ACALA

Geological Expertise, Mining Excellence

Open Pit Mine Design and Planning · ACALA mining optimisation

Open pit mine design and planning that turns a resource into a life-of-mine plan the numbers can defend.

Most of the world’s mineral production comes from open pits, where large volumes of rock must be moved efficiently through cycles in metal prices. ACALA’s mine planning methodology emphasises pit optimisation, including grade cut-off strategies, economic mining depth and operational scale. The outcome is a life-of-mine plan and a technical-economic model designed to maximise the potential of your mineral resource, from initial scoping to full optimisation and expansion.

Talk to a mining engineer on WhatsApp
See the services offered
Production rate against mine life: a 30 million tonne ore reserve at strip ratio 3, ore and waste moved per year as the annual ore rate changes Mt / year years ■ ore ■ waste (strip ratio 3) 5 Mtpa ore · 6-year mine life · 20 Mt total movement per year
Operational scale is a design decision: the same 30 Mt reserve, ten different mines. Faster mining shortens the life and raises the fleet; slower mining stretches fixed costs. Drag the handle from 1 to 10 Mtpa.
Pit optimisationNested shells and pushbacks that show where value sits at each price.
Cut-off strategyWhich blocks are ore, and when, so the plant is fed with the best material first.
Economic depthHow deep the pit should go before stripping outweighs revenue.
Operational scaleThe production rate that balances life, fleet and fixed cost.
Life-of-mine planYear-by-year ore, waste, grade and cash flow from first bench to closure.
Technical-economic modelThe spreadsheet behind the plan: costs, prices, capital, sensitivities.

Why ACALA

Practical, innovative solutions that respect geology, geotechnics, hydrogeology, economics and the environment.

Given the cyclical nature of metal prices, optimising mine design and scheduling is essential to maintaining profitability. ACALA’s specialised expertise supports strategic project development decisions that keep progress rapid and efficient.

Cut-off, pit shells and pushbacks decided in GEOVIA Whittle first, feeding the detailed design in Surpac, with the reverse order crossed outGEOVIA WHITTLE — VALUE FIRSTcut-offpit shellspushbacksSurpacdetailed designnot this waythe design follows the value, not the reverse

Optimise before you design

Pit shells, pushbacks and cut-off strategy in GEOVIA Whittle first, so the detailed design in Surpac follows the value rather than the other way round.

A dashed optimisation shell with the engineered pit design drawn inside it, showing benches, a berm, a ramp down the wall and a waste dump on the surfacedumprampbenchbermENGINEERED INSIDE THE SHELLoptimisation shellreserves reported against the design, not the shell

Design that can be mined

Benches, berms, ramps, dumps and roads engineered to geotechnical and operational constraints, with reserves reported against the design, not the shell.

Three accreditations, Specialist, Competent Person and Qualified Person, signing one report that goes to governments and exchangesSpecialistCompetent PersonQualified PersongovernmentsexchangesWHO SIGNS ITSNI · KCMI · JORC · SAMREC · NI 43-101accredited under the code the report is filed against

Reports that certify

Consultants recognised as Specialists and Competent Persons under international codes and accredited as Qualified Persons under SNI, KCMI, JORC, SAMREC and NI 43-101, for reports to governments and exchanges.

ACALA services offered

Ten services across the open pit lifecycle.

  1. 1

    Engineering studies

    Comprehensive assessments across all project phases, from scoping to expansion.

  2. 2

    Strategic planning

    Economic cut-off grade analysis and production rate optimisation.

  3. 3

    Mine design, optimisation and scheduling

    Using advanced geology and mining software: GEOVIA Whittle, Surpac and MineSched.

  4. 4

    Mining strategy development and implementation

    Customised methodologies for efficient and sustainable operations.

  5. 5

    Operational cost and productivity assessments

    Analysis of labour productivity, manpower requirements and expenditure estimates.

  6. 6

    Capital expenditure analysis

    Strategic financial planning for mine development.

  7. 7

    Open pit to underground transition studies

    Expert evaluation of when and where to go underground, for a smooth conversion.

  8. 8

    Technical studies

    Scoping studies, feasibility assessments, project reviews and technical audits, compliant with international standards.

  9. 9

    Independent reports and certifications

    Competent Person statements, independent expert evaluations and stock market listing documentation.

  10. 10

    Due diligence reviews

    Comprehensive risk assessments to support informed investment and operational decisions.

Open pit mine design with benches and ramps
Pit design: benches, berms and ramps engineered to the optimised shell.
Open pit planning model
Planning: pushbacks and periods that feed the technical-economic model.

End to end

From engineering studies and mine design to strategy, cost analysis and due diligence.

ACALA delivers integrated mining consulting, and reports for public and internal use under global frameworks, emphasising transparency and materiality. The same team that optimises the pit can certify the reserve and review the project for a lender.

Reading

Articles on pit optimisation and planning

Questions we get

Open pit design FAQ

What do you need to start a pit design?
A block model with grades and, ideally, density and geotechnical domains; slope recommendations; and price, cost and recovery assumptions. If some are missing, the scoping study defines them first.
How is the production rate chosen?
By testing rates against mine life, fleet size, capital and fixed cost in the technical-economic model, rather than by a rule of thumb. The optimiser shows where value peaks.
Can the reserve be reported publicly?
Yes. Reserves are reported against the mining design under SNI, KCMI, JORC 2012, SAMREC or NI 43-101, signed by ACALA’s Competent Persons.
Which software do you deliver in?
GEOVIA Whittle for optimisation, Surpac for design and reserves, MineSched for schedules, so your own planners can keep working on the files after the study.
Do you handle the open pit to underground transition?
Yes. Transition studies evaluate when and where to go underground, comparing the deepening pit against underground options on the same model.

Next step

Your project deserves clarity and confidence. Bring the block model; we bring the plan.

Tell us the deposit, its stage and what the plan is for. A mining engineer replies with a scope, data request and schedule.

Chat on WhatsApp
Use the contact form
Bekasi, Indonesia
+62 21 8066 9600
office@acala.co.id
WhatsApp