Cost per tonne in a quarry: how to know which face and which machine leaves margin
In an aggregate quarry, material price is often set by intuition or by what the neighbor charges, because the real cost per tonne is unknown. And the average lies: a harder face, a longer haul or an old machine change the number completely. Measuring cost per tonne per face and per machine is what separates selling with margin from giving away production without noticing.
What makes up cost per tonne
Cost per tonne of aggregate is not a number, it is a sum of pieces that move differently by day and by face:
| Component | What it depends on |
|---|---|
| Extraction | Face hardness, blasting or ripping, shovel hours |
| Hauling | Distance from face to plant, cycles per hour, fuel |
| Crushing and screening | Crusher hours, energy, wear on jaws and screens |
| Maintenance | Condition and age of each machine |
| Staff and structure | Headcount, payroll charges, quarry fixed costs |
Loading all this into a monthly spreadsheet gives an average. And decisions made on an average are bad, because it hides exactly what you need to see.
Why the average lies
Two tonnes from the same quarry can cost very differently, and the average blends them:
- By face: a harder face or one farther from the plant costs more per tonne. If you sell material from two different faces at the same price, one subsidizes the other without you knowing.
- By machine: an old truck with more fuel use and more stops raises the cost of every trip. Without charging per machine, you do not know which one to replace.
- By product: a coarse aggregate does not cost the same as a fine one that needs more crushing. The list price rarely reflects it.
The decision that makes or loses the most money (what price to sell at, which face to work, which machine to replace) needs the disaggregated number, not the average.
How to measure it without spreadsheets
The data already exists, scattered: equipment hours, fuel, production per face, maintenance stops. The work is capturing it where it happens and crossing it:
- Tonnage per face, loaded on the spot (or read from the plant control), not reconstructed at month end.
- Hours and fuel per machine, charged to the face where they worked.
- Maintenance per machine, so the cost of keeping an old machine shows up in the number.
- A cost-per-tonne dashboard that answers the owner's question: which face and which machine leaves margin, and what price to sell each product at.
It is the anchor module of the mining vertical: it is not digital transformation, it is cost per tonne. With costs rising, margin is defined inside the quarry, not in the price the market sets.