The first-ore sheet is worth more than the completion certificate

A completion certificate says the plant was built. A first-ore sheet says what the plant does. Those are different documents, and only one of them is useful two years later when the product drifts off specification.

What goes on the sheet

Closed-side setting per crusher, screen stroke, current draw per driven machine, and the capacity the plant actually achieved on the day, with the rock it was fed. Signed by both sides, dated, filed with the drawings.

Why it is the wear baseline

Wear rate is meaningless without a starting point. The first-ore sheet is that starting point: liner hours, tonnage and settings, all recorded before the plant has run a single commercial shift.

Why it closes the argument

If capacity is disputed at month six, the sheet is the evidence. Either the plant made the number under those conditions, or it did not, and either way nobody has to reconstruct it from memory.

What it is not

It is not a warranty document and it is not a performance guarantee for rock that was never sampled. It records one day, under stated conditions, and that is exactly why it is credible.