Tag Archives: diamonds

Weba Chute Systems solves choking problem at Botswana diamond mine

Comminution of minerals, Diamond mining, Equipment maintenance, Mining equipment, Mining services, , , , ,

Weba Chute Systems has come to the rescue of a large Botswana diamond producer suffering from continuous chute maintenance with a customised solution that came with a 12-month guarantee.

This primary crusher discharge chute had been a headache for the company, with the crunch coming when, after considerable capital expenditure, the new conventional chute needed maintenance just six weeks after installation.

Hilton Buys, Regional Manager at Weba Chute Systems, said: “This could not continue and the mine needed a long-term solution which is why we believe they came to us for a proposal. Senior experts from our company visited the site to take a careful look at the conditions the chute needed to deal with, and we took our conclusions back to our design office.”

Among the challenges were large lump sizes in the ore stream, contributing to build-up of material in the chute and regular choking, Buys said. Also, while Botswana’s dry season is long, the rain that does fall causes considerable problems to the flow dynamics. The kimberlite on the mine – depending on which part of the pit it comes from – can become very sticky in wet weather, according to the company.

“We therefore had to pay particular attention to flow angles, and the design had to effectively accommodate both wet and dry conditions,” Buys said. The concept design – which included quick-release lips on dead boxes – was approved by the mine and the final design, manufacture and successful installation was conducted.

Adding to the complexity was that the feed end of the primary crusher was some 8 m below ground level, while the crusher itself stood about 10 m tall. The chute had to be positioned below the rock box, which stores the material from the crusher discharge, channelling the stream into the Weba chute at a transfer height of 9 m to the conveyor belt.

“The conventional chute also created excessive dust through uncontrolled rock velocity over this considerable transfer height,” Buys said. “By contrast, our chute’s controlled flow meant that the mine did not even have to apply its dust suppression system.”

After installation, Weba Chute Systems gave the customer a 12-month guarantee on this chute, as it does with all its new chutes. This guarantee, which comes with regular inspection reports, assures the customer that the performance will meet their expectations.

“These inspections allow us to monitor wear, so we can advise the customer on what action is required so that they can schedule maintenance and avoid unexpected downtime,” Buys said.

Installed in 2017, the chute is still operating with little maintenance, having been delivered at a highly competitive price compared to the one it replaced.

“Designing a long-lasting chute is not just about creating a box with some reinforcing where you think there will be wear,” Buys said. “It is an endeavour that must be scientific, based on in-depth analysis of material and flow conditions.”

Buys highlighted the importance of asking a range of technical questions about the specific application so the design answers those needs. The latest software and modelling tools are then applied by the Weba Chute Systems team to guide the most effective design.

WEC Projects looks to nature for Lucara Karowe sewage treatment plant

Diamond mining, Environmental, Mining services, Water management, , , , , ,

WEC Projects has secured a R3 million ($187,460) contract to supply a new sewage treatment plant for the expansion of Lucara Diamond’s Karowe diamond mine in Botswana.

The mine, near the village of Letlhakane in the eastern Kalahari Basin region of Botswana, is planning to cease open-pit activities by 2026 after which it will continue mining underground, extending its operational life to around 2040. More than 1,000 m above sea level, the mine operates in a region where temperatures average 35°C and water is scarce; so much so that the Government of Botswana has legislated mandatory water saving requirements for industry.

WEC Projects installed the original treatment plant in 2012 and will integrate the new system into the existing facility, increasing throughput from 100 cu.m/d to 150 cu.m/d to meet the requirements of an increase in the number of staff at the mine. While the treatment plant itself is a fairly standard installation, the mine requested a variation to the original project scope – a man-made natural reed bed wetland system that will provide a “polishing” phase to the treatment process, using natural organisms and filtration processes to further clean the wastewater, WEC Projects said.

Wayne Taljaard, Managing Director of WEC Projects, said: “This is a particularly unique feature for a mine as usually such reed bed wetlands are built for much larger installations such as municipal sewage treatment. The government’s mandate for water conservation has forced companies in Botswana to apply creative thinking to overcome the challenge of operating in an arid country.”

