Published in the December 2005 American Longwall Magazine

Other than at the simplest level, planning an underground mine with accurate costs and margins was little more than a pipe dream. As a result, underground planners focused simply on harvesting the most coal given the deposit’s physical and technical constraints. Forecast costs were essentially average numbers derived for the whole deposit.

Nor was it possible to develop accurate models for reserve monitoring, and as for detailed run of mine scheduling – unthinkable.

Modern high-speed computing power has changed all that and, along with the advent of sophisticated software tools, has radically reshaped the face of mine planning.

Australian company Runge, a leading global supplier of mining software, has led the way in utilizing computing power to enhance and add bottom line value to the mining process, from initial planning right through to scheduling. As the company’s catchphrase sums it up: from borehole to bottom line.

The company sold its first scheduling package – XPAC – in the early 1980s. Since then eight major upgrades have been released to market along with several add-on modules such as Automated Scheduling. To support this continual process of product enhancement some 30% of turnover is reinvested annually in research and development.

Runge enjoys 97% retention of its software products among clients – a powerful endorsement of the product’s acceptance among users.

The Brisbane-headquartered company has witnessed extraordinary growth in recent years and today has software products in use in more than 25 countries, including 98 software customers in American mines with three American underground coal mines. To support growing global demand the company has established offices in the Americas, Malaysia, the UK and Africa.

The company nurtures aspirations of entrenching its suite of software in the US market and with demand increasing for greater differentiation in coal products, there’s no reason this can’t be achieved. The company contends no other software provider can offer the full range of tools Runge does.

In its home market Runge enjoys 100% market share in underground coal mines in particular with its XPAC Underground Coal Mining module, introduced five years ago.

Here American Longwall Magazine presents an overview of the products and approaches Runge has developed specifically for underground coal mine operators.

Using margin ranking in underground coal

Runge pioneered the development of cost and margin ranking in underground coal operations and it is carried out with the company’s mine scheduling package XPAC (see below).

The main benefit of cost and margin ranking is that it can be used to generate an "economic mud map" of an underground coal deposit.

This map – typically a graphic display – highlights relativities of cash operating margins over the extent of the resource.

Being able to rank areas of a deposit in terms of economic characteristics is an attractive option. In the current market this could give operators the opportunity to cash in on market shortages or changing specifications.

This would improve the mine planning engineer’s ability to develop mine plans and schedules that are more responsive to market conditions.

Building a margin ranking involves the following steps:

1. Identify the key production and cost drivers: typical roof and floor conditions, seam gas concentrations, stress magnitude and direction, seam dip, etc.

2. Identify the key revenue drivers: typically yields, key quality parameters etc.

3. Divide the deposit into a regular grid of reserve blocks (typically 200 meters square) and generate reserves.

4. Develop an estimate of the longwall to development ratio and overall expected extraction percentage.

5. Determine the impacts on both development and longwall production resulting from variations in the key production drivers.

6. Establish a revenue ranking across the deposit based on yields and variations in coal price to coal quality parameters.

7. Generate the final margin ranking results by taking the cost ranking results from the revenue ranking.

8. Use the margin ranking results combined with key geological and technical constraints to design layouts and produce value scheduling scenarios.

SCHEDULING TOOLS

XPAC is Runge’s long-term scheduling tool and the industry standard in Australia and South Africa.

XPAC Underground was developed specifically to make underground coal operations more effective and cost-efficient. It is a tool for reserves analysis, mine design and scheduling and accepts data from all major geological seam modeling software.

“XPAC Underground has been designed with a strong business focus – resulting in an emphasis on modeling scenarios for business analysis,” Runge said.

“Detailed scenario costing is easy with XPAC, and the module has graphics and reporting tools to help you communicate your scenarios to operations and management personnel.”

Mine designs or design changes can be done very easily using a simple CAD environment for inputting underground panels and roadways.

Reserves can be generated with production and cost drivers linked into the design. This gives engineers the means to run different scenarios and identify which scenario offers economic benefits.

XPAC also stores geological grid files as well as physical/quality parameters, allowing reserves (including quality) to be calculated automatically as the mine design is created. Geologists are not needed to recreate reserves for each design change and the manual transfer of reserves data is eliminated.

XPAC’s logic is systematic, auditable and accurate, providing a consistent approach across operations and better forecasting detail with less risk of rework.

Recent enhancements in XPAC include the introduction of Detailed Centerline Design.

This is to cater for those mine planners who prefer to create their detailed designs as a set of roadway centerlines rather than discrete roadways and pillars.

The new tool takes a detailed centerline design and automatically “explodes” it into individual roadways and pillars. This detailed plan can then be “captured” using already existing detailed design tools.

XACT

This year Runge released Xact, a new short-term mine scheduling application, to plug the 12-week scheduling gap generally covered by spreadsheets rather than purpose built scheduling packages..

The company said that if integrated with XPAC, the combined versatility is unprecedented.

Xact allows mines to adjust scheduling in response to day-to-day problems and improved decision making while still considering long-term goals.

“It is the only application to combine Gantt charts, a reporting mechanism, a hierarchical navigation system and 3D representation of the mine,” Runge said.

“Xact shows you – on multi-screen displays – exactly what transpires when any aspect of your daily or weekly mining operation is changed.”

Every task at the mine – complex equipment, personnel and rostering – can be modeled. This means short-term options can be evaluated in less time. Preventive maintenance scheduling is also less of a headache.

The software has the flexibility to generate work orders based on an individual operation’s needs.

Longwall simulation

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