Tag Archives: Lucara

TOMRA Mining tech to be used for the world’s largest lithium sorting plant

TOMRA Mining says it is in the process of installing what will be the world’s largest lithium mineral ore sorting plant at Pilbara Minerals’ Pilgangoora project in Western Australia.

The installation has already started and is expected to reach completion in late 2023.

Pilbara Minerals says it owns the world’s largest, independent hard-rock lithium mine, producing a spodumene and tantalite concentrate. Through its P680 Expansion Project, the company has plans to step-up its production run-rate at the operation to a total of circa-680,000 t/y of spodumene concentrate. The sorting plant is part of this project.

Dale Henderson, Managing Director and CEO, Pilbara Minerals, said: “This new facility to be constructed at our Pilgangoora Project will be the world’s largest lithium mineral ore sorting plant. TOMRA’s experience in large global sorting installations, innovative technology and ability to provide local support were significant factors in our decision to work with them. From the start, the TOMRA team has been working side by side with us and our engineering partner DRA Global to deliver this important project.”

As part of this expansion project, Pilbara Minerals turned to TOMRA Mining for assistance to address the key industry challenge in the processing of spodumene feed ore contaminated with barren host rock.

TOMRA has 50 years’ experience in sensor-based sorting technologies and has designed and built 90% of the world’s large-scale mining sorting plants with a capacity above 300 t/h, it says. These include plants such as the Ma’aden Umm Wu’al project, which is operating at 1,850 t/h and the Lucara diamond operation which runs 15 sorters.

Specifically for the Pilbara Minerals project, TOMRA Mining highlighted that it offered effective ore sorting solutions with high sensor resolution and ejection accuracy that ensure high lithium recovery and waste removal with a stable and consistent performance at high capacity.

The TOMRA Mining team conducted a geological assessment of sample ores supplied by Pilbara Minerals. It revealed the pegmatite deposit did have non-lithium bearing host rock intrusions. Some of these minerals have a high density like that of spodumene, which means that it is also concentrated when using heavy media separation (HMS). This reduces the efficiency of the downstream flotation and contaminates the final product. Sensor-based sorting technologies, on the other hand, can measure the colour, density and mineralogical variations in individual particles, enabling the accurate detection and removal of this barren material, the company explained.

Working closely with the Pilbara Minerals metallurgical team, TOMRA conducted extensive test work at the TOMRA Test Center in Sydney, Australia, to check all the options and answer any questions arising during the tests.

The samples were run at capacity on production sorters and included repeatability and variation testing. The test work benchmarked the expected performance of the sorters and was used to establish the sort quality on each of the ore types that will be fed through the plant.

Primero Group, which was awarded the contract for construction of the project, has now started bulk earthworks for the sorting plant.

The TOMRA team was involved not only in the testing and supply of equipment, but also provided assistance with the plant layout and understanding of the implications of sorting on the upstream mining and downstream process of the ore. This involvement throughout the development process will add to efficient operational ramp-up and technical optimisation.

TOMRA’s capability to support the project with a dedicated Australia-based team and a global support structure has been a significant factor and is an important part of de-risking the installation of this new technology. The team is working closely with Pilbara Minerals through the installation process, commissioning and start-up, and will continue to provide on-site support once the sorting plant is up and running.

UMS gearing up for shaft sinking work at Karowe Underground

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.