The main sewage treatment facility will consist of a WEC Projects Model A treatment plant, an extended aeration system using conventional activated sludge to process the sewage. The wastewater passes through a mechanical screen which removes solids and is then treated by a biological reactor which integrates anoxic, aerobic and clarification zones.

After treatment, the water will enter the reed bed wetland area where it will percolate through the reed bed allowing microorganisms to breakdown contaminants such as sulphur, heavy metals and chlorine. The water produced by this process, while not for human consumption, will be reused by the mine for applications such as irrigation and dust suppression, according to the company.

To create the wetland, a shallow dam will be built, its bottom to be filled with gravel and reeds planted. The water from the treatment plant will feed into the wetland area where nature will be left to take its course.

Taljaard added: “The reed bed solution offers a number of advantages for the mine as the effluent will be relatively odourless and is flexible enough to cope with fluctuations in input. It also requires little maintenance once it is up and running and will ensure that the mine remains within the constructs of the law.”

ALROSA looks to reclaim Aikhal tailings pit as part of 650 ha land restoration project

Diamond mining, Environmental, Mine operation news, Sustainable mining, , , , ,

ALROSA plans to reclaim the tailings pit of processing plant No. 8 at its Aikhal Division by 2029 in a project worth over RUB2.5 billion ($34.3 million) that will seek to restore 650 ha of land and have it planted with pine forests, the diamond miner says.

The tailings pit is located 1.2 km southwest of the village of Aikhal (pictured) in the Sokhsolookh River valley in Yakutia, Russia. The decision to reclaim the facility followed the completion of mining at the Komsomolsky open pit and the closure of processing plant No. 8 at the end of 2020.

During the plant’s operations, tailings were stored in the tailings pit as a liquid slurry. In terms of environmental danger, the slurry belongs to the lowest hazard waste category (virtually non-hazardous waste or category 5 under the Russian Federal Law on Industrial and Consumer Waste), ALROSA says. The tailings pit was a key hydrotechnical facility ensuring water recirculation at the processing plant: after the slurry settled in the pit, clarified water was fed back into the plant to be re-used in processing diamond ore, the company explained.

The reclamation project will be implemented in two stages.

The first stage will include draining the pit and restoring a part of the original course of the Sokhsolookh River back to its natural state.

Later on, from 2025 to 2029, the tailings facility will be dismantled, and work will be carried out to improve the land, dig drainage ditches, install waterproofing, lay fertile soil and landscape the area. To achieve this, 160,000 Scots Pine seeds have been sown in 2021 in a disused sand and gravel open pit not far from the Aikhal village. This conifer is not native to this area and does not grow locally on its own.

Once all the work is complete, the land beneath the tailings pit will be restored to its original condition and, as mentioned, over 650 ha of replanted area will be handed over to local authorities.

UMS gearing up for shaft sinking work at Karowe Underground

Diamond mining, Mine shafts and equipment, Mineral project development, Mining services, , , , , , , , , , ,

With a team comprising some of the most experienced professionals in shaft sinking, United Mining Services (UMS) says it is gearing up for the pre-sinking of two shafts for the Karowe Underground Mine Expansion Project (UGP) in Botswana.

Following the completion of the feasibility study for the Karowe UGP, UMS was appointed by Lucara Botswana Pty Ltd and JDS Energy & Mining Inc in October 2019 to engineer and design the shaft sinking of the production shaft (8.5 m in diameter), and the ventilation shaft (6 m diameter), both reaching a depth of approximately 750 m below surface.

Fully commissioned in 2012, Karowe is an open-pit diamond mine with operations until 2026. The UGP will extend Karowe’s mine life to at least 2040. At the end of 2020, Karowe’s total probable reserve stood at 53.9 Mt containing 7.4 Mct including stockpiles.

According to Lucara, the Karowe mine remains one of the best producing mines of high quality plus-10.8 ct diamonds, having yielded five of the 10 largest diamonds in recorded history. It is also the only mine to have recovered three diamonds greater than 1,000 ct.

