Surface Mine Planning – Principles and Sequence

Advertisement

Surface Mine Planning – Principles and Sequence

  • What is to be mined and when?

A Surface Mine – Planning, Design, Operation

Surface Mine 300x226 Surface Mine Planning   Principles and Sequence

Why so fancy shapes?

Surface Mine 1 270x300 Surface Mine Planning   Principles and SequenceSurface Mine 2 189x300 Surface Mine Planning   Principles and Sequence

Mine Planning Process

What do we plan for?

  • Planning goals

What are the planning targets?

  • Outcomes of planning process

Planning stages

  • Sequence of activities

Sample Planning Goals

  • Maximize NPV, ROR, Payback
  • Provide stable cash flow patterns
  • Uniform grade, grade decline or highgrading
  • Uniform or favorable stripping ratio
  • Uniform / stable (or required) ore tonnage
  • Other….. to comply with company goals???

Lowest cost producer?
Mine the best 320 mt over 20 years?

What Are Your Goals?

  • First, clearly define the goals to be achieved! They are site specific!
  • Communicate !!!!
  • Make sure that

All are familiar with the goals, and
These are understood and agreed to!

  • Periodically review your goals

Company’s management, goals, situation changes!!!

Planning Outcomes: Targets

1. Tonnage (volume) to be mined

  • TONNES

2. Grade to meet the plant requirement

  • GRADE

3. Cost and economics

  • DOLLARS

Quantity To Be Mined: Tons & Grades

  • Define how much material is to be mined & from where:

To achieve the objectives at the lowest cost
To size facilities and estimate capital expenditures

  • Do you mine several different materials?

Ore, waste, partings, etc.

More Than That!!!!

  • Time consideration
  • Sequence consideration

Time Component

  • The defined tonnes (or tons, bcm, bcy) need to be mined within a certain time frame

Continuity of operation
Need for advanced development
Impact on cash flow

  • Compare CAT’s FPC

Unit cost may be a trade-off for time

Sequence Component

  • Mining needs to follow a sequence
  • Define and pay attention to the best sequence of mining

Opening or box cut?
Waste to be stripped in advance to allow mining of ore
Which waste need to be stripped ???….

Degree Of Detail

  • Everything changes!

Location, quality & quantity of ore
Prices for your product(s)
Costs

  • Long range plan:

Little detail, rough estimates

  • Short range plan

All the detail, detailed & accurate estimates

Planning Period

  • Life of the mine plan: to ultimate pit limit
  • Long range: five to then years
  • Budget: one year plan
  • Short range: monthly and quarterly plans
  • Production schedule: weekly and daily

DOLLARS – GRADES – TONNES

Note This:

  • Customize your planning system to correspond to

The need for information
Availability of data / information
Cost of developing the information

  • Planning systems and terminology differ from site to site

.. and between the countries?

Surface Mine 3.jpg 300x193 Surface Mine Planning   Principles and Sequence

Mine Planning Sequence

  • Geologic Model
  • Economic Model
  • Pit Limits (LRP)
  • Pushbacks
  • Mining Schedules
  • Detailed mine plans and optimization studies

Mine Planning: 1st Step

Geologic orebody model

  • In: Results of exploration
  • Out: grades, tonnes, geometry, rock properties ……

Geologic Orebody Model 300x165 Surface Mine Planning   Principles and Sequence

Usually a digital 3D block model

Stage 1: Outcome
Information on:

  • Existence, location, properties and quality of mineralization
  • The same for other materials within your property
  • Variety of other geologic information

Can one trust a geologist?

Mine Planning: 2nd Step

Economic orebody model

  • In: Geological model, dilution, recovery, costs, prices, other
  • Out: Block values

Geologic or geological?

Economic Orebody Model 1 300x142 Surface Mine Planning   Principles and SequenceEconomic Orebody Model 300x145 Surface Mine Planning   Principles and Sequence

Example of Inputs

…. Required at this point:

  • Topography and geographical features
  • Ownership of the land, mineral rights, etc.
  • Other limits on pit boundaries (rrds, structures, etc.)
  • Inventory of environmental conditions & requirements
  • Estimate of costs: mining, processing, smelting, selling, etc.
  • Geological & geomechanical properties mat’ls to be mined

Step 2: Outcomes

  • Quantity, location and value of ore contained within the deposit
  • Quantity, location and cost of removal of other materials

Mine Planning: 3nd Step

Long Range mine plan (LRP)

  • In: economic model, mining restrictions (slopes, mining widths, other)
  • Out: Optimum (economic) pit limit

Floating cone (example)

Floating cone 300x123 Surface Mine Planning   Principles and Sequence

LRP Goal: Pit Limits

LRP Goal Pit Limits 300x190 Surface Mine Planning   Principles and Sequence

Example of Inputs

…. required at this point

  • Regulatory approvals: what agencies are involved?
  • Production targets / goals & life of mine
  • Type location and cost of facilities and projects
  • Overheads: admin., facilities, services ….
  • Inventory/availability of resources: financial, technical, human

Step 3: Outcomes

Economic pit limit:

  • Rate of return, other financial criteria
  • Tons and grades (but no detailed schedule)

Physical pit limits

  • May be different from economic ones

Mine Planning: 4th Step

Mine Life & Pushbacks

  • In: Size & location of deposit, pit limits, mining restrictions, “nested pits”, preferences …
  • Out: Stages in mine life

Stages, cutbacks, pushbacks, phases

Mine Life & Pushbacks

Pushbacks 300x185 Surface Mine Planning   Principles and SequencePushbacks 1 300x185 Surface Mine Planning   Principles and Sequence

Pushbacks 2 300x220 Surface Mine Planning   Principles and Sequence

Step 4: Outcomes

  • What is the potential value of the mine
  • Where to start mining
  • What and when is to be mined

Not much detail; round figures only
Changes many be needed as the scenario changes

Mine Planning: 5th Step

Short range plans
= production schedules

  • In: (a) Long range plan, updated geologic model; (b) Production requirements (t, %), equipment capacities, geotechnical restrictions, other
  • Out: sequence of mining

Case study: Large US Copper Open Pit

Large US Copper Open Pit 300x267 Surface Mine Planning   Principles and SequenceLarge US Copper Open Pit 1 300x211 Surface Mine Planning   Principles and Sequence

Example of Inputs

…….. required at this point:

  • Current status of the mine
  • Scheduled working time
  • Equipment availability, utilization, reliability and productivity
  • Mill / ore / coal recipient requirements
  • Human resources by skill / craft / profession
  • Availability of contractors and other external support available

Step 5: Outcomes

Details of

  • Who mines what?
  • When?
  • How?

Resources and revenues are of lesser importance at this stage

LOOP BACK AT EACH STAGE to the economic model, LR plan, budget …..

  • Updated mining & other costs
  • Updated prices & receipts
  • Updated pit limits
  • Updated production rates
  • Updated environmental, regulatory & other requirements
  • Other updates: admin, eng’g, etc.

Incoming search terms:

  • mine planning sequence
  • surface mine planning and design
Advertisement
Surface Mine Planning – Principles and Sequence | admin | 4.5