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.

Hancock Prospecting started exploration at the Hope Downs mine in 1992 and received the necessary approvals in December 2003. Rio Tinto joined Hancock as a 50% partner in the Hope Downs project in July 2005. The project is expected to have a mine life of 20 years.

Production was started in November 2007 and the first iron ore was transported by rail to Dampier Port for shipment in December 2007. The mine produced 33.79Mt of iron ore during 2013.

Hope Downs mine development

The Hope Downs mine comprises of six mineralised zones namely, Hope 1, Hope 2, Hope 3, Hope 4, Hope 5 and Hope 6. Mining is currently carried out at Hope 1 and Hope 4 zones.

Production at Hope 1 began in November 2007 with an initial capacity of 15 million tons per annum (Mtpa). The zone was developed in two stages, of which the first stage was completed in 2008 and increased the mine capacity to 25Mtpa. The second stage, completed in 2009, further increased the capacity to 31.4Mtpa.

Hope Downs 4 had a capital cost of approximately $1.2bn (Rio Tinto's share: $607m). Rio Tinto provided an additional $425m for connecting the mine to the existing rail, power and port infrastructure.

Construction on Hope Downs 4 commenced in February 2011 and production began in the first half of 2013. The mine is estimated to produce 15Mtpa of iron ore and uses autonomous haul trucks as part of Rio Tinto's Mine of the Future programme.

The Hope Downs 4 mine produced one millionth tonne of ore during the third quarter of 2013. It processes high grade, high phosphorus Brockman (HPB) ore to produce lump and fines products. It plays a pivotal role in Rio Tinto's goal to achieve production output of 330Mt per year by 2015 in the Pilbara region.

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.

Hope Downs iron ore mine reserves

As of 31 December 2013, the Hope Downs 1 mine is estimated to contain 6Mt of proven reserves graded at 61.4% Fe and probable reserves of 219Mt graded at 61.6% Fe.

Hope Downs 4 is estimated to contain proven reserves of 71Mt graded at 63% Fe, while the probable reserves are estimated at 67Mt graded at 63.2% Fe.

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.

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 is further processed to produce high quality iron ore pallets.

The final product is stockpiled and transported, by rail, to the Dampier port for export.

Contractors involved

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

Rio Tinto awarded two contracts worth $184m in August 2011 to develop the 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.