An Appetite For Diamonds

By: Nelendhre Moodley

The diamond industry has been under tremendous pressure over the past few years, owing to geopolitical and macroeconomic tensions, shifting perceptions related to sustainability and social welfare and more recently, the onset of COVID-19, which for a couple of months literally stalled the global economy.

The litany of challenges, which have greatly impacted the demand for and production of diamonds, also include legislative changes related to corporate social responsibility, the rising cost of electricity and the need for reduced consumption of natural resources, such as water.

With these market challenges front and centre, those in the diamond market value chain remain extremely conscious of the associated financial and cost implications.

As such, diamond miners continue to seek out solutions that help maximise diamond recovery while optimising costs, Geoffrey Madderson, diamond segment manager for Tomra Sorting Mining, tells SA Mining.

Despite the subdued demand, industry players remain hopeful of a resurgence in the diamond market, given that the global population continues to expand rapidly, currently sitting at just under eight billion people.

Tomra, a sensor-based solutions provider and leader in the X-Ray Transmission (XRT) market, offers an alternative to the traditional dense media separation/traditional cyclone recovery sorting technology. The company has been a key player helping diamond miners recover some exceptional stones.

“Tomra guarantees 100% detection in the specified range, irrespective of luminescence profile or coating, and a diamond recovery greater than 98%,” says Madderson.

The supplier of XRT sorting equipment has installed between 97% and 98% of all XRT installations globally and will soon be releasing a new product to the market – an XRT Final Recovery Sorter with the ability to detect and sort diamonds between -32+2mm, setting Tomra’s offering up to be “totally unique” and enabling a full recovery service with XRT from 2mm to 100mm.

An official product launch is set to take place in the first quarter of next year.

Tomra delivers cutting-edge technology

Unpacking Tomra’s product offering, Madderson explains that the company is able to tackle challenges a diamond operation might face, including having extremely low grades; fine diamond distribution, or the opposite, extremely course diamond distribution; and deposits with high-yielding ore or deposits embedded with diamond distributions in the highly prized type IIa or type IIb diamonds. Type IIa or type IIb diamonds are typically more difficult to recover using the traditional X-ray luminescence technology.

The company’s XRT technology is able to recognise and separate material based on its specific atomic density. Its high-capacity sorters are effective in the recovery of free, liberated diamonds at high feed rates up to 400tph.

In looking to assist clients, the company aims for a collaborative approach – ideally getting involved at a projects pre-feasibility study and bankable feasibility study stage to ensure that it can help unlock benefits early on in the process using Tomra technology.

“At the onset of a partnership with a diamond miner, Tomra undertakes a detailed analysis of the customer’s requirements and operational needs and works collaboratively to develop a tailor-made flow sheet redesign that combines its XRT technology with its near infrared (NIR) and laser solutions as needed.”

Its customised approach allows Tomra to deliver on its promise of guaranteed results in hard-rock kimberlite, lamproite or alluvial deposits – each of which presents its own specific challenges.

Tomra’s XRT machines have proved effective in alluvial operations as in the case of the Lulo mine in Angola which is operated by Lucapa Diamonds, where Tomra’s XRT technology is used to process material between 18mm and 55mm in size. The process allows for the recovery of diamonds up to 1 100 carats. Tomra’s technology was instrumental in the recovery of Angola’s second biggest diamond in 2017, a 227-carat stone.

“Tomra’s XRT technology replaces multiple stages of diamond concentration by virtue of its ability to concentrate diamonds to a hand sortable product after only as little as a single step,” explains Madderson. “This concentration factor allows for the removal of multiple recovery steps, thus drastically reducing both the capital investment and operational costs to recover diamonds.”

Tomra’s solution eliminates up to seven concentration stages, dramatically reducing the complexity of the supporting plant and infrastructure. This results in significantly lower power and water consumption, which not only reduces costs, but also the environmental impact of the recovery process.

Interestingly, Tomra’s XRT solution is also able to operate as a dry process, which drastically reduces its environmental impact and operational complexity. This makes it possible to mine deposits in arid areas where water access is minimal.

According to Madderson, once the system is fully operational, Tomra remains at the customer’s side through its service level agreement, to ensure that the solution continues to deliver the desired results.

A tailored agreement can include on-site presence as required, seven days/week product support, application engineer visits, tiered urgency support, targeted site response, training, as well as spare and wear parts coverage to ensure maximum uptime and protect the customer’s investment.

Africa – a strategic focus area for Tomra

Africa remains a key target area for Tomra, given that between 60% and 70% of its business is aligned with the Southern African and West African markets, particularly in Botswana, Angola, South Africa, Lesotho and parts of Zimbabwe.

“These are key diamond-producing areas and will remain so for many decades to come. Given that Africa has been identified as an important location for Tomra, we have established a large subsidiary based in Johannesburg, to service customers in the Africa region.”

Tomra has been extremely successful in Botswana, having established a close partnership with diamond producer Lucara Diamonds, where it has installed a number of its products.

“We have also been successful with a number of smaller diamond producers around the world, which have taken to adopting our technology. However, in Southern African, significant diamond producer De Beers has not been an adopter of our technology given the miner is invested in its own technology development initiatives.”

Tomra remains upbeat though stating that clients have been “actively calling us with requests to purchase our technology”.