In 2024, Kumba Iron Ore introduced the implementation of ultra-high-dense-media-separation (UHDMS) know-how at its Sishen iron ore mine in South Africa’s Northern Cape. The ZAR11.2 billion (about US$600 million) funding upgrades the prevailing dense-media-separation (DMS) plant and is predicted to increase Sishen’s lifetime of mine whereas materially enhancing product high quality and yield.
Extremely-Excessive-Dense-Media-Separation (UHDMS) is an evolution of standard Dense-Media Separation (DMS), designed to considerably prolong the density vary at which separation can happen. In an ordinary DMS plant, separation usually takes place at media densities of as much as round 3.6 g/cm³. UHDMS will increase that working density to above 4.0 g/cm³. That greater density window permits for a lot sharper separation between iron ore and gangue, notably the place the precise gravity variations are narrower at greater iron grades.
Like standard DMS, UHDMS makes use of a ferrosilicon (FeSi) suspension because the separating medium. Nonetheless, a key technical enabler is the usage of nitrogen gas-atomised FeSi. The spherical nature of those particles helps preserve manageable viscosity even at elevated densities, which is essential for cyclone stability and environment friendly separation at UHDMS working situations.
Every UHDMS module consists of a number of high-capacity dense media cyclones – within the present configuration, there are six models rated at roughly 650 t/h every. These cyclones create a centrifugal subject that separates materials based mostly on particular gravity – greater density iron ore particles report back to the underflow, whereas lower-density waste exits by way of the overflow.
Past the separation circuit itself, implementation required modifications to upstream and downstream infrastructure, together with upgraded washing and screening circuits, quaternary screens and extra conveyor capability to combine UHDMS modules into the prevailing plant and jig circuits.
Kumba instructed IM that the prolonged density vary is just not incremental; it’s transformational for the Sishen orebody. Firstly, it permits the miner to course of lower-grade feed that might beforehand have been uneconomic. By reducing the mining cut-off grade from roughly 48% Fe to round 40% Fe, it will possibly recuperate extra worth from materials that traditionally would have been labeled as waste.
Secondly, the sharper cut-point improves separation precision, which immediately enhances product high quality and yield. As soon as absolutely applied, the proportion of premium product at Sishen is predicted to extend from roughly 18% of manufacturing to roughly 55%.
Thirdly, the improved processing effectivity interprets into decrease total mining depth. The strip ratio improves from roughly 3.9 to round 3.3, equating to roughly 15 Mt/y much less waste mining. This reduces working prices and improves margin resilience. The modular cyclone-based design additionally permits phased implementation, lowering operational threat throughout conversion.
There are additionally broader operational and market advantages. At its core, UHDMS gives better flexibility throughout a wider vary of ore grades and densities. It successfully converts beforehand marginal materials into financial feed, extends Sishen’s lifetime of mine (at present projected to 2044) and structurally improves the mine’s value place.
Importantly, the uplift in premium iron ore manufacturing additionally aligns with structural modifications within the metal business. Greater Fe content material merchandise help improved blast furnace effectivity and are more and more engaging to steelmakers searching for to decrease emissions depth.
In brief, Kumba instructed IM that UHDMS is just not merely a plant improve. It’s a step-change in separation functionality that strengthens restoration, improves product high quality, lowers mining depth and enhances the long-term competitiveness of the asset.
The UHDMS venture at Sishen is being applied by means of a phased, modular conversion of the prevailing dense media separation plant. Over a multi-year interval, six of the eight coarse modules and 5 of the seven fines modules will likely be transformed to UHDMS configuration. This modular method is designed to minimise operational disruption and handle threat. At any given time, modules not underneath building stay in operation, alongside the prevailing jig circuits, permitting Sishen to take care of manufacturing continuity throughout the transition.
Following approval of the complete capital funding package deal, building commenced within the second half of 2024. Engineering and procurement actions have progressed consistent with schedule, and web site works have been sequenced to help the staged conversion plan.
The primary UHDMS module is focused for manufacturing in 2026, with the principle plant tie-in scheduled for this yr as nicely. Full conversion and ramp-up to steady-state operation are anticipated by the top of 2028. In the course of the implementation part, manufacturing will proceed to be supported by operational modules in addition to strategic use of completed product inventory to clean provide the place required. Total, the venture stays aligned to its deliberate timeline and is structured to stability capital execution with operational stability.
With regard to the event and commercialisation of the UHDMS know-how, in 2010 Kumba labored with a know-how associate for particular UHDMS data and excessive density characterisation approach that might help Kumba with the technical growth of a UHDMS pilot plant to demonstration and commercialise the know-how. This was finished efficiently and concluded in 2013.
Kumba then constructed the primary UHDMS modules for jig discard beneficiation adopted by the examine growth and implementation, all of which was finished inhouse because the know-how was embedded in Kumba operations.