Dr Pieter Louw, Group Executive Project Services at UMS and UMS’ Project Manager, says the company’s wealth of knowledge and expertise in shaft sinking played a key role in securing the contract, and that the company is bringing in the heavyweights in the industry for the project.

Louw, himself, has a long history in underground mining and shaft sinking, having worked for major players in the mining and engineering sectors. He was involved in the De Beers Venetia Underground Project feasibility study, as well as a number of other feasibility projects for mines that are now in development or have already started production.

Louw explains that the two shafts at Karowe will be blind sunk using conventional drill and blast techniques. The production and ventilation shafts will both have equipment installed to pre-sink to a shaft depth of 100 m, if required, to accommodate the main sink shaft equipment. The pre-sink phase also allows the sinking process to commence as soon as possible while the main sink infrastructure is being fabricated and installed.

The new underground mine’s production shaft will have an A-frame type headgear, which will hoist 21-t payload skips, and will have a single drum auxiliary winder for people movement, and a man/material winder with counterweight and a big cage to service the underground.

UMS has refurbished four winders, which will be going to the mine for shaft sinking, including two stage winders and two Kibble winders. The company also purchased and refurbished Scotch derrick winder cranes for the pre-sink.

Louw says that UMS is in the process of mobilising up to 170 people to site for the pre-sink, which is expected to commence at the end of August and will take between eight and 12 months to achieve changeover ready for the start of the main sink. The main sink will take another two years after that, ready for mine development to commence in 2024, and full underground operations in 2026.

To make sinking safer, Louw says that UMS has adopted different sinking methodologies and equipment to be used at Karowe.

“In the past, we used to sink with cactus grabs which needed people in the bottom,” Louw said. “We are now using vertical shaft muckers and are buying state-of-the-art jumbo drill rigs to drill at the bottom. We’re doing inline work as opposed to concurrent work with people working at the bottom.”

He adds that, as part of its safety management plan, UMS has established a training centre on site at Karowe that facilitates inductions and training of local operators on the various equipment. The company is constructing a mock-up training tower on the surface to train operators on vertical shaft muckers and will have a similar training simulator for excavator operators.

Louw says UMS is fully established in Botswana and has partnered with Botswana Investment and Trade Centre to ensure that the project work permits run smoothly. Furthermore, the UMS design engineers are registered with the Botswana certification boards and can sign off all engineering designs and drawings for the project.

UMS to start pre-sinking work at Lucara’s Karowe Underground Expansion project

Diamond mining, Mine operation news, Mine shafts and equipment, Mineral project development, Mining equipment, Mining services, Mining techniques, Power supply for mines, , , , , , , , , , , , ,

Lucara Diamond Corp’s Karowe Underground Expansion project (UGP) in Botswana is moving ahead with mobilisation of shaft sinking teams commencing late in June, and pre-sinking activities scheduled in the September quarter.

The Karowe UGP, which is expected to extend the operation’s mine life to 2040, is in a fully-financed position, with the latest schedule expected to see underground production hit full production by the end of 2026.

The 2019 feasibility study for the project envisaged life of mine production of 7.8 Mct, a payback period of 2.8 years and an after-tax NPV (5% discount) of $718 million; all from $514 million in pre-production capital.

COVID-19 delays have pushed the project off the original schedule – both in terms of timeline and cost – but the company says it is now making headway towards a 2026 start to underground production.

Lucara said no “material variances” between the 2019 feasibility study and the current execution plan have resulted, despite the delays.

“Rather, during this period in 2020 and 2021, all critical path items were addressed and a concerted effort was placed on detailed design, engineering and procurement which have helped to significantly de-risk the project,” it said.

Out of the total capital budget, the company has spent $51.4 million on project execution activities through 2020 until the end of June 2021, including shaft and geotechnical engineering, procurement of long lead time and essential shaft sinking items, surface infrastructure and construction activities, bulk power supply power line engineering and procurement.

Mobilisation of the shaft pre-sink team has commenced with shaft pre-sinking on track to commence in the middle of the current quarter.

