Imerys Ceramics
 
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Minerals
Imerys Ball clay
Imerys Chamotte
Imerys Feldspar & Pegmatite
Imerys Halloysite
Imerys Kaolin
Imerys Quartz
Imerys Talc
Ball clay, chamotte, kaolin, feldspar, quartz, talc
Mineral products

Imerys Ceramics has over 50 production facilities across Asia-Pacific, Europe and Americas. We manage our resources in a way that guarantees our customers a long-term supply of high quality mineral products.

  • Prepared bodies - Czech Republic, France, Germany, Italy, Mexico
  • Ball clay -  England, France, Thailand and the United States
  • Chamotte - France
  • Feldspar & pegmatite - France, India, Spain, Turkey and the United States
  • Halloysite - New Zealand
  • Kaolin - Brazil, England, France, New-Zealand, Thailand, Ukraine and the United States
  • Mica - France
  • Quartz - France and the United States
  • Talc - Austria, Belguim, France, Italy, Canada and the United States
Ball clay

Ball clay is a mineral formed from the weathering and transportation by water of parent rocks which are deposited in ancient river basins from where it is now extracted.

 

Key ball clay properties

Ball clay is essential for ceramic production because of its high plasticity and strength. Key ball clay properties include:

  • High plasticity
  • High unfired strength
  • Highly controlled rheological properties
  • Controlled organic content
  • Controlled residue
  • Excellent workability

 

Imerys Ceramics ball clays

Imerys Ceramics has at its disposal ball clays with a range of different properties .By blending selected clays from different locations Imerys can provide high quality products for a range of ceramic applications. English ball clays are renowned for their unique rheological properties and their rare combination of strength, plasticity, rheology and whiteness; all of which are maximised by Imerys for the benefit of our customers. Our English ball clay range includes:

  • Hycast - very fast-casting ball clays
  • Hywite - clays with high fired brightness
  • Hymod - clays exhibiting high modulus of rupture for applications where strength is of primary importance
  • Hyplas - clays with high strength and excellent workability. They are more siliceous than the other groups

The Imerys Ceramics ball clay products come from England, France, Thailand and the United States. We also make use of blending platforms, in India for example, to ensure that we produce ball clays that address the specific technical challenges of each region.

 

Production process

For example, the Hycast VC ball clay is made from 16 different component clays sourced from many different quarries. The blend comprises 45 parts, which are sub-divided into three sub-blends. These sub-blends are shredded and then fed through a paddle mixer, which mixes the final product. This production process is designed to give a high level of uniformity, ensuring that each consignment from a production batch is the same as the next. Ultimately, this is why our products are known for their consistent performances.

Chamotte

Chamotte is a calcined clay. The calcination process takes place in a rotary kiln at high temperatures of 1400 - 1600ºC. Sanitaryware pieces are fired at lower temperatures of around 1200ºC, therefore the chamotte is inert at the firing stage and acts like a skeleton to produce ware with lower shrinkage, better cracking resistance and lower deformation.


It is the introduction of chamotte that characterises the production of fine fireclay, which enables the production of bigger and more complex sanitaryware pieces. Fine fire clay is becoming well established in western Europe particularly in the Civita Castellana cluster, near Rome, Italy; it is of growing importance in the sanitaryware world.


Imerys Refractory Minerals Clérac, the Imerys Ceramics' chamotte producer


Imerys Ceramics chamottes are produced near Bordeaux, in France by Imerys Refractory Minerals Clérac. Its chamottes are well known for their high quality and consistency; offering reduced cracking, shrinkage and deformation of large complex sanitaryware pieces. These raw materials also make it possible to manufacture the most innovative design-driven pieces.


The following properties are of particular importance in chamotte:

  • Controlled particle size distribution
  • Minimal cristoballite to avoid dunting, cracking and health & safety issues
  • Low magnetic content

In consultation with customers our products can be tailor-made to match requirements. We can also provide chamotte in pellets or in milled form.

Click here to access Imerys Refractory Minerals - Calcined

Feldspar & Pegmatite

Feldspar & pegmatite can play vital roles during firing as they are used as the main vitrifying or fluxing agent in ceramic bodies. Imerys, as the leader in industrial minerals, has unmatched mineralogical knowledge and can assist customers in ensuring that the proportions of feldspar in the body recipe are exactly right to avoid over vitrification during firing.

