HPGR Evaluation And Circuit Design

From preliminary evaluation of HPGR at scoping level stages using ~10kg of core to comprehensive geo-metallurgical studies

Minpraxis conducts a range of metallurgical tests, from laboratory scale to pilot scale, to evaluate the process performance of HPGR technology in mineral applications. We offer test design and supervision services to ensure that HPGR technology is evaluated according to the stage of the project and the geo-metallurgical properties of the deposit.

Photo courtesy of Koeppern Machinery Australia

Piston press testing

Piston press testing is offered to enable HPGR assessment for early stage projects as well as to supplement pilot HPGR testing to account for variability within an ore deposit. Samples are carefully prepared and subjected to high pressure grinding conditions that are similar to those that occur in HPGRs. Only 10 kg of sample is required to determine the HPGR process performance of a geo-unit.

Major advantages of piston press testing:

  • Preliminary HPGR assessment at a low cost and sample commitment. Results can be referenced to justify proceeding with pilot HPGR testing programs
  • Combined with pilot HPGR testing, piston press testing provides an opportunity to test individual geo-metallurgical units within a deposit. This approach allows for identification of ore types that require special process considerations. Calibration between the piston press and HPGR unit is carried out on a bulk sample, thereby increasing the applicability of the piston press method to the ore being analysed.

The reference test database contains numerous pilot HPGR and piston press test results. Specific energy accuracy ranges from +/-15 % in the case where calibration with pilot HPGR testing is carried out to +/- 25% where only piston press testing is conducted for provided samples.

Reference database piston press and HPGR test results (Davaanyam et al, 2015)
Reference database piston press and HPGR test results (Davaanyam et al, 2015)