Tag Archives: gold

Master Drilling continues diversification plan in uncertain market

Master Drilling Group continued to add to its client and service base over the course of 2020, with bright spots reported in exploration drilling and the West Africa gold sector.

Its 2020 financials were hit by COVID-19, with revenue dropping 17% year-on-year to $123.1 million and operating profit declining to $12.3 million, from $24.1 million in 2019.

Danie Pretorius, CEO of Master Drilling, said: “Master Drilling’s overall performance for the year was weighed down by the weak global economic growth environment entering 2020, which was compounded by the material impact of COVID-19, across the 23 countries in which we operate, from a human, financial and operational perspective.

“Although the group experienced a significant decline in revenue in the South American operations, primarily due to government-imposed COVID-19 restrictions, this was offset by regions such as India, Africa and Scandinavia which remained operational and received various stimulus packages.”

Despite a decrease in revenue, the company’s net cash generation increased 72.7% to $25.5 million as it contained capital expenditure by balancing maintenance with emerging opportunities.

In the second half of the year, Master Drilling was awarded new exploration projects and mobilised an additional fleet to service existing clients, with a considerable turnaround in drilling and exploration activity becoming more apparent and creating a healthy pipeline, it said.

Around a year ago, Master Drilling fulfilled the conditions to acquire Geoserve Exploration Drilling, increasing the South Africa-based company’s ability to offer exploration drilling, reverse circulation drilling, geotechnical investigations and grade control drilling services.

Its commitment to Africa saw the continent become the largest contributor to the group in terms of revenue and profits over the course of the year. Aggressive expansion into West Africa continued as part of the group’s diversification strategy, with a specific focus on gold, which has seen a surge in demand since 2019.

Master Drilling also continued to grow its presence in new markets, including Australia, Russia and Central Asia. It secured new contracts with a focus on raiseboring and mechanised mining services, too.

As at December 31, 2020, Master Drilling’s sales pipeline totalled $539.9 million with a stable order book of $212.8 million (2019: $142.1 million).

“In the short to medium term, the sales pipeline is expected to normalise and increase with further tactical acquisitions and joint ventures supporting performance,” it said. “Opportunities to diversify outside of the traditional drilling business into areas such as artificial intelligence will also continue.”

Although capital has been tightly managed in response to the uncertain environment, Master Drilling says technological innovation remains a key priority for the company.

Aligned to this, Master Drilling announced a 40% investment in AVA Solutions, a specialist in data-driven mining fleet management solutions, this month.

Commenting on the investment, Pretorius said: “Our recent investment in AVA is aligned with our strategy to diversify our services and invest in businesses that help us meet our clients’ demand for increased mechanisation and digitisation. Other opportunities with low capital requirements and short return cycles are currently under review.”

He concluded on the annual results: “Although the shape of recovery remains uncertain, we have seen a turnaround in the past six months across the commodities and regions that we are already exposed to. Having made significant investments in our fleet, technology and geographical diversification over the past couple of years, we are now positioned to capitalise on the predicted commodities bull run without requiring additional capital investment.”

Metso Outotec to supply Vertimills, cone crusher to IAMGOLD’s Côté project

Metso Outotec is to supply key comminution technology to IAMGOLD Corporation and Sumitomo Metal Mining’s joint venture Côté gold project, in north-eastern Ontario, Canada.

The delivery consists of two energy-efficient Vertimill® 4500 grinding mills (pictured) and one MP1250 cone crusher for the Côté gold project.

Andy Lingenfelter, Vice President, Minerals Sales, North & Central America, Metso Outotec, said: “Low energy and wear part consumption, as well as process flexibility, were decisive factors for the Côté gold project team when selecting the comminution equipment.

“Metso Outotec was consulted during the prefeasibility study and supported IAMGOLD on several projects. IAMGOLD’s technical team had solid confidence in the Vertimill technology, and they were also familiar with the high-performance capability of the MP crushers.”

The value of the order exceeds €10 million ($11.9 million) and has been booked in Minerals’ March quarter 2021 orders received.

