Mine Planning and Design: From Concept to Production

Mine planning and design is the engineering discipline that transforms a geological resource — a body of mineralised rock beneath the ground — into a practical, profitable mining operation. It is the bridge between exploration and production, the stage at which scientific data is translated into engineering drawings, production schedules, capital budgets, and operating plans that will guide every aspect of the mine's life.

A well-executed mine plan maximises the economic value extracted from a deposit while ensuring safety, environmental compliance, and operational efficiency. A poor mine plan can render even a rich deposit uneconomic, expose workers and communities to unnecessary risks, or create environmental liabilities that persist for generations. The stakes are high, and the process demands a rigorous, systematic approach grounded in reliable data and sound engineering judgement.

This article walks through the mine planning process from initial concept through to production readiness, covering each major phase in the sequence that practising mine planners follow. While the principles apply to mining projects of all scales and commodities, we place particular emphasis on the small-to-medium scale operations that characterise much of East Africa's developing mining sector, including Uganda.

For context on the exploration work that generates the data used in mine planning, see our guide to the mineral exploration process and our article on mining feasibility studies.

Phase 1: Data Collection and Geological Understanding

Mine planning begins with data — and the quality of the plan can never exceed the quality of the data on which it is built. Before any mine design work commences, the planning team must assemble and validate a comprehensive dataset that describes the deposit and its surrounding environment.

Geological and Resource Data

The foundation is the geological model and resource estimate produced during the exploration phase. This includes:

Drill hole database. All exploration drilling data — collar locations, downhole surveys, lithological logs, assay results, geotechnical measurements, and density determinations. The drill hole database is the primary input for resource modelling.
Geological model. A three-dimensional interpretation of the deposit geology, including ore body geometry, grade distribution, structural controls, weathering profile, and waste rock characteristics. Modern mine planning uses computerised geological models built in specialised software such as Surpac, Datamine, Vulcan, or Leapfrog.
Resource estimate. A classified mineral resource (Inferred, Indicated, and Measured) calculated in accordance with internationally recognised reporting codes such as JORC, NI 43-101, or SAMREC. The resource estimate quantifies the tonnes and grade of mineralisation available for mine design.

For more on how ore reserves are estimated, see our article on ore reserve estimation methods.

Geotechnical Data

Geotechnical information determines the safe and achievable geometry of the mine excavation:

Rock mass quality. Data from oriented diamond core, including Rock Quality Designation (RQD), joint spacing, joint condition, intact rock strength, and rock mass classification (RMR, Q-system, or GSI).
Slope stability analysis. For open pit mines, geotechnical data informs the design of pit wall slopes — the steeper the walls can safely be, the less waste rock must be removed to access the ore, and the more economic the mine becomes.
Underground stability. For underground mines, geotechnical data governs the selection of mining method, the dimensions of openings (stopes, drives, shafts), and the ground support requirements.

Hydrogeological Data

Groundwater conditions affect mine design, operations, and costs:

Water table depth and aquifer characteristics. Mines that extend below the water table must manage groundwater inflow through dewatering wells, sumps, and pumping systems.
Permeability and storativity of surrounding rock. These parameters determine the volume and rate of water inflow that the mine will need to manage.
Water quality. Acidic or mineralised groundwater may require treatment before discharge, adding to operating costs.

Environmental and Social Data

Baseline environmental studies. Flora, fauna, water quality, air quality, noise, and soil conditions.
Social and community data. Land ownership, community demographics, cultural heritage sites, and stakeholder concerns.
Regulatory requirements. Environmental impact assessment (EIA) obligations, permitting requirements, and closure planning regulations.

Topographic and Infrastructure Data

Detailed topographic survey. High-resolution survey data (typically from drone photogrammetry or LiDAR) provides the terrain model on which the mine design is placed.
Existing infrastructure. Roads, power lines, water supply, settlements, and other features that constrain or support the mine layout.

Phase 2: Mining Method Selection

With a thorough understanding of the deposit and its context, the next step is selecting the appropriate mining method. This is one of the most consequential decisions in the entire mine planning process, as it determines the capital investment required, the operating cost structure, the production rate, and the overall project economics.

