Bulk Solids, Mining, Aggregates & Material Processing worked example

Screening Reject Rate at 68% target screening efficiency: a worked example

Suppose target screening efficiency falls to 68%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate screening reject rate for screening reject rate for bulk solids, mining, aggregates, and material processing using plant-floor material, production, quality, capacity, or cost inputs.

The inputs for this scenario

On-spec material passing the screen: 850 tons (held at the documented default)
Total screen feed in the same period: 1,000 tons (held at the documented default)
Target screening efficiency: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

The calculation starts from the formula this tool documents: Screening Reject Rate = screening reject rate accepted or affected material ÷ total screen feed, oversize, undersize, fines, or saleable aggregate in same period × 100.
Screening Reject Rate works out to 85 % at these inputs, and this is the headline figure for the scenario.
Screening Reject Rate gap to target works out to -17 points at these inputs.
Screening Reject Rate accepted or affected material works out to 850 count at these inputs.
Total screen feed, oversize, undersize, fines, or saleable aggregate in same period works out to 1,000 count at these inputs.

How this compares with the baseline

Against the tool's baseline example, where target screening efficiency sits at 95% and the headline result is 85 %, this scenario lands almost exactly on the baseline at 85 %.
It computes screening efficiency as on-spec material divided by total feed, then reports the point gap to your target. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

Screening Reject Rate: 85 % (headline result)
Screening Reject Rate gap to target: -17 points
Screening Reject Rate accepted or affected material: 850 count
Total screen feed, oversize, undersize, fines, or saleable aggregate in same period: 1,000 count

Run it with your numbers

To rerun this with your own numbers, open the live Screening Reject Rate calculator, set target screening efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.