Côté comes with estimated contained gold reserves of over 7 Moz. Construction of the gold mine commenced in late 2020, and is expected be completed in mid-2023.

Managem partners with Wanbao Mining to expand Sudan gold mining efforts

Morocco-based Managem Group has entered into a second cooperation partnership with China-based Wanbao Mining Group for the development of a large-scale gold mining project in Sudan.

Under the terms of the partnership, Managem will retain 65% ownership (excluding any interest attributable to the government of Sudan) in the exploitation and exploration licence – Block 15 – and the associated Gabgaba gold mine (pictured) and expansion project, as well as exploration licences, being Blocks 9 and 24, with Wanbao Mining owning the remaining 35%. In addition, Managem will own a 35% stake in the exploration licenses Blocks 64 a-b-c and 66 a-b-c currently owned by Wanbao Mining.

Through this partnership, Managem and Wanbao Mining will be aiming to:

Expand the existing Gabgaba operation
The Gabgaba (Block 15) expansion project assumes an increase in annual gold production from around 60,000 oz/y to 200,000 oz/y with an estimated capital expenditure of some $250 million. Both partners intend to deliver a definitive feasibility study in order to expand the Gabgaba gold mine within three years. Managem will remain the operator of Gabgaba mine and project. As part of its commitments under the terms of the partnership, Wanbao Mining is to provide the requisite assistance in securing up to 70% of the project funding, Managem says.

Develop new projects within the existing exploration licences
The goal of the partnership is to capitalise on the vast untapped exploration potential embedded within the existing licences and develop another gold mining operation within three years with projects ultimately owned on joint, 50/50 basis, Managem says. Wanbao Mining has agreed to fund up to $30 million of exploration and evaluation expenditures, and to conduct the exploration work as the operator with co-management of Managem on the licences subject to the partnership.

Cooperate and grow the presence in Sudan
Managem says it has a long-standing track record of successful operatorship and presence in Sudan and the newly established partnership with an experienced and committed partner, such as Wanbao Mining, provides an even stronger base for future growth in gold production within and beyond the existing licences of both partners in the country with unparalleled untouched potential.

Imad Toumi, Chairman and CEO of Managem, said: “Today, we give new impetus to our growth strategy in Sudan by bringing forward the development of a large-scale gold project in Block 15, with target production of 200,000 oz/y in the medium term, in addition to strengthen our exploration efforts for a new mining project in the other blocks.

“I am convinced that this new strategic cooperation, based on trust and mutual respect, will have positive impact on both our companies and will lead to a multi-million-ounce gold mining operation in Sudan.”

eHPCC: the future of grinding in mining?

A lot has been made of the potential of high pressure grinding rolls (HPGRs) to facilitate the dry milling process many in the industry believe will help miners achieve their sustainability goals over the next few decades, but there is another novel technology ready to go that could, according to the inventor and an independent consultant, provide an even more effective alternative.

Eccentric High Pressure Centrifugal Comminution (eHPCC™) technology was conceived in 2013 and, according to inventor Linden Roper, has the potential to eliminate the inefficiencies and complexity of conventional crushing and/or tumbling mill circuits.

It complements any upstream feed source, Roper says, whether it be run of mine (ROM), primary crushed rock, or other conventional comminution streams such as tumbling mill oversize. It may also benefit downstream process requirements through selective mineral liberation, which is feasible as the ore is comminuted upon itself (autogenously) in the high pressure zone via synchronous rotating components. Significant product stream enrichment/depletion has been observed and reported, too.

As IM goes to press on its annual comminution and crushing feature for the April 2021 issue – and Dr Mike Daniel, an independent consultant engaged by Roper to review and critique the technology’s development, prepares a paper for MEI Conferences’ Comminution ’21 event – now was the right time to find out more.

IM: Considering the Comminution ’21 abstract draws parallels with HPGRs, can you clarify the similarities and differences between eHPCC and HPGR technology?

