Brazil produced over 250 million tonnes of iron ore in 2003
with about two thirds of that being exported.

ALL of this was scheduled with NPV Scheduler... are you missing out?..

NPV Scheduler comprises three main modules: the ultimate pit shell optimizer, the pushback generator, the optimizing scheduler and with NPV Scheduler+, stockpiling and haulage optimization are also included. NPV Scheduler+MFO combines cut-off grade optimization seamlessly within the same framework.

The user is guided through the operation of each module with a flow sheet style menu which gives a clear indication of the processing path and the options available at each step. These options include improved 2D and 3D charting, contouring and visualization tools allowing the user to quickly validate and present the results of an optimization. NPV Scheduler is also supplied with the Data Source Drivers for easy import and export of block models from Datamine, Vulcan, Medsystem, Surpac, Micromine and generic text and SQL database files.

The ultimate pit optimizer is based on the industry standard Lerchs-Grossman method and features treatment of multiple ore types, multiple processing methods and multiple grades or products. Interactive tools are provided for creating slope region boundaries and surfaces, and definition of pit limit polygons. The user can specify a discount rate and mine production rate to generate a block extraction sequence which delivers the optimal net present value to the project. Each block in the output model is individually numbered to show the theoretically best mining sequence. In a single optimization run, any number of pit phases can be generated using a value reduction factor. The pit phases provide a family of nested pits which indicate the sensitivity of the ultimate pit to cost-price variations. The sequence and phase numbers stored in the output model provide an excellent guide to any first pass manual design of interim pits. The ultimate pit shell optimiser and block sequencing components of NPV Scheduler are also available in a separate program, MaxiPit.

Although NPV Scheduler includes ultimate pit and pushback generation, these modules can be by-passed allowing users to import their own pit shells and interim pit designs for scheduling. Wireframe or DTM models from most mine design and CAD programs are supported.

Chart of Cashflow ($) vs Optimal Extraction Sequence

The pushback generator is used to build a practical series of interim pits or pushbacks which follow the optimum extraction sequence as closely as possible. The user can specify the size of each pushback in terms of tonnages of ore or waste or by recovered product. Pushback runs can be unconstrained i.e. the program uses only the optimal extraction sequence to construct the pushbacks, or, the user can interactively force or restrict mining in specified pushbacks within polygonal limits or by depth.

The optimizing scheduler module is controlled through a series of easy to follow dialog boxes in which the user specifies time flow, calendar, production and target parameters. Any attribute contained in the input model can be used to either measure time flow or define schedule targets. Targets may be defined in terms of either rates or ratios with user defined mathematical expressions. Targets such as mill feed, grade or stripping ratio can be quickly specified along with more complex expressions for ore blending, ore contamination and other multi-parameter targets.

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Multiple targets can be specified and varied over the term of the schedule. The optimizer attempts to find the optimal schedule which satisfies all targets and, at the same time, maximizes the project NPV. If an optimal solution cannot be found, the scheduler will selectively relax targets until a viable schedule is obtained. Once obtained, schedules can be quickly charted or exported to a Windows spreadsheet program. The pit model generated contains the schedule period number for each block in the model. The model may also contain the sequence, phase and pushback numbers if these optional modules were used prior to scheduling. The output block model can finally be exported using the data source drivers as text or SQL tables, or in one of the many third party file formats available.

NPV Scheduler is all about turning an ultimate pit into an optimal pit - the pit which delivers both the highest possible cashflow and net present value, and at the same time, observes the varied constraints required to satisfy the practical design needs of the long term planning engineer.

With NPV Scheduler+, schedules also take into account building and reclaiming of any number of stockpiles. Any number of products (elements) and any number of processing methods can be analyzed. Product prices, mining costs, processing costs, and discount rates can be varied over time. Stockpiles specified by ore type, cut-off grade, capacity, reclaim rate and rehandling costs can be defined. Time dependent constraints for processing capacity, ore blending and output limits can also be included.

Practical scheduling is all about satisfying mill or process feed capacities while maintaining a steady truck fleet. Scheduling by strip ratio or a fixed production rate does not deliver a final, practical schedule. The tools available in NPV Scheduler take optimization beyond the economics of 'what to mine and when to mine it'. Haulage optimization provides the next practical step in managing extraction.

NPV Scheduler+MFO integrates cut-off grade and production rate optimization functions seamlessly with the standard ultimate pit, pushback, scheduling and stockpile optimization modules.

