The short answer
A per-tonne crushing rate normally covers the plant, its erection, the operating crew, routine maintenance and wear parts. It normally leaves out the rock, royalty, electricity or generator diesel, and the land. The rate falls as the monthly tonnage rises, and it climbs with harder rock, a finer product mix and a tighter grading.
Two crushing rates that differ by a few rupees a tonne are often quotes for different scopes. Before comparing the figures, compare the lists underneath them.
01Inside and outside
| Item | Usually | Why it varies |
|---|---|---|
| Plant, structure and conveyors | Inside | It is the contractor's asset |
| Transport and erection | Inside, or as a mobilisation advance | Long moves and short contracts get it priced separately |
| Operators, fitter, electrician | Inside | They arrive with the plant |
| Jaw plates, cone liners, screen mesh, belts | Inside | Abrasive rock raises the allowance |
| Loader feeding the hopper and stockpiling | Either | Depends on whose machines are already on site |
| Shot rock delivered to the hopper | Outside, unless mining is in the scope | Drilling, blasting and haulage are a separate rate |
| Electricity or generator diesel | Outside, or reimbursed at cost | Grid supply is cheaper and not always available |
| Royalty and transit passes | Outside | They follow the lease holder |
| Land, approach road, water | Outside | They belong to the site |
| Testing at an outside laboratory | Outside | The contract names the laboratory |
02Five things that move the rate
Monthly tonnage
A plant and its crew cost nearly the same whether they make 15,000 tonnes in a month or 30,000. Spread over twice the tonnes, that fixed cost halves. This is the single largest lever, and it is why a contractor asks for the monthly figure and not the total.
The rock
Hard, abrasive stone eats manganese. Liners that last months in limestone last weeks in quartz-rich granite, and each change costs steel and a shift. Hard rock also passes through more slowly. Both effects end up in the rate, which is why a sample or a site visit comes before a figure.
The product mix
A plant making mostly GSB is doing easy work. One making mostly 10 mm and dust is sending stone round the circuit two or three times. The same machine may produce a third fewer tonnes in the hour, and the rate per tonne moves with it.
The length of the job
Dismantling, moving and erecting a plant costs the same for a six-month job as for a thirty-month one. On a short contract that cost is a large share of every tonne. Mobilisation is usually shown as its own line for that reason.
The feed
A crusher fed with well-fragmented rock at a steady rate runs near its rating. One fed with boulders and gaps does not. If the drilling, blasting and haulage sit with a different firm, expect the crushing contractor to ask for a maximum feed size and a minimum tonnage at the hopper, because without them the output is not theirs to promise.
03The clauses that matter more than the rate
- Minimum offtake. The monthly tonnage you undertake to accept, and what happens in a month you cannot.
- Escalation. Whether the rate moves with the price of diesel, and by what formula.
- Measurement. Weighbridge at dispatch, with dockets, or a stockpile survey. Dockets end arguments that surveys start.
- Grading. The table the stone must meet, the laboratory that decides, and who bears a rejected stockpile.
- Idle time. Who pays when the plant is ready and the site is not.
- Demobilisation. How much notice ends the contract and who clears the yard.
04What to send for a real figure
Four things are enough to price a job properly: where the site is and how far the plant stands from the road head, the gradings required, the tonnes needed each month, and the start date with an honest view of how firm it is. Add the rock type if you know it and a note on whether grid power reaches the site.