours to qualify.
- Downloads has the approved documents. Stamped COAs are typical samples — shipment COA is issued per lot. A sample lot number is an example. The lot number on your shipment is the one on that shipment’s COA.
Start with pentahydrate for many wet body and glaze trials. Choose anhydrous where crystal water must stay low. Choose granules where dust and hopper flow dominate at the charging point. Grade optional — send application, quantity, packing and port. We reply to the RFQ within 12 hours.
Confirm application, monthly quantity, packing, destination port and buyer type on the RFQ form.
Ready to RFQ for this application
A quotation needs application, monthly quantity (MT), packing, destination port and buyer type. Grade is optional. Send those with the RFQ and we reply within 12 hours.
- Grade
- Monthly quantity (MT)
- Packing
- Destination port
- Documents needed
FAQ
Is every silicate in a ceramic slip sodium metasilicate?
No. Sodium metasilicate is the solid alkaline salt supplied as anhydrous, pentahydrate or granules, used here for slurry alkalinity and electrolyte control. Instant sodium silicate powder is the higher-modulus solid silicate (LGS-20 or LGS-30). Name the grade the slip trial uses so the quotation matches the recipe.
Can we sample before a bulk ceramic order?
Yes. Send the intended grade, monthly volume, packing and destination with the RFQ. A laboratory sample can be arranged before the first commercial shipment so the slip trial is done on the same hydrate you intend to buy.
Which grade should a ceramic plant trial first?
Pentahydrate is the usual starting point for wet body or glaze make-up. Anhydrous is used where crystal water must stay low. Granules are chosen when dust and hopper flow matter at the charging point. We do not pick a grade from the word “ceramics” alone — body vs glaze, iron limit and addition point decide it.
Can it be combined with STPP or my current deflocculant?
A blend with STPP, or with the deflocculant you already run, is possible in practice. It is not a fixed recipe. On a tile body it can sit beside that deflocculant. Confirm the blend on your own slip — clay, mill time and, for tiles, the slip that goes to the spray dryer — before you scale it.
Where does sodium metasilicate for ceramic tiles sit in the body line?
In the body slip. It is charged with the ball-mill electrolytes so the clay stays deflocculated, and the same slip has to stay pumpable into the spray dryer. Pentahydrate is the usual wet-mill form. Anhydrous is the form where crystal water must stay low. Granules are the form where dust and hopper flow matter at the mill charge. The plant confirms the addition on its own clay, mill and dryer.
Which documents and packing come with a tile-plant order?
TDS, SDS and a shipment COA for the grade ordered. Anhydrous is CAS 6834-92-0. Pentahydrate is CAS 10213-79-3. Transport on the typical SDS is UN3253, Class 8, PG III — verify the current SDS. Packing is a 25 kg bag with a liner, or a 1,000 kg FIBC. Full containers are quoted FOB Qingdao. Zhongzhi Chemical is the manufacturer.