Pensana’s plan to change into one of many world’s main suppliers of magnet steel uncommon earths took a serious step ahead this week with receipt of approvals for funding the $268 million first section of its flagship Longonjo venture, in Angola.
Tapping the likes of the Africa Finance Company, Absa Financial institution Restricted and the Angolan Sovereign Wealth Fund, the corporate says it now has the money in its coffers to get to its section 1 design capability of 20,000 t/y of combined uncommon earth carbonate (MREC).
Having hit this milestone, IM investigated the design of this operation to see how the corporate plans to extract, focus, calcine and chemically refine the close to floor materials to make that MREC product.
The venture presently below growth contains an open pit, concentrator and restoration crops, tailings storage facility (TSF, designed to fulfill the necessities of the International Trade Commonplace on Tailings Administration (GISTM)), course of water provide, bulk energy provide, mine infrastructure, workshops, workplaces, lodging village, leisure services and different related infrastructure.
Website infrastructure works commenced in 2023 with building actions commencing final 12 months as a part of an early works program.
The open-pit operation is predominantly free-dig, with a Pensana spokesperson saying minimal work is required forward of mining the preliminary pits, aside from clearing and grubbing the topsoil (300-500 mm), which might be stockpiled for concurrent rehabilitation functions because the pits progress. The first in-pit and mixing stockpile administration tools contains two 74-t hydraulic shovels, 5 35-t payload ADTs, two grade management drill rigs and 6 wheel loaders.
The spokesperson added: “Ancillary tools devoted to haul highway and stockpile upkeep contains monitor and wheel dozers, graders, gas and water vans, vibrating compact rollers, telehandlers and light-weight obligation automobiles. Nearly all of this tools might be provided as a part of the mining and stockpile administration contract.”
Grupo Nov, an Angola-based civil and earthworks contractor, has been established on web site for the previous 12 months in the course of the early works program. It has been getting ready the development camp, course of plant and contractors’ laydown space, in addition to clearing and compacting, upgrading roads and managing stormwater to make sure minimal disruption in the course of the wet season, Pensana says. Its present fleet on web site might be expanded as fundamental building actions enhance.
“Based mostly on in depth giant and small diameter drill core knowledge so far, no blasting is anticipated till late within the lifetime of the mine when mining approaches the weathered/hard-rock interface, ranging between 30-70 m,” the spokesperson mentioned. “Sometimes much less weathered boulders might be put aside as they’re encountered (if any) in the course of the preliminary five-to-seven years.”
From the run-of-mine pad, the ore goes by way of a scrubbing/milling circuit earlier than reagents are added forward of two-stage flotation. Pensana, final 12 months, positioned an order with NCP Worldwide, a world provider of latest and refurbished comminution tools primarily based in South Africa, for the $2.3 million ball mill for the concentrator plant. The focus is then thickened forward of the refinery, whereas the rest goes to ultimate tailings thickening earlier than placement within the TSF.
The TSF is among the components reinforcing Pensana’s “Accountable Mining” method at Longonjo, with the corporate stating on its web site that building and operation might be allied with ESG finest apply together with alignment to the GISTM.
The spokesperson defined: “The event of the tailings resolution has gone by way of many iterations to reach on the present resolution, taking a conservative method to the TSF design. This contains thickened tailings spigotted deposition right into a double-HDPE-lined, penstock TSF, totally recycled to course of water for zero discharge and diminished water consumption.”
Thickened tailings through mechanical compaction, plus accelerated mud compaction on the TSF, are being thought-about and has labored nicely on comparable tailings traits and rheology, in line with the spokesperson. “This has the potential to considerably scale back the final word lifetime of mine TSF footprint and is meant to be launched following trials within the commissioning section however is presently excluded from the design,” the spokesperson added.
On the subject of the refinery, focus drying and filtration is step one forward of acid mixing and baking. CCD leaching follows, with nano filtration and impurity elimination levels coming forward of the MREC precipitation. The CCD leaching and impurity elimination steps additionally generate a tailings stream that’s neutralised forward of transferring onto ultimate thickening and TSF placement. A MREC product is produced that Pensana intends to ship through Lobito Port, some 270 km away by rail.
Based mostly on a reserve of 30 Mt at 2.55% whole uncommon earth oxides (for 166,000 t of NdPrO reserves), Longonjo has a mine lifetime of over 20 years. Subsequently, a section two growth can be within the pipeline to double output to 40,000 t/y of MREC.
If it will get to this scale, the mine will, by present estimates, produce round 5% of the world’s manufacturing within the type of a excessive worth MREC, able to being transformed into everlasting magnets for electrical automobiles and offshore wind generators, the corporate says.