MD & LR: These are the similarities:

  • Both offer confined-bed high-pressure compression comminution, which results in micro fractures at grain boundaries;
  • Both have evidence of preferential liberation and separation of mineral grains from gangue grains at grain boundaries; and
  • Both have an autogenous protective layer formed on the compression roll surfaces between sintered tungsten carbide studs.

These are the differences:

  • eHPCC facilitates multiple cycles of comminution, fluidisation and classification within its grinding chamber, retaining oversize particles until the target product size is attained. The HPGR is a single pass technology dependent on separate materials handling and classification/screening equipment to recycle oversize particles for further comminution (in the event subsequent stages of comminution are not used);
  • Micro factures around grain boundaries and compacted flake product that are created within HPGRs need to be de-agglomerated with downstream processing either within materials handling or wet screening. In some instances, compacted flake may be processed in a downstream ball mill, whereas, in eHPCC, preferential mineral liberation is perfected by subsequent continuous cycles within the grinding chamber until mineral liberation is achieved within a bi-modal target size (minerals and gangue). The bi-modal effect differs from ore type to ore type and the natural size of the minerals of interest;
  • The preferential liberation of mineral grains from gangue grains generally occurs at significantly different grain sizes, respectively, due to the inherent difference in progeny hardness. eHPCC retains the larger, harder grains, hence ensuring thorough stripping/cleaning of other grain surfaces by shear and attrition forces;
  • eHPCC tolerates rounded tramp metal within its grinding chamber, however does not tolerate high quantities of sharp, fragmented tramp metal that create a non-compressible, non-free-flowing bridge between roll surfaces, which risks the damage of liner surfaces;
  • The coarse fraction ‘edge effect’ common in HPGR geometry is not an issue with eHPCC. In fact, the top zone of the eHPCC grinding chamber is presumed to be an additional portion of the primary classification zone within the grinding chamber. The oversize particles from the internal classification process are retained for subsequent comminution;
  • The maximum size of feed particle (f100) entering the eHPCC is not limited to roll geometry as is the case with HPGRs (typically 50-70 mm). eHPCC f100 is limited to feed spout diameter (for free flow) and dependent of machine size ie eHPCC-2, -5, -8 and -13 are anticipated to have f100 60 mm, 150 mm, 240 mm and 390 mm, respectively. The gap between rolling surfaces is greater than the respective f100; and
  • eHPCC technology shows scientifically significant product stream enrichment.

IM: What operating and capital cost benefits do you envisage when compared with typical HPGR installations?

MD & LR: Both operating and capital cost benefits of the eHPCC relative to HPGR technology are due to the eHPCC not requiring the pre-crushing and downstream classification equipment required by HPGRs.

The eHPCC operating cost benefits are associated with eliminating maintenance consumables, downtime, reliability issues and energy consumption associated with the equivalent HPGR downstream equipment listed above.

The eHPCC capital cost benefits are associated with eliminating the real estate (footprint) and all engineering procurement and construction management costs associated with the equivalent HPGR upstream/downstream equipment listed above. eHPCC flowsheets are likely to be installed as multiple ‘one-stop’ units that maintain high circuit availability due to ongoing cyclic preventative maintenance.

IM: Where has the design for the eHPCC technology come from?

LR: It was invented in early 2013 by me. I then pioneered proof-of-concept, prototyping, design and development, culminating in operational trials in a Kazakhstan gold mine in 2020. A commercial-grade detailed design-for-manufacture has since been undertaken by a senior team of heavy industry mechanical machine designers and engineers.

IM: In your conference abstract, I note that the eHPCC technology has been tested at both laboratory and semi-industrial scale with working prototypes. Can you clarify what throughputs and material characteristics you are talking about here?

LR: The first iteration of the technology, eHPCC-1, was tested at the laboratory scale from 2013-2015. This proof-of-concept machine successfully received and processed magnetite concentrate, copper-nickel sulphide ore, alkaline granite, marble and a wolfram clay ore dried in ambient conditions. The typical throughput was between 200-400 kg/h depending on the feed size, particle-size-reduction-ratios (dependent of grain size) and target product size. The feed size was limited to a maximum of 25 mm to ensure free flow of feed spout.