Detailed engineering and design of the underground infrastructure and layouts will commence this quarter and are expected to be competed in the September quarter of 2022, with no major changes from the 2019 study plan anticipated.

Underground mine development is scheduled to commence in the second half of 2024 with underground production ramp up starting in 2026. Full production is scheduled for the end of 2026.

At the same time, open-pit mining operations have been adjusted to limit the risk of production shortfalls during the ramp up of the underground mine operations commencing in the first half of 2026. The open-pit mine is expected to terminate in mid-2026, Lucara said.

Access to the underground mine will be via two vertical shafts, the production and ventilation shafts. The shafts will be concrete lined with the production shaft acting as the main air intake and the ventilation shaft as the exhaust.

The number of shaft stations and nominal elevations remain the same as the feasibility study, with the planned depth of the production shaft still at around 767 m. The final planned depth of the ventilation shaft has, however, increased marginally to 733 m, from 716 m.

A 7,200 t/d shaft operation using long hole shrinkage (LHS) mining will provide an additional 13 years of mine life to the Karowe operation after a five-year construction period. The 767-m-deep production shaft will be equipped with two 21 t skips for production hoisting and a service cage for man and material movement through the mine. This shaft will also serve as the main fresh air intake to the mine.

The pre-sink construction contract and shaft sinking equipment procurement were awarded to UMS Botswana and UMS South Africa, respectively. METS International Ltd, a subsidiary of UMS, was awarded the shaft engineering contract.

The company explained: “Detailed design and engineering work on the production and ventilation shafts is now 90% complete, and has resulted in the following changes to the 2019 feasibility study: i) production shaft diameter has increased from 8 m to 8.5 m, ii) ventilation shaft permanent headframe, hoists and internal conveyances have been removed, iii) parallel pre-sinking of both shafts, iv) ventilation fans and coolers to be located on surface, v) in-shaft grouting of water strikes changed from grout curtain installation from surface, vi) planned development of an additional sublevel to assist in drilling of drawbells, and vii) removal of 670L de-watering galleries.”

Increased schedule time related to shaft sinking has been a result of the increased production shaft diameter, time allowances for in-shaft grouting during sinking operations planned at known water strike horizons, holing through all shaft stations between shafts and additional ground support for underground stations/level breakouts, the company said.

UMS is in the process of mobilising crews to Karowe to initiate pre-sink works. Pre-sinking of the two shafts will run in parallel and start with mobile cranes and then transition to Scott Derrick cranes with the final depth of pre-sink at around 40 m below surface.

With the exception of an additional sublevel (340L) to assist with drill and blast of drawbells, the design, layout and infrastructure of the underground mine all remain aligned with the 2019 feasibility study, the company noted.

Temporary power for shaft sinking is required until such time as the upgrade bulk power supply infrastructure is commissioned in the December quarter of 2022. A three-phased ramp up of the generator capacity is planned to support the increasing power requirements related to the shaft sinking activities.

A power supply and services contract for the temporary generators has been signed with Aggreko International Projects Ltd. Mobilisation has been initiated with the generator pad established. Commissioning of Phase 1 is scheduled during the September quarter to support the start of pre-sink activities.

The Karowe UGP is targeting the substantial resources remaining below the economic extents of the open pit in the South Lobe.

The LHS method is planned to systematically drill and blast the entire lobe on a vertical retreat basis. In LHS, a significant proportion of the blasted muck is left in the stope during blasting and stoping to stabilise the host rock with only the swell extracted during the drill and blast phase. Mucking will take place from draw points from the 310L extraction level. Once the column is fully blasted, the stope will be drawn empty by mucking the draw points.

The bottom-up approach of the LHS mining method takes advantage of the higher value EM/PK(S) kimberlite unit at depth in the South Lobe at Karowe, and balances high initial capital costs with low operating costs while de-risking the project with respect to the geotechnical and hydrogeological aspects of the host rocks, according to Lucara.

A revised project cost and schedule has been developed that captures the detailed engineering and design work through 2020 until May 2021, incorporating all changes, improvements, and COVID-19 related delays. Overall capital expenditures, including contingency, have increased marginally by some 4%, to $534 million, driven by the increase to the production shaft diameter and additional mine development.