MineFlow Optimizer allows you to optimize cut-off grades and production rates over the life of the mine. This can make a significant difference to the NPV of the operation. The optimization method allows for a greater range of practical constraints than any other product. This is achieved by combining Ken Lane’s original ideas on cut-off grade optimization with dynamic programming and linear programming. Effectively the Mine Flow Optimizer allows you to combine short term planning decisions (cut-off grade and production rate optimization) within the framework of a total long term plan and schedule. MIneFlow Optimizer not only offers more features than other packages but is also the only package which can intelligently integrate cut-off grade optimization within an NPV maximized long term mine plan.

You can upgrade your existing NPV Scheduler+ installation to NPV Scheduler+MineFlow Optimizer by simply downloading and running the self-installing executable.

NPV Scheduler+MineFlow Optimizer requires a different Serial and License Number to the standard NPV Scheduler+ license. The program will operate in "demo mode" once the new executable has been installed. Contact your local Datamine office for more information on how to purchase and register this upgrade.

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Features:

• Choice of input block model formats;
• Windows 98/NT/2000 ease of use;
• In-built pit surface contouring;
• In-built charting and graphics;
• Integrated Windows text editor;
• Integrated Windows spreadsheet;
• Choice of output block model formats.

ULTIMATE PIT OPTIMIZER

• Lerchs Grossman method;
• Multiple slope regions and sectors;
• Interactive definition of slope region boundaries and surfaces;
• Handles multiple rock types;
• Handles multiple processing methods;
• Handles multiple grades and products;
• Underground economic limit option;
• Pit limits controlled by internal and external, depth limited polygons;
• NPV optimised extraction sequence;
• Nested pit generation.

PUSHBACK GENERATOR

• Use optimal pit shell, or Import user designed pit shells;
• Generate pushbacks (stages) to maximise project NPV inside ultimate pit;
• Mining rate and minimum mining width criteria;
• User defined pushback sizing;
• Contour pushback surfaces and differences between stages;
• Report and chart pushback statistics;
• Manual editing and restrictions on pushback redesign.

OPTIMIZING SCHEDULER

• Use generated pushbacks and optimal pit, or Import user designed pits for scheduling;
• Variable calendar periods;
• Production rates set per ore type/process and per period;
• Multiple user defined scheduling targets;
• Rate and ratio targets e.g. waste removal rate, stripping ratio, ore blending ratio;
• Targets varied by period;
• Target relaxation option;
• All feasible schedules analysed;
• Optimal NPV schedule generated;
• Contour pit surface at any selected period in schedule;
• Report and chart schedule statistics;
• Export schedule to MS Excel™ or Lotus™ Exported block model includes optimal block sequence, pushback and period numbers.

STOCKPILE OPTIMIZER

• Define multiple stockpiles by ore type, cut-off grade, capacity, reclaim rate and rehandling costs;
• Vary product prices, mining costs, processing costs and discount rates over time;
• Multiple products;
• Multiple processes;
• Time dependent processing capacity, ore blending, grade and output constraints;
• Generate optimal strategies for each time period;
• Chart all major statistics;
• Export statistics to a spreadsheet program;

CUTOFF GRADE OPTIMIZER

• Optional cut-off grade and production rate optimization plug-in.
• Vary product prices, mining costs, processing costs and discount rates over time;
• Multiple products and processes;
• Time dependent processing capacity, ore blending, grade and output constraints;
• Generates optimal mining rates over the lifetime of the mine;
• Generates optimal cut-off grades for each rock type and each processing method;
• Fully integrated with ultimate pit, pushback, optimized scheduling and stockpiling functions.

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Who's using MaxiPit and NPV Scheduler?

Brazil produced over 250 million tonnes of iron ore in 2003 with about two thirds of that being exported. ALL of this was scheduled with NPV Scheduler.

MaxiPit and NPV Scheduler have been applied to a wide variety of deposit types right across the globe, including:

What users say...

"Based on established algorithms, NPV Scheduler offers the power and flexibility combined with an extraordinarily easy to use interface that simply out performs the competition ..... The pushback generator in NPV Scheduler has allowed us to experiment with the sequencing of our mine plans and has easily paid for itself many times over by increasing the NPV of the company"

John Kobobel, Mine Planning Engineer, Cripple Creek & Victor Gold Mining Co., Colorado.

Read the full text of John's article.

"We have just replaced Whittle Four-D with NPV Scheduler. Apart from it’s superior functionality, the most impressive feature of NPV Scheduler is just how easy it is to use. Within minutes of installing the program I was able to import a block model and start building a new project. I found the online help and tutorials instructive, logical and relevant. Well done."

Pete Millan, Planning Manager, Potgietersrust Platinums Ltd., Amplats, South Africa