Alkaline granite: eHPCC-2 coarse product (left) and fine product (right)

MD & LR: From 2016-2020, we moved onto the semi-industrial scale testing with the eHPCC-2 (two times scaled up from eHPCC-1). This was designed for research and development (R&D) and tested on magnetite concentrate, alkaline granite, and hard underground quartz/gold ore. The throughput capabilities depended on the geo-metallurgical and geo-mechanical properties of feed material, such as particle size, strength, progeny (grain) size and particle size-reduction-ratios (subject to confined bed high pressure compression). Larger-scale machines are yet to be tested against traditional ‘Bond Theory’ norms.

The eHPCC, irrespective of the outcomes, should be evaluated on its ability to effectively liberate minerals of interest in a way that no other comminution device can do. The maximum feed size, f100, at the gold mine trials was limited to 50 mm to ensure free flow through the feed spout. R&D culminated in pilot-scale operational trials at the Akbakai gold mine (Kazakhstan), owned by JSC AK Altynalmas, in 2020, where SAG mill rejects of hard underground quartz/gold ore were processed. The mutual intent and purpose of the tests was to observe and define wear characteristics of the eHPCC grinding chamber liners (roll surfaces). These operational trials involved 80% of the feed size being less than 17 mm and a variety of targeted product sizes whereby 80% was less than 1 mm, 2 mm, 2.85 mm and 4.8 mm. The throughput ranged from 1-5 t/h based on the size.

IM: What throughputs and material characteristics will be set for the full-scale solution?

LR: There will be a select number of standard eHPCC sizes. Relative to the original eHPCC-1, the following scale-up factors are envisaged: -2, -3, -5, -8, and -13. These are geometrical linear scale-up factors; the actual volumetric capacity is a cube of this factor, with adjustments for centripetal acceleration. Currently -13 times seems to be the maximum feasible size of the present detailed design philosophy, but there are no foreseeable limitations in terms of feed materials with exception to moist clay. Clay was successfully processed after drying the feed in ambient temperatures during testing. Further testing of moist clays blended with other materials that can absorb the moisture as they comminute would be desirable.

IM: Other HPGRs can also be equipped with air classification technology to create dry comminution circuits. What is the difference between the type of attrition and air classification option you are offering with the eHPCC?

MD & LR: Two modes of comminution occur in the particle bed of eHPCC repetitively and simultaneously. First, confined bed pressure compression breakage occurs at a macro level that promotes shear/compression forces greater than the mineral grain boundaries. Second, Mohr-Coulomb Failure Criteria (shear/attrition) that completes the separation of micro fractures on subsequent cycles takes place.

The nip angle between the rotating components of eHPCC technology never exceed 5°. During the decompression and fluidisation portion of the cycle, the softer species – which are now much smaller – are swept out of the fluidised particle bed against centrifugal and gravitational forces by process air. The larger species, influenced by centripetal acceleration, concentrate at the outer diametric and lower limits of the conical rotating grinding chamber, continuing to work on each other during each subsequent compression phase.

HPGRs are limited to one single-pass comminution event, requiring downstream external classification and subsequent recycling/reprocessing of their oversize and/or flake product.

IM: How will it improve the mineral liberation and separation efficiency compared with other grinding solutions that combine both?

MD: eHPCC technology could compete with the Vertical Roller Mill and Horomill, however, eHPCC is likely to be more compact with high intensity breakage events contained within the all-inclusive system of breakage, classification and removal of products.

IM: When was it most recently tested and over what timeframe?

LR: The eHPCC-2 pilot plant was mobilised, setup and commissioned in March 2020, but its operation was suspended until June 2020 due to COVID-19 quarantine restrictions and a need to cater to abnormal amounts of ball fragments in the feed, the latter of which pushed the treatment of tramp metal to the extreme. The machine operated for the months of June and July using liners constructed of plasma transferred arc welded (PTAW) tungsten carbide (TC) overlay. During this period, a total of 795 t was processed at various targeted product sizes, with, overall, an average throughput of 3 t/h (nominally 265 operating hours) processed.