Surface Mining Methods

Surface mining — also known as open pit or open cast mining — involves removing overburden (waste rock and soil above the ore) to expose and extract the mineralised material from above. It is generally preferred when:

The deposit is located at or near the surface
The ore body is relatively flat-lying or gently dipping
The stripping ratio (volume of waste to volume of ore) is economically acceptable
The deposit is large enough to justify the capital investment in earthmoving equipment

Open Pit Mining is the most common surface method. It involves excavating a progressively deeper pit with benched walls, using a combination of drilling, blasting, loading (excavators or front-end loaders), and hauling (dump trucks). Pit design involves optimising the pit shell geometry to maximise the net present value of the ore recovered while maintaining safe wall angles.

Strip Mining is a variant used for near-horizontal, tabular deposits (such as coal seams or laterite nickel deposits) where the overburden can be stripped in parallel strips and the waste from each strip used to backfill the previously mined strip.

Quarrying is used for dimension stone, limestone, aggregate, and other construction minerals where the extracted material is the product itself.

Underground Mining Methods

Underground mining is employed when the deposit is too deep, too steeply dipping, or has too high a stripping ratio for economic surface extraction. Underground methods involve sinking shafts or driving declines to access the ore body, then extracting it through various stoping methods:

Room and Pillar — used for flat-lying, tabular deposits in competent rock, where rooms are excavated and pillars of ore are left to support the roof.
Cut and Fill — ore is mined in horizontal slices, and the void is backfilled with waste rock, tailings, or cemented fill before the next slice is taken. Suitable for steeply dipping, irregular ore bodies.
Sublevel Stoping — large, regular ore bodies in competent rock are mined by drilling and blasting vertical or near-vertical slices (stopes) between sublevels.
Block Caving — used for large, low-grade deposits where the ore body is undercut and allowed to collapse under its own weight, with broken ore drawn from below.
Shrinkage Stoping — ore is mined in ascending slices, with broken ore left in the stope to serve as a working platform; the excess is drawn off from below.

Selecting the Method

The choice between surface and underground mining — and the specific variant within each category — depends on:

Depth of the deposit. Shallow deposits favour surface mining; deeper deposits require underground methods.
Ore body geometry. Flat, wide deposits suit open pit or room and pillar methods; narrow, steeply dipping veins may require cut and fill or shrinkage stoping.
Rock mass quality. Competent rock allows larger openings and steeper pit walls; weak rock requires more conservative designs and additional ground support.
Grade and value of the ore. Higher-grade, higher-value ore can justify the greater cost of underground mining.
Stripping ratio. The ratio of waste to ore determines the breakeven point between surface and underground methods.
Scale of operation. Large deposits may support capital-intensive methods (block caving, large open pits); smaller deposits are better suited to selective, lower-capital approaches.

In Uganda and much of East Africa, where many mineral deposits are small to medium in scale and infrastructure is still developing, mine plans often favour lower-capital approaches: small open pits with modest equipment fleets, or underground methods that can be implemented incrementally.

Phase 3: Mine Design

Once the mining method is selected, the mine planning engineer creates a detailed three-dimensional design of the mine excavation.

Open Pit Design

Open pit design involves the following key elements:

Pit Optimisation. Using the geological block model, metal prices, mining costs, and processing costs as inputs, optimisation software (such as Whittle or Pseudoflow) generates a series of nested pit shells representing the economically optimal pit boundaries at different revenue assumptions. The mine planner selects the pit shell — or combination of shells — that maximises the project's net present value (NPV).

Pit Geometry. The selected pit shell is converted into a practical pit design with benched walls. Key parameters include:

Bench height (typically 5 to 15 metres)
Bench face angle (determined by geotechnical analysis)
Berm width (catch benches for safety)
Overall wall angle (the effective slope from pit crest to pit floor)
Ramp width and gradient (for haul road access)

Waste Dump Design. The mine plan must include locations and designs for waste rock dumps, considering stability, drainage, environmental impact, and potential for progressive rehabilitation.

Water Management. Surface water diversion channels, in-pit sumps, dewatering wells, and sediment control structures are incorporated into the design.

