The geopolymeric mortars obtained by the chemical process of geopolymerization of waste from the Peruvian informal mining industry and subsequent addition of fine sand, were mechanically evaluated under ambient temperature and atmosphere conditions. The mechanical results found in the geopolymer mortars were compared with those found in conventional Portland cement mortars (control). The maximum uniaxial compressive stress values for the geopolymer mortars ranged from 7.5 to 27.1 MPa, with the best results when a binder:fine sand ratio of 1:2, molarity of the hardener solution of 20 M and a hardener solution:binder ratio of 0.6 was considered. The microstructure found for both types of mortars studied (control and geopolymeric) consisted of a continuous interconnected phase of binder (cement or geopolymerized inorganic mining residue) and a dispersed phase of small fine sand particles, located within the binder phase. The average real density and porosity of the geopolymeric materials studied were 2.71 g/cm3 and 27%, respectively.