The schedule to 75% of full production has increased by 1.3 years, driven mainly by COVID-19-related delays to commence the shaft pre-sinking and additional planned time for shaft station break-outs and ground support, Lucara added.

During 2020, Lucara negotiated and signed a self-build agreement with the Botswana Power Corp (BPC) for the construction of two substations and a 29-km-long 132 kV transmission line from BPC’s newly established Letlhakane substation to the Karowe mine. The planned route follows an existing regional 400 kV line and then runs parallel to the existing 11 kV transmission line currently supplying bulk power to the Karowe mine.

The new power infrastructure will provide the required power for the current open pit, processing plant and the underground mine expansion. Commissioning of and handover to BPC is scheduled for the December quarter of 2022. Construction of substations is scheduled to commence this quarter and power line construction in the March quarter of 2022, the company said.

JDS Energy & Mining Inc is the engineering procurement and construction manager for the execution of the Karowe UGP and is currently building up the on-site project team in conjunction with Lucara’s owners team and working in close cooperation with the Karowe Diamond Mine operations team.

ALROSA looks to ABEL HM pumps for filter press feeding

Diamond mining, Mine operation news, Mining equipment, Mining services, Water management, , , , , , , , ,

Piston diaphragm pumps from ABEL are helping Russia’s ALROSA with its filtration process at one of its diamond mines in the country.

In Spring 2021, ABEL received an order for the delivery of six of these piston diaphragm pumps, HM pumps, following an initial HM pump order in 2020. This inaugural pump was delivered to ALROSA in February 2020 as replacement for a centrifugal pump previously used for filter press feeding. At the beginning of August, the ABEL pump was commissioned at the diamond producer’s plant. The dewatering result (higher solids content, shorter filtration time) was so convincing that ALROSA decided to feed all filter presses in this plant with the pumps, ABEL said.

The latest delivery is being facilitated by ABEL’s official distributor in Russia, SibComplectService.

ABEL’s HM pumps are available as single- or double-acting versions. They come with a high flow rate, reliable function and particularly low operating and maintenance costs, the company says.

In addition to filter press feeding, the hydraulic diaphragm pumps are also used for sludge transport, spray dryer feeding, rotary kiln feeding, autoclave feeding, and sealing/rinsing water supply, among other applications.

TOMRA completes the diamond recovery loop with new XRT solution

Comminution of minerals, Diamond mining, IoT, Mineral processing, Mining equipment, Mining services, Mining software, , , , , ,

TOMRA Sorting Mining says it is breaking new ground with a “unique” X-ray Transmission (XRT) Final Recovery solution that guarantees 99% diamond recovery.

With the new introduction, TOMRA is the first company in the industry able to supply a full diamond recovery solution using XRT technology from 2-100 mm, coupled with all the benefits of cloud computing for monitoring and managing the entire process, it said.

The new TOMRA COM XRT 300/FR final recovery sorter delivers concentration factors of up to one million with limited stages and is the only solution on the market that guarantees more than 99% diamond recovery, according to the company.

“The new sorter stands out for the high sorting efficiencies, the high diamond-by-weight concentrate, and the benefits deriving from its focus on a single consistent detection principal, diamonds,” the company said. “With this new introduction, TOMRA offers a complete partnered diamond recovery ecosystem with a flowsheet covering the entire process – from concentration to final recovery and sort house – and includes custom development with the end-user all the way to installation, then continued management of the asset and support with specialised services and training.”

The TOMRA COM XRT 300/FR is the latest step in TOMRA’s long-term diamond sector strategy, Geoffrey Madderson, Diamond Segment Manager for TOMRA Sorting Mining.

“We always had this clear objective, but the technology just didn’t exist,” he said. “We knew that to achieve our goal, we would need extremely advanced sensor technology. We have been working in-house on the development the new ultra-high resolution sensor more than five years, and now we are able to close the loop: the COM XRT 300/FR is the last piece within our recovery process, covering the final recovery and sort house applications to produce an ultra-high diamond-by-weight concentrate.”