 

Key properties

Feldspar & pegmatite strengthen and ensure the durability of fired bodies. Imerys Ceramics offer high potassium content with low iron and titanium, which are essential for whiteness and translucency. Through a stringent control of the production processes, Imerys feldspars provide the tableware manufacturer with the assurance that the fusibility of the product satisfies technical requirements.

Pegmatites are rocks composed of several minerals: usually potassium feldspar, quartz and a little kaolin, which give a natural fluxing capability and, because of low colouring oxides, are especially suitable for white tableware.

 

Production sites

Currently, Imerys produces and exports feldspar from France, Spain, Portugal, Turkey, India and the United States. We also have pegmatite production facilities in the north east of Bavaria in Germany.

Halloysite

Halloysite is a industrial mineral that is part of the kaolinite group. Like kaolin, hallyosite is essentially composed of alumina-silicates, however it has a hollow tubular crystal structure, which is markedly different from the booklet or platelet crystal structure of kaolins.

Commercial deposits of halloysite is very rare so the addition of the New Zealand China Clays (NZCC) halloysite to the Imerys Ceramics portfolio in 2000 was crucial. This is now a key part of our offering for whiteware production for example bone china, porcelain and aluminous hotelware.

Key properties

Like all Imerys minerals, our halloysite products are processed to provide a high level of consistency that customers can depend on. The key properties offered by halloysite include:

  • Brilliant whiteness
  • High translucency
  • Reduction of fired sag
  • Low iron and titania

 

 

 

Kaolin

Each grade of Imerys Cerramics' kaolin products deliver what is probably the most important criteria of all - consistency. Raw materials are monitored and controlled at each stage of production to ensure that their performance meets stringent specifications, to provide manufacturers with a predictable and trusted performance.


Key properties & production sites


Imerys supplies a range of kaolin products optimised for both traditional and pressure casting. Some of the main properties include:

  • Highly controlled rheological properties
  • Highly controlled casting rate and deflocculant demand
  • Good dry strength
  • Excellent particle packing and associated good factory yields
  • Outstanding whiteness

Imerys Ceramics has kaolin production sites in England, France, Thailand and the United States. The kaolin deposits, in the southwest of England in particular, are internationally renowned for their quality. They have been worked since the mid-18th century and highly successful part of the Imerys product portfolio. The precise requirements of customers can be met by the use of substantial resources and unparalleled technical experience in the processes of extracting, refining and drying of kaolins. To satisfy our customers' requirements, the Imerys portfolio contains specially engineered kaolins to ensure the products on offer cover a wide range of casting rates and casting concentrations.

Quartz

Imerys Ceramics capitalises on our mineral and technical expertise in the exploitation of quartz for certain non-ceramic markets such as the production of ferroalloys and ferro-silicon and the construction industry. We have two quartz operations in France, at Lot and Dordogne in the South West of the country.



Lot and Dordogne quartz operations

Imerys supplies the leading European silicon smelters with high purity products from these quartz production units. The specific chemical characteristic of this quartz ore are high silica content (>99.8%) with low iron and titanium content. The quality and the consistency are ensured by our manual and optical sorting processes. The raw material is transported to the plant for further screening and purification. This enables the production of high quality silicon under good safety and operational conditions.

The quartz produced at these sites also have a distinctive round shape. Therefore we are able to offer pure silica for technical applications, pebbles for decorative use and granulates for construction and public works.

Talc

Talc's role in ceramics process depends on its interaction with the other minerals in the formulation. It has an influence on each of these properties:
• Porosity (water absorption, close, open...)
• Colour after firing
• Thermal shock
• Moisture expansion
• Thermal expansion - CTE
• Mechanical resistance (MoR)
• Shrinkage (drying, firing, total).

Imerys Ceramics offers a complete range of talcs for several applications: tiles, sanitaryware, technical ceramics and catalyst supports.

Tiles
• Optimized firing cycle
• Improved mechanical properties for large format and thin tile bodies.

Sanitaryware
Specially engineered solutions to optimize the performance of casting slips in automated processes:
• improved vitrification
• gloss and whiteness enhancer
• glaze-body fit improver.

Technical ceramics
• Excellent mechanical properties
• Shock and abrasion resistance
• Good electrical and thermal shock resistance.

Catalyst supports
A range of talc products crucial in the performance of both catalyst supports and DPF:
• very low CaO content
• wide range of microcrystalline and platy talc products.

A number of critical functions:
• provide a relic pore structure
• provide critical lubrication to the thin wall profile when the honeycomb is extruded
• contribute to critical rheology for the body during mixing, extrusion and green body drying
• stable surface area.

   
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