There is a conflict emerging between the trend to lower grade ores and the trend toward more efficiencies from mineral processing. Degrading ores need more processing, with more energy and equipment being used.

Glencore Technology, which develops, markets and supports technology that delivers flowsheet improvements, has created a new concentrator which helps solve this conflict, writes CHANTELLE KOTZE.

THIS ARTICLE FIRST APPEARED IN MINING REVIEW AFRICA ISSUE 3, 2021
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The fine grinding IsaMill and Jameson Cell flotation technologies, which were originally developed at Glencore’s mining sites, have undergone significant change and improvements over the years as they reduce plant footprint, save water and energy and improve mineral grade and recovery. The result is a major evolution from conventional concentrator circuits.

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Speaking during a webcast, Glenn Stieper, manager for mineral processing at Glencore Technology, detailed how the new and optimised concentrator design, using the trademarked IsaMill and Jameson Cell technologies, could dramatically reduce footprint, improve performance and decrease CAPEX and OPEX expenses.

The right technology for the job

Stieper announced that Glencore Technology has been awarded a contract to install its new concentrator at the the Ozernoye polymetallic project in Buryatia, Russia. The lead/zinc concentrator will, from its 2023 commissioning, process 875 tph from a circuit comprising new high-throughput Jameson Cells and newly launched M20,000 IsaMill.

“The whole flotation circuit will be half the footprint of conventional technology and will need about half the energy,” Stieper points out, noting that the 19 Jameson Cells within the optimised concentrator, replace 63 conventional tank cells, while three M20,000 IsaMill with 5 MW motors will also be installed.

Ozernoye’s mineralogy is complex and requires the right flowsheet to improve the recovery and concentrate quality to ensure the economic viability of the project. Its mineralogy is remarkably similar to Glencore’s McArthur River zinc-lead-silver mine in Norther Australia.  It’s that operation that originally brought about the need to create the IsaMill ultrafine grinding technology to achieve the required grind size to liberate the zinc.

Meanwhile, combined with the Jameson Cell – a high-intensity froth flotation cell that combines intense mixing with small bubbles achieving rapid flotation without mechanical agitation – more value can be created from lower grade ore and sulphides.

“In a world progressively moving toward lower grades and higher throughputs, this concentrator circuit could be a game changer,” says Stieper, not only at Ozernoye but any operation with complex base metal mineralogy.

Iterating this, Alexandr Kanarskiy, chief metallurgist at Ozernoye said that due to the depletion of high-grade mineral resources and the tendency towards decreasing the size of the valuable component in the initial ore, the processing flowsheet at Ozernoye will likely become the benchmark in the field of complex finely disseminated ore enrichment across the globe.

The flotation complex is expected to be delivered to site during Q1 to Q2, 2022, installation should be completed around early-2023, with full plant commissioning scheduled for Q2, 2023.

Meanwhile, base and precious metals miner Hudbay Minerals is refurbishing its New Britannia mine in northern Manitoba, Canada, and has chosen to create a new flotation circuit made entirely of Jameson Cell flotation cells, to process ore from the Lalor mine, which contains copper, zinc, gold and silver.

The 70 tph flotation circuit will use four Jameson Cell flotation cells, (compared with 11 conventional cells) – a decision that was driven by the realities of the Lalor ore body and desire to reduce costs and footprint and increase net value.

Matthew Taylor, metallurgy manager at Hudbay Minerals, says that the company chose Jameson Cell technology for its ability to handle varying swings in the head grade, for its range in carrying capacity and its ability to wash within each cell. “These factors will allow us flexibility to produce either a final concentrate from the rougher feed within the first cell or enable us to send the rougher tail to a cleaner circuit for further upgrade, depending on the head grade, says Taylor, noting that the Jameson Cell can be used in rougher, scavengers and cleaner flotation.

Although typically deployed in the cleaner stages of a processing plant, Taylor believes that Jameson Cell technology could find future applications within the rougher stage of mineral processing and potentially even overtake mechanical cells in this application. Jameson Cells may also be suitable for circuits for metals that it has not traditionally been used in, such as copper and molybdenum separation. At the same time, he felt the IsaMill may find application closer to the head of the flowsheet – to where the bulk of the materials handling is taking place, with the potential of displacing ball mills in certain applications where feasible.

Installation at New Britannia is currently in progress and the flotation circuit is due for commissioning in Q4, 2021.