One of the oldest industries in the history of man, mining has evolved over the centuries. Gone are the days of canaries in cages, pick-axes, and candle-lit headlamps. With Global Positioning Systems (GPS) and automated machinery, today’s operating mines are at the cutting edge of technology – taking the best of space-age advances to drive the industry. The role of the engineer in mining operations has evolved along with the industry. Today’s mining engineer is the link between production and technical services, determining the direction the project will take, and how it will get there.
The mining engineer looks for processes, not independent solutions that link the computer model of the geology to the production crews who recover the reserve. These processes are integrated with each other in a flow – Geological Model to Mine Design to Mine Plan to Production Schedule to Mine Reconciliation. A well-integrated process flow allows the engineer to mesh and sequence steps in the process, maintaining the consistency of data that leads to meaningful results.
The engineer employs the software systems that are most in demand in the industry. Historically, geological modeling and mine design and planning have been packaged together, while scheduling, reporting, and costing were often done using spreadsheets or a separate package. Many packages attempted to bridge this division, but due to their inability to effectively meet the requirements of mining operations, no clear leader has emerged in scheduling software. However, as scheduling software developers delve into mine design, while modelling companies increase their scheduling capabilities and expertise, the playing field levels out.
The typical requirements for planning and scheduling a mine include:
1. The Resource and Geological Model as a starting point for engineering design and planning work. It is a geologist’s interpretation of drill hole information, and allows the engineer to visualize and suitably design access to the ore and decide on the methodology to extract it. In particular, SRK’s in-house expertise can provide 3D geological models on nearly every computer system used around the world.
2. The Engineering Model is the key component in the planning and scheduling process. It uses engineering parameters to determine the extent of the deposit and assess the mineable quantities and qualities of ore. It provides the practical, mineable interpretation of the geological model.
3. The Scheduling Model is the tool used to determine the rate, quantity, and sustainability of the engineering model. Adding this “time” component allows the engineer to calculate what practical production can be generated and maintained over the course of the mine’s life. It pinpoints periods of stress, where parameters may need to be modified to continue effective operations, and alerts the engineer to make adjustments to designs and plans to accommodate deficiencies in mine production before they become operational or contractual problems.
SRK is proficient in using proven geological modeling and design packages. SRK Australia has demonstrated its expertise in using the following packages:
• Gemcom • Minescape
• Surpac • Minesight
• Vulcan • Minex
• Xpac
The most commonly used software packages in geological modeling for coal are MineScape and Minex. SRK Australia’s coal group adds Surpac to the mix to calculate the reserves and conduct mine planning and scheduling of mining activities.
With these resources available in-house, the SRK coal group can provide a full range of services to the mining industry that cover geological modeling, mine planning and scheduling, for both open pit and underground coal mining projects and operations.
Underground Mining
Underground mining is the oldest method of mining coal. From the late 1970s to early 1980s open pit operations increased, achieving high quantities of production and lower production costs. However, today, with environmental considerations and the greater depth of coal seam deposits, underground mining is proving to be the more viable alternative.
Underground mining technology has experienced a revolution in the last few centuries, from pick-and-shovel mining to fully automated systems in every aspect of the process. This has not only improved productivity by leaps and bounds but, more importantly, has significantly improved safety standards. Modern underground mines are highly mechanized as new technology continues to evolve.
This high level of mechanization must be accompanied by a high level of monitoring and reporting, as the investment in these systems is extremely costly. For example, the cost of a typical longwall installation could vary between A$100 million and A$300 million. Investments at that level must be supported by accurate geological data, resource and reserve estimation, mine planning and economic projections. The application of mine planning software systems contribute significantly to proving the economic viability of the mine, by handling large data sets with flexibility and speed. Using these tools engineers can assess the geological information, prepare 3D models of the seam, develop quality parameters and conduct structural interpretation. In turn, data is available for engineering and mine planning using specific modules for underground and open pit respectively. Engineers use these packages to calculate resources and reserves within mining parameters, such as method of mining, presence of structural interferences, quality parameters and seam extraction height.
Following the mine plan, the development and production quality parameters and seam extraction height can be scheduled to identify the achievable production rates and the optimum utilization of the available resources. These software packages and mechanized mining methods have improved the economics of underground coal mining operations, despite high capital investments.
Open Pit Mining
The old adage that “bigger is better” manifests itself in open cut mining for coal. In the last decade, open pit mining equipment has exploded in size and productivity. Coal mines have benefited greatly from the technology boom, as previously “unmineable” resources are now well within the capabilities of the new generation of equipment. Open pit coal mines are typically large, table-like, flat-lying deposits with minimal cover. Since coal is extremely susceptible to oxidation, the deposit must be thick enough to absorb a degree of oxidation without losing its economic value. The equipment used to mine the overburden must maintain a high level of productivity to ensure that such deposits can be mined economically.
Typically, it was assumed that open pit coal mines required dragline excavators – the massive slow moving machines that compensate for their ungainly movements with the sheer size of the bucket that moves waste material. Today, advances in truck and shovel technology allow quick-moving, extremely mobile fleets of hydraulic excavators, shovels, and haul trucks to reach, and even exceed, the productivity levels of draglines. Instead of tying up tens of millions of dollars in a single piece of excavating equipment, it is possible to obtain three or more excavators for the same price as a single dragline – and still maintain production levels, while increasing the availability and utilization of the fleet. Continued advances in technology successfully provide operators the tools to monitor fleet productivity and equipment performance that prevent breakdowns before they happen, ensuring that the open pit operations will continue to produce for years to come.
