The aim of this work is to characterize four copper smelters slag nineteenth century, from abandoned landfills in Atacama Region - Chile, using the techniques of X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), particle analysis by laser diffraction (ADL), Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). Copper slags studied were chemically classified as acidic slags, this slags presented higher SiO2 content (38-49%) than Fe2O3 (18-37%) and a significant amount of CaO (8-26%) and Al2O3 (8.5%). Mineralogy and structure was varied, presenting one of them an amorphous structure and the remaining three, a crystalline structure with partially amorphous character. The majority mineral phases presented in the copper slag were diopside, fayalite, magnetite, cristobalite and clinoferrosilita. Calcium levels indicate that the slags could have cementitious properties for use as a binder in construction materials. Moreover, the significant amount of slag available and CuO content (0.6-1.2%) show that may be of interest as raw material for metal recovery.