Magnesia cement boards or panels are a category of ecological lightweight construction elements used for floor, wall/frame, ceiling and roof insulation and applied either vertically or horizontally. They have several advantages over the more widespread gypsum panels, exhibiting dimensional stability, low water take-up, fire-resistance, high thermal and/or acoustical insulation and high mechanical strength.
The magnesia cement used is of the Sorel type (magnesium oxychloride or magnesium oxysulfate) which is the reaction product of caustic calcined magnesia powder and a solution of magnesium chloride or magnesium sulfate. The type and quantity of fillers used depend on the panel type and the application and typically consist of saw dust, calcium carbonate and perlite. Special applications are the acoustic panels, where the magnesium cement plays the role of binder for wood shavings, and fire-resistant wood-base boards where the cement is applied as coating.
The magnesium oxide must have adequate available MgO content, controlled reactivity and grain size to offer suitable dimensional stability, mechanical strength and setting times; each application has its own specific requirements.
The unique micro-crystalline grades offered by Grecian Magnesite give Sorel cements with better mechanical properties and the capability to produce faster setting time formulations than the macro-crystalline grades present in the market.
Activemag® 92 is a is white, self-flowing, odorless, calcined magnesium oxide powder produced under controlled conditions and milled to fine particle size to achieve high chemical reactivity and specific surface area.
Activemag® 85 is a calcined magnesium oxide, produced under closely controlled conditions to give a finely divided white powder with controlled acid insoluble, accurate reactivity and grain size.