| The INCO finishing procedure represents the near final stages of copper production at the Copper Cliff Smelter in Sudbury, Ontario, whereby semi-blister copper, at 4--6 wt % Ni and 2--3 wt % S, is processed into blister copper, at 100 ppm S and 0.4 wt % Ni in a modified Pierce-Smith converter combining top-blown oxygen injection and bottom-blown nitrogen stirring of the melt to accelerate semi-blister desulfurization. The procedure is performed in two stages of equal duration: in the first, melt saturation with oxygen and sulfur elimination from 2--3 wt % S to 300 ppm is achieved by 45 minutes of oxygen top-blowing and nitrogen bottom stirring; in the second stage, oxygen injection is terminated and sulfur removal from 300 ppm to 30--100 ppm. proceeds by the ppm to 30--100 ppm proceeds by the reaction of dissolved S and O under a further 45 minutes of nitrogen stirring.;Cu-S and Cu-Ni-S alloys were also exposed to the open atmosphere to examine desulfication of stagnant melts under air. (Abstract shortened by UMI.). |