TOMRA says its holistic approach and unique offering has earned a strong market trust in its XRT technology. As a result, the first three TOMRA COM XRT 300/FR sorters produced have already been sold to customers, all of whom purchased the machines on the back of their experience of previous TOMRA sorters.

The makeup of the TOMRA COM XRT 300/FR sorters sees input material evenly fed via a vibration feeder onto a conveyor belt. An electric X-ray tube creates a broad-band radiation, which penetrates the material and provides spectral absorption information. This is measured with an X-ray camera using DUOLINE® sensor technology, which focuses on a single, constant property of the material, density, it explained.

The advanced ultra-high resolution sensor information is processed and analysed by our TOMRA’s new Image Processing Pipeline to provide a detailed “density image” of the material, allowing it to be separated into high- and low-density fractions. If diamonds are detected, it commands the control unit to open the appropriate valves of the ejection module at the end of the conveyor belt. The detected diamonds are separated from the material flow by jets of compressed air. The sorted material is divided into two fractions in the separation chamber.

The tight tolerances and accurate alignment of the new ultra-high resolution sensor results in a high-quality picture that ensures a clear discrimination between diamonds and low-density materials down to 2 mm, according to TOMRA. The sorter features high-speed valves with a fine nozzle pitch, which significantly reduces non-diamond material in the concentrate. The result is ultra-high diamond-by-weight concentrate with a guaranteed recovery of more than 99%, the company claims.

It is possible to replace multiple sorting stages with a single TOMRA COM XRT 300/FR sorter all the way down to hand sorting, according to the company. In the final recovery application, the sorter targets the highest tonnage through the sorter that can be achieved with the highest recovery efficiency, which ranges from five tonnes to one tonne. As a result, the operation benefits from a smaller footprint and achieves much better grade.

It is also possible to replace hand sorting with a TOMRA COM XRT 300/FR. In a sort house application, it targets the highest diamond-by-weight concentrate possible, with about half the tonnage than final recovery, bringing multiple benefits. It removes the traditional bottlenecks around hand sorting efficiencies and eliminates the human error factor, the company says. In addition, it provides a high level of security by protecting the product from human intervention.

TOMRA’s partnered diamond recovery ecosystem includes consultation services during the development of the system and throughout the lifecycle of the equipment, support running the sorters, and help with specialised services and training. The company has also leveraged digital technologies to provide effective support, through its Virtual Demonstration and Test Solution and features such as the TOMRA Visual Assist Augmented Reality tool for remote assistance.

“With TOMRA, the customer’s entire recovery system falls into one ecosystem,” explains Madderson. “This allows for better compatibility and interconnectivity between the different applications of the recovery process. It gives our customers the full benefit of using cloud computing through our TOMRA Insight platform, which turns our sorters into connected machines. This enables customers to monitor and manage their recovery process in one easy-to-access place for both on-site and off-site management teams.”

TOMRA has set up a showroom dedicated to demonstrations of the TOMRA COM XRT 300/FR sorter at its Test Center in Wedel, Germany. Later in the year, TOMRA will also offer virtual demonstrations for those unable to travel to the Test Center.

Kwatani branching out from South Africa roots

Comminution of minerals, Equipment maintenance, Mineral processing, Mining equipment, Mining services, , , , , , , , , ,

Vibrating screen and feeder specialist Kwatani says it is transitioning from equipment supplier to solutions provider, as it attracts customers from well beyond its South Africa headquarters.

According to Kwatani General Manager Sales and Service, Jan Schoepflin, the company’s strong in-house expertise and design capability – combined with the manufacturing quality it consistently achieves – ensures its customised solutions deliver optimal performance at the lowest possible lifecycle costs.

“Our recent orders show that our customer base in Southern Africa remains strong, while there is growing recognition of our cost-effective offerings in West Africa, East Africa and North Africa,” says Schoepflin. “At the same time, orders from countries like Canada and Russia indicate that our markets abroad continue to grow.”

