#1 Direct Block Scheduling

Summary

  • Outer shell of block model delineates optimisation region

  • Cut outer shell of block model into 3D grid of mining blocks

  • Calculate attributes for mining blocks by aggregating blocks and parts thereof from block model

    • Effectively reblocking with custom fields and aggregation rules

    • Block aggregation reduces size of optimisation problem

  • Use grid indexes to determine task (mining block) dependencies

  • Optimiser extracts mining blocks to limit of outer shell to satisfy objective, subject to slope angle dependencies and production constraints

  • Derives optimum pit and schedule simultaneously for each period

Benefits

  • Maximise or minimise any quantifiable objective

    • Not restricted to maximising NPV

  • Satisfies production, grade and sequencing constraints

  • Blends from multiple sources to deliver required grades

  • Supports time-dependent constraints

  • Material flow network supports constraints on material into and out of processing facilities and customers to optimise product delivery

  • Schedules and designs for each period

Steps

  1. Resource block model

  2. Outer shell of block model

    • With topographic surface only

      • Mining | Task Preparation | Incremental Solids

        • Do not select Surfaces > Topography

        • Set first Surfaces > DTM/Contour to topographic surface

        • Set Output > Remainder Solids to Type = Block Model Outer Shells (for example)

    • OR … With topographic and end-of-month surfaces

      • Mining | Task Preparation | Incremental Solids

        • Set Surfaces > Topography to topographic surface

        • Add Surfaces > DTM/Contour for each end-of-month surface

        • Set Output > Remainder Solids to Type = Block Model Outer Shells (for example)

    • OR … From mined-out model

      • Wireframe | Shell | Generate Shell | Block Model Outer Shell

        • Filter block model as required (e.g. [Density] > 0)

        • Set Output Wireframes > Type = Block Model Outer Shells (for example)

  1. Create schedule

    • Schedule | Attributes | Task Attributes must include Block Index as CHARACTER attribute

Schedule Definition

  • Task Sources > Pit Wireframes

    • Cuts shells (pit or block model outer) into mining blocks, calculates attributes for mining blocks and adds them to schedule

    • Define each pit/mine …

      • Set Input > Single to shell solid

        • e.g. last wireframe for block model in “Block Model Outer Shells” wireframe type

        • Do not set Discard when block volume less than or Merge when block volume less than

      • Set Cutting Profile > X Cell Size and Y Cell Size to dimensions of mining block

      • Set Benches > Bench Height to height of mining block

      • Add Output > Attributes for Block Index and Bench Z

      • Set Tasks > Task Type to task type that defines mining blocks for pit/mine

        • Set Tasks > Block Model to appropriate block model

        • Press Tasks > Attributes… to map mining block attributes to task attributes

  • Dependencies > Slope Angle

    • Add rule sets as required …

      • Set Task Filter to identify tasks for which dependencies are required

        • Leave blank if Dependency Rule Set applies to all tasks

      • Set Dependency Rule Set to specify slope angles for identified tasks

  • Press Forms | Save As… to save schedule definition

  • Press Run to create tasks and build schedule from definition

    • Cuts shells into mining blocks

    • Calculates attributes for mining blocks by aggregating blocks, and portions thereof, from block models

    • Adds task to schedule for each attributed (reserved) mining block

    • Creates dependencies between tasks