Side view of pilot system including feed hopper and weigh-scale feeder (right), feed conveyor (middle foreground), control and auxiliaries (middle background), eHPCC-2 (left foreground), dust bag-house (left background) and product conveyor and stockpile (not shown left background)
Front-end loader filling feed hopper with SAG mill rejects f80 18 mm

The PTAW-TC overlay was deemed unsustainable as it was consumed rapidly and demanded continuous rebuilding due to the high pressure intensive abrasive wear on the convex cone. The pilot plant operation was mostly suspended during the month of August while an alternative tungsten carbide studded liner, analogous to HPGR studded rolls, was manufactured for simulating a trial of this studded liner philosophy. The studded liner philosophy was operated in the eHPCC-2 in Kazakhstan for sufficiently long enough to ascertain the creation of the autogenous protective wear layer of rock between the studs, with the simulation trial deemed a success. The design philosophy shall be adapted on the commercial-grade eHPCC.

eHPCC-2 TungStud™ as-new (left) high-pressure-air-cleaned (middle) and brushed (right)

The pilot plant was demobilised from the Akbakai site laydown area on September 10, 2020, to release the area for construction of a non-related plant expansion. The operational experiences of the pilot plant at Akbakai provided valuable knowledge and experience pertaining to mechanical inertia dynamics and design for eliminating fatigue within eHPCC components.

IM: Aside from the test work on trommel oversize at the Kazakhstan gold mine, where else have you tested the technology?

LR: eHPCC has no other operational experiences so far. Investment and collaboration from the industry to progress the commercialisation of eHPCC is invited. The commercial-grade eHPCC-2.2 is designed and ready for manufacture.

IM: Is the technology more suited to projects where multiple streams can be produced (fines, coarse piles, etc)?

LR: eHPCC is configurable to meet the demands and liberality of a diverse spectrum of feed materials and the potential downstream extractive processes are complementary to eHPCC product streams. Therefore, it would be incorrect to categorise it as more suitable in any one niche; it is configurable, on a case-by-case basis, to meet the liberality of the specific progeny of the feed.

IM: What energy use benefits do you anticipate by creating a one-step comminution and classification process over the more conventional two-step process?

MD & LR: The energy saving benefits include:

  • Elimination of tumbling mill grinding media consumption;
  • Elimination of the liberal wastage of randomly directed attrition and/or impact events that indiscriminately reduce the size of any/all particles (gangue or precious mineral) with the conventional tumbling mill; and
  • Elimination of energy consumption of the materials handling systems between the various stages of comminution and classification, be it dry belt conveying, vibrating screens, classifiers, cyclone feed pumps, cyclones and their respective recirculating loads that can be upward of 300% of fresh feed.

IM: Do you anticipate more interest in this solution from certain regions? For instance, is it likely to appeal more to those locations that are suffering from water shortages (Australia, South America)?

MD & LR: We suspect the initial commercialisation growth market to be from base metals producers seeking to expand or retire existing aged/tired comminution classification capacity, followed by industry acknowledgement of the technology’s potential to shift the financial indicators of other potential undeveloped projects into more positive territory. This latter development could see the technology integrated into new projects.

In general, the technology will appeal to those companies looking for more efficient dry comminution processes. This is because it offers a pathway to rejection of gangue at larger particle sizes, early stream enrichment/depletion and minimal overgrinding that creates unnecessary silt, which, in turn, hinders or disrupts the integrity of downstream metallurgical extraction kinetics, and/or materials handling rheology, and/or tailings storage and management.

LR: There are a number of rhetorical questions the industry needs to be asking: why do we participate in the manufacture and consumption of grinding media considering the holistic end-to-end energy and mass balance of this (it’s crazy; really why?)? Why do we grind wet? What are the barriers preventing transition from philosophising over energy efficiency, sustainability etc and actually executing change? Who is up for a renaissance of bravely pioneering disruptive comminution and classification technology in the spirit of our pioneering forefathers?

The more these questions are asked, the more likely the industry will find the solutions it needs to achieve its future goals.

