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UltraCarb is a natural halogen-free mineral that can be used as a fire retardant filler suitable for plastics and rubbers. It is produced from a deposit of Hydromagnesite and Huntite.

Your contact for 

Magnus Johansson

Sales Manager Polymers & Coatings

Each of the two minerals – Hydromagnesite and Huntite (HMH) – are flame retardants on their own, the combination, however, results in a unique product which specific properties may be adjusted by selected mining and processing to fit a variety of applications.

UltraCarb has a unique 3-stage fire retardant mechanism. Whereas the classical endothermic flame retardant fillers act by releasing water in a single action process, UltraCarb works as following:

  • Water is released at temperatures of ~220°C (thermal decomposition)
  • CO2 release at temperatures of ~330°C
  • At temperatures of ~560°C, UltraCarb particles accumulate at the surface of the burning polymer to form a stable cementitious char which inhibits the combustion process and thus the propagation of the fire through burning droplets.


The platy, high surface area particles of UltraCarb provide excellent properties when used as a functional filler in polymers. The products' high heat absorption protects polymers from a rapid thermal degradation and the formation of combustible products.

UltraCarb is used as a fire retardant filler in a wide range of polymers such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) and rubber.

UltraCarb applications

  • Fire retardant wire & cable

    UltraCarb in wire & cable

    UltraCarb provides cost effective sustainable solutions to the global cable industry. Through its char formation when burning, the mineral combination brings a low smoke effect to PVC or rubber used in e.g. cable sheathing. The char also prevents the melting polymer from dripping which further prevents the fire to spread.

  • Foam insulation with UltraCarb

    UltraCarb in foam insulation

    In foam insulation UltraCarb replaces e.g. Aluminium Trihydroxide and is therefore the natural alternative for fire retardancy. The char formation prevents insulation foams to act as a fire accelerant and support it being a fire prevention.

  • Rubber conveyor belt with boxes

    UltraCarb in rubber

    In any rubber application where fire retardancy is necessary, UltraCarb is beneficial. UltraCarb can effectively reduce the rate at which flames spread across a flat surface and reduce dripping of molten polymer for applications such as conveyor belts or flooring.

UltraCarb packaging

Our UltraCarb product range is available in paper sacks, big bags or in bulk.

UltraCarb standard grades

Primary Hydromagnesite  

LH 15

  (stearate surface treated) LH15C
  (proprietary surface treated) LH15X
Primary Huntite  
  (stearate surface treated) 1251
  (proprietary surface treated) 1253
  (stearate surface treated) 1291
  (proprietary surface treated) 1293

Stearate surface treatment improves wetting and reduces the agglomeration in the compound, proprietary surface treatments are beneficial as an external lubricant, act as a processing aid for extrusion and improve the LOI in EVA.

The typical properties of UltraCarb are:

Physical properties of UltraCarb

Specific gravity [g/cm3] 2.4
Refractive index 1.56
Hardness (Mohs) 2.5
Surface area [m2/g] 11 - 17
Loose bulk density [kg/l] 0.4

Chemical properties of UltraCarb

MgO [%] 36 - 39
CaO [%] 6 - 9
SiO2 [%] 0.2 - 1
Loss on ignition at 1,000°C 51 - 54

Hydromagnesite Huntite origin

Hydromagnesite and Huntite mineral deposits are formed by near surface thermo-chemical geological processes. The formation of our Turkish desposits is the result of three specific conditions:

  • a depositional area of magnesium rich ultramafic basement rocks;
  • a lake environment which evolved into a basin;
  • tectonic activity: This allowed magnesium rich hydrothermal solutions to reach the surface.

The precipitation of Hydromagnesite and Huntite is related to the mixing of these hydrothermal solutions with fresh water from the lake environment.

Hydromagnesite Huntite toxicology

A non-toxic, non-hazardous stable mineral. You can download the Safety Data Sheet in the section on the right hand side for further information.


Interested in what UltraCarb can do for you?

Start by selecting your country to get the right contact person

My name is Magnus Johansson and I'm a UltraCarb product expert located in United States.

If you are interested in what this product can do for you, please give me a call or send me a message.

Office .
Mobile +1 513 375 2599

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08:00 AM - 17:00 PM

Local time in United States is 17:23 PM (UTC -4)

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