Preparation of building materials from Bayer red mud with magnesium cement

In this paper, influences of red mud on the properties of magnesium oxychloride cement (MOC) and magnesium oxysulfate cement (MOS) were studied with a 200 day time scale. The results showed that the addition of red mud greatly enhanced the 28d water resistance of MOC cement from 0.84 to 1.10, of MOC cement, significantly increased the compressive strength of MOS cement from 24.12 MPa to 33.31 MPa and water resistance from 0.48 to 0.68. At 200d, the addition of red mud had little effect on MOC cement but greatly increased compressive strength and water resistance of MOS cement. The red mud and magnesium cement produced an amorphous gel, which made the matrix more compact. Meanwhile, magnesium cement played the role of solidification soluble salt in red mud and only slight frosting appeared. The research results show the potential of red mud as a modifier of magnesium cement and its application potential as a building material.