Effect of Magnesium Oxide Particle Size and the Filler Content on Magnesium Potassium Phosphate Cement Properties

The radioactive aluminium waste generated by the VVR-S nuclear reactor decommissioning after nearly 15 years from shut-down is represented as low and intermediate radioactive waste and is divided as activated and contaminated aluminium metal. To realize a conditioning matrix for radioactive aluminum is necessary to study alternative cementitious systems such as magnesium potassium phosphate cement. This paper presents the influence of magnesium oxide and the filler content on properties of magnesium potassium phosphate cement, such as: fluidity, setting time, pH, and compressive strength (in fresh and hardened state). In this study were used two types of MgO with different specific surface area and different types of filler (fly ash and red mud). The mechanical tests for samples of MKPC will be correlated with XRD characterization data. The studies in this paper were carried out on the engineering properties of the resulting paste or mortar and attempted in order to obtain an optimized formula of magnesium potassium phosphate cement based on the raw materials available.