Welcome to Imerys Performance Minerals

Cement Board

Cement Board Imerys minerals enhance the properties of fiber cement composite boards

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

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. 


Recommended grades:

  • 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.

We recommend our Harborlite® products for this application.

Calcium carbonate

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

We recommend our ImerFill grades for this application.

Natural pozzolans

Imerys Micrasil®, is a superfine pozzolanic material that, among other benefits, adds plasticity to cement board during processing, allowing the layered sheet to adjust to the shape of the mold without cracking or delaminating. It reduces the microporosity of the final board, improving freeze thaw resistance, bending performance and durability.

We offer a full range of bespoke 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 only too happy to help

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