Kwatani says it remains the market leader in the supply and servicing of vibrating screens and feeders on iron ore and manganese mines in South Africa’s Northern Cape province. It also counts platinum, coal, diamond and gold mines in its customer base. Its West Africa orders have been mainly to gold mines, and there is growing potential for gold mining in East Africa, Schoepflin says.

Over its four decades of operation, Kwatani has produced about 16,000 custom-designed screens, and is building, on average, 30 to 40 units a month in its ISO 9001:2015 certified facility close to OR Tambo International Airport in Johannesburg.

“Our reputation has been built on prioritising what our customers need, and doing business with integrity and trust,” Schoepflin says. “This means delivering on what we promise and making sure that customers achieve the expected value from our products.”

The company’s solution focus is underpinned by its significant and ongoing investment in local skills, ensuring that its designs leverage strong mechanical and metallurgical engineering expertise, according to Schoepflin.

“This confidence in our products allows us to offer a process guarantee to customers, to deliver the tonnage, throughput and fractions that they expect,” he says. “Depending on which country our customers operate in, they may also have different industry and quality standards/certification expectations and we work closely with them to understand these clearly and meet their requirements.”

Schoepflin also emphasises the company’s service capabilities, which include its local service centres closer to customers, and its support partners in other countries.

“The careful selection of these partners is vital to meet customers’ stringent technical expectations,” Schoepflin says. “In some countries, our partners can also manufacture components according to our drawings and specifications, should there be an urgent requirement from a customer.”

De Beers taps Sandvik expertise for Venetia underground diamond mine transition

Automation, Bulk handling, Communications in mining, Diamond mining, IoT, Mineral project development, Mining equipment, Mining services, , , , , , , , , , , , , , , , , ,

De Beers Group has ordered 19 units of high-tech equipment from Sandvik Mining and Rock Technology for its Venetia Underground Project (VUP), in South Africa.

According to Simon Andrews, Managing Director at Sandvik Mining and Rock Technology Southern Africa, the company will supply a range of intelligent equipment including LHDs, ADTs, twin-boom drill rigs, roof bolters and cable bolters. Amongst the advanced models are the 17 t LH517i and 21 t LH621i LHDs, 51 t TH551i ADTs, DD422i face drills, DS412i roof bolters and DS422i cable bolters.

Partnership will be the watchword in the technological collaboration between the global diamond leader and mining OEM.

South Africa’s largest diamond mine, Venetia has been mined as an open pit since 1992. De Beers Group is investing circa-$2 billion to start mining underground from 2022, extending the mine’s life beyond 2045. The VUP represents the biggest single investment in South Africa’s diamond industry in decades, according to the company.

Allan Rodel, Project Director of the VUP, says the use of new technology is critical in building the mine of the future and will ensure the safety of its people, as well as create unique employment opportunities.

He adds that the successful implementation of this technology holds the key to further improve the mine’s productivity and cost effectiveness, enabling the quality and accuracy required for precision mining. This will also provide real-time geospatially referenced data that supports digitalisation of processes and provide a wealth of data for analysis and continuous improvement.

The underground mine will use sublevel caving to extract material from its K01 and K02 orebodies. Initially the ore will be hauled to surface using a combination of underground and surface haul trucks. As the operation matures, the hauling systems will transition to an automated truck loop in combination with vertical shafts for steady state production.

Sandvik’s Andrews said: “As important as the equipment itself is, De Beers Group was looking to partner with a company who would support them through the VUP journey. Taking a mine from surface to underground has many challenges, including the change in operational philosophy.”

Andrews highlighted that change management processes are as crucial to success as the capacity and performance of the mining equipment. The implementation of the new technology is seldom a straightforward process, and always requires a collaborative effort.

“The expectation of the customer is for a strong relationship with a technology partner who will help them to apply, develop and fine-tune the systems they need, over a period of time,” he says. “This way, the technology is assured to deliver the safety, efficiency and other positive results that the new mine will demand.”

