Por: Ing. Luis Huere, docente de Procesamiento de Minerales e Hidrometalurgia, Tecsup.AbstractChalcopyrite is one of the most abundant copper minerals on earth; the high grade ores of this mineral are processed by concentration, by flotation, to finally move to smelting by obtaining a copper anode that is refined in electrolytic cells. This processing, until obtaining metallic copper as a cathode, is very expensive, being the leaching of chalcopyrite an alternative to extract it by electrowinning at a lower industrial cost. Chalcopyrite is one of the most difficult copper minerals to leach, being possible to generate a PLS in a very oxidizing medium, but recoveries are too low to consider it as a processing alternative.Several metallurgical tests have been performed in order to increase copper recovery in the PLS obtained, using a specific oxidizing agent. In this study, several leaching tests were performed on a chalcopyrite copper ore to determine the optimal parameters that produce the highest recovery in the PLS directed to solvent extraction and electrowinning, respectively.The tests performed included ozone oxidation, ferric sulfate, ozone-ferric sulfate, ferric sulfate-ozone and ferric sulfate, raising the temperature. The results of these tests, in which the ORP, which generates the dissolution of copper in the leaching process, was controlled, showed that ferric sulfate produces the highest recovery.The test that generated low PLS extraction results was the chloride leaching test, considered from the beginning of the PLS grades that were extracted. Two tests were performed under conditions of pH = 1 and ozone, ferric chloride with ultrasound with an average ORP of 550, obtaining an improvement of 16.33% in the extraction of copper, higher than the leaching with pH = 1, ORP of 490, ozone and ferric chloride without the use of ultrasound. The lowest extraction result of this process, which serves as a reference for comparison between the various tests, was 2.815 of dissolution. In the ozone and ferric chloride test, the recovery did not produce better results, they were similar to the best chlorine test. The test in which only ozone was used as an oxidizing agent for chalcopyrite showed better results compared to the chloride leaching with more than 47.96% extraction.Regarding the ferric sulfate leaching tests, one was performed with a solution flow of 0.025 M and another with 0.01 M at a pH of 1.5 with an ORP of 490 for the first and 480 for the second. Copper recovery in the first case, with respect to chlorine, improved by 63.26%, and in the second case, the improvement was 246.94%, with the latter being the one that produced the best results. Experimental tests were conducted at Tecsup's hydrometallurgical laboratories, as well as chemical analyses of head grades and solutions. In order to confirm the results, samples were sent for analysis to a certified laboratory for contrasting the tests performed.