Underground Mine Design

Underground mine design involves:

Access development. The design of shafts, declines, adits, or ramps to access the ore body from the surface. The choice between shaft and decline access depends on depth, production rate, and ventilation requirements.
Level layout. The horizontal development (drives, crosscuts, ore passes, ventilation raises) on each mining level.
Stope design. The dimensions and sequencing of production stopes, including drilling patterns, blasting designs, and backfill requirements.
Ventilation design. Underground mines require forced ventilation to supply fresh air, remove blast fumes, and control temperature and humidity. The ventilation network is a critical component of the mine design.
Ground support. The type and pattern of rock bolts, shotcrete, mesh, steel sets, or other support required to maintain stability in the mine openings.

Phase 4: Production Scheduling

The mine design defines what will be mined. The production schedule defines when it will be mined. Scheduling is where the mine plan comes to life as a time-sequenced programme of extraction that determines the project's cash flow profile.

Strategic Scheduling Principles

Early access to high-grade ore. Scheduling strives to bring higher-grade material into production as early as possible, accelerating revenue generation and improving the project's NPV.
Blending and grade control. The schedule must manage grade variability by blending ore from different areas to maintain a consistent feed grade to the processing plant.
Waste stripping ahead of ore. In open pit mining, sufficient waste must be removed in advance to expose ore for extraction in future periods. This pre-stripping creates a significant early capital requirement.
Equipment utilisation. The schedule must balance production targets with the available equipment fleet and workforce capacity.
Smooth production profile. Lenders and investors prefer mine plans with steady, predictable production profiles rather than volatile year-to-year swings.

Scheduling Tools and Outputs

Production schedules are typically generated using specialised mining software (MineSched, XPAC, Deswik, or similar) that links the three-dimensional mine design to a time-sequenced extraction plan. The primary outputs are:

Tonnes of ore and waste by period (monthly, quarterly, annually)
Head grade of ore delivered to the processing plant by period
Equipment and labour requirements by period
Waste dump and stockpile volumes by period
Cash flow projections by period

Phase 5: Infrastructure Planning

A mine does not exist in isolation. The mine plan must include the design of all supporting infrastructure.

Processing Plant

The mineral processing plant — or concentrator — is designed to extract the valuable mineral from the mined ore. The choice of processing technology depends on the mineral being recovered, the ore characteristics, and the project scale. Common processing routes include:

Crushing and grinding followed by gravity separation, flotation, or leaching for metallic ores
Simple crushing and screening for construction materials and industrial minerals
Dense media separation for certain industrial applications

The processing plant capacity must be matched to the mine production rate, and the plant location must consider ore haulage distances, water supply, tailings storage, and access.

Tailings Storage Facility (TSF)

The tailings storage facility is one of the most critical and environmentally sensitive components of any mine. It must be designed, constructed, and managed to international standards (GISTM — Global Industry Standard on Tailings Management) to prevent catastrophic failure and long-term environmental contamination.

Water Supply and Management

Mining operations require substantial volumes of water for mineral processing, dust suppression, equipment maintenance, and camp supply. The mine plan must identify reliable water sources — typically a combination of groundwater, surface water, and recycled process water — and design the conveyance, treatment, and storage systems.

Power Supply

Reliable power is essential for mine operations. The mine plan must assess available power sources — national grid connection, on-site diesel or gas generation, solar arrays, or hybrid systems — and design the distribution network to serve the mine, processing plant, and camp.

Roads and Transport

Access roads, haul roads within the mine, and transport routes for product (ore concentrate, finished product) must be designed to handle the expected traffic volumes, vehicle sizes, and weather conditions.

Camp and Facilities

For remote mine sites — which are common in Uganda — the mine plan includes accommodation for the workforce, offices, workshops, stores, fuel storage, medical facilities, and communications infrastructure.

