The acid-base cements are materials developed by means of reactions between an acid component and another basic one. This type cement belongs to the family of the so called "chemically bonded phosphate ceramics" (CBPCs), new types of inorganic materials that have special physico-chemical properties and that, in contrast to most advanced ceramics, are made by processing the material at ambient temperature. In the present work, cylindrical specimens were molded (30 mm × 50 mm) with magnesium phosphate cement and grinding dust (waste from an automobile industry) which was added to ceramic matrices in varied contents (0% to 40% in mass). The influence of this addition with regard to phase formation and to mechanic resistance (axial compression and traction by diametrical compression) of the compositions (3, 7 and 28 days after the molding) was evaluated using a universal test machine. The samples of magnesium phosphate cement mortars containing grinding dust were then analyzed after being subjected to an accelerated aging test for a period of 1200 hours (50 days), equivalent to one year of natural aging. The results obtained showed a decrease in the compressive strength of the mortar between 28 days and 1 year of age but this loss in performance is not associated with the presence of grinding dust and the CBPCs proved highly satisfactory for the encapsulation of hazardous wastes.
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