WORLD PROSPECTS
De Beers GemFair to create secure artisanal diamond market
De Beers Group has announced it is preparing to pilot a programme called GemFair to create a secure and transparent route to market for ethically-sourced artisanal and smallscale mined( ASM) diamonds. GemFair will use dedicated technology to record ASM production at mine sites that meet demonstrable ethical standards, with the aim of purchasing rough diamonds from approved locations while helping improve working conditions and livelihoods for those working in the sector.
GemFair is partnering with the Diamond Development Initiative( DDI) for the pilot, an NGO that has been leading efforts to formalise the diamond ASM sector in several parts of Africa. Miners that wish to participate in the GemFair pilot must be certified by the DDI as meeting their standards, as well as additional standards specific to the GemFair business model.
Once ethically certified, De Beers will provide qualified miners with a technology solution that includes an app and dedicated tablet, supported by a diamond‘ toolkit’ that will enable the digital tracking of ASM diamonds throughout the supply chain.
The pilot will run in Sierra Leone where a number of artisanal mine sites are already participating in the DDI’ s Maendeleo Diamond ™ programme and where significant advancements have been made by the Government of Sierra Leone to formalise the ASM sector.
Bruce Cleaver, CEO, De Beers Group, said:“ The ASM sector represents a critical income source for many poverty-affected communities. However, due to parts of the sector being largely informal and unregulated, it lacks access to established international markets and the ability to derive fair value for participants. By providing a secure route to market, offering fair prices and helping to raise standards, we hope to play a role in enhancing the prospects for those working in the sector, while also potentially opening up a new source of supply for De Beers over the longer term.”
Dorothée Gizenga, Executive Director, Diamond Development Initiative, said:“ The DDI is focused on ensuring artisanal and small-scale miners have access to the opportunities, information and tools that help create self-sustaining communities and formally recognise the sector’ s contribution to economic development. We believe GemFair has the potential to significantly transform the sector by providing a new and secure route to market through the world’ s leading diamond company. We look forward to continuing to work with De Beers, the Government of Sierra Leone and all other stakeholders as we progress.”
The pre-pilot phase of GemFair will involve setting up a local presence in Sierra Leone and working with the DDI and registered mine sites to ensure the agreed standards are being met, that participating miners are trained in how to use the technology solution, and that they have an enhanced understanding of diamond classification. Once GemFair and DDI are confident the sites are compliant and the technology is working effectively, the pilot will commence with GemFair starting to purchase diamonds from participating miners. While offers will be made for any diamonds presented for sale, regardless of quality, miners will
Lithium processing and magnetics
Mineral processing for high-tech markets mined materials such as lithium, cobalt and graphite is now very much in focus. Beyond tramp removal magnets for the mined ore, Jose Marin, Eriez Director, Minerals and Materials Processing says on the downstream process:“ Once the mineral has been crushed and milled, spodumene can be processed with low and high intensity magnetic separators to separate weakly magnetic gangue minerals that naturally occur with lithium ore. Experts strongly recommend using a wet drum separator to remove any ferromagnetic particles prior to the WHIMS( wet high intensity magnetic separator). The foremost reason to use a wet drum ahead of a WHIMS is to prevent ferromagnetic materials from building up in the WHIMS matrix as this can drastically reduce the efficiency of that machine.”
If the plant has a dry process, high intensity Rare Earth( RE) Rolls can be employed to remove weakly magnetic gangue minerals such as tungsten or hornblende from lithium ore. He adds:“ One of the limitations of dry processing is particle size. RE Rolls can effectively process material down to about 150 mesh. Anything finer can generate handling and dust issues.”
Once the ore has been processed and converted into lithium carbonate( or chloride), the world market is ready to accept it, as long as the metallic contamination of this product is in ppm( parts per million) or ppb( parts per billion) levels. In order to achieve those levels of purity, a series of magnetic separators must remove the ferrous and be under no obligation to sell to GemFair if they elect not to do so. Any approved purchases would be sold via De Beers’ industry-leading Auction Sales channel.
The pre-pilot phase commenced in April 2018, with the aim of a first purchase occurring later in 2018. There is no set timeframe for the pilot to be completed.
Following extensive research to understand the ASM sector and its specific needs, De Beers is developing a fit for purpose technology solution comprising a tablet and a software application that incorporates GPS locations and QR-coded‘ bag and tag’ equipment. The software has been designed to work both online and offline, to support the ability of miners to use it in different locations. The diamond toolkit includes hardware that can work in tough rural conditions, including being powered by solar chargers. The programme also involves providing participating miners with training on diamond classification to help improve their understanding of the products they sell.
If proven successful, the technology used in GemFair will be integrated with the diamond industry blockchain platform De Beers is currently developing, allowing the ASM sector to participate in the blockchain and providing an added layer of assurance for ASM production. www. debeersgroup. com
paramagnetic metal contamination. Multi-stage grate magnets in combination with Dry Vibrating Magnetic Filters( DVMF) have proven to be the most effective method when materials are under 150 mesh. Multi-stage Rare Earth Roll separators can be incorporated to process lithium carbonate in dry, free flowing granular form.
Extraction of lithium from a brine solution from a‘ salar’ is also a good candidate for the separation process from low to high intensity magnetic separators. Magnetic traps can be utilised early in the process to separate some of the coarse metallic contamination from the brine.“ A single magnetic separator is not enough to effectively reduce the unwanted metallic contamination. Employing multiple stages of magnetic separators in various locations in the process is crucial for generating acceptable results. Once the lithium carbonate has been precipitated from the brine solution, the process of cleaning the dry fine powder or granular material is no different than the magnetic separation process from a hard rock deposit. Multi-stage grate magnets, DVMFs or Rare Earth Rolls can be utilised, depending on the particle size.” www. eriez. com
6 International Mining | MAY 2018