A maiden mineral resource estimate by MRG Metals (ASX: MRQ) at the Koko Massava target in Mozambique has identified what the company believes is the “most significant” heavy mineral sands discovery in the last decade.
The total estimate of 1.423 billion tonnes at 5.2% total heavy minerals (THM) using a cut-off grade of 4% THM comprises an indicated resource of 289Mt at 4.9% THM and an inferred content of 1.13Bt at 5.3% THM.
The resource contains 74Mt of valuable heavy mineral (VHM) assemblage comprising 42% ilmenite, 2% low titanium ilmenite/titanomagnetite, 2% zircon, 1% rutile, 1% leucoxene and 0.2% monazite.
Several zones show subsets of higher VHM assemblage indicating further potential for optimisation.
MRG’s estimation exercise also identified an exploration target at Koko Massava in the range of 234Mt to 967Mt with up to 5.9% THM at cut-off grades of 3% and 5% THM.
MRG chairman Andrew Vanderzwan said the discoveries align with the company’s mission to aggressively seek additional high-grade and high-value tonnages for the Corridor Central heavy mineral sands project.
“Koko Massava represents the most significant heavy mineral sands discovery in at least the last decade, underpinning the value of MRG and our potential place in the global titanium feedstock industry going forward,” he said.
“The potential to achieve [our mission] appears to be very high across the Corridor tenements and could result in a multi-decade asset with built-in potential to optimise operations in the early years to enhance project returns.”
Mr Vanderzwan said the detailed mineral assemblage data shows ilmenite grades to be above average in a number of areas, particularly in the northern portion of the resource which coincides with high THM grade resource blocks and some of the thickest zones of mineralisation.
For zircon and rutile, the highest grades occur near surface in the central-eastern portion of the resource.
“Going forward, increasing the density of mineral assemblage analyses will allow us a clearer picture of the distribution of valuable minerals over Koko’s extremely large resource footprint,” he said.
The Koko Massava deposit is mineralised from surface and two broad geological domains have been defined based on material colour and slime characteristics.
Zone 1 is an upper zone of red-brown sand with lower slime, whereas Zone 2 is lower with yellow-brown sand and higher slime content.
Both zones are up to 25 metres thick and are high-grade ilmenite domains with potential for further extension north and east as the extents of mineralisation.
Aircore and auger drill programs similar to those used for the resource estimate have been planned for late 2020 to provide additional samples and data required to test the validity of the exploration target and potentially convert part or all of it into a new mineral resource.
Further work will include metallurgical testing of bulk samples to investigate the treatment of the potential ore and determine product quality; additional infill drilling to increase grade confidence in certain areas and extend other areas; plus various geotechnical tests.
“Koko Massava is now our foundation asset … we see the possibility of expanding it into a regional resource of massive scale and significant grade,” Mr Vanderzwan said.
In morning trade, shares in MRG were trading 11.11% lower at $0.08.