Andrews believes Sandvik Mining and Rock Technology leads the pack from a technology point of view, having introduced its intelligent i-Series machines to enhance remote operation capability. This advanced range combines automation with data management capacity, aligning with the philosophy that De Beers Group has applied to this world-class operation, which prioritises the safety of its people.

Also included in the package for VUP is the Sandvik OptiMine® control system which enables continuous process management and optimisation, focusing on key areas such as face utilisation and visualisation of the operation in near real time. Using data generated by the i Series machines, OptiMine helps mining operations to achieve the lowest operating costs and highest levels of productivity.

Andrews noted that Sandvik Mining and Rock Technology is not new to the Venetia site, having worked with Venetia’s surface operations for some years, providing tools for drilling as part of a performance contract.

“We’ve been following the VUP with great interest and were ideally placed to contribute as we have extensive South African experience with mining customers in transitioning from opencast to underground,” he said. “This has involved providing equipment, implementing the systems and getting a full operation running with the latest equipment.”

He added: “Sandvik Mining and Rock Technology has successfully completed numerous large and ambitious projects, and it reflects our experience in applying automation technologies from first principles. The learnings from these projects will be seen in the VUP as the mining systems are rolled out. We will take the very latest technology and assist the mine to implement it in an underground environment through a collaborative approach using local skills and supporting it from a local base of expertise.”

He emphasises that the automation will be applied through a phased approach, beginning with manual operation and closely monitoring performance through data analytics. Automation can be gradually introduced with the necessary training and experience, ensuring consistency of operation which is the key to success.

“This will allow costs to be driven steadily lower, using the data from the operation of the fleet to guide the transition to automation,” he says. “We will work with the mine to introduce automation and further data management as work progresses deeper into the mine, and as mine employees become more comfortable with this way of working.”

Sandvik Mining and Rock Technology (soon to be Sandvik Mining and Rock Solutions) is geared to support the trackless systems implemented at the mine through the full lifecycle of the machines by supplying spare parts, tooling and components from an on-site Vendor Managed Inventory stockroom and its other South African based facilities.

TOMRA XRT units help recover unbroken 998 ct diamond at Lucara’s Karowe mine

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TOMRA’s COM XRT 2.0/1200 ore sorters have aided Lucara Diamond’s Karowe diamond operations, in Botswana, once again, recovering an unbroken 998 ct high white clivage diamond from the 100%-owned mine.

The diamond, measuring 67 x 49 x 45 mm, was recovered from direct milling of ore sourced from the EM/PK(S) unit of the South Lobe, and follows a series of significant diamond recoveries during this recent production run, including several top quality clivage and gem-quality stones of 273 ct, 105 ct, 83 ct, 73 ct, and 69 ct in weight.

“The EM/PK(S) forms an important economic driver for the proposed underground mine at Karowe and continues to produce large gem-quality diamonds in line with expectations, a further testament to the strong resource performance at Karowe,” the company said.

Last year, a feasibility study showed the company could double the mine life of Karowe by establishing an underground mine for $514 million in pre-production capital.

The 998 ct diamond (pictured) was recovered in the MDR (Mega Diamond Recovery) XRT circuit that allows for diamond recovery post primary crushing and prior to milling. The MDR circuit has, in the past, treated material in the size range between 50-120 mm. This latest recovery represents the second plus-500 ct diamond recovered from this circuit in 2020, Lucara noted.

Year to date, Karowe has produced 31 diamonds greater than 100 ct, including 10 diamonds greater than 200 ct comprising of the 549 ct Sethunya, and the 998 ct diamond.

Eira Thomas, Lucara CEO, said: “Lucara is extremely pleased with the continued recovery of large high-quality diamonds from the South Lobe of the Karowe mine. To recover two plus-500 ct diamonds in 10 months along with the many other high-quality diamonds across all the size ranges is a testament to the unique aspect of the resource at Karowe and the mine’s ability to recover these large and rare diamonds.

“Operations at Karowe have continued through 2020 and operational challenges, due to COVID-19 restrictions, have been met with professionalism by the team. We look forward to a safe finish to 2020 and continued success at Karowe as we remain focussed on strong operations to ensure maximum resource performance.”