[Article 03 of 05] The Mining Production Chain: Planning, Mine Design and Mining – Strategy, Risks and Operation

Mine planning and design represent one of the most strategic phases of the mineral production chain, as they define how the deposit will be exploited throughout its lifespan. Decisions made at this stage determine not only the safety of operations but also the costs and sustainability of the entire project.

Geological Model and Mine Design

From a geological perspective, the accuracy of the geological model and the block model is critical. Inadequate characterization can result in:

• Overestimation or underestimation of reserves.
• Errors in the mining sequence.
• Failures in the project schedule and financial return.

Planning the exploration of areas that, in practice, do not have an economically viable grade or volume is a risk that can compromise the entire mine cycle.

Geotechnical Aspects of Planning

From a geotechnical perspective, the challenge lies in defining stability parameters, such as slope angles, drainage conditions, and construction techniques that ensure operational integrity over time. Projects that fail to adequately consider the geomechanical properties of the massif or the hydrogeological variations of the terrain run the risk of serious instabilities, such as landslides, subsidence in underground mines, or failures in support structures. Furthermore, a lack of integration between geological, geotechnical, and geomechanical models can lead to incompatibilities, rework, and additional costs.

Financial Risks in Planning

From a financial perspective, risk is linked to three main factors:

1. Overestimation of economic potential.
2. Underestimation of implementation costs.
3. Wrong choice of mining method (open pit or underground).

This combination can result in investments far exceeding those anticipated. Subsequent changes to correct planning flaws often lead to increased CAPEX and OPEX, reducing the project's attractiveness to investors and financiers. Therefore, mine planning must be supported by multidisciplinary integration, advanced modeling software, and scenario analysis, ensuring the project's technical, geotechnical, and economic viability.

The Mining Stage: Mineral Extraction

The mining (mineral extraction) stage constitutes the operational core of the production chain, being the moment when the resource is effectively extracted from the massif. This is an intensive phase in scale, involving large-scale equipment, high operational complexity, and direct interaction with the geological and geotechnical characteristics of the deposit.

Main Geological Risks in Mining

In the geological field, the main risks are related to grade variability and ore heterogeneity. Even with robust models, it is not uncommon for:

• Discrepancies between the estimated and found content.
• Unmapped structural faults.
• Weathering change zones.
• Unexpected presence of sterile materials.

These factors can compromise productivity and the continuity of mining.

Geotechnical Risks of Mining Operations

From a geotechnical point of view, mining is the most critical stage.

• In open-pit mines, slopes are directly affected by fracturing, drainage, weathering and pressure conditions induced by excavations, which can lead to localized or large-scale failures.
• In underground mines, risks such as subsidence, falling blocks, pillar instability and failures in support systems require constant attention.
• External factors, such as heavy rainfall or fluctuations in the water table, can aggravate instability, making continuous monitoring and the adoption of emergency containment measures essential.
  

Economic Impacts of Mining

From a financial perspective, mining is directly impacted by unexpected variations in ore grade and dilution, which impact both revenue and processing costs. Geotechnical instabilities or accidents can lead to partial or total shutdowns, generating significant losses. Furthermore, additional interventions, such as reinforcements of containment, drainage, or infrastructure, represent unforeseen costs that affect the balance between CAPEX and OPEX.

Multidisciplinary Integration and Support Technologies

Thus, both planning and mining highlight the need for integration between geology, geotechnics, and finance. The use of real-time monitoring technologies, combined with flexible planning and structured risk management, is essential to ensure the safe, efficient, and economically viable continuity of mining projects.