*J. STARKEY, 1,2 B.HILSCHER1,S. REEVES1, J. HEDDERSON1
2Starkey & Associates Inc, 212 - 151 Randall Street, Oakville, Canada L6J 1P5
Presented at the Canadian Mineral Processors Conference, 23-25 January 2018, Ottawa, Canada
HPGRs operate in a wide array of applications in mining and minerals. These range from relatively coarse crushing of copper and gold ores at one end of the spectrum to the processing of fine iron ore pellet feed and fine industrial mineral products at the other. Traditionally these circuits involve the treatment of relatively moist materials in pre-griding circuits; using single stage HPGRs in open circuit or as a closed circuit operation with screening or partial product recycle. More recently, HPGR is increasingly deployed in dry grinding in combination with air classification.
The high throughput demand by larger HPGRs has stretched the application towards coarser size reduction duties for a number of new projects. At the same time, the basic principle of inter-particle crushing for generating a product with a high fines proportion gives ground to investiage applying the technology further towards finished product duties.
The advantages that HPGR brings are clear. Multi Stage grinding enables energy efficient size reduction across more of the comminution circuit. Primary HPGR serves for a coase grinding duty, whereas a secondary HPGR is geared towards generating a fine product for downstream processing or even a finished product.
This publication summarizes some of the features of staged HPGR circuits and discusses some examples of operating and projected applications.
CEEC acknowledges and thanks the CMP Society for organising the 51st Canadian Mineral Processors Conference. Conference proceedings can be purchased here.