High Pressure Grinding Rolls (HPGR)

HPGRs are modern and efficient comminution machines, which are becoming increasingly popular within the minerals processing space.

HPGR technology as an alternative to crushers and mills

HPGR technology is a qualified alternative for large-scale comminution circuits and is becoming increasingly popular. The technology's working principle is that two counter-rotating grinding rolls expose a column of material to high pressure, which is distributed across the gap between the rolls. Interparticle comminution is the HPGR specific grinding process in which material particles are crushed and ground within the compressed material bed and not by contact with the roll surface. Feed material can be smaller than the gap, which is an important distinction as compared to crushers, for example. The high pressure comminution process causes micro-cracks in the particles, which lead to the liberation of minerals and a higher portion of fines. HPGR treated minerals show better leaching performance, because the micro-cracks increase the particle contact surface for the leaching liquid. Also, flotation efficiency is further enhanced through the use of HPGR comminution.

Cost and energy efficiency

Grinding of material in HPGRs has proven to be more cost efficient as compared to conventional mills and crushers. Especially downstream processing stages such as ball-milling are more energy-efficient with an HPGR due to the finer product size distribution coming out and the additional effect of micro cracks within the product particles. In essence, the main motivation to use HPGR's is to save energy and production costs.

Varied uses of an HPGR

HPGRs can be employed in brownfield projects to de-bottleneck conventional crushing/milling circuits so as to increase total plant capacity. They can also be used as tertiary and/or quaternary crushing stages or in the pebble-crushing stage to improve downstream milling performance.

In addition to the industry-leading equipment that TAKRAF already offers, the TAKRAF HPGR is a benchmark in further developed comminution technology.

Please watch our video about refurbishment of roll bodies here:

Change of roll bodies of a roller press or HPGR

Downloads

Brochure: Grinding technology

Value for Money
- Low cost of fabrication, erection, operation and maintenance
- High system availability and reliability, low maintenance requirements
Efficiency
- Grinding of material in HPGRs is more cost efficient compared to conventional mills and crushers - especially when it comes to down-stream processing stages such as ball-milling
Safety
- Safe maintenance solutions
- Control and alert system for fail-safe operation
- Specialised equipment for safe transport
Service
- Finite Element Modelling (FEM) for load optimized parts
- Short shutdown time for maintenance and repair
- New edge protection for rollers
- Long lifetime of wear parts
- Standard spare and wear parts
- Quick link system for fast and easy roller change
- Optimized bearing support for higher bearing lifetime
Environment
- Low specific energy consumption
- Low noise level
- No harmful emissions
Digitalization

Fully automated and semi-automated operation possible
Technical Excellence
- Our machines are designed in a modular build and are thus available in a range that can fit all process needs
- Pilot machine can be completely assembled and ready for commissioning in a 20`container