Astron Corporation Limited announced an updated Mineral Resource Estimate (MRE) for Mining Licence MIN5532, which is the site of Phase 1 of the Donald Rare Earth and Mineral Sands Project (Donald or the Donald Project). The Donald Project is an advanced, globally significant critical minerals project located 300km west- northwest of Melbourne in the Wimmera Region of Victoria. The Donald Project comprises the Donald deposit (MIN5532 and RL2002) and the Jackson deposit (RL2003) and has the benefit of a favourably assessed Victorian Environmental Effects Statement (EES), a concluded Federal Environmental Protection and Biodiversity Conservation (EPBC) Licence and a granted Mining Licence (MIN5532).

It is proposed that Donald will be developed in a number of Phases. Phase 1 is centred on MIN5532 which represents only 17% of the total HM of the Donald Project Mineral Resource. The Mineral Resource Estimate is 525Mt @ 4.0% total heavy minerals (HM) containing 21Mt total HM and comprises a Measured Resource Estimate of 394Mt @ 4.2% total HM for 17Mt of contained total HM; an Indicated Resource Estimate of 110Mt @ 3.5% total HM for 4Mt of contained total HM; and an Inferred Resource Estimate of 20Mt @ 2.3% total HM for 0.5Mt of contained total HM.

The MRE is based on a 245 Reverse-Circulation Air Core (RCAC) drillhole program which was completed in March 2022 1 and covered 97% of MIN5532. Analysis included sizing, heavy liquid separation (HLS) and mineralogy and was completed in October 2022. The MRE is classified and reported in accordance with the guidelines of the JORC Code (2012 edition).

The March 2022 drilling and sampling program was designed to expand the resource estimation of valuable heavy minerals (VHM) within the known mineralisation of MIN5532 greater than 1% total HM in areas which had not been previously analysed for valuable heavy minerals. Analysis for xenotime and the 20 to 38 micron (µm) fine-grained fraction, which is known to contain rare earth minerals and zircon, was also included in the program. This work was carried out using industry accepted methods and practice for very fine mineral sands deposits and increases the confidence in the Mining Licence's VHM content.

The results from the 2022 program also led to an update of the previous Donald Project MRE which was determined in 2016. The 2016 MRE of 2.4Bt @ 4.8% total HM 2 is now updated to 2.6Bt @ 4.6% total HM. Comparison with Previous Estimate: In 2016, AMC Consultants Pty Ltd. (AMC) prepared the previous MRE within the VHM domain (for which composited samples were analysed for zircon, ilmenite, rutile/anatase, leucoxene and monazite) in MIN5532 based on a cut-off grade of 1% total HM.

The key features include: Total Mineral Resource tonnage increased by 66% to 525Mt: Total in-situ heavy mineral (HM) resource increased by 25% to 21Mt, including increased in-situ valuable mineral resources of: zircon increased by 5% to 3.4Mt; monazite increased by 18% to 376kt; and maiden in-situ xenotime resource of 136kt. There are differences in the contained ilmenite, leucoxene and rutile, mainly due to different titania mineral grouping, with an overall increase in the combined titania minerals of 3%. All sampling for total HM, slimes and oversize content has been carried out on 1m intervals down hole.

Sampling from 2000 to 2015 was by collecting the entire 1m interval sample and later riffle splitting the dried sample down to size for analysis. In 2022, subsamples were collected directly from a drill rig mounted rotary splitter netting on average 1.6kg (dry) with the remainder of the sample interval also being collected for recovery analysis. Composite samples prior to 2022 were created by grouping samples' HLS sink fractions down hole based on the presence of heavy mineral (>1.5% total HM) even though the MRE models were quoted using a 1% total HM cut-off grade.

In 2022 mineralogy composites were created by grouping samples' HLS sink fractions across multiple adjacent holes and also down hole within the same geological domain (where total HM is >1%). These composites were analysed by XRF, optical grain counting and QEMSCAN methods prior to 2022 and additionally by laser ablation ICP-MS in 2022. There have been multiple drilling campaigns conducted across the Donald deposit since the early 1980s.

All drilling since 1987 has been conducted by licensed and trained drillers from Wallis Drilling using the reverse circulation air core (RCAC) method and NQ rods with a nominal drill bit diameter of 82mm. Assay information from drilling prior to 2004 has not been used for the resource estimate, only for geological interpretation. Sample analysis method: All of the samples from the 2022 drilling program were prepared and analysed by Bureau Veritas Minerals Pty Ltd. (BV) at their Adelaide laboratory.

The samples were screened at 20µm, 250µm and 1 mm. Slimes is the -20µm fraction, oversize is the +1mm fraction and total HM was measured in the +20µm/-250µm fraction and reported as a percentage of the whole sample. For assay analysis work done prior to 2022, different in-size fractions have been used for defining analysis of the total HM contents of the whole sample processed post break up and splitting: Zirtanium 2000 and 2002 +38µm to -1mm for total HM% and mineralogy determined in +38µm to -90µm and then adjusted to % of whole sample.

Zirtanium 2004 +38µm to -1mm for HM% and mineralogy determined in +38µm to -90µm and then adjusted to % of whole sample. DMS 2010 and 2015 +38µm to -90µm. All samples used for the 2022 Mineral Resource estimate were analysed for total HM content within the stated size ranges by the heavy liquid separation technique (TBE 2.936 S.G.). HLS analysis prior to 2022 was predominantly carried out by Western Geolabs Pty Ltd. in Perth, WA and Titanatek Lab in Ballina, NSW.