Discrete-Event Simulation of Mining Systems:

This model is a planning tool that could be reused for future studies and planning. The optimal short-term production schedule is the main input to the simulation model in an Excel file format. Short-term planning blocks will be aggregated into selective minable shapes based on a similarity index which could be defined as a weighted function of grade, rock-type, recovery, block dollar-value, or other attributes of interest. These clusters of blocks will represent mining-faces with uniform material. The clustering approach allows practical mining-faces to be defined with accurate dilution factors. These mining-faces are one of the main components of the simulation model. In the simulation model shovels move to a mining-face and load the material associated with the blocks that belong to that mining-face. The destination of the material is already decided by the short-term production schedule. Vertical and horizontal precedence among mining-faces are defined, which follow a minable precedence among the blocks honoring overall pit-slopes. The precedence of mining-faces will be honored in the simulation model. This means that at any given time there are a number of available mining-faces that shovels could be allocated to them. The general structure of the main components and modules in the simulation are as follows:

• The input interface for the probability distributions in Excel,
• The interface of the short-term production schedule and the simulation,
• The input interface of the haulage-network in Excel
• The logic for the mining-face extraction sequence in Arena
• The logic of truck-shovel systems linked to the short-term plan
• The logic of auxiliary equipment
• The cost calculation and reporting methodologies for the operation
• The failures of mining-systems and downstream activities logic in Arena,
• The strategies to change the short-term plan due to failures,
• The dispatching logic that mimics the mine’s dispatching system,
• The stockpiling strategies,
• The fuel consumption calculation logic,
• The real-time animation dashboards for the systems’ KPIs,
• The reporting and charting simulation output analysis in Excel and PDF reports.




Results and Deliverables
Results and deliverables expected as key outcomes of this research project are truck-shovel operational planning methodology, simulation software, and documented best-practice guidelines which are able to:


Truck-shovel allocation


Optimize loading and haulage systems efficiency
Optimally allocate trucks and shovels to mining-faces to comply with
Maximize the mine’s production utilizing the available truck-shovel system
Minimize the number of trucks required to meet the production target
Meet hourly plant head-grade blending requirements
Avoid unnecessary shovel moves
Meet target production in tonnes and grade with minimum number of mining-faces
Expose material for excavation in a timely fashion as per the short-term schedule
Minimize unit mining costs
Optimize the truck-shovel fleet size
Maximize productivity with available equipment
Achieve a desired production with minimum equipment


Productivity


Improve system efficiency by reducing truck waiting time at processing plants
Assess mining-systems’ productivity
Evaluate various operating techniques and scenarios to maximize fleet productivity
Investigate the impact of the selected equipment and operating decisions on fleet performance
Assess multiple fleet possibilities and investigate various scenarios
Study the impact of various heuristic dispatching policies on improving haulage productivity
Understand the factors that impact on fleet productivity and cost

Production Schedule


Assess impact of haulage system, cycle times, and correct matching on the schedule
Maximize tonnes per truck ready hour
Provide more accurate short-term forecasts for equipment operating hours
Model crushers as units that interact with the truck-shovel system
Assess the goodness of selection of the number of trucks assigned to the mine
Design the mine-layout to fit equipment characteristics
Evaluate the impact of haul road profiles and rolling resistance on optimum truck match
Quantify the economic effect of over and under-trucking
Serve as a planning tool to estimate the compliance of planned vs. actual tonnes and grades
Integrate cost data and calibrate haulage systems against actual historical performance data
Evaluate how the system characteristics change due to changes in the haulage distance
Assure adequate working room for equipment


Dispatching


Assess the operational outcome of the truck-shovel system based on the reliability
Gauge the impact of different dispatching rules on the overall efficiency of system
Achieve a lower probability of queuing at shovels and crushers
Assess functioning of trucks, mean times of truck work cycle phases and corresponding statistics
Minimize the wait time seen by the shovels and trucks in the system
Enhance the analysis and comparison of available heuristic truck dispatching policies
Increase utilization of truck-shovel systems and reduce waiting times in the haulage network
Reveal bottlenecks in the proposed truck haulage-system
Simulate complex traffic behaviour of platoon formation and congestion propagation
Minimize truck wait-time
Minimize shovel wait-time
Minimize shovel production requirement
Minimize truck cycle time
Minimize shovel saturation
Assist in auxiliary equipment management
Minimize the impact of shift-change and scheduled crew changes on equipment utilization
Assess the impact of trainee, qualified, and experienced shovel and truck operators on production
Assure proper change of shovel operators
Calculation of fuel consumption and load factor for haul profiles and trucks


Maintenance


Develop a maintenance schedule based on variations in truck-shovel utilizations over time
Evaluate required number of spare loading machines
Assess the number of trucks in reserve and the number of repair stands in the repair-shop
Measure the changes of reliability states of the mining systems (work-repair-reserve)
Determine reliability of truck-workshop system to schedule repairs and overhauls