Calculator: what crusher blockages cost you every year

A crusher blockage costs hours; what nobody has at hand is the annual figure. This calculator produces it from six inputs your site already has, then compares it with the scenario where clearing takes a few minutes with an unblocking boom.

The values shown at the start are an example, chosen to illustrate the mechanics — not a site benchmark. Replace them with yours. The calculation runs entirely in your browser: nothing is sent, nothing is stored.

How to fill in each field

Crusher nominal throughput. The crusher's hourly production rate in normal operation, not the annual average. If the crusher is the site bottleneck, that is the rate lost during the stoppage.

Total duration of a blockage. From feed stop to return to nominal throughput — lockout, decision, mobilization, clearing, restart, ramp-up. Not just the clearing time. If you have never measured it, time the next three or four events and take the average.

Margin per crushed tonne. The contribution margin a crushed tonne would have earned or, on a mine site, the recoverable value per tonne of mill feed. It is not the sale price. If management accounting does not publish it, run the calculation twice — low and high assumption — and present the range.

Labour and equipment mobilized. The loaded cost of the crew, the crane and its operator, a blaster where applicable, for the whole mobilization time — including waiting time and a contractor's minimum call-out.

Attributable premature wear. The share of the annual wear-part cost that clearing with bars, hooks or an excavator, and the impacts of rocks giving way suddenly, impose on the crusher — brought back to a per-event figure. If you do not have that number, enter zero: the result will be conservative.

Blockages per year. The actual number of events over the last twelve months. The shift log or the maintenance management system has it; failing that, an operators' estimate, which rarely understates.

Total duration with an unblocking boom. The time, from stop to return to nominal throughput, when clearing is done from a protected station without mobilizing a crane or a crew. The order of magnitude is a few minutes of clearing plus the restart; adjust to your procedure.

What the result tells you — and what it does not

The annual cost with the current method is what blockages cost you today, before three items the calculator does not price: the downstream circuit stopping for lack of feed once the surge stockpile is exhausted, the contractual penalties of a production shortfall, and the risk of an incident during manual clearing. Each of those adds to the result; none reduces it. The full method is detailed in what a blockage really costs.

The annual gap between the two scenarios is the figure to set against the cost of an unblocking boom — supply, installation, commissioning — to get a payback period. The "with a boom" scenario assumes the crane, the crew and the clearing-attributable wear disappear, and keeps only the production lost during the residual duration; that is a reasonable assumption for a boom properly sized for the chamber and suited to the crusher type.

Two cases where the result deserves a particular reading:

• The crusher is not the bottleneck — a sufficient surge stockpile separates crushing from grinding. As long as the stockpile holds, the production item is overstated; the calculation remains valid for events that outlast the stockpile. Reduce the throughput entered, or count only the long events.
• Throughput is low but events are frequent — labour, wear and above all risk dominate. The figure is smaller, the decision no less clear: it is made on safety and consistency, not on tonnes.

Going further

If you would like this costing done with your actual data and documented — assumptions, sources, sensitivities, payback period — that is the kind of work our feasibility studies service covers. For a boom configuration suited to your crusher, see the IC Boom System product page or request a proposal with the crusher type, the rock and the blockage frequency.

Frequently asked questions

Does the calculator store my data? No. The calculation is done by your browser; no value is transmitted to a server or kept. If you want to keep the result, write it down or take a screenshot.

Why does duration matter more than frequency? Because the production item is the product of throughput and duration: cutting the duration by a factor of six cuts that item by the same factor, for every event. Frequency, for its part, is reduced by fragmentation and upstream scalping — useful, but rarely sufficient.

Can I use it for a jaw crusher or an HSI? Yes, the items are the same. Durations and clearing methods differ by type, which changes the values entered, not the mechanics of the calculation.