Aim-listed emerging African phosphate producer and developer Kropz has remodelled its Elandsfontein mine resource after having encountered delays as a result of ore variability and higher-than-anticipated volumes of compact material in Pit 1 of the current mining area in August.
Previous geological modelling identified phosphorite as a compact material present in the otherwise sandy resource, while a 2018 resource model estimated that the relative proportion of phosphorite to semi-consolidated material was less than 8%.
The previous geological modelling had described the hard bank material as lenses; however, excavation in the pit in June and July revealed undulating slabs, rather than discontinuous lenses. The compact material was subsequently redefined as “hard bank”.
In September, following the re-logging of historical core samples, independent geologists for Elandsfontein remodelled the resource using an implicit modelling function. They also included the drilling results of closely spaced infill drilling which took place in late 2021 and the most recent results from the current 2022 infill drilling programme.
Although higher volumes of the hard bank were present in previous modelling work, the initial updated model indicates that there is sufficient sandy ore available within Pits 1 and 2 to support mining and processing activities until at least the end of 2023. The updated modelling also indicates that Pits 1 and 2 contain about 12% hard bank.
While the initial slab of hard bank, uncovered in July, was contrary to expectations based on previous work, the revised volume of hard bank does not appear to differ significantly from the previous modelling.
However, Kropz reports that further drilling work, yet to be completed, is expected to support the longer-term mining plan and that mineralogy can confirm whether the hard bank is a post-formation event, which would assist in further refinement of the model.
In this regard, the company states that the geological interpretation of the occurrence of the hard bank is still work-in-progress and will be supplemented by additional drilling.
Going forward, Kropz says geophysical methods are being investigated as an alternative to drilling to further improve the interpretation of the extent of the hard bank material, while alternative mining methods are also being investigated.
As such, independent geological consultants have been commissioned to provide an updated mineral resource estimate to confirm the confidence levels in terms of grade, contact elevation, physical properties and continuity. This is expected to be finalised before the end of the year, pending the outcomes of the ongoing 2022 infill drilling programme.
Nonetheless, Kropz reports that the Elandsfontein project continues to progress during its ramp-up phase and has moved to a revised shift cycle, resulting in improved plant performance.
Although enhancement at the plant is still ongoing, the company notes the occurrence of meaningful improvements in the plant running times, leading to improved plant stability over the past eight weeks, which has contributed to increased concentrate production.
In addition, Kropz notes that Elandsfontein is building up stock for its first bulk sale, expected later this year, with 18 500 t of phosphate rock concentrate stockpiled at a Saldanha Bay storage facility as at October 24.