TS. Stockpiles

Owned by iarmstrong
Nov 30, 2021
6 min read

Stockpiles are points in space that keep an inventory of the reserves dumped to and reclaimed from their location. Each material remains discrete and does not mix with the others in the stockpile.

Different options for setting up stockpiles

Stockpiles can be added and removed using the plus and minus icons in the toolbar.

Name

Stockpiles must be represented by a node in Haul Infinity. The names must follow this convention:

  1. Tactical Scheduler: "MyStockpileName".

  2. Haul Infinity: "Stockpiles/MyStockpileName".

Capacity Field

The schedule calendar contains a capacity row for each stockpile. The capacity field is the unit of measurement of stockpile size, such as volume or tonnes.

Parcel Fingers

Choose how material types are binned in the stockpile.

With the default <All Parcels> selected, each material type is binned separately within the stockpile. For example, payloads of High Grade are all merged in the High-Grade pile, and payloads of Low Grade are all combined in the Low-Grade pile. When reclaiming from a parcel in the stockpile, the grades will be the weighted average of the total binned tonnes of that parcel. 

Parcels are merged and stored in piles according to their Parcel type

If scheduling in Optimise Products mode, the Optimiser can selectively reclaim parcel bins within a stockpile. For example, in a period where you are targeting higher grade material, the Optimiser may target the HG piles and leave the LG material behind. In reality, parcels sent to a stockpile will be blended into a homogenous pile, making it difficult to target and reclaim a specific parcel type. For more precise modelling (as may be required in short term plans), a Mutex Subset can be used.

Step 1. Create a new parcel to represent the blend of Stockpile material

Parcels can only be merged into another (already) existing parcel. Generating a new parcel to represent the blended stockpile material is recommended. To do this, tick the Specify Known Parcels option must be enabled in the Configuration Options step. 

At the Known Mining Parcels step, specify the parcel to represent the stockpile material. 

Step 2. Create a Mutex Parcel group 

Generate a new Mutex Parcel Group to be used in conjunction with the stockpiles by going to the Reserves tab > Data panel. When there press  icon to open Mutex Parcel Groups wizard.

The "Unassigned" value in Subset Name column for each parcel needs to be paired to a "Known Parcel". For parcels which will be part of the Stockpile blend, this "Known Parcel" will be the one created in the previous step. Parcels which are not part of the Stockpile blend can simply be mapped to there own parcel name. 

Finger Piles

Choose whether to build and reclaim stockpiles in discrete fingers.

  • Projects in Optimise Products mode must always use Weight Averaged piles.

  • Projects in Constrain on Trucks mode may choose to load First In First Out (FIFO) or Last In First Out (LIFO) logic. In Tactical Scheduler, FIFO and LIFO refer to the reclaim sequence of the piles within the stockpile fingers. 

Finger Pile Size

  • The size of each pile within the parcel finger.

  • A pile cannot be reclaimed until it reaches this size (unless you tick the box in Finish Pile at Period End column).

  • A pile can be reclaimed over multiple periods. 

The example below shows a setup for a stockpile which has fingers for all parcels. Each parcel finger is comprised of piles with a capacity equivalent to the value defined under the Finger Pile Size column. Pile number 3 in both the MG finger and the HG2 finger has not yet reached the 20,000t threshold, and therefore can't be reclaimed. If "LIFO" was selected in the Finger Pile Type column, this would cause there to be no reclaiming of HG2 or MG material.  

The same logic applies if a Mutex Subset is chosen as the Parcel Finger Type. In the example below, there is one finger comprising of material type SP BLEND. Within that finger, there are multiple piles, each having a capacity equivalent to the value defined under the Finger Pile Size column. If a pile has not met the threshold, it cannot be reclaimed.

Through FIFO and LIFO, it is possible to force a stockpile which comprises of a single material type to be fully built before it can be reclaimed. This can be achieved by setting the Finger Pile Size to the capacity of the stockpile. 

Finish Pile at Period End

  • Enabling this option allows piles which have not been fully built, to be reclaimed during the next period.

If we consider that setup of ROM_2 which has the Finish Pile at Period End option enabled, it can be observed that material is reclaimed off the stockpile before a 40,000t pile has been constructed. When using this option, the quantity reclaimed cannot exceed the closing balance of the previous period. This is why in period 3, only 3,631 tonnes of material is fed to the crusher despite there being 18,605 tonnes at the end of the period. 

Manual Reclaim

Enable this flag, if you want to manually reclaim the stockpile selected.

Stockpiles Mutex Subsets

In some projects, reporting can be made simpler with Stockpile Mutexes.

Example

A project has 20 stockpiles numbered "ROM1_001, ROM1_002, ...". The user wants to report total tonnes on "ROM".

In the above example, the user filters the report on MutexStockpile.Reporting = "ROM", which they have set to include all ROM stockpiles.