[retracted] Assessment of geochemistry and reprocessing capacity of old copper tailings in Province of Benguet, Philippines

With the rising demand for copper driven by technological advancements and the depletion of high-grade resources, there is increasing interest in recycling secondary sources to extract copper and reduce mining tailings. This study examined legacy copper mine tailings from Benguet, Philippines, to assess their reprocessing potential, using historical data and geochemical analysis. The tailings have a loamy sand texture, with measured porosity of 39.2% and a permeability coefficient of 1.0952 x 10-² cm s-1, indicating low porosity and medium permeability. Water infiltration rates vary from 0.37 to 4.71 cm min-1, suggesting a heterogeneous particle size distribution. The primary components of the tailings are quartz, biotite, and plagioclase feldspars, with minor amounts of calcite, magnetite, chalcopyrite, and pyrite. Copper (0.19%) and sulfur (0.11%) ratios indicate copper is present in both chalcopyrite and smectite minerals. Notably, the highest copper concentration is found in particles smaller than 63µm, with 0.29 wt.% Cu and 0.24 g t-1 Au, or 0.434 wt.% Cu equivalent, exceeding the mining company's cut-off grade of 0.274% CuEq. This study highlights a promising opportunity to recycle secondary sources of copper and gold, helping to meet the increasing demand for these metals driven by modern technological advancements.