The purpose of the flotation process is to be able to concentrate the copper ore from the comminution stage (crushing and grinding). This stage is used for the processing of copper species that contain sulfides, because being hydrophobic makes it easier for them to float, generating a concentrate and being able to be separated from the gangue in the form of tailings. Figure 1 shows the currents involved that are going to be in that instance. However, it must be borne in mind that as long as the pH is maintained at a value close to 3, the pine oil added for the generation of bubbles will generate the amount expected for the estimated recovery of copper for the flotation circuit. The Cochilco mine in operation treats a mass flow of 1000 tons/h of ore that contains both copper (Cu), iron (Fe), Molybdenum (Mo) and other species that are not of interest (Ganga), coming from the stage of grinding that enters the flotation circuit, the head grades that this feed current has are 1.15% for Cu, 0.86% for Fe, 0.15% for Mo and the rest will be Ganga. The tailings have a flow of 250 tons/h of processed ore where, according to the chemical analysis carried out on this current, it indicates that it has 0.34% Cu, 0.17% Fe, 0.02% Mo, the rest being Ganga. On the other hand, in the upper part of the flotation cell, the concentrate leaves, which will later be directed to the pyrometallurgy stage. It is known that the ratio between concentrate flow and tailings will be 1:3.

A) Determine the Flow and the compositions that Cu, Fe, Mo and Ganga will have in the concentrate. (25 points) B) The mining laboratory area finds that, in the chemical analyzes carried out on the concentrate, they indicate that they have a lower amount of copper than expected. How could this situation have come about? (25 points) C) If for every 1000 Ton/hr processed in the flotation stage, 0.2 kg of CH3COONa are used with 150 g of CH3COOH dissolved in 1 L of water, Ka = 1.8 x 10-5 . What will the pH value be? (25 points)

Proceso de Flotacin para minerales sulfurados Fuente: Elaboracin propia