Technology
How the breakage test works.
Two counter-rotating wheels nip and crush rock at a controlled reduction ratio, one particle after another without stopping. Force comes from load cells and energy from the loss of wheel momentum, measured for every particle. From those measurements the test produces the Geopyörä Index and predicts the industry-standard parameters: Axb and DWi for impact breakage, BWi for grindability, plus rock mechanical properties such as UCS and PLT.
Product
Geopyörä Breakage Test
Each test needs only a small, discrete sample: a one-metre section of full or halved drill core, or under a kilogram of crushed rock. That lets it slot straight into existing geochemical assay workflows and capture variability across the orebody. From a single test, Geopyörä measures the data needed to estimate standard comminution parameters and rock mechanical properties with high accuracy.
Get a quoteIllustrative values, not measured data.
Device specifications
- Footprint
- 1500 × 1000 × 1100 mm
- Mass
- 400 kg
- Feed size
- 13.2–31.5 mm
- Particles
- 30+
The test procedure
- 01
Sample prep
Crush with a jaw crusher at 20 mm CSS, sieve into size fractions, and pick the largest fraction with more than 30 particles. Avoid flaky particles.
- 02
Breakage
Set the wheel gap for the fraction, weigh and feed the particles, and break them one after another without stopping. Collect the progeny.
- 03
Size analysis
Sieve the progeny on a nine-sieve deck for five minutes on a RoTap or similar.
- 04
Results
Upload the data to Geodata to get the Geopyörä Index and the predicted parameters.
Validation
Benchmarked against the reference tests.
The following compares the accuracy of the Geopyörä test against the primary tests in the comminution market. All the data has been collected from peer-reviewed papers and publications.
Geopyörä DWi comparison
The Drop Weight Index (DWi) is an important measure of rock strength and competency, originally derived from the SMC Test®. Geopyörä predicts the DWi using a deep neural network model trained on our extensive global database, which spans reference data from deposits worldwide.
The parity plot compares the Geopyörä prediction against the reference test values collected from peer-reviewed publications. The accuracy statistics are shown with the chart.
- Mean error
- 9.3%
- Std deviation
- 0.93 kWh/m³
- Relative std
- 10.6%
Geopyörä BWi comparison
Geopyörä also uses a machine-learning model to calculate the BWi (Bond Ball Mill Work Index) from the data generated by our test.
The parity plot compares the Geopyörä prediction against the reference test values, with the accuracy statistics shown alongside.
- Mean error
- 7.6%
- Std deviation
- 1.67 kWh/t
- Relative std
- 9.5%