Política de reclamación

Lectura estimada: 5 minutos 1180 puntos de vista

Política de recuperación de existencias: Principles and Decisions

Stockpiles are handled as a post-processing unit of the optimization algorithm (leer más). También, another important point is to understand what guides MiningMath’s algorithm decisions for stocked and reclaimed blocks. MiningMath’s reclaim policy is based on the valores económicos. This goal is aligned with the objective of maximizing the NPV. Esto significa, blocks with higher value will be reclaimed first, regardless of the period in which the block has been mined and stocked.

How could we further control stockpiles and make it suitable to different sorts of controls?

Reclaim Policies vs Selectivity

Different mining packages may adopt different conventions for Stock Reclaim Policies, overall, based on the main goal for each application or module. Some of the possibilities may include:

FIFO: First In, First Out.
FILO: First In, Last Out.
Reclaiming an average grade for the entire stockpile.
Reclaiming the highest-value blocks first (MiningMath uses this method).

Each one of these possibilities is an approximation of reality, with its pros and cons. FIFO and FILO are quite logic but represent a level of selectivity that is not practical. The angle of repose and the positioning of each block are likely the most intuitive examples of lower selectivity in practice.

An average grade for the entire stockpile is naturally an approximation, considering the amount of material that should be blended to make it close to the reality.

Reclaiming the high-value blocks first is also a selectivity level that is not possible in reality. Por otra parte, it is quite aligned with the mathematical goal of maximizing the project’s NPV for strategic evaluation.

After all, notice that none of these approaches are fully operational. Aquí, the decision is still based on the professional in charge of strategy optimization, one’s preferences, experience, and skills to add further ways of control.

Preserving Value and Guiding the Reclaim Policy

This section aims to bring a few ideas on how the user might guide the algorithm in order to follow one’s preferred reclaim strategy.

Baseline Knowledge

For this article, the user should have prior knowledge in the following concepts.

Manipulating the Valores económicos para pre-define destinations.
Creating multiple economic assumptions para handle fake destinations.
Handling different output files (Mined Blocks and All Blocks).

Baseline Scenario

The general idea is to set up and run a baseline scenario to find what is optimal for the long-term value. The solution obtained in this step will guide further executions.

Output Format

The first step is to switch the output format to export the entire block model along with the optimization output information, which is represented by the Todos los bloques.csv. This is a basic step for any iteration that requires re-optimizing a previous solution. Por defecto, MiningMath exporta solo los MinedBlocks.csv.

Results will present a guide o which blocks should be mined, cuando, and which ones were mined, immediately processed, stocked then processed, or discarded.

Iterating over multiple scenarios

The idea here is to use previous outputs to create new columns of economic values, assuming the use of fake destinations, es decir. creating multiple processing streams that does not coexist and, En realidad, represent the same single plant. These fake destinations, along with a pre-definition of the destination through valores económicos is what allows the user to impose whatever sort of control is preferred.

Along with that, and based on the previous results, the user must manipulate new economic values pre-defining the final destination for each block.

Hands-on Approach

Steps here comprise:

Define a criteria for stocked blocks (Period Mined different from Period Processed) that should be reclaimed early or later. This criteria must be based on the previous results from the Todos los bloques.csv expediente (Figura 1), and on the columns Bloque minado, Período minado, Período Procesado, y Destino.
Pre-define destinations, based on the criteria adopted, by manipulating economic values. Use very negative values to prevent a block from going to a given destination, como se muestra en la figura 2.
Set up your scenario considering the pre-defined destinations will not coexist, as illustrated in Figure 3. Darse cuenta de:
- Proceso 1 and its stockpile will be used from Período 1 to Period 5.
- Proceso 2 and its stockpile will be used from Período 6 to Period 10.
- Proceso 3 and its stockpile will be used from Período 11 para .
Optimize the new scenario tener una mejor aproximación para el VAN final, considerando la estrategia de tu preferencia.

Enfoque FIFO (Ejemplo)

Para el enfoque FIFO, un bloque almacenado durante el segundo período en la primera ejecución, debe ser enviado a la reserva de Proceso 1 ser reclamado primero. Por eso, este bloque debe tener un valor muy negativo para todos los demás destinos.

MiningMath

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Política de reclamación

Política de recuperación de existencias: Principles and Decisions

Reclaim Policies vs Selectivity

Preserving Value and Guiding the Reclaim Policy

Baseline Knowledge

Baseline Scenario

Output Format

Iterating over multiple scenarios

Hands-on Approach

Enfoque FIFO (Ejemplo)

CONTENIDO

MiningMath

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Política de reclamación

Política de recuperación de existencias: Principles and Decisions

Reclaim Policies vs Selectivity

Preserving Value and Guiding the Reclaim Policy

Baseline Knowledge​

Baseline Scenario

Output Format

Iterating over multiple scenarios

Hands-on Approach

Enfoque FIFO (Ejemplo)