Calcium silicate insulation – machineable, structurally strong, and offering superb performance at 1000 °C

Over the last 50 years Promat has evolved into the global market leader in calcium silicate insulation products. This leadership position has been achieved by absolute dedication to only the very best in product quality coupled with the development of technology that fully optimises the properties of the various calcium silicate grades.
Calcium silicate technology

Calcium Silicate – control of heat loss (plus strength)

Our calcium silicate products offer very stable thermal conductivity values over a wide range of temperatures. Our best products can be used continuously at 1000 oC without deterioration or excessive shrinkage. However, what makes calcium silicate really special is the fact that the high compressive and flexural strength make it also ideal as a structural component in an assembly. This means that almost any type of thermal equipment can be built and insulated in a single operation.

Promat HPI leads the world with PROMAXON®

Promat HPI offers the most advanced calcium silicate technology of any global manufacturer of insulation products. Our unique approach, registered under the trademark name PROMAXON®,  creates a controlled smaller pore size through our exclusive engineered mineral matrix structure.

When this is combined with opacification, similar to that used in our Microtherm® microporous insulation, the result is an insulation  with a thermal conductivity as low as 0.10 W/mK, dramatically better than any other calcium silicate product on the market.
The Promaxon effect

The Promat HPI approach – optimise the product for optimum performance

Calcium silicate is made by reacting calcium oxide with silica in various ratios to create the different grades.

Our PROMAXON® technology enables the manufacture of calcium silicate products with superior properties. PROMAXON® is a synthetic hydrated calcium silicate that has the appearance of a white mineral free flowing powder.

By means of a special crystallization process our technique of mineral and matrix engineering controls the crystal growth and the porosity of temperature-stable phases, forming preferred crystal shapes and aggregate structures. Very small particles are created consisting of spherical shells with very large numbers of fine needle-shaped crystals and a core interior with fewer but larger needle crystals.

The resulting product range offers very stable and very low thermal conductivity, excellent thermal shock resistance, non-combustibility, plus superb structural integrity.

Calcium silicate – engineered for excellent thermal protection

The thermal conductivity of a porous material is controlled by the thermal conductivities of its components and their spatial arrangement within the composite structure, e.g., the material’s microstructure.

The spherical morphology of PROMAXON®,  together with the stringent quality control of the raw materials selection, results in an extremely low and stable thermal conductivity in all of the Promat HPI calcium silicate range. Obviously, the solid conduction component of heat transfer  through the insulation will increase slightly with the denser products in the range, but overall, thermal performance is excellent.
Material properties & characteristics
  • Excellent thermal conductivity values that remain stable over a wide temperature range up to 1000 oC and higher
  • Excellent resistance to thermal shock
  • Non-combustible
  • Minimal shrinkage, even when exposed to continuous maximum rated temperatures
  • Excellent compressive and flexural strength
  • Excellent machineability
  • Wide range of densities
  • Excellent electrical insulating properties when dry
  • Insoluble in water
  • Resistant to oils, weak alkalis and many other chemicals

Typical applications
The unique characteristics of calcium silicate offer clear benefits in use in any application where high temperatures and high energy use are encountered.  A Promat HPI engineered solution will take advantage of the varied properties of each grade to minimise unnecessary energy wastage through controllable heat losses.

Typical applications include:

  • Petrochem – furnaces, process piping and equipment
  • Glass – forehearths, melting furnaces
  • Metals and their processing
  • Energy – power plants, fuel  cells, solar plants, building insulation
  • Furnaces
  • Chimney – industrial and domestic
  • Transport – all forms including aerospace and defence
  • Home appliances – storage heaters, domestic ovens
Product portfolio
The Promat HPI selection of calcium silicate products can be simply sub-divided into  low, medium, or high density insulation products.  Each product category has quite distinct  properties and advantages.

High performance calcium silicates

Low density calcium silicate boards are very efficient insulating products. They have a low thermal conductivity which leads to low heat losses. The very light insulation systems also reduce the heat storage of the lining. These materials are stable up to 1050 °C and classified as A1, non-combustible according to EN 13501-1 and building material class DIN 4102.
Low density calcium silicates are the “classic” back-up insulation in combination with dense refractories, insulating bricks and castables for a broad range of applications. They are very cost effective due to their price/performance in comparison with other insulating products.


Structural calcium silicates

Medium density structural calcium silicate products from Promat are asbestos free thermal insulators that can be used as functional supporting components in a construction. They are versatile materials combining good thermal insulation, high thermal stability and structural integrity within a wide range of temperatures up to 1000 °C. They are the preferred choice for high performance mechanical insulation in harsh industrial environments in a wide variety of industrial sectors.


Technical calcium silicates

These insulating technical ‘ceramics’ are engineered high density calcium silicate boards, originally developed to be a high temperature replacement for asbestos boards. Due to their very high mechanical strength and electrical resistance combined with minimal shrinkage they are generally preferred for applications up to 1000 °C where good electrical resistance is required.


Composite insulation boards

PROMATHERM®-VE composite elements consist of an insulating core material which is covered by either steel sheets or thin PROMATECT®-H boards.
DURASTEEL® is a composite insulating board made of a calcium silicate core reinforced on both sides by galvanised and perforated steel sheet coverings.

Click here to see the whole microporous product range of Promat. 

Or download the current version of the Calcium Silicat Products brochure here.