Last-in-first-out (LIFO) Stockpiles
Last-in-first-out (LIFO) stockpiles are stockpiles in which the last materials mined and added to the stockpile (Last-In) are the first to be removed and processed (First-Out). This strategy may be useful the most recently mined materials have priority for processing, such as when ore quality varies over time. As material is stacked onto and reclaimed from a LIFO stockpile, MineMarket creates 'layers' to track quality and tonnage data specific to that material.
Important: Most stockpiles should be created as weighted-average-grade (WAG). If not carefully managed, using LIFO stockpiles may create system performance issues.
LIFO stockpiles consider both the quantity and quality loaded onto and off the stockpiles in their calculations. Data is stored for each layer, and can be viewed on the Layers tab.
Example: A mine has the following stockpiles:
- MS-1—Mine Source stockpile 1 has Cu=25%, H2O=10% and has ABC Mining as a 100% contributor.
- MS-2—Mine Source stockpile 1 has Cu=20%, H2O=5% and has Diversified Mining as a 100% contributor.
- LIFO—LIFO stockpile starts with 0 tonnes of material.
- PROD—Production stockpile starts with 0 tonnes of material.
The following transactions take place:
- 5000 tonnes is stacked onto LIFO from MS-1.
- 5000 tonnes is stacked onto LIFO from MS-2.
- 7500 tonnes is reclaimed from LIFO and stacked onto PROD.
The following table displays the transaction history of the LIFO stockpile.
|
Sequence |
Mass |
Balance |
Cu % |
Cu (t) |
H2O% |
ABC Mining |
Diversified Mining |
|---|---|---|---|---|---|---|---|
|
1 |
5,000.00 |
5,000.00 |
25.00 |
1,125.00 |
10.00 |
5,000.00 (100.00%) |
|
|
2 |
5,000.00 |
10,000.00 |
22.43 |
2,075.00 |
7.50 |
5,000.00 (50.00%) |
5,000.00 (50.00%) |
|
3 |
7,500.00 |
2,500.00 |
25.00 |
562.50 |
10.00 |
2,500.00 (100.00%) |
