Microsilica 951

Elkem Microsilica® 951 is a key ingredient in low and ultra-low cement castables. It is highly reactive during sintering, which leads to improved ceramic bonding at reduced firing temperatures. The grade is used in mortars, gunning mixes and other shaped and unshaped materials

Only for Asia and Oceania


  • Improved flow – easier to cast
  • Improved particle packing - denser castables
  • Gelification (coagulation) in gunning mixes
  • Improved hot-strength properties 


  • Low and ultra-low cement castables
  • Castables, mortars, gunning mixes and other shaped and unshaped materials. 


The product is available in 25 kg or 20 kg small bags and various sizes big bags. Please contact our sales representative for more details. 

Storage conditions

Store in the original packaging (or re-seal opened packages) under dry conditions above 0°C. 

Chemical Analysis (weight %)
 SiO2  % min  94.0
 C  % max  2.0
 Fe2O3  % max  1.0
 Al2O3  % max  1.0
 CaO  % max  1.0
 MgO  % max  1.0
 K2O  % max  1.2
 Na2O  % max  0.5
 H2O *  % max  1.0

Physical Data
Loss on Ignition  % max  3.0 
Coarse particles >45µm % max 1.0 
Bulk density* kg/m3  200 - 450 

* When packed

Test methods

Test methods are available upon request