Abstract
A series of process optimization initiatives were implemented at the Kansanshi Copper Smelter (KCS) Peirce–Smith Converters (PSCs) to increase overall converting capacity. These efforts formed part of the KCS initiatives to meet the smelter expansion target, which aimed to raise annual concentrate treatment capacity from 1.3 million to 1.6 million tonnes. The PSCs currently achieve a campaign capacity of approximately 77,000 tonnes of matte. Increasing converting capacity beyond this threshold was essential to ensure that with the 1.6 million tonnes smelter treatment capacity, the PSCs do not become a bottleneck to the increased throughput.
Key initiatives included increasing the copper matte grade from 55% to 62%, 62% to 64% and then to above 64%, partially replacing the conventional roll-out method for the addition of cold dope during copper blow with online cold doping, and optimizing converter blowing rates. Increasing the matte grade from 55% to 62% reduced slag blowing time by approximately 11 minutes per cycle, while an increase from 55% to 64% resulted in a 27 minute reduction. This represented an overall 6% reduction in processing time. Adoption of online cold doping reduced converter cycle time by 7 minutes corresponding to a 2% reduction in total processing time per blow, while optimization of blowing rates to improve process control and shorten blowing times is underway.
Collectively these initiatives have so far increased the converting capacity by 111 tonnes of matte per day, representing an 8% throughput gain. The total processing cycle time has been reduced to 6.5 hours compared to 7.0 hours prior to implementation. These results demonstrate that targeted process and operational improvements can significantly enhance converting capacity and efficiency without major capital investment, providing a scalable model for copper smelters seeking to improve throughput within existing infrastructure constraints.