Phase 6: Equipment Selection and Workforce Planning

Equipment Selection

The mine plan must specify the type and quantity of equipment required, sized to match the production schedule:

Drilling equipment. Production drill rigs for blast hole drilling (or exploration rigs for smaller operations).
Loading equipment. Excavators, front-end loaders, or underground LHDs (load-haul-dump machines).
Hauling equipment. Dump trucks (rigid or articulated), underground trucks, or conveyor systems.
Support equipment. Dozers, graders, water carts, service vehicles, and light vehicles.
Processing equipment. Crushers, mills, flotation cells, leach tanks, or other processing machinery.

For smaller operations in East Africa, the equipment fleet is often scaled down significantly, using smaller trucks, simpler processing circuits, and more labour-intensive methods where appropriate.

Workforce Planning

The number and skill mix of the workforce must be planned to match the production schedule and equipment fleet. This includes mine operators, maintenance technicians, geologists, surveyors, engineers, environmental officers, safety personnel, and administrative staff. Training programmes — particularly for local employees — are an important component of workforce planning.

Phase 7: Cost Estimation and Financial Modelling

The mine plan culminates in a comprehensive cost estimate that forms the basis of the project's financial model.

Capital Costs (CAPEX)

Capital costs include all expenditures required to bring the mine from its current state to full production:

Mine development (pre-stripping, shaft sinking, decline development)
Processing plant construction
Infrastructure (roads, power, water, camp, tailings storage)
Equipment purchase or lease
Permitting and environmental compliance
Working capital and contingency

Operating Costs (OPEX)

Operating costs are the ongoing expenses of running the mine:

Mining costs (drilling, blasting, loading, hauling)
Processing costs (crushing, grinding, reagents, consumables)
General and administrative costs
Maintenance and repair
Environmental management and monitoring
Royalties and government levies
Transport and logistics

Financial Model

The financial model integrates the production schedule, metal prices (or product prices), capital costs, operating costs, taxation, royalties, and financing terms to calculate key metrics:

Net Present Value (NPV) — the sum of discounted future cash flows; the primary measure of project value.
Internal Rate of Return (IRR) — the discount rate at which the NPV equals zero; a measure of project profitability.
Payback Period — the time required to recover the initial capital investment from operating cash flows.
All-in Sustaining Cost (AISC) — for precious metals projects, the total cost of production including sustaining capital, expressed per unit of output (e.g., USD per ounce of gold).

Small-to-Medium Scale Mining in Uganda

Uganda's mining sector is characterised by small-to-medium scale operations, and mine planning for these projects requires a pragmatic approach that balances technical rigour with capital efficiency.

Key considerations for smaller projects include:

Phased development. Rather than committing all capital upfront, mine plans for smaller operations often stage development in phases, using early production revenue to fund subsequent expansion.
Appropriate technology. Equipment and processing methods should be matched to the project scale. A small gold operation does not need a fleet of 100-tonne haul trucks; well-maintained 30-tonne articulated trucks and a simple gravity-flotation plant may be far more appropriate.
Flexibility. Smaller mine plans should be designed with flexibility to respond to geological uncertainty. As production proceeds and more geological information becomes available, the plan can be adjusted.
Community integration. In Uganda's social and regulatory context, mine plans must incorporate meaningful community engagement, benefit-sharing mechanisms, and local employment commitments.

ALOM Mining & Geohydro Services provides comprehensive mining services including mine planning and design for projects at all scales across East Africa. Our team brings practical experience in designing mine plans that are technically sound, financially realistic, and tailored to the operating conditions of the region.

Conclusion

Mine planning and design is where geology meets engineering, and where scientific data is translated into the practical blueprint for a mining operation. The process is systematic — progressing from data collection through method selection, mine design, scheduling, infrastructure planning, equipment specification, and financial modelling — and each phase builds upon the work of the previous one.

The quality of the mine plan is ultimately determined by the quality of the underlying data, the experience of the planning team, and the discipline of the engineering process. A robust mine plan provides the technical and financial framework that attracts investment, satisfies regulators, guides construction and operations, and maximises the value of the mineral resource for all stakeholders.

For mining projects in Uganda and East Africa, where the sector is growing rapidly but many deposits remain at an early stage of development, professional mine planning is not a luxury — it is the difference between a successful operation and a stranded asset. If you are advancing a mining project and need expert mine planning support, contact ALOM Mining & Geohydro Services to discuss your requirements.