Reactive magnesium oxide cements
First Claim
1. A hydraulic cement composition consisting essentially of:
- a hydraulic cement component;
a magnesium oxide component; and
a pozzolan component,wherein the magnesium oxide component consists essentially of reactive magnesium oxide hydratable to brucite and prepared by low temperature calcination at a temperature of less than 750°
C. from materials excluding dolomite, and substantially ground to a particle size with greater than 95% of the particles less than 120 μ
m in size, the magnesium oxide component making up at least 5% by weight of a combination of the hydraulic cement component and the magnesium oxide component,said composition excluding components which form magnesium oxychlorides and magnesium oxysulfates with the reactive magnesium oxide.
0 Assignments
0 Petitions
Accused Products
Abstract
Novel hydraulic cements are disclosed that include reactive magnesium oxide prepared by low temperature calcination. The cements can be formulated to suit a large number of applications with various setting times, strength and levels of sustainability either by adding iron salts such as ferrous sulfate or blending with other compatible faster setting hydraulic cements such as Portland cement or by using both methods.
The compositions are able to incorporate relatively large amounts of low cost pozzolans such as fly ash to advantage as well as wastes. Many excellent properties are exhibited and in particular good comprehensive strength and resistance to sulfates is able to be achieved.
126 Citations
12 Claims
-
1. A hydraulic cement composition consisting essentially of:
-
a hydraulic cement component; a magnesium oxide component; and a pozzolan component, wherein the magnesium oxide component consists essentially of reactive magnesium oxide hydratable to brucite and prepared by low temperature calcination at a temperature of less than 750°
C. from materials excluding dolomite, and substantially ground to a particle size with greater than 95% of the particles less than 120 μ
m in size, the magnesium oxide component making up at least 5% by weight of a combination of the hydraulic cement component and the magnesium oxide component,said composition excluding components which form magnesium oxychlorides and magnesium oxysulfates with the reactive magnesium oxide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A hydraulic cement composition consisting essentially of:
-
at least one a hydraulic cement; a magnesium oxide component; and optionally, at least one pozzolan, wherein the magnesium oxide is at a level of at least 5% by weight of a combination of the at least one hydraulic cement and the magnesium oxide and wherein the magnesium oxide consists essentially of reactive magnesium oxide hydratable to brucite prepared by low temperature calcination at a temperature of less than 750°
C. and fine grinding to a particle size with greater than 95% passing 120 μ
m. - View Dependent Claims (10, 11, 12)
-
Specification