FIRST she conquered Australia - next the world.

Gina Rinehart has defended her crown as Australia's richest person, navigating a year of bitter financial battles that saw her family name dragged through the courts.

Riding Australia's resources boom like no one else, BRW magazine's annual rich list yesterday revealed the 58-year-old mining magnate's wealth has ballooned by an unparalleled $18.87 billion in the past year to $29.17 billion.

That equates to $598 a second, more than $1 million for every half an hour - and almost $52 million a day.

Ms Rinehart is now the richest woman in the world, surpassing the $25 billion of Christy Walton, the widow of Wal-Mart founder John Walton, who still has a major stake in the US retail giant.

Ms Rinehart's meteoric rise led experts to speculate she is a serious contender to become the world's richest person. She would have to pass the $69 billion fortune of Mexican telco mogul Carlos Slim.

BRW Rich List editor Andrew Heathcote said a $100 billion valuation was not out of the question within a few years.

A report from major bank Citigroup on worldwide resources projects - dubbed Generation Next - last year evaluated 400 mining projects not currently in production that are tipped to generate billions of dollars in revenue over the next decade.

Ms Rinehart has three projects in the top 10, the same number as Rio Tinto. BHP Billiton has none.

"If the demand for natural resources remains strong, additional multi-billion-dollar mines are almost inevitable," Mr Heathcote said. "There is a real possibility that Rinehart will become not just the richest woman in the world but the richest person in the world."

Unlike many wealthy heirs, Ms Rinehart has not just maintained her fortune but multiplied it many times over.

When she made her debut on the rich list after her mining magnate father Lang Hancock died in 1992, her net wealth was estimated at $75 million. Now she is worth 386 times as much.

It hasn't been without its difficulties. Three of Ms Rinehart's four children - John Hancock, Bianca Rinehart and Hope Welker - launching a lawsuit against their mother last September to oust her as trustee of the multi-billion-dollar family trust established by her father. Ms Rinehart is worth almost $20 billion more than our next richest person, commodities boss Ivan Glasenberg.

A newcomer last year, he retained his second spot despite his wealth falling to $7.4 billion from $8.8 billion. This was caused by a decline in the share price of global commodities trading firm Glencore since its listing 12 months ago.

Westfield shopping tycoon Frank Lowy was one of the movers, rising to third spot after his wealth jumped to $6.47 billion from $4.98 billion. Miner Andrew Forrest fell to fourth from third.

Originally published as Gina Rinehart will one day own the world. Fact