Gina Rinehart, an Australian mining magnate, has become the world’s richest woman, according to the country’s respected business magazine BRW.

The magazine says Gina Rinehart, 58, is now worth A$29 billion ($28 billion), having increased her wealth by nearly A$20 billion in a year.

It is now possible that she could become the world’s first $100 billion person, the magazine says.

It says the heiress to an iron-ore prospecting empire earns A$52 million a day, A$1 million every half hour or A$ 600 a second.

Gina Rinehart, 58, is now worth A$29 billion ($28 billion), having increased her wealth by nearly A$20 billion in a year

“The increase in her wealth is unparalleled. It is a product of foreign investment in new projects, increased production and a recovery in the iron-ore price over the past six months,” BRW wrote.

Gina Rinehart’s rise in wealth means she now surpasses the $25 billion of Christy Walton, the widow of the founder of America’s Wal-Mart retail chain.

However, Gina Rinehart has caused controversy by campaigning against government attempts to tax mining companies.

Gina Rinehart has also been involved in a nasty fight with three of her four children over control of the family trust.