One of the largest rough diamonds in recorded history, a 2,492-carat stone, was recovered last August by Lucara Diamond Corp. with TOMRA X-Ray Transmission (XRT) technology at the Karowe Mine in Botswana.  This extraordinary diamond is the latest of many impressive record-breaking recoveries achieved at the mine’s Mega Diamond Recovery Plant since the installation of the two TOMRA COM XRT 1200 / D 2.0 sorters in 2017, when Lucara Diamond Corp. truly initiated a revolutionary transformation in the diamond mining industry’s recovery process. By integrating XRT early into the flowsheet, post primary crushing, it is possible to recover liberated and free exceptionally large diamonds earlier in the process,  thereby extracting revenue from the flowsheet faster and safeguarding diamond value from potential downstream damage or breakage. The 2,492-carat stone is historically the second-largest diamond ever discovered, following the 3,106.75-carat Cullinan diamond found in 1905. However, it is the largest diamond ever recovered directly from run-of-mine ore. It was followed, just a few weeks later, by a 1,094-carat diamond – the sixth rough diamond weighing more than 1,000 carats to be recovered at the mine, and one of the top 10 largest diamonds in history.

“We at TOMRA Mining are immensely proud to be part of Lucara’s incredible journey,” says Albert du Preez, Head of TOMRA Mining. “Our XRT technology has played a pivotal role in their historic recoveries, including the 1,758-carat Sewelô and the 1,109-carat Lesedi La Rona diamonds. These milestones are a testament to the power of innovation and collaboration in the mining industry. This achievement underscores the exceptional capabilities of our XRT technology and the dedication of our team. We are committed to supporting Lucara, and ensuring they continue to achieve remarkable success.”

“TOMRA’s XRT technology has transformed diamond recovery, achieving unprecedented results and breaking records,” comments Corné de Jager, Diamond Segment Manager TOMRA Mining. “Fifteen of the top 23 largest diamonds, bigger than 400 carats, recovered since TOMRA XRT bulk concentration installations commenced fully in the diamond industry in 2014, were recovered with our technology – thirteen of them at Lucara’s Karowe Mine, which holds record-breaking finds in various categories. In fact, our TOMRA XRT technology has contributed to the recovery of 7 of the top 10 largest diamonds in history at the Karowe Mine.”

The exceptional find at Lucara’s Karowe mine was swiftly followed by the announcement of another remarkable recovery with TOMRA’s XRT technology in Sierra Leone. The 391.45-carat diamond was unearthed at the Meya Mine in Kono District. In 2017 the famous and historic Type IIa 476.7-carat Meya Prosperity was also recovered with TOMRA’s XRT.

TOMRA’s unique complete diamond recovery solution

TOMRA’s innovative high-capacity XRT technology is a true game-changer in bulk diamond concentration. The extremely precise detection and ejection of exceptionally large and even the smaller particle sizes, and proprietary image processing deliver 100% detection in the specified size range irrespective of luminescence or surface coating, with a guaranteed diamond recovery rate above 98% and remarkably low yields. In addition, the unique TOMRA COM XRT 300 / FR final recovery sorter featuring TOMRA’s proprietary ultra-high resolution sensor technology and precise ejection has revolutionized final recovery processing to efficiently deliver an ultra-high diamond-by-weight concentrate, thereby contributing to improved & focused downstream security and reduced hand sorting.

Today, TOMRA is the only manufacturer to offer a full recovery service from 2mm to 100mm with a flowsheet covering the entire process – from high-capacity Concentration (+4-100mm) to Final Recovery and Sort House applications (+2-32mm), which includes a detailed analysis of customers’ requirements and the collaborative development of an XRT technology-based flowsheet. With its holistic approach and XRT technology,  TOMRA is helping diamond operations in Africa, Canada, Brazil and other countries around the world to maximize recovery while optimizing costs – with the additional benefit of a smaller environmental footprint.

TOMRA’s XRT technology has delivered consistently exceptional performances in a number of key diamond operations. At Gem Diamond’s Letšeng Diamond Mine in Lesotho, shortly after commissioning a TOMRA XRT sorter in 2018, TOMRA’s XRT technology recovered the biggest stone ever seen at the mine, the 910-carat Lesotho Legend. TOMRA’s XRT technology delivered an effective solution for coarse fractions in the mining operation’s historical tailings dumps, recovering 15 times the initial investment in 4 years. The Mothae mine in Lesotho, known to produce high-value diamonds, is also using TOMRA XRT technology combined with the TOMRA Insight digital platform and TOMRA ACT user interface to recover exceptional diamonds from the mine with high sorting efficiency and high throughput, benefiting from lower operating costs. At Mothae, twelve +100-carat diamonds were recovered by TOMRA XRT with an average size of 153-carat/stone. At Lucapa Diamond Company’s Lulo Alluvial Mine in Angola, also known to produce premium value diamonds,  Lulo’s second highest value 227-carat Type IIa diamond was recovered by TOMRA XRT.  These are examples of the outstanding results diamond mines are achieving with TOMRA’s cutting-edge sorting technology.

These significant recoveries contribute to the development of the diamond industry in the countries where they occur, which in turn can bring positive socio-economic benefits by enabling funding in areas such as education and healthcare.