A simulation-based horizontal water transport management strategy in deep-level mines

Abstract

Dewatering and water transfer pumping are two of the main consumers of electricity in the South African mining industry. In the ever-unstable electricity supply regime, it is important to consider all possible angles to a specific system to ensure maximum possible energy savings and efficiency (electrical, water consumption, etc.) This thesis focuses on pumping systems which were previously excluded in improvement techniques. An opportunity was identified to allocate a scientifically derived water management strategy for horizontal water pumping (which are excluded in improvement strategy literature) in deep-level mines. Production level systems will be primarily analysed, and conclusions made accordingly. This will be achieved by obtaining improved process configuration through integrated simulation for current and future mining activities. Preliminary audits were done to ensure the system simulation reflected accurate actual values. It was found that no predetermined analysis regarding water demand was done upon installation of bullnose spindle pumps situated at cross-cut entrances. Normal procedure entailed the installation of one uniform pump size on every cross-cut’s entrance (bullnose), regardless of the actual water demand in the section. System simulations were done for the currently installed systems based on updated return water flows on each level. Additional simulations were done to establish maximum demand limits for the currently installed system and new proposed pumps. Results revealed that the installed spindle pump system is over specified for the application. Scope, therefore, exists to exchange the majority of the bullnose spindle pumps with a smaller, better suited pump, based on current and future water demands. Implementation will result in an annual electrical cost reduction of 54% spent on horizontal water pumping.