Cubicizer or Tertiary Impact Crusher? A kW per t/h Analysis From Catalogue Data

When the final stage of an aggregate line calls for both cubical grains and low energy consumption, the cubicizer crusher is one of the first machines that comes to mind. In this article we put the real catalogue values of the GNR K series cubicizers and the GNR tertiary impact crushers on the same table and calculate, for each series, the motor power needed per tonne of material per hour.

How a cubicizer works and where it parts ways with an impact crusher

In a cubicizer, most of the crushing happens through stone striking stone. Material flung by the rotor breaks as it hits the bed of its own material that builds up inside the housing over time. In a conventional tertiary impact crusher, by contrast, the material makes direct contact with a metal impact plate. This structural difference has two consequences: wear-part consumption falls in the cubicizer, and the mechanical power needed for crushing goes down.

Catalogue data for the GNR K series cubicizer

The reference for comparison: GNR tertiary impact series

A 36% gap in motor power per tonne

To compare the two series fairly, we take the midpoint of each model's capacity range and divide the motor power by that value. The resulting ratio shows how many kW of motor must be installed to process one tonne of material per hour.

The cubicizer series comes out at an average of 0.77 kW/(t/h), and the tertiary impact series at 1.20 kW/(t/h). In other words, the cubicizer's installed power requirement is about 36% less. In practice this means running the same tonnage with a smaller motor, which puts less load on the grid and lets the site make do with a smaller generator.

The second thing the table shows: only the impact crusher benefits from scale

Across the tertiary impact models, power per tonne falls step by step as the machine gets bigger: 1.32 → 1.28 → 1.21 → 1.00. Put differently, the smallest model in the series is the most expensive to run per tonne. No such trend appears in the cubicizer series; all three models stay close together in the 0.72–0.82 range.

What this means on site: the gap between the two types widens as capacity shrinks. In the 60–110 t/h band, the GNR K50 and K100 run on roughly half the kW/(t/h) of the nearest impact model. By around 250 t/h the gap has almost closed (0.78 for the K110 against 1.00 for the GNR 150).

Do not overlook feed size

The maximum feed size accepted by the cubicizer series lies between 120–210 mm and rises with model size. In the tertiary impact series the feed is fixed at 150 mm on all four models; what increases with size is the rotor width, and with it the throughput. This shows that the two machines suit different jobs within a plant: the GNR K110 can accept coarser material, while the GNR 150 handles the same size of material at a higher throughput.

Which model should you choose?

If your priority is the share of cubical product and energy cost, and the feed size stays below 210 mm, the cubicizer is the right choice. If the feed is fixed at 150 mm and you need high throughput, the tertiary impact crusher is a better fit. To assess all of a plant's crushing stages together, see our article explaining primary, secondary and tertiary crushing stages.

The figures in the tables come from our product catalogue; actual consumption can vary with site conditions such as material hardness, moisture content and feed arrangement.