The Botswana International University of Science and Technology (BIUST) invention for diamond sorting has been has passed the International Patent (Patent Cooperation Treaty (PCT)/World Intellectual Property Organization (WIPO)) examination.
More about the invention
The technology, which is a method and system for sorting of diamonds,was invented by Prof. Adamu Murtala Zungeru, Engr. Ernest Gomolemo Modise and Prof. Joseph Monamati Chuma,. It is the first Botswana National Granted patent that succeeded in the International Examination.
The motivation for the development of the new paradoxical dual modality x-ray diamond sorting method was inspired by two perspectives. In the first dimension, Botswana has been involved with mining for at least five decades, with mining being a key national income generator.
However, the growth in mining has not been matched with an equivalent growth in technology development, leaving many Botswana engineers and scientists being technology consumers of European and Asian products. BIUST’s endeavour thus was to demonstrate understanding and capability within Botswana and Africa of developing an internationally upheld product.
The second dimension is a commercially driven perspective taking into consideration market forces that influence mineral pricing. Botswana has outplayed significant capital investment in setting up operations to beneficiate and recover its previously rich diamond ores. Consequently, it is under pressure to break even and make profits from its investments. Investments are generally timed, and a good investment is one that has a fast return, sustainable and competitive.
The introduction of artificial diamonds with comparable quality at a very low price is now becoming a real threat and placing significant pressure on Botswana’s diamond companies to, by whatever means, implement methods that will optimize recovery. Thus, it is important to be mined cost-effectively when a resource has been identified.
The cost-effectiveness of a diamond recovery plant is driven by throughput and quality of recovery. In the diamond value chain, most subsystems are capable of handling high tonnages or throughput up to and exceeding 500 tonnes per hour (tph).
Modern-day diamond sorting is achieved through the application of x-ray luminescence (XRL) and x-ray transmission (XRT) techniques due to diamond ores containing small-size diamonds < 32 mm, and large size diamonds > 10 mm. Such applications have hitherto been used independently of each other and have subsequently progressed mutually exclusively. With these methods, object classification is based on the material absorption coefficient under irradiation with Xrays. Key challenges affecting classification are self-absorption and contrast, which are subjects of luminescence and transmission.
Luminescence suffers from self-absorption for large particles and high energy measurement, while transmission suffers from poor contrast on small particles.
With this patent, BIUST developed a new paradoxical method of sorting diamonds combining the strengths of XRL and XRT techniques. Key features of the BIUST new paradoxical model performance are contrast mitigation for small particles, self-absorption rejection for a large particle at high energy, and improved particle detectability and classification.
The Invention has 10 Claims and describes a system for sorting of diamonds. The system comprises a conveying system including a conveyer belt to transport material samples including diamonds. Further, the system comprises an x-ray source configured to fire or emit x-rays at the material sample.
Furthermore, the system comprises an x-ray luminescence (XRL) detector configured to measure radiated intensity of the x-rays from the material sample and an x-ray transmission (XRT) detector configured to measure transmitted intensity of the x-rays through the material sample.
Also, the system comprises a processor that is configured to: receive the radiated intensity and the transmitted intensity from the XRL detector and the XRT detector, respectively; process the radiated intensity and the transmitted intensity to determine an equivalent absorption coefficient; and identify the material sample as diamond based on a comparison of the equivalent absorption coefficient and a pre-stored model species absorption coefficient.