Dr Mike Daniel’s talk on eHPCC technology will be one of the presentations at the upcoming Comminution ’21 conference on April 19-22, 2021. For more information on the event, head to https://mei.eventsair.com/comminution-21/ International Mining is a media sponsor of the event

Byrnecut and Wiluna Mining strengthen ties with five-year alliance

Wiluna Mining says it has formally agreed to enter a five-year alliance with contractor Byrnecut Australia Limited for the performance of underground development and production mining services at the Wiluna Mining Complex in Western Australia.

Wiluna Mining has commenced a three-year, staged development plan that will see it capable of treating all ore types at Wiluna through four processes including an existing 2.1 Mt/y carbon-in-leach process plant; a 750,000 t/y flotation and concentrator, commencing construction this month with commissioning due in October, scaling up to 1.5 Mt/y capacity by the 2024 financial year; gravity circuit; and tailings retreatment plant.

On conclusion of the staged development plan, which is being developed to match the rate of the underground mining development, Wiluna Mining says it will be capable of processing all its ore at the Wiluna Mining Operations and will be producing some 250,000 oz/y. Most of the gold at this stage will be produced as a concentrate, however gold doré produced on site in parallel to concentrate sales will be continued to improve and optimise operating margins.

Wiluna said back in October that Murray Engineering had been contracted to supply and maintain mine fleet for current production, associated development and stoping at the operation, while Byrnecut would provide equipment and personnel for existing development rehabilitation and new development for resource-reserve drill out programs and production from new mine areas.

Byrnecut, following the most recent agreement, will be responsible for development and eventually the mining of the underground mine at the Wiluna Mining Centre, Wiluna Mining said.

The Byrnecut pact will also allow Wiluna Mining to amortise significant agreed mine capital and establishment costs over the five-year alliance period and provides the framework and certainty to a long-term seamless integrated approach to both mine planning and mining services execution to ensure the best outcomes and risk mitigation, it said.

Milan Jerkovic, Wiluna Mining’s Executive Chair, said: “We are pleased to enter into the five-year alliance with a world-class mining contractor in Byrnecut. We see great synergies and efficiencies as well as cost and capital benefits through the alliance. It provides, with a great degree of confidence, that the underground development and ongoing mining will be executed with the highest standard of efficiency, safety, timeliness, and profitability.

“We look forward to working with Byrnecut to transitioning the Wiluna Mine, once again, into one of Australia’s biggest and most profitable gold mines.”

This agreement is conditional on the completion of the final contract documentation, which is underway, and respective board approvals.

Condor Gold accelerates La India development with Metso Outotec SAG mill acquisition

Condor Gold has entered into an agreement to purchase a completely new Metso Outotec SAG mill package from First Majestic Silver to serve its La India project in Nicaragua.

The purchase consideration is around $6.5 million – made up of cash and shares – with the SAG mill representing a key item of the plant required to bring La India into production, Condor said.

The SAG mill is estimated by Metso Outotec’s technical support group to have a 2,300 t/d (800,000 t/y) throughput on a sustained basis, based on the metallurgical characteristics of the ore and mineralised material at La India. Based on internal technical studies and mining dilution studies conducted by SRK Consulting, initial production at La India is expected to be 80,000-100,000 oz/y of gold.

Condor says the SAG mill and parts are 90% ready to be shipped. The 2,300 t/d capacity forms “Stage 1 of production”, with capacity to be expanded materially after two to three years of production. Its delivery reduces the order time of this key long lead item by 12 months, fast tracking La India project into production. Condor said there is the possibility of increasing throughput by 22% to 2,850 t/d by installing a 4,100 kW motor (currently a 3,330 kW motor).

Mark Child, Chairman and CEO, said: “The key message is Condor has purchased and sized the mill at 2,300 t/d, significantly shortened the mill delivery time, set a trajectory for detailed project design and an accelerated path to production. What’s more, Condor has acquired a state-of-the-art, complete new SAG mill package with warrantees, manufactured and supplied by Metso Outotec, the premier manufacturer of grinding mills and entire grinding systems for the global mining industry.”

