Comparative Analysis Of Autogenous And Semi-Autogenous Grinding For Duguru Lead- Zinc Ore From Alkaleri, Bauchi State

Abstract

The mining industry plays a critical role in economic development, and lead and zinc are essential metals extracted globally for various industrial applications. However, extracting and processing these metals, particularly from complex sulphide ores like sphalerite and galena, poses significant challenges due to their intricate mineralogical associations. This research compares two grinding methods—autogenous and media-assisted grinding—in the beneficiation of Duguru lead and zinc ore from Alkaleri, Bauchi State, Nigeria. The grinding tests were conducted at three different revolution speeds (200, 400, and 600 rpm) using two modes: New Charge (NC) and Addition of Difference (AD). Results show that media-assisted grinding, which uses steel balls, consistently outperforms autogenous grinding in terms of grindability across all revolutions. At 200 rpm, the grindability for autogenous grinding was 0.04985 g/rev (49.85 kg/t/rev) and for media-assisted grinding, it was 0.05075 g/rev (50.75 kg/t/rev). At 600 rpm, autogenous grinding achieved 0.07212 g/rev (72.12 kg/t/rev), while media-assisted grinding reached 0.09838 g/rev (98.38 kg/t/rev). The Addition of Difference (AD) mode produced higher grindability values than the New Charge (NC) mode for both grinding methods. These findings indicate that media-assisted grinding provides superior efficiency due to the enhanced ore breakage facilitated by the grinding media, making it more suitable for continuous operations requiring high throughput. It is recommended that the mining industry adopt media-assisted grinding for better performance, with further studies aimed at optimizing energy consumption and recovery rates. Additionally, combining autogenous and media-assisted grinding techniques in hybrid methods could offer a balanced approach for cost-effective processing