Some of the finest minds behind Fortescue's ascent, who went on to set up potash explorer Sirius Minerals, scored an unexpected win when the North York Moors National Park approved an application to build a $US3 billion ($3.88 billion) potash mine within its boundaries.

It is good news for Sirius boss Chris Fraser - who in his Citigroup days helped orchestrate a $2 billion capital financing for Fortescue - and some of the miner's original executive team, Russell Scrimshaw and Chris Catlow.

Scrimshaw is now chairman of Sirius and Catlow is his deputy.

In a 2011 interview with Fairfax Media, the trio - who own more than 12 per cent of Sirius between them - predicted that the company had the potential to emulate Fortescue, which was worth around $20 billion at the time.

"If you look at the analogues of potash companies that are in production, if you've got a couple of million tonnes of [annual] production, it doesn't take much to justify a valuation of $15 billion to $20 billion. If you get 3 million to 5 million tonnes per annum of production, they're the sort of valuations that are now being ascribed to potash companies," said Fraser.

Scrimshaw did caution at the time - rather prophetically - that "there's a lot of water to go under the bridge."

Tuesday's victory went against the run of play after a preliminary report released ahead of Tuesday's meeting said the benefits of the proposal to dig up a couple of billion tonnes of potash would not outweigh the harm it would cause to the national park. It sent the Sirius share price crashing last week.

On Tuesday, a special planning committee of the park voted 8-7 in favour of the development.

"This is a once-in-a-generation opportunity ... and the benefits will be felt by your grandchildren," Fraser told attendees at the meeting.

There is still a lot of work to do.

The potash is around 1 kilometre under ground, and the company has yet to arrange financing of the mine which is expected to cost around £1.5 billion ($3.1 billion) to build.

This includes a 23-mile tunnel to transport the raw material, which is mostly used for fertilisers, to a purpose built export berth at the nearest port.