During the care and maintenance period, a core team of full-time employees will be retained across a range of disciplines to maintain the plant and work on intellectual property projects associated with the HIsmelt technology.
Those employees not retained in the core team will be given the option of being considered for employment elsewhere in the Rio Tinto group.
Rio Tinto Iron Ore Chief executive, Sam Walsh said, "This is a tough decision, but unfortunately one that relates directly to the current market conditions and the uncertainty of a market recovery in the near term."
"We retain every confidence in the viability of the HIsmelt technology, which is proven and successful, and we remain hopeful for an upswing in the market to enable a restart in the future."
The Kwinana HIsmelt plant uses a revolutionary direct smelting technology to smelt high phosphorous iron ore fines and non-coking coal to produce a premium grade iron product. It has operated in Western Australia since 2006.
The Kwinana HIsmelt plant is owned by Rio Tinto (60%), Nucor Corporation (25%), Mitsubishi Corporation (10%) and Shougang Corporation (5%).