R. S. Suglo

NUMERICAL SIMULATION OF SURFACE MINE PRODUCTION SYSTEM USING PIT SHELL SIMULATOR

Surface mine production systems involve complex, multi-faceted and costly sequence of processes that must be planned, designed and evaluated to promote well-conditioned decision processes. Strategic and tactical mine plans are used to provide a long-term production vision and the resource requirements for meeting specific periodic mine and plant capacities. The schedule and sequence of material movement must respond quickly to changing technical, safety and economic constraints within the surface mining environment. Many production planning, scheduling and resource allocation methods are based on simplistic methodologies without rigorous technical and economic basis. These methods fail to consider the random processes governing critical production variables. With increasing demand for efficient schedules for low-cost bulk production requirements, the need for efficient tools is critical. In this study, the authors develop an innovative pit shell simulator to address these problems. Rigorous geometric formulations of the ellipsoidal approximations of the pit shells geometry, their planar expansions and vertical interactions are modeled to mimic material displacement dynamics in an open pit operation. Numerical simulation techniques are used to provide solutions to the time-dependent geometric models in random multivariate states. The pit shell simulator is used to solve the Pine Valley open pit mine production schedule for the first three years of production. The simulator provides the schedule and sequence of all the cuts from various quadrants in the four pit shells within the optimised pit layout. The simulator results show that, in order to maximize the mine value, the mine must produce 304,000, 180,000 and 140,000 tonnes of ore respectively for years 1, 2 and 3. The total materials within this period also include 72,000, 80,000 and 190,000 tonnes of stockpiles and 30,000, 80,000 and 30,000 tonnes of waste materials respectively for years 1, 2 and 3. This results in a maximum NPV of

Dynamic Torque and Soil Deformation Mechanics and Simulation of the GAP Virtual Machinery

27,000 at a discount rate of 12 percent over the 3-year duration.

An assessment of dilution in sublevel caving at Kazansi Mine

Global crude oil demand is growing at a faster rate than supply. Many conventional oil fields have peaked in the middle of a growing demand across the globe. Oil sands and heavy oil reserves will provide partial solution to this problem in the foreseeable future. Research is thus required to provide answers to difficult and challenging problems associated with the economic extraction of oil sands. The ground articulating pipeline (GAP) system is a novel and potential technology being considered for oil sands production. This paper deals with some results of the current research initiatives on the GAP system dynamics and machine-oil sands interactions. Mathematical models governing the GAP mechanism and the oil sand terrain dynamics are modeled based on the theory of multi-body and soil mechanics, which are derived from Newton-Euler dynamics. These models consist of the GAP dynamic model for analyzing the dynamic driving torque of the system, GAP track-oil sand contact model for generating the contact force between oil sands and track and load-deformation oil sand model for capturing the dynamic behavior of oil sands. The results are used to develop 3D virtual prototype simulators using the ADAMS software. The virtual prototype models are validated using real-world data to generate the driving torque for the various GAP machine carriages and the dynamic response of the oil sands to carriage motion. The simulation results of the effect of the friction between oil sands ground and carriage, the angular velocity of the pipeline and the load applied to each machine carriage on the driving torque show that the load and friction have a greater influence on the driving torque value than angular velocity. The interactions between oil sands and tracks at an environmental temperature of 25°C are analyzed in detail under visco-elastic material conditions. The simulation result of the effect of load on oil sand deformation indicates that maximum deformation value increases non-linearly with load varying from 0 to 60t. The research results provide fundamental insights into the effective deployment of the GAP machinery in the tough oil sands conditions.

Environmental Impact of Mining and Ore Processing – A Case Study at Satellite Goldfields Limited

Dilution, which is difficult to quantify accurately, is a major concern in underground mining. The level of dilution in the sublevel caving areas at Kazansi Mine is currently difficult to assess owing to the lack of data. The acceptable dilution levels differ from mine to mine but the current planned dilution of 35% on the mine is too high. This paper attempts to assess the dilution levels in sublevel caving areas (Blocks 5 and 6) at Kazansi Mine. The excess tonnage concept when used to compute the dilution factor for the blocks gave a dilution factor of 44.45% while the lowering grade concept gave a factor of 17.91%. The overall dilution factor for the block was found to be 31.18%. The lowering grade concept of dilution factor computation is recommended as it gives smaller value of 17.91%.

Novel At-Face-Slurry Performance Modeling with Elliptical and Spherical Geometries

The increasing number of surface mines in Ghana and the consequent adverse effects of mining operations on the environment have been of great concern to the local communities, government and non-governmental organisations in Ghana over the last decade. Satellite Goldfields Limited (SGL) is an open pit gold mine in the Mporhor Wassa East District which produces about 10,000 tpd of ore at an average stripping ratio of 2.1:1. Ore is processed by crushing, treatment by agglomeration, stacking, heap leaching, electro-winning and smelting.

Determination of the cutting resistance model of soil

Surface mine production scheduling and sequencing are used to maximize the expected profit and investment returns from mining operations. The pit geometries and expansion rates, and the periodic volume of materials from different benches in a multi-bench, multi-face open pit mine determine the equipment requirements, which impact the maximize just-in-time (JIT) production decisions. The analytical geometric volume calculations require time lags that prevent rapid information for JIT decisions. The introduction of the novel At-Face-Slurry (AFS) oil sands method require fast, accurate and repeatable pit volume estimation using continuous flow process. The first part of this paper shows how partial differential equations (PDEs) and geometric techniques were used in modeling material volume, as well as pit layout changes with circular and elliptical geometries of an oil sands mine. The second part contains the economic analysis on the current mining system (CMS) and the cyclic excavator conveyor belt control system (CycEx CBCS). A continuous flow process via PDEs was used to model material volume, as well as pit layout changes with circular and elliptical geometries of an oil sands mine and compared with analytical geometric methods. PDEs were used in the modeling due to the continuous nature of the changes in the volumes of the pits with time. The geometric and PDEs values are similar for the pit configurations. This work represents the first successful attempt at using PDE in geometric calculations for open pit mines. The economic analysis shows that the NPV of the current mining system (CMS) is

Computer simulation of underground room and pillar mining

3.2×1010 while that for the cyclic excavator conveyor belt control system (CycEx CBCS) is

Assessment of the Efficiencies of Auxiliary Ventilation Systems Using Empirical Methods

4.06×1010. The Profitability Index (PI) for the CMS and CycEx CBCS options are 19.37 and 43.37 respectively. The IRR of the CMS option is 29.02% while that of the CycEx CBCS option is 33.37%. The DPBP for the CMS and CycEx CBCS options are 3.24 months and 1.92 months, respectively. The CMS option has an operating cost of

Contract Mining versus Owner Mining - The Way Forward*

1.386/tonne (

Simulation of at face slurrying method and continuous miner truck system in an open pit mine

2.774/barrel) while that of the CycEx CBCS option is