Welcome to Imerys Performance Minerals


Concrete Imerys minerals can improve the strength and durability of concrete formulations

Imerys provides a range of high quality minerals and additives that provide reliable cost-effective solutions for the production of various types of concrete and cement

Natural Pozzolans

Naturally occurring alumino silicate minerals react with calcium hydroxide formed during the cement hydration, creating more stable calcium silicate and calcium illuminate compounds that improve the strength and durability of concrete. Imerys provides a variety of ultra-fines natural pozzolans that conform to the requirements of ASTM C618.


Metakaolin is manufactured from refined kaolin calcined under controlled conditions designed to optimise pozzolanic reactivity.

Imerys metakaolin provides multiple benefits:

  • Improves compressive strength in Portland cement-based concrete
  • Quicker curing times: making it ideal for applications where high strength is required within a short timeline, such as airport runways 
  • Efflorescence: by reducing the porosity of the concrete and reacting with calcium hydroxide before it reaches the concrete surface
  • Protects reinforcing bars from corrosion: refined pore structure inhibits corrosive acids, salts, and sulfates from permeating the concrete structure, making it ideal for road and marine applications 
  • Reduces crack formation: by lowering heat of hydrating and refined pore structure prevents cracks caused by freeze-thaw cycles
  • Viscosity: reducing the tendency to bleed, making leveling and achieving a good surface finish easier
  • Reduces deleterious expansion from certain types of reactive aggregates: helps mitigate alkali-silica reactions

We recommend our Argical M100, Argical M1200S and MetaStar 501HP, SAC 100 GP metakaolin ranges for concrete.

Expanded perlite for lightweight concrete

Lightweight concrete is characterized by a low loose bulk density (below 2000 Kg/m3) and high thermo-acoustic properties. It is produced by partial or total replacement of the aggregates in the concrete by lightweight aggregates. 

Used as aggregates in lightweight concrete, our raw graded perlites provide low densities (below 1,200 Kg/m3) and excellent thermal-acoustical insulation properties.



Wollastonite is a naturally occurring mineral with a high aspect ratio that serves as fiber reinforcement in concrete. The calcium silicate composition of wollastonite allows it to chemically bond with the cement matrix, providing superior strength and resistance to crack formation.

Wollastonite has a synergetic effect when used in combination with natural pozzolans that enhance the strength and durability of concrete.

Imerys wollastonite products:

  • Improve early age strength
  • Reduce micro-cracking
  • Increase flexural and compressive strength
  • Provides superior ductility and fracture toughness
  • Provides greater shrinkage resistance
  • Is an excellent extension to macro fibers and textiles
  • Provides ease of mixing 
  • Is a sustainable replacement/reinforcement on a micro scale
  • Is a naturally occurring, safe mineral additive

We recommend our Nyad® G product for concrete applications.

Mineral Fillers

Imerys offers high purity marble products that can be used as aggregate, sand, or mineral filler in concrete applications. The white color of carbonate products enhance the appearance and aesthetics of concrete by improving the consistency color.

Calcium Carbonate

  • Improves particle packing which in turn reduces permeability 
  • Increases resistance to freeze thaw cycling- reduced cracking
  • Reduces efflorescence
  • Improves placement and workability 
  • Enhances the performance of other reactive additives, such as fly ash

We recommended:

  • ImerFill 3
  • ImerFill 25
  • ImerFill 50


Aggregates increase the volume of concrete while enhancing workability and strength. Imerys offers a variety of coarse and fine
aggregate products. 

We recommend:

  • Landscape chips
  • ImerCarb 1650
  • ImerFill 600


Sand contributes to reduces drying shrinkage and improves workability, making it easier to place and finish fresh concrete mixes. 

We recommend:

  • Pool Mix
  • #1 MaxiMix
  • Specification Sand
  • GM 1650

Cement Board

Imerys offers a range of wollastonite, micas, perlites and carbonate for improving the properties of composite boards used in the construction industry.


Fiber cement, silicate and fire resistance insulating boards

Wollastonite and Mica
Imerys wollastonite and micas are excellent solutions for controlling thermal and dimensional stability, board integrity in fiber cement and silicate board applications.

Our minerals can be used in cement boards to improve fire-resistance and stability in wet environments.

When produced for wet rooms or for fire-resistant applications, these boards have to meet strict dimensional stability performance criteria. Using specific minerals and specific mineral combinations, manufacturers can achieve these dimensional stability
performance requirements.  

  • Nyad® G and Nyad® MG high aspect ratio wollastonites provide high temperature resistance, dimensional stability in wet-room and fire-resistant in fiber cement board formulations. 
  • Suzorite® 20 S and Suzorite® 30 S low bulk density phlogopite mica improve thermal shrinkage and control hydric movement in fiber cement boards for wet room applications. 

Often both minerals are formulated together to create a synergetic effect in fiber cement board. 

Loading levels will depend on board specifications, but generally both minerals are formulated in the formulation at 4-7m% for wollastonite and 8-10 m% for coarse mica.

Expanded Perlite
Used in fiber cement board, Imerys raw graded perlite, when expanded to a lightweight aggregate provides:

  • Unit weight reduction
  • Higher thermal insulation
  • Acoustic insulation
  • Improved freeze-thaw
  • Fire resistance

During processing, it works as a bonding aid between the layers forming the board.

Recommended products: 

  • Harborlite 12x20S

Calcium Carbonate
Fine ground calcium carbonate can be used as an additive in cement board to improve particle packing, which reduces permeability and efflorescence

Recommended products: 

  • ImerFill 3
  • ImerFill 25
  • ImerFill 50

Mortars, Renders and Plasters

Imerys minerals make ideal multifunctional fillers in mortars, plasters, renders, ETICS and EIFS where they improve mechanical properties and surface appearance.  


Pinholes are generally the result of the capillary effect between the coarser plaster particles and renders, and cracks are due to shrinkage. 

Carbonate, diatomaceous earth and perlite reduce pinholing and cracking in plasters and renders.

Coating and finishing mortars, plasters and renders

Imerys perlites key advantages when included in the production of plasters and mortars used primarily for coating and finishing for walls.

Expanded perlite is a vital ingredient in lightweight plasters and mortars where it brings:

  • Lightweighting
  • Substantial increase in insulation properties
  • Improved fire protection
  • Enhanced fluidity and strength of the paste during pumping
  • Higher workability and a smooth release of water during hardening less cracking
  • Greater elasticity combined with higher wall adhesion
  • Improved color
  • Reduction of raw material required


Imerys muscovite micas are good solutions for improving mixing and trowelling properties in mortars and to improve the flexibility of the finished product.

Imerys reactive metakaolin pozzolans are ideal for achieving hydraulic sets in traditional lime putty mortars and plasters and for improving the mechanical strength of floor mortars. Pozzolans are particularly helpful when applying lime putty mixes in damp, frost prone or exposed locations.

The addition of metakaolin pozzolans to lime putty mixes increase compressive strength which helps offer additional protection during the carbonation period.

Ground carbonate provides particle packing to improve workability and improve water retention.  Carbonate can be used as a partial replacement for white cement, which reduces costs in the formulation. 


We offer a full range of custom formulation and technical and process support services to help you match the right mineral grade to your application requirement.

Please contact us, we will be happy to help

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