WESTERN Mining Corporation Olympic Dam Operation (ODO) is located in central South Australia some 560 kilometres north of Adelaide.
It is Australia’s largest underground mine and integrated processing plant. In world rankings, it is the eighth largest copper deposit and the largest uranium deposit. ODO has a nominal capacity of 230,000 tonnes of copper and up to 4200 tonnes of uranium along with significant amounts of both gold and silver. The nominal hoisting capacity of the underground mine is 12 million tonnes per annum, and in 2003 the mine hoisted a total of nine million tonnes.
The mine reliability program was initially implemented to improve productivity of the underground rail haulage system of the Clark Shaft, increasing the output capacity of the mine in support of Olympic Dam’s overall production goals.
This program specifically focused on the excessive breakdowns of the two automated trains that transport ore to the crusher and ore handling system.
Excessive downtime in the rail system tends to cause delays in loading ore from the stopes (ore body) and to lower hoist efficiencies when no ore is available. Thus increasing reliability of the trains is a crucial element in boosting mine output capacity. The success of this project has provided a sustained increase in capacity of 20 percent in the rail haulage system with minimal capital expenditure. (Three hours per working day equates to an additional 20 percent in availability.)
According to Brendan Day, the mine reliability engineer, one of the mine’s initial tasks was to increase the ability to capture accurate downtime data for analysis. Citect ’s CitectIIM Downtime system had been implemented on the site in August 2002 and therefore the mine had the facilities to bring it online.
The successful rollout of the system (January 2003) resulted in the replacement of the dated pen and paper system for the control room operators.
Day describes the subsequent data that was being automatically captured as “outstanding”, only requiring some minor revisions of the Cause Code menu to focus the downtime data.
“The quality of data that was being captured provided a new level of detail that was not previously available with the original downtime recording system,” he said.
The CitectIIM Downtime system has proved itself to be an integral part of the mine reliability program.
During the weekly meeting, the maintenance team reviews the previous week’s downtime for the rail haulage and hoisting systems via the Downtime system. Management then delegates appropriate personnel to investigate events as required.
The reaction time to downtime events has significantly decreased with the ability to review the breakdowns on a day by day or hour by hour basis. This software has also given the mine operators the ability to easily track downtime events and their impact over extended periods.
The mine’s coordination of the Six Sigma based reliability program utilises the Downtime system in conjunction with SAP Work Orders to draw any historical downtime events and analyse them accordingly. From this software, operators can easily view any resulting impact on the availability of plant from individual Six Sigma projects.
The level of detail provided by the Downtime system has enabled operators to focus not only on downtime/reliability issues but also on productivity issues.
These include, for example, the reduction in the “idle time” of the trains by encouraging the operators to run the trains in a full auto mode. This equates to an additional capacity of approximately two percent with no capital expenditure.
Furthermore, the Downtime system has allowed the mine operators to focus on optimising the performance of the rail haulage system by quantifying the gains available if the mining production schedule is aligned to suit the rail haulage. This was realised as the production schedule was modified over the course of 2004. Gains from this alignment were in the order of four percent, again with minimal capital expenditure.
These are all steps closer to reaching full nameplate capacity of the mine.
As the reliability program progresses, the Downtime system continues to play an integral part in providing direction and historical information for refinement of the entire ore handling system.
The total capacity gains identified and or realised are in the order of approximately 24 percent, all of which could not have been achieved over a such a short period of 18 months without the utilisation of the Downtime system.