Hope Downs Iron Ore Mine, Australia

The Hope Downs iron ore mine is situated 100km north west of Newman in the province of Pilbara, Australia. The mine is owned jointly by Hancock Prospecting (50%) and Rio Tinto (50%).

It has been developed at a cost of $1.34bn (A$1.3bn) and is being operated by Rio Tinto.

A total of six mineralised zones namely, Hope 1, Hope 2, Hope 3, Hope 4, Hope 5 and Hope 6, were identified at the mine.

Production at Hope 1 began in November 2007 with an initial capacity of 15 million tons per annum (mtpa).

Two stages of construction were carried out to expand the capacity of the mine.

Stage 1 was completed in 2008 to increase the capacity to 25mtpa. The second stage, which was completed in 2009, increased the capacity to 31.4mtpa.

About $1.6bn was approved by Rio Tinto in August 2010 for the development of Hope Downs 4 iron ore mine. The company also provided additional $425m for connecting the mine to the existing rail, power and port infrastructure.

Kellogg Brown & Root (KBR) was awarded a $1.3bn engineering, procurement and construction management (EPCM) contract by Rio Tinto in September 2010 to develop Hope Downs 4. The mine buildings and support facilities will be provided by Cimeco.

Construction on Hope Downs 4 commenced in February 2011 and is scheduled for completion in 2013. Hope Downs 4 is expected to produce 15Mtpa of iron ore.

The mine life is estimated to be 20 years.

Rio Tinto awarded two contracts worth $184m in August 2011 for development of Hope Downs 4. A joint venture between Leighton Contractors and Ngarda Civil and Mining received the first $104m contract to carry out earth works at the mine. The second contract worth $80m was awarded to a joint venture between Pilbara Logistics and Cimeco for building mine support facilities.

Reserves at the Hope Downs iron ore mine

Hope Downs 1 contains 175mt of proven reserves graded at 61.6% Fe. Its probable reserves are estimated to be 225mt graded at 61.6% Fe.

Hope Downs 4 hosts 73mt of proven reserves graded at 63% Fe. The probable reserves are 64mt graded at 63.2% Fe.

Geology of the mine area

The Hope Downs mine is located in the Hamersley Group which forms the middle layer of Mount Bruce Group in the Marra Mamba Iron Formation.

The Marra Mamba Iron Formation belongs to Archaean and Palaeoproterozoic age. It was mineralised as a result of the volcanic eruption and sedimentary sequence of the Mount Bruce Super Group.

The Marra Mamba Iron Formation is classified into three members, namely Mount Newman, MacLeod Member and Nammuldi Member. The upper most Mount Newman Member is 65m thick at Hope Down and hosts major mineralisation. The lower most Nammuldi Member is 109m thick at Hope Downs and comprises less iron ore deposits.

Mineralisation

The BIF contains haematite and goethite with high graded iron ore deposits and low graded silica, phosphorus, carbonate, magneta and chert contaminants.

The mine is currently producing 31.4mtpa of iron ore from open-pit operations.

Open-pit mining

The iron ore deposits are extracted using conventional open-pit excavation techniques. The drilling in identified mineralised zones was carried out by one Reedrill SKF-12, three Reedrill SKSS-15, three Reedrill SKSS-16 and one Atlas Copco L8 Contour drill rigs. Ammonium nitrate or fuel oil was tucked in the drill holes and blasted to create a decent size pit for digging.

Two Hitachi EX5500 shovels, one Hitachi EX3600 shovel, three Komatsu WA1200 wheel loaders, three Komatsu WA900 and one Komatsu WA500 wheel loaders, one Hitachi EX1200 and one Hitachi EX1900 excavator were used in the digging process.

Other auxiliary equipment deployed at the mine during its production encompass four Caterpillar D10 and D11 Dozers (two each), two Caterpillar 16H and three Caterpillar 16M graders.

Hancock Prospecting started exploration at the Hope Downs mine in 1992. The prefeasibility report was finalised in 1997. The technical feasibility was established in July 2002. The development of the mine began in January 2004 after receipt of necessary approvals from the government in December 2003. Rio Tinto joined Hancock as a 50% partner in the Hope Downs project in July 2005.

Ore processing

The ore extracted from the mine is transmitted to the processing plant by 22 Komatsu 830E and 930E haul trucks. The plant features a primary crusher, secondary dry screening and crushing and gravity separation system.

The plant can produce 47% lump ore and 53% fines. It was constructed in two phases. The first phase was designed to produce 15mtpa. The second phase enhanced the capacity to 25mtpa. The processing capacity was further increased to 31.4mtpa in 2009.

The ore is cut into small pieces to create high rated haematite and magnetite. The gravity separation system segregates the magnetite from haematite, which will be further processed to produce high quality iron ore pallets.

The final product is stockpiled and blended for transportation.

Transportation and handling

The stockpiled iron ore pallets are transferred to Port Hedland through the Hamersley & Robe River heavy haul railway to load onto ships for export. A 30km spur line known as Lang Hancock Railway was built to connect the Hope Downs mine site with the existing railway system.

A total of three trains, each with three locomotives, are being run from the mine to Port Hedland. Each train carries 28,250t of ore on 226 cars.