Ramelius Resources Limited ('Ramelius', 'the Company') to provide an update on ongoing mining studies at both the Mt Magnet and Edna May production centres, within its portfolio of projects in Western Australia. The Galaxy Underground (primarily Saturn and Mars deposits) project to convert existing resources into reserves has progressed to the completion of a Pre-Feasibility Study (PFS). Access to the mineral resources has allowed the mining study and the associated project start date to be brought forward, as opposed to waiting for completion of the Stage 2 open pit at Eridanus.

The opportunity to establish another underground mining centre at Mt Magnet, at a moderate capital cost, has been recognised by the mine planning team and whilst it was included in the 2021 Mine Plan from the start of fiscal year 2024, the project has been approved for commencement in late fiscal year 2022. Since the 2021 Scoping Study: a detailed geotechnical assessment has been completed; the mine design has been refined and scheduled in detail; contractor rates based on the mine plan have been updated; and all external permits required for commencement obtained. Mineralisation is principally hosted within Banded Iron Formations (BIF) where gold is spatially associated with north-east trending faults and associated with pyrrhotite and pyrite mineralisation.

BIF units occur within a mafic and ultramafic stratigraphy with felsic sill and cross-cutting intrusives occurring. Stratigraphy is sub-vertical and BIF units largely have deep vertical continuity. Galaxy Mineral Resources are based on a number of models generated between 2012 and 2020 and reported as the Galaxy Group (open pit) and Saturn Underground Mineral Resources.

Significant drilling and mining activity has been conducted by Ramelius in this period and major pit cutbacks occurred on the Saturn, Mars, Perseverance, Titan and Vegas open pits. Recent surface diamond drillholes targeting the Saturn and Mars deposits were carried out for general infill and to provide core for geotechnical assessments. Results from these drillholes included: 40.3m at 1.71g/t, from 465.9m in RDDD0013 (Saturn); 9.4m at 3.49g/t, from 444m in RDDD0014 (Saturn); 30m at 1.79g/t, from 279m in RDDD0016 (Mars); and 11m at 2.15g/t, from 459m in RDDD0017 (Mars).

For resource modelling the geology has been interpreted first and formed the basis of a separate interpretation of mineralisation envelopes. Multiple domains were generated to reflect geological host, mineralisation style or local spatial trends and hard bound assay information at a nominal 0.2 - 0.5 g/t cut-off. Estimation was carried out by anisotropic Ordinary Kriging or ID methods using 1m composited assay data in parent cells only.

Top-cuts were applied by domain determined by review of population stats. All resources were compared to previous versions or recent production. The PFS mine design and sequence has been assessed following onsite geotechnical logging of core drilled late in 2021.

This work has highlighted a lower quality ultramafic unit to the east of Saturn and Mars. A review of ground conditions encountered during the lower phases of open pit mining, directly above the proposed underground, supports the need for a more conservative approach with a bottom-up approach replacing the previous top-down assumption and access infrastructure being relocated to the east of orebodies. The historic workings of the Hill 50 underground mine are interconnected with the Mars underground workings down to 150mRL (natural surface is approximately 450mRL).

The Perseverance pit also connects to the Hill 50 underground workings because the crown pillar has been removed. Similarly, the Mars pit intersects underground voids. A historic surface shaft (3 Boys) situated to the north of Hill 50 that is interconnected at depth has been used with a borehole pump to reduce the Galaxy water level to the maximum accessible limit of 280mRL.

In December 2021, a borehole has been drilled from the eastern side of Perseverance pit down to intersect the Hill 50 workings at the 210mRL. The hole will shortly be equipped with a borehole pump thus allowing dewatering well ahead of development activities. The main decline is nominally 5.5m wide by 5.5m high, with an arched profile and is mined at a gradient of 1:7 down.

The exception to this is the upper part of the rehabilitated 1980s era Hill 50 decline which was mined at similar dimensions with a square profile and a 1:9 gradient. No stripping is anticipated to be required to accommodate modern 60t payload trucks in the rehabilitated decline. All new decline development is designed with a stand-off distance of 30m from the ore zones.

Level spacing 20m vertical floor to floor. Dilution applied is reflective of competency of rock exposed and potential dilution from backfill if applicable. Mining method will be downhole drilling and charging with remote loaders (large 17t payload units) bogging ore.

Truck loading will be undertaken on the crosscut /decline intersection. The underground schedule is based upon: Up to two jumbos developing at a maximum rate of 260m development advance per month each with higher rates of advance where existing development is being re-supported; Long hole drill rig drilling 89mm holes and achieving a yield of 7.5t per drill metre; Up to 5 x LHDs; and Up to 3 x 60t trucks.