Abstract: To address the high failure rate, insufficient processing capacity, and unsatisfactory grinding performance observed during trial operation of the semi-autogenous grinding （SAG） system for slag beneficiation at Yangxin Hongsheng Copper Industry Co., Ltd., a systematic study was conducted and corresponding measures were implemented to improve system stability and grinding efficiency. Through field investigation and an in-depth analysis of downtime data from the previous two years, the belt conveyor system, vibrating screen, and SAG mill itself were identified as the main sources of failure. Equipment modifications, process parameter optimization, and management procedure improvements were then implemented, significantly reducing unplanned downtime in the SAB grinding system. The results show that, after modification, the mass fraction of −200-mesh material in the undersize product of the linear vibrating screen increases from 32.69 % to 39.92 %, the mill utilization coefficient increases from 0.426 t/（m³·h） to 0.518 t/（m³·h）, SAG system downtime due to failures decreases by 185.92 h, or 65.44 %, and the mass fraction of −325-mesh material in the feed slurry increases from 75 % to over 82 %. The direct economic benefit is approximately CNY 2.24 million per year. This optimization practice provides an effective technical solution and valuable experience in modifying similar SAB grinding systems to achieve efficient and stable operation.