Tag Archives: carbon in leach

Cora Gold adds SENET, CSA Global and Epoch Resources to Sanankoro DFS team

Cora Gold Ltd has made key appointments related to the definitive feasibility study (DFS) it is carrying out on the Sanankoro gold project in southern Mali, bringing SENET, CSA Global and Epoch Resources into the study team, as well as naming Russell Bradford as Project Manager.

SENET, a DRA Global group company, has been appointed as independent project manager to oversee the critical elements of the DFS, while CSA Global, a member of the ERM group of companies, will be the geological and mining consultant, tasked with managing the updated mineral resource estimate and mining study. Epoch Resources has been appointed to oversee the tailings storage facility of the DFS.

The DFS will build upon the January 2020 scoping study, which outlined average annual production from Sanankoro of 45,632 oz.

Following positive metallurgical test work results in the second half of 2020, in addition to more recent positive drilling results, the company says it is likely it will look to focus on a conventional gravity/carbon in leach processing route at Sanankoro to allow higher recoveries.

Bert Monro, CEO of Cora Gold, said: “2021 has seen significant activity at Sanankoro with exceptional results reported from our largest ever drill campaign at the project. These results will support an updated mineral resource estimate in the coming months, which, in turn, will be used as the basis for our DFS aimed at outlining the optimum route to develop Sanankoro into a new gold mine in Mali.

“Last year’s scoping study highlighted the potential high returns for Sanankoro and fuelled our confidence in Sanankoro’s strong fundamentals, and the company looks forward to publishing the DFS in the first half of 2022.”

Outotec addresses carbon losses in CIP, CIL gold circuits

Outotec has released a fully automated in-situ measurement system that, it says, can minimise gold solution losses in carbon-in-pulp (CIP) and carbon-in-leach (CIL) circuits.

Outotec CarbonSense is a system that is directly immersed in the slurry, eliminating the need for sample transfer and ensuring optimal carbon management, according to the company. It is designed to operate continuously in the agitated area of the reactor to ensure a highly representative analysis. It also features a reference probe to ensure reliable measurement even in changing process conditions.

As part of the solution, a single connection cabinet can support up to eight measurement assemblies, along with fibre-optic and copper media connections to the plant network, according to Outotec. “The system supports virtually any network topology, including star and ring configurations,” it said. “Maintenance is simplified with all power supplies and fuses located in one place.”

The portable calibration unit uses authentic slurry and carbon to ensure the best possible results and reliable measurement performance, Outotec said. No recalibration is needed when slurry properties change since the measurement is based on the difference between the measurement probe and the reference probe.

Continuous and reliable carbon concentration measurements minimise gold losses by enabling accurate control over carbon transfer between reactors, according to Outotec, with the Outotec ACT Carbon Management application designed to take full advantage of the measurement data.

The system is delivered as a ready-to-install package including measurement assemblies, connection cabinets and analysis software and licences.

The key benefits of Outotec CarbonSense, according to the company, are:

  • Enables continuous, representative, and reliable carbon measurement;
  • Supports development of efficient strategies for advanced CIP/CIL control;
  • Fully automatic operation;
  • Simple to install, operate, and maintain with no moving parts or sample transfer; and
  • Increases safety by helping to avoid blockages and other sampling issues.

Africa first for Gekko’s Carbon Scout technology

Gekko Systems says Endeavour Mining’s Ity gold operation, in Cote d’Ivoire, has become the first mine in Africa to install a Gekko Carbon Scout.

The self-contained Carbon Scout device collects slurry samples from carbon-in-pulp (CIP) and carbon-in-leach (CIL) tanks to determine the distribution of the activated carbon in the pulp for each tank, to an accuracy of ± 0.5 grams of carbon per litre of pulp, according to Gekko.

Gekko, following a collaboration agreement signed with Curtin University for the development and commercialisation of a cutting-edge carbon management technology, went commercial with the technology in 2017. At that point, the company said the product promised to quickly become critical for gold process plant optimisation and for minimising soluble gold losses on tails.

By advancing the accuracy, regularity and consistency of sampling, the self-contained, ground-level unit will improve measurements in CIL and CIP circuits, Gekko said, adding that the Carbon Scout will also greatly improve the safety of operations by reducing operator exposure to cyanide and other hazards.

As recently as November, Endeavour announced it had completed a planned CIL plant expansion at Ity, upping capacity from 4 Mt/y to 5 Mt/y. This followed the commissioning of the 4 Mt/y plant in April 2019.

Xtract Resources and Mutapa enter hard-rock processing collaboration pact

Xtract Resources has signed up to a collaboration agreement with Mutapa Mining and Processing (MMP) that could see the building of a carbon in leach (CIL) plant and the subsequent processing of hard-rock ore from its Manica deposit in Mozambique.

