A major salt project in WA's Pilbara region has been given final approval from the Commonwealth government, paving the way for jobs and export near Karratha.

The $1.4 billion project has not been without its headaches.

In an announcement released on Tuesday, BCI Minerals said it had received approval from Environment Minister Tanya Plibersek to start operations at its Optimised Mardie Project (OMP) immediately.

BCI managing director David Boshoff said the approval was an important and pivotal moment for the minerals producer.

"Australia hasn't developed a salt project of this significance in 25 years," he said.

"The Mardie Project will be Australia's largest solar salt project and the third largest globally."

Mr Boshoff said there was a projected growth and demand for industrial salt from Asia and the new project would be instrumental in supplying global markets.

BCI confirmed it would start filling the first three evaporation pools before submitting data to environmental regulators to gain approval to fill the remaining six pools.

It expected to start shipping salt in late 2027.

The project was expected to be the largest of its kind in Australia and would support 750 construction jobs and 140 permanent jobs once completed.

BCI has reached about halfway in the construction process of the Mardie salt project, having already injected $700 million of investor funding.

The project was expected to be landmark in terms of its energy use.

BCI has said 99 per cent of the energy required to produce salt and sulphate of potash would be drawn from solar and wind sources.

The project was set to produce 5.35 million tonnes of salt every year for the export market.

It was expected that production would contribute nearly $5 billion to the national GDP over the next 60 years.

'Sexy' project faces challenges

WA resources analyst Tim Treadgold said the development was unlikely to turn many heads within the general market, but salt had recently progressed into a key export mineral.

"It's not big, but it is in the world of salt, which is a very specialised world," he said.

"Salt is in demand worldwide for use in a whole variety of chemicals.

"For whatever reason, salt has become a fairly sexy product in the last couple of years."

He said WA was in a prime position to take advantage of the growth in the market.

"There's that unique advantage of having a vast unused coastline with lots of saltwater washing up against the coast and lots of sun to dry the salt," he said.

But Mr Treadgold said the ambitious project had faced several challenges in the past decade.

"It's been a long, hard road for them because it was initially supposed to be a potash project but they flipped to salt because extracting the potash from sea water became a bit too difficult," he said.

"It's been a beast of a thing to build."

He said engineering problems had plagued the project, combined with changing management.

Mr Treadgold said Mardie's focus on salt, with sulphate of potash as a by-product, was another example of potash projects struggling to get off the ground.

"The entire potash game in WA has been a bit of a disaster," he said.

"There have been six or seven inland potash proposals which have never been able to get far from ground zero."

But he said despite the difficulties, the Mardie project gaining approval was a positive step for the industry.

"It's a basic product – most people think of salt as something they put on their fish and chips," he said.

"But this salt is destined for industrial products and to be turned into chemicals and that's a good business to be in."