Roseby Copper Project
The Roseby Copper Project (Roseby) is located 95km NE of Mt Isa in north/west Queensland, Australia.
Altona plans to develop Roseby after the Outokumpu Copper Project in Finland, with production estimated to commence in mid-2014.
Roseby is 100% owned by Altona and contains 177 million tonnes of ore grading 0.6% copper and 0.1g/t gold for some 1,055,000 tonnes of copper metal and 296,000 ounces of gold.
Altona has a agreement with major miner, Xstrata, where prior to June 2012 Xstrata can buy a 51% interest in the project at market value. Xstrata is conducting exploration for large deposits at depth in the central part of the project.
The Roseby Copper Project has been the subject of a Definitive Feasibility Study which envisage the production of 26,000 tonnes per annum of copper and 7,500 ounces per annum of gold for 10 years from a 5Mtpa open pit mining operation. Environmental and regulatory approvals for construction of this substantial mining operation are well advanced following the approval by the regulatory authorities of the Environmental Impact Statement for the project.
The greater Roseby Project area is over 1,400km2 in size and is a major strategic land holding being only 95km northeast of the major mining centre of Mt Isa in northwest Queensland.
The Mt Isa area is one of the world’s foremost base metal mining provinces. It is estimated that the area hosts approximately 11% of the world’s zinc, 5% of its silver and 1% of its copper.
Despite the large copper and gold Resources that have already been declared, most drilling at Roseby is limited to the known deposits and is very shallow. The Project remains highly prospective and underexplored. In addition to excellent copper and gold exploration potential, the project is prospective for the discovery of uranium, molybdenum, rare earth elements (REE) and zinc deposits.
Resources
Copper resources and prospects at Roseby have been defined within a broad north-south zone some 40km long and 4km wide. Mineralisation occurs in deposits of two types:
- Seven sediment-hosted copper deposits. Copper mineralisation is largely defined in weathered rocks where copper occurs as readily recoverable native copper (metallic copper). Gold is absent. Limited drilling has been conducted of sulphide mineralisation in fresh rock below the weathered zone.
- Four iron oxide copper-gold (IOCG) deposits hosted in altered volcanic and sedimentary rocks. Copper and gold mineralisation occurs as readily recoverable copper primary minerals such as chalcopyrite.
Approximately 250,000 metres of RC and diamond drilling has been completed.
Resources are reported at a lower cut-off grade of 0.3% copper with Little Eva reported at 0.2% copper. For a detailed breakdown of the resources at the project broken down by deposit please click here.
Definitive Feasibility Study
The company completed a Definitive Feasibility Study for the Roseby Copper Project in 2009 and published the Study in January 2010. The study for was premised on the open pit mining of 3 ore bodies, Little Eva, Blackard and Scanlan followed by the treatment of the ore through a 5Mtpa conventional flotation processing plant to produce a concentrate product. The Executive Summary of the study can be accessed by clicking here.
In parallel with further exploration drilling to increase or reserves, a new study was commenced in May 2011. An increase at Little Eva and a modified approach to optimising copper recovery has allowed Altona to revise the scope of the study to focus on Little Eva alone. The key benefit of this approach is to simplify the project by treating a single high recovery copper-gold primary ore from Little Eva and placing all infrastructure adjacent to that pit. By focusing initially on a single pit there will be a reduction in both the pre production mining expenditure and operational complexity that was previously associated with establishing multiple pits simultaneously.
Selected remaining deposits including the Blackard deposit will be the subject of a seperate Expansion Study. This study will be largely based upon the information presently known of the various depositis to be included, with minimal additional resource or metallurgical work to be carried out to support the study. The Expansion Study will examine introducing other ore to the process plany. Including native copper ores that require the installation of a gravity recovery circuit.
In addition to above an Oxide Study will be carried out. To review options and carry out testwork to determine how Altona can treat the copper oxide cap. This oxide cap was previously assigned no value.
Ore Reserves
Ore Reserves total 47.9Mt grading 0.70% copper and 0.04g/t gold. Reserves have been estimated in the 2009 study for three of the eleven declared Resources being; Blackard, Little Eva and Scanlan. To view Reserves click here.
Processing
The processing plant was previously designed to treat a blend of high recovery primary and moderate recovery native copper ores. The process flowsheet has been simplified and now proposes treatment of nominally 6Mtpa of primary ore through a conventional primary crushing, SAG and ball milling, floatation, filtration and stockpiling circuit to produce a copper-gold concentrate for sale.
The plant will treat 5-6Mtpa of ore.
Provision will be made in the initial process plant layout to facilitate retro fit of processing equipment required to support future campaign treatment of native copper ores.
Infrastructure
The Project is located 65km on sealed roads north of Cloncurry, a mining service town some 110km east of Mt Isa. Cloncurry is on the national highway network and has a concentrate shipping facility and a rail connection to Townsville and Mt Isa. The proposed plant site is a further 10km by unsealed road from the highway.
A major water pipeline passes adjacent to the Roseby plant site, where an off-take point has been established.
The Mica Creek power station at Mt Isa generates power for the region and delivers electricity to a sub-station near Cloncurry, around 70km from Roseby. A new 220kV power line will be required to be constructed by Altona to connect Roseby to the grid.
Mt Isa is a major mining centre and the area already supports and services a number of major mines.
Xstrata Option
Although Roseby is 100% owned by Altona, Xstrata have an option to participate in Roseby by purchasing a share of the project.
Xstrata may earn 51% of an area beneath and around the large copper resources at Roseby by spending $15 million on exploration and resource definition drilling, or by spending $10 million and completing a DFS by 30 June 2012.
Xstrata have advised they have spent $7.6 million to 30 June 2011. Should Xstrata earn a 51% interest in this exploration area, it is compelled to purchase 51% of the balance of the Roseby project (copper resources, reserves and exploration tenure) for an agreed or expert-determined fair market value.
Xstrata also has an option until 30 June 2012 to purchase 51% of the balance of the project for an agreed, or independent expert-determined, fair market value.