A primary smelting reactor (PSR) is an important unit in the pyrometallurgical process for the production of copper. This article presents a performance analysis of a PSR with respect to the effects of various operating parameters. The model of the PSR was developed using a metallurgical process simulator, METSIM. Reactor parameters, i.e., heat loss and phase distributions of matte and slag, were estimated from actual plant data. The model predictions were validated with plant data, and good agreement was observed. The developed PSR model was used to analyze the influence of the feed rates of copper concentrate, oxygen, silica flux, and revert on the PSR performance in terms of the percentage of copper in white metal and PSR slag, the percentage of magnetite and silica in PSR slag, and reactor temperature.