About Standard Ceramic Grade Ball Clay
Standard ceramic grade ball clay is a general-purpose plastic clay for bodies that do not need a white-firing result. It offers moderate to good plasticity and dry strength, normal coarse residue, and a fired colour from cream to light buff. That balance makes it the practical choice for high-volume products where cost per tonne and consistent processing count for more than the appearance of the unglazed body.
Typical uses include red and buff wall and floor tile bodies, glazed ceramic floor tiles where the body is covered by engobe and glaze, stoneware, studio pottery and terracotta ware. Outside whiteware, it serves as a plastic bond in refractory mortars, castables and ramming mixes, and in some foundry and clay-bonded products where a fine, plastic clay improves cohesion. It also blends well with higher-specification clays to adjust plasticity in a body without a large increase in raw material cost.
Obsidian Minerals supplies the grade with chemistry, residue and dry strength checked lot by lot, so pressing and extrusion behaviour stays predictable from one delivery to the next. It is available as dry powder or noodles, and blends for a specific body, together with samples for plant trials, can be discussed on request.
Typical specifications
| Parameter | Typical Value | Test Method |
|---|---|---|
| SiO₂ | 52–62 % | XRF (internal method) |
| Al₂O₃ | 22–28 % | XRF (internal method) |
| Fe₂O₃ | ≤ 2.5 % | XRF (internal method) |
| TiO₂ | ≤ 1.8 % | XRF (internal method) |
| Loss on ignition | 7–11 % | Internal method (1,000 °C) |
| Dry modulus of rupture | ≥ 2.0 MPa | ASTM C689 |
| Residue on 45 µm (325 mesh) | ≤ 3.0 % | ASTM C325 |
| Fired colour (1,150 °C) | Cream to light buff | Visual, against reference |
Typical values for guidance. Guaranteed limits are stated on the Technical Data Sheet and batch CoA.
Key features & benefits
Balanced plasticity
Moderate to good plasticity gives standard ceramic grade ball clay enough workability for pressing and extrusion without the slow drying that very plastic clays can cause.
Economical body binder
Where fired whiteness is not critical, this grade supplies the plastic fraction of a body at lower cost than white-firing or high-strength clays, reducing overall batch cost.
Predictable processing
Lot-by-lot checks on chemistry, residue and dry strength help keep press fill, extrusion pressure, shrinkage and drying behaviour steady from one delivery to the next.
Refractory and foundry bond
Its fine particle size and plasticity make the clay a useful bond in refractory mortars, castables and ramming mixes, improving workability and green strength before firing.
Blending flexibility
The grade blends readily with kaolin and with higher-specification ball clays, letting body formulators fine-tune plasticity, shrinkage and fired colour while staying within a cost target.
Applications
Wall and floor tiles
The plastic component in red and buff wall tile and glazed floor tile bodies, where the body is covered by engobe and glaze and strength matters more than colour.
Stoneware and pottery
Used in stoneware, studio pottery and terracotta bodies, giving good throwing, jiggering and extrusion behaviour with a warm, even cream to light buff fired colour.
Refractory mortars and castables
A plastic bond in fireclay-based mortars, castables and ramming masses, improving trowelling and placement and helping the installed material hold its shape before first heating.
Body blending clay
Combined with higher-grade clays to raise plasticity or dry strength in a body economically, or to stretch premium clays where full whiteness is not required.
Usage & handling
- Wall and floor tile bodies often contain about 20–40 % of this grade, depending on the other clays used.
- Refractory mortars and castables commonly use around 3–10 % as a plastic bond.
- Disperse fully in the slip or mixing water and check residue after milling to avoid surface defects.
- Store under cover and protect noodles from drying out before use.
Packaging & supply
- 25 kg and 50 kg HDPE or paper bags
- 1 MT and 1.2 MT jumbo bags for bulk tile and refractory users
- Custom and private-label packing on request
Frequently asked questions
What is standard ceramic grade ball clay used for?
It is used in wall and floor tile bodies, glazed ceramic tiles, stoneware, pottery and terracotta, and as a plastic bond in refractory mortars, castables and ramming mixes. It suits products where good workability and unfired strength are needed at an economical cost, and where the body does not need to fire white.
What fired colour does this grade give?
At typical tile firing temperatures of around 1,150 °C, it fires to a cream to light buff colour, depending on the lot and kiln atmosphere. This is acceptable for glazed and engobed products and for coloured bodies. For white-firing bodies, the high whiteness grade is the better choice.
Can it be used in refractories?
Yes. Ball clay is widely used as a plastic bond in fireclay-based refractory mortars, castables and ramming masses, where it improves workability and green strength. Its fluxing impurities mean it is normally used at modest additions, so refractory formulators should check the effect on refractoriness and hot strength for their temperature range.
How does it compare with the high plasticity grade?
The standard grade is somewhat coarser and less plastic, with lower dry strength and a darker fired colour, but it is more economical. The high plasticity grade is designed for sanitaryware casting where strength and casting behaviour are critical. For pressed tiles and general bodies, the standard grade usually provides sufficient strength.
Can this ball clay be blended with other clays?
Yes, blending is common practice. The standard grade is often combined with kaolin or with high plasticity or high whiteness ball clays to reach a target balance of strength, shrinkage and fired colour at a controlled cost. Samples of several grades can be supplied together so you can run blend trials.