GNR Series VSI Crusher – The Final Stage in Manufactured Sand Production

The cubical rather than angular particle that concrete and asphalt producers want from their aggregate is created in this machine. The GNR series vertical shaft impactor (VSI) accelerates material to high speed with a vertical rotor and breaks it by flinging it against an anvil or against its own rock bed (rock-on-rock). That makes it a shaping machine more than a reduction machine: its aim is outstanding cubicity and manufactured sand, and it delivers the most cubical product to meet the Flakiness Index requirements of concrete and asphalt.

For sand making and cubical aggregate, the VSI is the industry's standard answer; the rounded-edge particle shape required in concrete and asphalt aggregate is formed at this stage.

Model Table

How Does It Work?

The vertical rotor accelerates material up to about 80 m/s; breakage and shaping take place either in rock-on-rock (autogenous) mode or in anvil mode. Because it only accepts small feed (≤55 mm), it is the final-stage machine in a plant, after the cone or tertiary crusher. Its place in the line: tertiary/quaternary crushing plus shaping.

Where Does It Perform Best?

Its ideal task: producing manufactured sand and cubical fine aggregate from high-silica, abrasive material (granite, basalt, river gravel, slag). Since rock-on-rock mode keeps metal wear to a minimum, it outperforms a tertiary impactor on abrasive material. It also noticeably improves particle cubicity in limestone.

Reduction Ratio and Wear Cost (TCO)

A VSI is a shaping machine rather than a reduction machine; the net reduction ratio varies from project to project. The wearing parts are the rotor tips, wear plates and the anvil or bed. In rock-on-rock mode a "rock bed" takes the place of these parts and part life is extended on abrasive material. For high-silica material, ceramic or tungsten-carbide reinforced tips are used; the cost-per-tonne advantage shows most clearly in autogenous mode.

The vertical shaft impactor is the last link in the manufactured sand, washing and dewatering chain. We build this line from a single source, together with the washer and fine-material screen.