Billionaire Gina Rinehart’s company Hancock Iron Ore is about to swing the axe on hundreds of mining jobs at its Pilbara operations to add another decade of life to its ageing mines.Hancock Iron Ore is Australia’s biggest iron ore operation and produces more than 60 million tonnes of the industrial metal destined for overseas markets each year.NewsWire was unable to confirm how many jobs would be cut, but media reported between 150 and 500 jobs could go across the Pilbara operations after Hancock’s Roy Hill merged with Atlas Iron last year.It is estimated about 5000 people are employed at the site.A Hancock spokesman said the decision came after a review of its processes looked at ways to streamline operations.“Hancock Iron Ore has recently completed its annual life of mine planning, identifying opportunities to optimise how ore is mined, processed and blended across its operations,” the spokesman said.“We continuously look at optimising our mine plan and the latest iteration extends our life of mine by 10 years, maximising how much of the orebody we can turn into product and reduce the amount of waste we mine. “The result is that we need to reduce our mining activity at the Roy Hill mine while still maintaining our production rate above 63MTPA for the Roy Hill system. “We are working through the impact and will work with all affected.”Roy Hill generated $1.8bn in profit last financial year, blaming record rainfall, a cyclone and falling iron ore price for profits slumping almost by half from the previous year.The job cuts come days after Hancock Prospecting announced Ms Rinehart, Australia’s wealthiest person, purchased a $1.4bn stake in trillionaire Elon Musk’s SpaceX.The mining firm made the huge investment as part of SpaceX’s biggest public offering.