Condor plans to commence gold production at La India in 24 months.

The SAG mill agreement has come about as First Majestic ordered a complete new SAG mill package, which, Condor says, is now superfluous to its requirements.

The SAG mill has a mill diameter of 24 ft (7.3 m) and an effective grinding length of 18.5 ft and a structural charge mass of 315 t, Condor Gold said. The structural design ball charge is 11% with a structural design load volume of 35%. Specific gravity of the material is 2.55. The structural steel liner mass is 240 t; however, with the use of lighter composite liners, the weight and corresponding power requirement can be reduced significantly to 120 t.

The complete SAG mill package manufactured and supplied by Metso Outotec includes:

  • Mill shell fabricated in 8 x 90° segments;
  • Mill heads cast in 4 x 90° segments with demountable trunnions;
  • Ductile ring gear and carbonized pinion shaft;
  • Pinion shaft assembly equipment;
  • Erection cradles;
  • Bracket, coupling and guard;
  • Pinion bearings-2-pad polymer hydrostatic bearings;
  • Transformer for the mill;
  • Gear unit, steel guard and fasteners;
  • Allen Bradley variable speed drive;
  • Allen Bradley PLC mill local panel;
  • 3,300 kW WEG SCIM (motor);
  • Bearing housing;
  • Torque limiter and hubs;
  • Complete feed assembly. ‘Rock box’ feed chute with replaceable steel wear liners;
  • Complete discharge assembly. Fabricated discharge cone (no trommel screen) with replaceable rubber wear liners;
  • Discharge trunnion liner with replaceable rubber wear liners;
  • Installation materials and some spares;
  • Trunnion bearing;
  • Hydraulic torque wrench kit;
  • Liner handler; and
  • Howard Marten lubrication systems (trunnion oil lube, reducer/pinion oil lube, gear spray grease lube).

It is assumed that a pebble crusher will be used in the comminution circuit to provide some additional grinding power and to manage critical size fraction material, Condor said. The SAG mill is equipped with a variable speed drive to allow the mill to operate between 1,500 t/d and 2,300 t/d. Furthermore, it is possible to increase the daily throughput by increasing the motor size, as previously indicated. The 22% boost in throughput could potentially allow gold production to increase by a similar amount, the company said.

The SRK 2017 Technical Report on La India outlined an overall process flowsheet based on a single stage SAG comminution and conventional carbon-in-leach circuit.

ZED70 Ti battery-electric vehicle takes trip underground at OZ Minerals’ Carrapateena

The Zero Automotive ZED70 Ti has become one of the first Australia-made street legal light electric vehicles to enter an underground mine after making a trip into the Tjati Decline at OZ Minerals’ Carrapateena copper-gold operation in South Australia.

The vehicle made the trip in January and, according to OZ Minerals, managed over four complete round trips ‒ from the surface to the bottom of the mine and back ‒ without requiring a plug-in charge.

OZ Minerals said: “A big shout out to Zero Automotive for their hard work in developing such a great vehicle and commissioning it for underground use within two days!”

The Zero Automotive ZED70 Ti uses LTO chemistry and comes equipped with a specially selected battery housing, control systems and charging capability to endure the “hyper saline underground environment” at Carrapateena, OZ Minerals previously said.

OZ Minerals previously tested a Zero Automotive ZED70 battery-electric light vehicle on site at Carrapateena.

In June 2020, it also outlined a prefeasibility study on an expansion of Carrapateena that included a trial of electric light vehicles and establishment of a renewable energy hub.

Vuzix Smart Glasses keep Rio global teams connected at Oyu Tolgoi Underground

Rio Tinto has deployed Vuzix Smart Glasses at the Oyu Tolgoi copper-gold mine in Mongolia to continue progressing the development of the underground project in the face of travel restrictions tied to COVID-19.

Vuzik, a supplier of smart glasses and augmented reality technology and products, says the company is using its smart glasses to enable technical experts from all over the world to work with local teams on the underground project.

