TY - THES

T1 - REVIEW OF THE SANDVIK DP1500 DRILL RIG APPLICATIONS / PRODUCTIVITY AND ITS EFFECT ON ORE PROCESS OPTIMISATION AT THE TARKWA GOLDFIELDS MINE GHANA.

AU - Awumee, James Yao

N1 - embargoed until null

PY - 2010

Y1 - 2010

N2 - The purpose for a performance analysis to be carried out on a drilling machine at a mine is important. This analysis would usually be done at the start during the mine planning stages. However, as it progresses several changes happen. The rocks get harder, and the geology shifts considerably. It is therefore important to analyze the performance of the drilling equipment occasionally to ascertain if same is adequate for the current dynamics at the mine. The main criteria are the penetration rates (in meters per hour) and the specific energy, the amount of energy required to break or crush a unit volume of rock (in kilo Newton per cubic meter). The later is compared accurately and directly with the specific energy of the rock itself. Where the rocks demand is equal or higher than that provided by the machine penetration rates will drop substantially, costs of repairs would rise and other energy input sources (such as fuel) will rise in consequence. This information then becomes indispensable to the original equipment manufacturer. The fragmentation and ore size distribution have a direct relation to the volumetric flow at the mine. When materials are coarse the volume transferable to the primary crusher is limited and expensive re-handling happens. Materials in range would produce adequate amounts at the milling stages and the energy consumption at the crushing plant is reduced. Generally, two blasts cannot be the same. Same powder factor (patterns implied) in two different places could produce two different results. Rock mass, hardness and character change from one place to the other. There are two ways of tackling such situations: first, select a high powder factor that covers the adversities of rock changes in the mine or second, use drilling information coming from the rig on a case by case situation to forecast the powder factor requirement. The first could result in high explosives costs while the second appears suitable for a mine with changing rock dynamics. From their penetration rates and specific energy, percussive rigs, can provide a means to acquire the blastability index of kuz-ram formula. From then the ore size distribution can be derived as well as other important blast information.

AB - The purpose for a performance analysis to be carried out on a drilling machine at a mine is important. This analysis would usually be done at the start during the mine planning stages. However, as it progresses several changes happen. The rocks get harder, and the geology shifts considerably. It is therefore important to analyze the performance of the drilling equipment occasionally to ascertain if same is adequate for the current dynamics at the mine. The main criteria are the penetration rates (in meters per hour) and the specific energy, the amount of energy required to break or crush a unit volume of rock (in kilo Newton per cubic meter). The later is compared accurately and directly with the specific energy of the rock itself. Where the rocks demand is equal or higher than that provided by the machine penetration rates will drop substantially, costs of repairs would rise and other energy input sources (such as fuel) will rise in consequence. This information then becomes indispensable to the original equipment manufacturer. The fragmentation and ore size distribution have a direct relation to the volumetric flow at the mine. When materials are coarse the volume transferable to the primary crusher is limited and expensive re-handling happens. Materials in range would produce adequate amounts at the milling stages and the energy consumption at the crushing plant is reduced. Generally, two blasts cannot be the same. Same powder factor (patterns implied) in two different places could produce two different results. Rock mass, hardness and character change from one place to the other. There are two ways of tackling such situations: first, select a high powder factor that covers the adversities of rock changes in the mine or second, use drilling information coming from the rig on a case by case situation to forecast the powder factor requirement. The first could result in high explosives costs while the second appears suitable for a mine with changing rock dynamics. From their penetration rates and specific energy, percussive rigs, can provide a means to acquire the blastability index of kuz-ram formula. From then the ore size distribution can be derived as well as other important blast information.

M3 - Master's Thesis (University Course)

ER -