As part of this agreement, MMP, in partnership with Omnia – a company Xstract previously signed a joint venture and collaboration agreement with in 2018, will be appointed as independent mineral processing contractor on the various gold-bearing mineral deposits on the Manica concession.

MMP has agreed to finance and conduct the mining operations at Manica, including all capital and operating costs, with Xtract receiving between 20% and 23% (depending on the prevailing gold price) of the hard-rock after tax operating cash flow.

At the same time as this, Xtract intends to exploit gravity-recoverable gold during the CIL plant-build phase, assuming suitable material is available.

Colin Bird, Executive Chairman of Xtract, said: “This agreement allows for the extraction of CIL-amenable resources to be commenced in the mid-term whilst alluvial operations continue. The income to Xtract, once commercial levels of production are achieved, is expected to be significant and continuing for in excess of six years.”

While alluvial operations continue and the CIL plant plan is finalised, alluvial gold will still be exploited through an agreement Xtract has in place with Huafei Gold Resources.

And a concession exploration programme will be initiated with a view to enlarging the currently known resource by drilling at depth and testing areas not yet investigated, according to Bird.

MMP is currently the owner of a 42,000 t/mth hard-rock processing plant, which includes crushing, milling and gravity recovery circuits and furnace, for mining and mineral processing, located in the Manica region of Mozambique, according to Xtract. This plant has already had over $11 million invested to date and, as Xtract is aware, represents the only sophisticated hard-rock processing capacity in the Manica region, the company said.

“The MMP plant is the key reason supporting the rationale of agreeing the collaboration agreement, as it reduces both capital expenditure requirement and the time to production of the Manica project,” Xtract said.

MMP has undertaken to commence construction of the CIL plant and to provide Xtract with a schedule of purchases and an activity chart indicating initial production and a target date for commercial production of no later than July 1, 2020, Xtract said. Commercial production is defined in the agreement as the installation of a processing plant with throughput capacity of not less than 29,000 t/mth (being 70% of the planned 42,000 t/mth throughput).

Endeavour Mining pours first gold from Ity CIL project in Côte d’Ivoire

Endeavour Mining Corp says it has poured first gold from the Ity CIL project in Côte d’Ivoire, ahead of schedule and under budget.

The first pour yielded around 1,800 oz of gold, while some 135,160 t of ore has been processed since being first introduced into the CIL processing plant on February 20.

The initial estimated budget was $412 million, with first gold pour coming four months ahead of the previous schedule.

Endeavour said commercial production was expected to be declared early in the June quarter with performance trial testing soon to commence, as the crushing, milling and CIL circuits have quickly attained a stable nameplate capacity of 4 Mt/y.

Following the performance tests already conducted, Endeavour launched optimisation and de-bottlenecking work which is expected to increase the plant nameplate capacity by 1 Mt/y to 5 Mt/y, at a minimal cost of $10-15 million.

The volumetric upsize work mainly comprises an upgrade in pipes and pumps, and a second 50-t oxygen plant with no additional mining fleet required. “These plant upgrades are expected to be completed during scheduled plant maintenance shut-downs throughout the next six months,” the company said.

Sébastien de Montessus, President and CEO, said: “As we approach commercial production, I would like to acknowledge the hard work of our in-house construction team for successfully delivering the Ity CIL project ahead of schedule and under-budget, with an exceptional safety record of over 8.5 million hours without a lost time injury.

“This first gold pour and the remarkably quick ramp-up period is a transformational event for Endeavour as the Ity CIL project will quickly contribute to group’s cash generation potential.

“Given its current 15-year mine life and strong exploration potential, our ability to increase the plant size by 1 Mt/y to 5 Mt/y for minimal additional capex represents a very compelling investment and is in line with our focus on capital allocation efficiency and return on capital employed criteria. With this upgrade, Ity has the potential to produce circa 300,000 oz of gold per annum at a low all-in sustaining cost (AISC).”

The Ity CIL project capex spend is tracking under-budget compared to the initial guidance of $412 million.

“As construction is tracking ahead of schedule and below budget, Endeavour decided to conduct additional works such as the construction of a fuel farm, building exploration facilities, and an additional $7 million of crop compensation and resettlement related to prospective exploration grounds,” Endeavour said. “Due to these additional works, and the $10-15 million required for the above-stated plant upgrade to 5 Mt/y, the total project capex spend is expected to amount to circa-$420 million.”

An $11 million exploration programme totalling around 71,000 m of drilling has been planned for 2019, with the aim of delineating additional resources at the Le Plaque target, and testing other targets such as Floleu, Daapleu SW and Samuel.

As previously guided, Ity is expected to produce 160,000-200,000 oz in 2019 at an AISC of $525-590/oz, with the bottom-end of production guidance corresponding to the 4 Mt/y nameplate capacity while the top-end factors in upsides such as an earlier start date, an expedited ramp-up and the plant producing above its nameplate.