The chairman of Indian mining giant Adani gives the final investment approval for its multi-billion dollar Carmichael mine in central Queensland's Galilee Basin.

Key points: Adani chairman says decision marks "official start" of Carmichael coal mine

Adani chairman says decision marks "official start" of Carmichael coal mine Environmental advisory firm dismisses announcement as a PR stunt

Environmental advisory firm dismisses announcement as a PR stunt Queensland Premier opens Adani's regional headquarters in Townsville

Adani is yet to confirm finance or whether it has secured a loan for rail infrastructure.

But Adani chairman, Gautam Adani, said the decision marked the "official start" of the project.

"We have been challenged by activists in the courts, in inner-city streets, and even outside banks that have not even been approached to finance the project," Mr Adani said.

"We are still facing activists. But we are committed to this project.

"We are committed to regional Queensland and we are committed to addressing energy poverty in India."

Mr Adani said the $16.5 billion Carmichael projects would generate 10,000 direct and indirect jobs, with pre-construction works starting in the September quarter of 2017.

The company also recently announced contracts totalling more than $150 million for railway tracks and concrete sleepers for the planned 388-kilometre rail link between the mine and Abbot Point coal port had gone to regional cities.

'This project will deliver jobs across the state'

Queensland Premier Annastacia Palaszczuk was in Townsville for the announcement where she opened Adani's regional headquarters for the project.

She said the decision was a vote of confidence in the Queensland economy.

Queensland Premier Annastacia Palaszczuk with Adani Group chairman Gautam Adani in Townsville in late 2016. ( AAP )

"There will be jobs right across the state, this project will deliver those jobs," Ms Palaszczuk said.

"We want to make Queensland the investment choice state of the nation, and that's what we are doing by diversifying our economy."

She said the Government was opening up areas such as the Galilee Basin through its new royalty arrangement.

"What I'm saying very clearly to the rest of the state and to other companies, that you're welcome to invest in Queensland, that we have a government that will back you 100 per cent," Ms Palaszczuk said.

Federal Resources Minister Matt Canavan said Adani submitted its environmental impact statement for the project 2,392 days ago.

Sorry, this video has expired Canavan welcomes Adani to Queensland

"Now the time for waiting is over and the time for doing is beginning. That is a great thing for our state," Mr Canavan said.

"A great message for north Queensland and a great future now that we can all get along and work on."

'Just a PR stunt'

Environmental advisory firm Market Forces dismissed the announcement as a PR stunt.

Executive director Julien Vincent said Adani was yet to raise a cent of the billions needed to capitalise the project.

"Announcing an intention to invest is a far cry from having the finance to do so," Mr Vincent said.

The Stop Adani Alliance spokesman and chairman of the Australian Conservation Foundation Geoff Cousins said an investment decision did not mean Adani had secured the finance it needed.

"Adani is yet to lure any financial institutions willing to bankroll the project, which is proving hugely unpopular with the Australian public," Mr Cousins said.

"Without this support and public subsidies, the heavily leveraged balance sheet of Adani Enterprises leaves no internal capacity to fund this multi-billion dollar project proposal."

Adani Australia chief executive Jeyakumar Janakaraj said the company was closer to raising the money it needed.

"This decision is to inject equity into the project and as you all know the finance world works at certain debt equity ratios for every project," Mr Janakaraj said.

"So obviously this decision by the company and the chairman is to inject further equity into the project to take the project forward so that's a significant step."

He said the company planned to have financial backing in place by December.