Rio, in its 2020 Annual Report, said it had been increasing its use of drones and mine pit cameras, and introduced video headsets (including smart glasses) to conduct visual inspections of tailings facilities and equipment while complying with travel restrictions and physical distance requirements.

“Vuzix Smart Glasses usage continues to expand across an ever-widening array of industry verticals,” Paul Travers, Vuzix President and Chief Executive Officer, said. “Companies like Rio Tinto, which is a global leader in its field, continue to provide validation of the value and effectiveness of our products in real world situations.”

BQE Water achieves several firsts with Zhongkuang SART plant operation

BQE Water says it has advanced the SART plant it designed for a gold metallurgical facility owned by Shandong Zhongkuang Group Co Ltd, in China, to full production.

Located in the Shandong Province in eastern China, the plant is now being operated under the ongoing technical supervision of BQE Water.

Implementing SART (sulphidisation, acidification, recycling and thickening) at the site improves both the environmental performance and project economics of the metallurgical facility, BQE said. Specifically, the SART plant eliminates the need for cyanide destruction, recovers copper and zinc as separate sulphide concentrates, and recycles free cyanide recovered by the plant to gold leaching.

BQE was awarded the SART plant contract back in 2019 following the positive outcome of an engineering feasibility study and on-site testing completed by BQE Water earlier in the year.

The Zhongkuang SART plant also represents many firsts, according to BQE:

  • It is the first application of SART globally where the cyanide competing base metals, copper and zinc, are recovered simultaneously from the leach solution as two separate high-grade concentrates that can be sold to generate incremental revenues;
  • It is the first commercial scale application of SART in China;
  • It is the first SART plant where lime is used to control gas emissions to reduce operating costs and control the build-up of salts in the process water; and
  • It is the first SART plant to be integrated into a complex metallurgical flowsheet that combines mineral flotation with cyanidation and SART in a Zero Liquid Discharge metallurgical facility with complete water recycle.

Songlin Ye, Vice President for Asia at BQE Water, said: “We are very proud of our China-based operations team for this significant achievement and that they were able to do so considering the challenges associated with the COVID-19 pandemic. The Zhongkuang SART plant is our flagship project for the China gold sector and other gold producers in the country are taking notice.”

David Kratochvil, President & CEO of BQE Water, added: “The many firsts associated with the Zhongkuang SART plant demonstrates our leadership in SART technology. And through the unique combination of engineering know-how and operations expertise, the project also shows our ability to reduce risks and achieve predictable outcomes for our clients.”

Macmahon lines up open-pit/underground work at Red 5’s King of the Hills gold project

Macmahon Holdings Ltd has been awarded its second major contract in as many weeks in the Goldfields region of Western Australia, receiving a letter of intent to carry out contract mining services at Red 5 Ltd’s King of the Hills (KOTH) gold project.

The KOTH project is an open pit and underground gold deposit with a projected mine life of over 16 years. This could see the company produce 176,000 oz/y of gold over the first six years, according to a recent feasibility study.

Red 5 has commenced the construction of the camp and processing facilities on site and is planning for mining to commence in early 2022. First gold production is expected to occur in June 2022.

Just last week, Macmahon was appointed the underground mining contractor at St Barbara’s Gwalia gold mine at Leonora Operations in Western Australia.

Following a detailed tender process for both the surface and underground mining activities, Red 5 has issued a letter of intent to Macmahon for a proposal combining both scopes of work. Under the agreement, the parties are working to finalise the documentation by which Macmahon will provide all surface and underground mining services to the project over a five-year contract term, commencing in the March quarter of 2022.

Macmahon expects this documentation will be completed by June 2021 and that the contract will add over A$650 million ($497 million) to the company’s order book.

Macmahon’s CEO and MD, Michael Finnegan, said: “We are delighted to be in advanced discussions with Red 5 for its King of the Hills gold project in Western Australia. We have a strategy to expand our presence across the mining services value chain, and this project highlights the benefits of being able to offer a combined surface and underground mining solution from the outset. We look forward to continuing our relationship with the Red 5 team and supporting their development of this important project.”