Krzyzanowska, J., University of Pretoria, Pretoria, South Africa
Venetia Mine, an open-pit diamond mining operation in the Limpopo Province of South Africa, currently has a mixed haul truck fleet consisting of Caterpillar 785B and C; 789C; modified 793D and 793D. Even in an ideal situation these trucks have different cycle times, which causes queuing at the loading area and their different speeds cause bunching on the ramps, leading to higher overall cycle times and lower productivity. This problem was identified but the root causes of the problem were not investigated and quantified. A time and motion study on the haul trucks was thus undertaken to measure actual cycle times and compare them to ideal cycle times as well as to observe any reasons for deviations. Ideal cycle times are partly evaluated on the basis of simulation and partly from production optimization expert input. Several areas that affect production were identified and these include: haul road conditions, the control room, dispatching programme and dispatching data management, as well as truck-shovel matching. The investigation was important in establishing control parameters for haul fleet operation since time spent queuing is production time lost, which defers waste tonnes to later in the life of mine, thus decreasing the tempo at which kimberlite is exposed. © The Southern African Institute of Mining and Metallurgy, 2007.
Control parameters; Control rooms; Cycle times; Data management; Diamond mining; Different speeds; Haul trucks; Haul-road conditions; Loading area; Mining operations; Motion study; Open pits; Production Optimization; Production time; Root causes; South Africa; Automobiles; Control system analysis; Control theory; Diamonds; Fleet operations; Management information systems; Mine trucks; Mines; Mining; Mining engineering; Open pit mining; Parameter estimation; Solid wastes; Trucks; Time and motion study