The Western Australian Supreme Court last month ruled the wealthy heirs of mining pioneer Peter Wright and engineer Don Rhodes were entitled to some of their claims for royalties from the massive Rio Tinto-operated Hope Downs mining complex, in WA's ore-rich Pilbara region.
Hancock Prospecting, of which Mrs Rinehart is executive chair, this week lodged appeals against most of the court orders related to the decision, including findings related to decades-old partnership contracts between her company and Wright Prospecting and DFD Rhodes.
Mrs Rinehart is also resisting a finding that Wright Prospecting is entitled to damages for contract breaches, and orders to hand over years of financial records related to the proceeds and royalties earned from Hope Downs' rich ore deposits.
Justice Jennifer Smith's 1655-page judgment found Hancock Prospecting would be required to pay royalties, damages, interest and costs, which could be worth hundreds of millions of dollars.
At the heart of the issues raised in the 51-day trial were agreements made decades ago between Mrs Rinehart's father Lang Hancock, Peter Wright and engineer Don Rhodes, who were mates and colleagues at the time.
Justice Smith dismissed Wright Prospecting's claim for a half share of some of Hancock's iron ore deposits, worth billions of dollars.
Wright had demanded a stake in mined and unmined Hope Downs tenements and royalties amid a claim Hancock breached a 1980s partnership agreement.
DFD Rhodes also claimed a royalty share of Hope Downs' production over an alleged deal with Mr Hancock and Mr Wright that handed over tenements in the 1960s.
The trial also drew in Mrs Rinehart's children, over a previous claim by John Hancock and Bianca Rinehart stating their grandfather left them a hefty share in the Pilbara mining resources he discovered in the 1950s.
Rio Tinto was also involved in the battle as the joint-venture partner in Hope Downs.
Mrs Rinehart inherited her father's iron ore discovery in the Pilbara region and forged a mining empire after he died in 1992.
She developed mines from tenements at Hope Downs, signing a deal in 2005 with Rio Tinto, which has a 50 per cent stake in the project.
The Hope Downs mining complex near Newman is one of Australia's largest and most successful iron ore projects, with multiple open-pit mines.
Hancock Prospecting rejected the Wright Prospecting and DFD Rhodes' claims during the trial, maintaining that it undertook all the work, bore the financial risk involved in the development and is the legitimate owner of the assets.
Mrs Rinehart's wealth is estimated to be about $40 billion.
