The extraction of nickel has been from sulfides and silicates ores, this extraction now is made from low grade nickel ores, because the nickel content has decreased considerably. These ores are processed by pyrometallurgical processes. Nowadays, the study of these ores is necessary in order to give a great understanding when these type materials are processed. In this study, it is given an alternative activation energy process, the mechanism possible that it is presented, and recovery percentage of nickel and iron metallic. A sample with 1.42% nickel was used. This sample was processed, it was obtained ferronickel to 1450, 1500 and 1550°C. The ferronickel slags were characterized by diffraction ray X, atomic absorption and scanning electronic microscopy, in order to obtain the amount nickel and iron, lost in the slag. The recovery of nickel and iron was above 90% in ferronickel percentage.