Copper losses to slags obtained from the El Teniente process

The smelting and converting El Teniente process for copper concentrates as well as slag cleaning furnace technologies to treat slags coming out from the El Teniente furnaces are widely applied today in Chile and around the world. Several industrial applications of this process have shown their ability to treat copper concentrates in a wide range of chemical and mineralogical compositions. Main operational parameters determining performance of the process are: oxygen enriched air flow rate; degree of oxygen enrichment; moisture content of the solid materials processed; molten material levels inside the vessel; frequency of molten materials tapping; bath temperature; and copper losses in slags. In this work, the copper losses in the slags from the El Teniente pyrometallurgical process are predicted by calculation from thermodynamic data and compared with those determined by microscopic examination and slag industrial data. Results obtained show that the main part of copper losses in the slag from the El Teniente furnace are mechanically entrapped or floated unsettled droplets of the co-existing matte phase. Conversely, the very low copper losses in the slag from the slag cleaning furnace are limited by the physicochemical form.