Global miner BHP Billiton Limited is set to embark on two multi billion projects over the next three years.

On Wednesday, BHP Billiton announced a US$822 million investment to develop its Orebody 24 mine. Orebody 24 is a sustaining mine that maintains iron ore production output from the Newman Joint Venture operations. BHP Billiton will shell out US$698 million as its share for the project.

Orebody 24 will start initial mining in the second half of 2012.

The miner had also approved the development of its190-megawatt gas-fired Yarnima Power Station that will ensure stable power supply for its Western Australia Iron Ore mining operations in the Pilbara. Total project cost is pegged at approximately $597 million, of which BHP Billiton will shoulder $507 million.

The Yarnima Power Station will be available in the first half of 2014.

BHP Billiton is Australia's second largest iron ore company behind Rio Tinto PLC. It holds long-term supply contracts with steel mills across Asia, majority of which are in China. The company intends to lift production out by 37 per cent rise to 220 million tonnes by 2015.

To further these expansion plans, BHP Billiton sold $3 billion of bonds. It was its first U.S. dollar-denominated offering in more than two years, according to Bloomberg.

BHP Billiton issued US$1.25 billion ($A1.23 billion) in 10-year senior notes, US$750 million ($A738.95 million) in five-year senior notes, and US$1 billion ($A985.27 million) in three-year senior notes.

Its proceeds will be used for general corporate purposes, including the retirement of commercial paper, the miner said in a statement.

The new Orebody 24 mine, located in the Pilbara region of Western Australia, will have a capacity of 17 million tonnes per annum. Projects plans also include constructing an ore crushing plant, train loadout facility, rail spur and other associated support facilities.

The combined cycle gas turbine (CCGT) Yarnima Power Station will be built, owned and operated by BHP Billiton. Located in Newman, it will replace supply from the existing Newman Power Station. The Itochu Minerals & Energy of Australia Pty Ltd., Mitsui-Itochu Iron Pty Ltd. and Mitsui Iron Ore Corporation Pty Ltd., BHP Billiton's partners in its Pilbara Iron ore operations, hold minority stakes.

BHP Billiton reported a net profit of $22.3 billion in fiscal 2011.