Magnum expands Piracanjuba North rare earth footprint with fresh assays

Magnum Mining and Exploration (ASX:MGU) has increased the mineralisation footprint at the Piracanjuba North target to 116 square kilometres, a 36% expansion from the earlier 85 sq km interpreted by geophysics. The update came from the second batch of total rare earth oxide (TREO) assays and ammonium sulphate desorption screening. All 122 holes drilled across the Azimuth project in Goiás, Brazil, have now returned anomalous TREO values – a repeatability that managing director Antonio Vitor Junior called a key validation of the ionic adsorption clay system.

The best interval came from hole PIR-AH-0010: 12 metres at 690 ppm TREO, including two metres at 1,409 ppm TREO from a depth of 8 metres. That two-metre zone showed 57% desorption of magnet rare earth oxides (MREO). Another hole, PIR-AH-0083, returned 12 metres at 1,045 ppm TREO from surface, with a two-metre interval at 1,671 ppm TREO from 6 metres. Multiple intervals showed elevated terbium and dysprosium, the heavy rare earths used to improve the coercivity of NdFeB permanent magnets.

The desorption rate measures how easily rare earth ions separate from clay particles without aggressive acid leaching. Higher desorption means simpler processing and lower operating costs. For an ionic clay deposit, the combination of scale, near-surface grade, and desorption rates above 50% is the template for a potentially economic resource. Vitor Junior said the results continue to demonstrate the key characteristics the company looks for: scale, desorption, favourable element mix, infrastructure, and state and community support.

The expanded geophysical footprint came from a reinterpretation of existing radiometric data, not new surveys. The company said the repeatability of anomalous values across all drilled holes reinforces the significance of the larger footprint. Six rigs are now active on site: five auger rigs handling reconnaissance and deeper regolith work, plus a diamond rig to validate the regolith architecture and collect material for mineralogical and geometallurgical testing. Many holes ended in anomalous TREO values, suggesting the clay zone may extend deeper than the auger rigs can penetrate. The diamond rig will test that vertical extent.

Vitor Junior said drilling will continue at pace. More assays are due from the active rigs. By lunchtime Wednesday, MGU shares traded 20% higher, reflecting the market's view that the dataset strengthens the exploration thesis. The global rare earth supply chain remains tight, with China controlling most heavy rare earth processing. A deposit that can deliver high desorption of magnet-grade oxides in a stable jurisdiction attracts attention. The diamond drill results, expected in the coming months, will test whether the clay horizon extends deeper and maintains the grade and desorption seen in the shallow auger holes.