MINERAL SEPARATION
The first gold pour is expected in the September quarter , with the mine expected to produce 175,000 oz of the yellow metal in its first 12 months .
The latest generation of Knelson , the Knelson GX Concentrating Cone , was unveiled last year by FLSmidth , with the OEM saying it will deliver a key breakthrough in performance that increases recovery and cuts maintenance downtime .
The new patented GX Cone delivers impressive recovery enhancements due to enhanced water distribution within each ring , according to the company .
FLSmidth explained : “ As water enters from the base , it flows through zone separator nozzles for a customisable fluidisation profile . This allows for even distribution of water in each ring ; the new design also significantly increases the active recovery surface area . The result is a step change in overall coarse and fine gold recovery .”
Test data shows that gold recovery in all size fractions , from coarse to fine , improved significantly with the GX Cone , FLSmidth said .
The ILR used at Bibiani offers superior gold recoveries in a high-efficiency , low-cost system , according to Gekko .
The innovative ‘ rolling barrel ’ design of the ILR agitates and leaches coarse gold concentrates under intensive cyanide and oxygen conditions . It is available as a completely automated batch model for processing small volume gravity gold concentrates from batch separators and as a continuous model for treating high-throughput gold and complex sulphide concentrates from an InLine Pressure Jig and flotation circuits .
RC pickup
Of late , FLSmidth ’ s REFLUX™ Classifier ( RC™ ) technology has also come into the gravity separation equation after what was , according to Nicolas Boonzaier , Product Manager Reflux Classifiers at FLSmidth , a slow period of initial industry uptake .
The RC , invented by Professor Kevin Galvin from the University of Newcastle , is a slurrybased gravity separator designed specifically to upgrade fine minerals generally finer than 2 mm , the company says .
The operating principle of the system is based on three mechanisms : hindered settling , autogenous dense medium and lamella settling . The unique application of inclined lamella plates in conjunction with a fluidised bed separator makes the technology more efficient from a metallurgical and footprint perspective , according to the company . This results in a dominant highly efficient density separator .
Due to the more localised nature of the heavy mineral market , the uptake has been slow , Boonzaier said , saying that distrust formed by historical promises of “ best ever equipment ” has made for a slower and more cautious adoption .
“ Over the last 15 years , the availability of many laboratory and pilot scale campaigns has helped to spread knowledge and promote installation of RC plants around the world ,” he said . “ Naturally as more companies and stakeholders become invested , there is an increase in RC product knowledge across mine sites , universities , laboratories and engineering houses which has led to new process options being considered in the heavy minerals market .”
In the iron ore market , laboratory work commenced all the way back in the mid-2000s and production scale units were later installed and have been in operation for several years now . This has allowed for development of long-term operational confidence which subsequently led to far larger installations – replacing outdated and more established technology alternatives on account of the undeniable benefits ( grade and yield ) presented by the RC technology , Boonzaier said .
A similar pattern has recently been observed in the lithium sector , and the RC technology is now being considered as part of standard process models for some engineering houses .
He concluded : “ It is expected that as the RC installation base grows , the technology will be considered a standard processing step in many sectors of the mining industry and will replace technologies that have been dominating the industry for decades .”
IM
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