Production and Characterization of Magnesium Cement Using Kaolinite Clay

Magnesium silicate cement is produced by mixing reactive magnesium oxide with a source of reactive silicon oxide. This cement is an interesting alternative to Portland cement due to the potential for low energy consumption, reduced greenhouse gas emissions, and use of renewable resources. Aluminosilicate-based raw materials can also be utilized to produce this type of cement. Thus, this work aims to study the use of kaolinite clay to produce magnesium aluminosilicate cement. The cement was produced by calcination of magnesium carbonate (MgCO₃) and kaolinite clay at a temperature of 800 °C for 45 minutes with MgCO₃/kaolin mass ratios of 90/10, 80/20, and 70/30. Mortars and pastes samples were cured at 60 °C for 1, 3, and 7 days. The results showed that the maximum compressive strength (32.7 MPa) was yielded for the 70/30 mortar mix after 3 days of curing. Microstructural studies of pastes indicated the incorporation of aluminum for the formation of magnesium aluminosilicate hydrated products, in addition to the formation of brucite.

Keywords:
Magnesium cement; kaolinite; sustainable cement