Study And Application Of Minor Clinker Magnesium Slag Cementitious Material

The magnesium slag is the sub-product generated in the production of the mettalic magnesium.These magnesium slag will pollute environment so it is very important to research the use of this sub-product.Minor clinker magnesium slag cement was prepared successfully with magnesium slag-furnace slag-clinker system.The effect of dosage of magneium slag and clinker,the hydration time,grinding process,dosage of activators on the cementitious materials poperty during the production of minor clinker magnesium slag cementitious material has been study in this paper. Based on the effect of single activator on the property of Magnesium slag cementitious, an orthogonal test is used to investigate the effect of composite activator. The hydration and microstructure of this composite cement with activator were analyzed by X-ray diffraction and scanning electron microscopy, and the interaction mechanism was researched. The results show that mixture first is better than grinding first; the cementitious material performed good mechanical property when the adding amount of magnesium slag and furnace slag is equally ; For the slow hydration process of magnesium slag cementitious material,the strength of 3d is only the 25% of 28d,and the strength of 28d is more or less 60% of 90d; the activity of magnesium slag is enhanced significantly by adding small amount of activator and the mechanics properties of the material is remarkably improved;activators increase both the early and later strength of magnesium slag cementitious;Different activator have different effects and composite activator have the best effect;the species of hydration products of magnesium slag cementitious materials mortar are influenced slightly, the species of hydration products of magnesium slag cementitious materials are C-S-H,Ca(OH)₂,AFt. anorthite, gismondine, paragonite, margarite also are found. Based on the previous experiments,the application of this cement in the wall material has been studied in this paper,the factors effecting the properties of wall material have also been analysed.The results showed that the wall materials have good performance which prepared by using minor clinker magnesium slag as binder ,EPS as light aggregate and some addtion.The compressive strength of this material was 6.35MPa.The soping ratio of wall material was only 10%, thermal conductivity was 0.139 W/(m·K).Under the conditions of the freeze-thaw cycle, temperature between-25℃and 25℃,the mass loss was only less than 1%,the strength loss of material was more or less 10%.