SPD contains total reserves of 73.8 million tonnes at an average grade of 0.75% vanadium for 560,000t of contained metal, of which 31Mt sits within the proven category.
The reserves contain a higher grade portion of 40.3Mt at 0.96%.
The definitive feasibility study, that was announced past month, aims to improve the figures.
CEO Eugene Nel said proven and probable reserves covered the entire 25-year mine life studied by the prefeasibility study, which meant the DFS can be completed without any need to upscale portions of the wider 662Mt at 0.77% resource.
SPD is envisioned as a fully-integrated mineral beneficiation project, developing open pittable material that will supply a concentrator, producing vanadium pentoxide concentrate, which would then be trucked to a company-owned salt roast leach facility to producing 12,500tpa of final dry flake product at greater than 98% purity.
Nel said VR8 now had a defined economically extractable deposit, which meant SPD was "well poised to be progressed into production".
Last month, the company's PFS showed SPD can be delivered with lower costs and higher returns than its peers.
VR8 owns 74% of the project, and estimates it will need US$200 million to develop the 1.6Mtpa stage one, with an expansion to 3.2Mtpa planned for year six.
The DFS will examine other technologies and the potential to create battery-grade vanadium pentoxide, and iron, titanium, and silicon by-products, as part of an optimisation process.
VR8 hopes to complete the DFS in March 2022, with construction expected to commence in late 2023, and first production in early 2024.
Shares in the company, which have traded between A1.9-9.7c over the past year, closed yesterday at 5.7c, valuing it at almost $24 million.