British billionaire businessman Sanjeev Gupta is seen by many as Whyalla's saviour — now he is planning for yet another major investment in the city.

At an SA Chamber of Mines and Energy dinner in Adelaide last night, Mr Gupta said he was investigating the possibility of building a copper smelter and refinery in Whyalla.

The entrepreneur bought the city's financially troubled steelworks last year, announcing plans to increase its production.

He has also invested heavily in renewables, buying a controlling stake in South Australian-based Zen Energy and announcing plans for solar and pumped hydro plants.

Mr Gupta said it was too early to go into the finer details of his copper smelter plan, but described it as "strongly viable".

"What it needs is good infrastructure, which we have," Mr Gupta said.

"It needs cheap energy, which we will have.

"It needs a great workforce, which we have and can develop more of, and it needs the supply of copper [concentrate], which we've had some interesting discussions with vendors for that."

Mr Gupta said he would be in a position to release more details before the end of the year.

"We've hired and will join within a month-and-a-half a new CEO who will head this objective, so it's still in development but we're very serious about it," he said.

Copper was first mined in South Australia in 1842.

BHP-owned Olympic Dam is one of the world's largest copper mines, but the company has its own smelter at the mine site, about 580km north of Adelaide.

Plans for a new Australian bank

At the industry event, Mr Gupta also discussed his plans to buy or set up a bank in Australia.

It is something he has already done in the UK, where he said there was a gap for a bank servicing medium-sized businesses.

SA has copper mines at Olympic Dam, Prominent Hill and Kanmantoo. ( Supplied: Glencore )

He said Australia was in a similar position.

"Because it's too expensive to serve that sector, there's a gap in the middle and we felt that gap very acutely in the UK and we addressed that," he said.

"In the UK, we've bought two banks in the UK and repurposed them.

"We'd prefer to do that here, because it means we can short cut the timeline and set up a bank, but if we have to set up, we'll apply for a licence and set up from scratch."

Last week, Mr Gupta spoke at an energy conference in Adelaide, where he said his company also plans to build an electric car factory in Australia.