Glencore Technology has introduced a new conical spacer that it claims can reduce specific energy requirements for grinding by up to 21.5 per cent.
The spacer provides energy benefits over traditional spacers as its conical design has no bearing on particle size distribution, helping to reduce the required energy to produce a specific product size.
According to Glencore Technology, the spacers are designed to be used with its IsaMill range of grinding technology. They have shown significant energy reduction in pyrite concentrate processing tests for gold recovery when compared with traditional ball mills and tower mills.
The use of the conical spacers showed that these energy savings increased in parallel with the fineness of the grind, Glencore Technology stated.
For example, the tests showed a 12.7 per cent energy saving when grinding to 22 micrometres, up to 21.5 per cent when grinding to 15 micrometres.
The refinement of the technology is consistent with Glencore’s philosophy regarding the development of IsaMill, which grew out of a need in the late 1980s to provide a more energy- and media-efficient solution for grinding ores below 25 micrometres in size.
The company carried out tests on the spacers in a laboratory environment before scaling up to a pilot and then a production environment using an M1000 IsaMill, where they were eventually permanently installed.
Glencore Technology manager Virginia Lawson said the spacers would be well suited to operations requiring relatively fine grind size targets and high specific energy consumption.
“These specific energy savings offer the potential for a significant reduction in the operating costs of fine grinding,” Lawson said.
“The IsaMill is already delivering industry leading energy efficiency and availability. But these savings make it incredibly compelling to retrofit existing IsaMills and to specify an IsaMill in any redesigned or new flowsheet.”