Rex Minerals (ASX:RXM) is advancing the funding process for its Hillside copper-gold project on South Australia's "Copper Coast".

The fully permitted project hosts a substantial resource of 1.9 million tonnes of copper and 1.5 million ounces of gold.

An optimised feasibility study for the first stage of the project was released in December 2022, returning pre-production capital costs of A$854 million, a post-tax net present value of A$847 million and a post-tax real internal rate of return of 19%.

Speaking at the RIU Sydney Resources Round-up, Rex executive general manager investor relations and business development Peter Bird pointed out that the study used a copper price of

US$3.92 per pound and gold price of US$1610 an ounce.

The copper price is currently trading at US$4.44/lb, while gold is sitting at more than US$2300/oz.

"Clearly the 4.3-year payback period is not getting worse," Bird said.

The stage one mine plan would produce about 42,000 tonnes of copper per annum and 30,000ozpa of gold over 11 years.

There is the potential for three additional stages which would result in a mine life in excess of 40 years.

"Resources remain open at depth," Bird said.

"This is going to be around for a very long time."

In a research note published last week, Euroz Hartleys analyst Mike Millikan described Hillside as "one of the most significant copper-gold developments in Australia".

Rex raised A$22.6 million in the March quarter, welcoming MACH Energy Australia as a cornerstone investor and leaving the company in a strong funding position as it advances project

financing.

Rex has also signed a non-binding letter of intent with Nittetsu which would see the Japanese company take an initial 15% stake in the project with the potential to move to 45%.

"We're in very good company," Bird said.

Rex has a current enterprise value of A$150 million, which Bird said equated to A3.5c/lb of Hillside's contained copper.

"That's pretty cheap for a project in South Australia that's permitted and ready to go," he said.

He also pointed out the projected rise in copper demand and the lack of quality development projects.

"There's heaps of demand but not much new metal coming onto the bat."

Millikan said the electrification thematic would continue to drive copper demand.

"Rex provides excellent leverage to copper price and is also expected to benefit from gold by-product credits for operating cost advantages," he said.

Euroz calculates Rex's net asset value at A62c per share, or A$1.19 when using the current copper spot price.

The firm has a price target of A65c for Rex, almost triple Tuesday's closing price of A22c.