Century Processing Plant & Supporting Infrastructure
The 7.0Mtpa capacity processing plant, in excellent condition after 16 years of use, is currently on care and maintenance following cessation of processing operations. Key equipment includes:
- Primary crushing facilities, which reduce ROM feed to approximately 100mm;
- Grinding facilities consisting of one SAG mill (12MW gearless drive) and two balls mills (8MW gearless drive & 6.7MW single pinion drive);
- Milling facilities consisting of fifteen ultrafine sand mills (355kW);
- A conventional froth flotation circuit, comprising 21 stirred mills and 79 flotation cells;
- Remnant mobile fleet (reduced from original full scale operations) including 6 × Komatsu 630E dump trucks, 5 × Caterpillar D10/D11 dozers and 4 × Komatsu PC excavators;
- Five exploration and grade control drilling rigs;
- Full site laboratory capable of handling all exploration and plant samples; and
- Equipment workshops and stores for all mobile and fixed plant maintenance.
Century Mine processing plant & mobile fleet workshop
Karumba Port Facility
Built as part of mine development in the late 1990s, Century’s Karumba Port Facility includes dewatering and drying circuits, maintenance workshop, a concentrate storage shed and administration buildings.
During operations the Karumba Port Facility received 3,000t of slurry each day into one of four balance tanks. The slurry was dewatered by five pressure filters, with concentrate then passed through a rotary dryer to remove excess water before being stockpiled in the concentrate storage shed in preparation for shipping.
In late 2012, a three-year A$32M project to refurbish the concentrate storage shed and other facilities was also completed, ensuring the port area remains in operational condition.
Equipment at Karumba includes:
- Dewatering/filter/drying plant and fully mechanised concentrate storage shed;
- Jetty and bulk ship loading facilities; and
- Administration buildings & workshops.
Electricity consumed at Karumba was supplied by the on-site diesel power station with a nameplate capacity of 5.8MW. The diesel power station has been decommissioned following cessation of operations, however all associated civil and electrical infrastructure has been retained for future use.
Like the Lawn Hill mine site, Century’s infrastructure at Karumba has been kept in a state of operational readiness to allow for the future restarting of operations.
Karumba Port Facility
M.V. Wunma Transhipment Vessel
Century’s transfer vessel, the M.V. Wunma, is custom-built for the shallow waters of the Norman River channel and is used to transfer concentrate to export ships anchored in the Gulf of Carpentaria.
It takes approximately 12 hours for the vessel to load, transport and discharge concentrates and return to the Karumba Port. The vessel can operate day and night, depending on tides and weather conditions.
Upon cessation of operations, the M.V. Wunma was sailed to Papua New Guinea where it is currently dry docked on care and maintenance.
M.V. Wunma Transhipment Vessel
Karumba Property Ownership & Pelicans Inn Lease
Within the township of Karumba, MMG owned a portfolio of thirteen houses which have also been acquired as part of the transaction. The houses were previously used to accommodate employees, however have been transitioned to rental properties since closure of operations. A lease over the Pelicans Inn in Karumba is also in place. The Inn remains on care and maintenance pending re-establishment of port operations and/or development of tourism potential.
Pelicans Inn, Karumba
The 304km buried slurry pipeline was commissioned in November 1999 and is a unique and leading edge design for a pipeline in Australia. Providing unmatched access to the coast for the region, the pipeline is buried over most of its length to a depth of approximately 1m.
The host steel pipe is high tensile 12 inch pipe, lined with high density polyethylene pipe. The liner was included to eliminate wear/corrosion of the host pipe.
Slurry batch transit time for the 304km journey is ~72 hours and the overall elevation difference is -155m from the site to the port. The pipeline is capable of transporting zinc concentrate at a maximum rate of 155t/h at 37% solids and lead concentrate at a maximum rate of 161t/h at 37% solids.
Century Mine underground slurry pipeline infrastructure
All mine site accommodation is at the Darimah village, located approximately 3km from the mine, which has a capacity of 700 people per night.
Accommodation comprises mostly en-suite rooms in accommodation blocks (four rooms each). Facilities include a wet and dry mess, a gymnasium, pool, football and rugby ovals and various other sport facilities. The accommodation precinct also includes a sewage treatment plant, water treatment plant and communication towers.
Century Mine Accommodation Camp
Mine Site Airport
The mine is serviced by a private airport located on the mining lease. The airport has a sealed runway equipped for night landings, and has an office building and semi-enclosed passenger waiting area.
During operations at Century, medium sized jet aircraft (Fokker F100) were used to transport staff to and from Townsville and Cairns and smaller light aircraft to bring in employees from some of the closer towns such as Mt Isa, Doomadgee, Normanton and Karumba.
In January 2016 the airstrip, taxiway and general apron were re-sealed and lines re-marked at a cost of approximately A$1M.