TechnoMine has previously posted an article from Wardrop on High Pressure Grinding Rolls (HPGR) in the mining industry. At this link is a beautiful photo of the HPGR installed at the Golden Queen Mine. Another great photo is on slide 19 of the powerpoint presentation at this link.

Wardrop recently completed three trade-off studies comparing the use of HPGR as a replacement for conventional SAG milling circuits.

Seabridge Gold Inc - Courageous Lake Project

Wardrop has recently completed a HPGR trade-off study for Seabridge Gold Inc. The trade-off study was carried out to evaluate the application of HPGR as an alternative technology to the conventional SAG milling process for the Courageous Lake project. The Courageous Lake Gold Project is located approximately 240 kilometers northeast of Yellowknife, Northwest Territories.

Adanac Moly Corporation - Ruby Creek Project

The Ruby Creek Molybdenum Project located approximately 24 km northeast of Atlin, British Columbia, is a proposed open pit mine and concentrator for the production of high quality molybdenite from a lowgrade resource. As part of the feasibility study, a trade-off study to evaluate the HPGR as an alternative technology to the conventional SAG milling process for the Ruby Creek project was completed. The plant was designed with a conventional SAG milling process to operate at a capacity of 20,000 tonnes per day with an availability of 91 percent and an overall plant recovery of 90 percent. Results of the trade-off study indicated that the application of HPGR to the Ruby Creek project would result in significant operational cost savings amounting to more than 25 percent. In addition to the operational cost savings, the introduction of a second on-line HPGR would result in an increase in the availability of the plant from the conventional SAG mill process availability of 91 to 96 percent. With HPGR in place, the power requirements of the grinding circuit would be reduced by more than 4kWh/tonne. The impact of this is a significant reduction in power requirements for the project. This trade off study indicated significant benefits for the project through more energy efficient crushing/grinding. It is now included in the updated bankable feasibility.

Eureka Mining - Miheevskoye Project

A trade-off study was completed comparing the capital and operating costs of using HPGR technology to the SAG milling option in the comminution circuit for the Miheevskoye project. This project is located in the Urals region of Russia, close to the border of Kazakhstan. It covers the Miheevskoye copper porphyry deposit, which is part of the Chelyabinsk project. The plant is capable of processing 21 million tonnes of ore per annum. A significant savings in capital costs, particularly in the operating costs, was indicated from the tradeoff study in favour of using the HPGR option.

Suppliers of HPGR equipment include: JK Tech, and 92 other listed in the InfoMine Suppliers Database.. The University of Queensland, Australia is doing considerable research on HPGR use in the mining industry. So too is the Australian CSIRO.