All of the PMC underground fixed plant is controlled and operated by Siemens S7 PLCs via a central control room running a Siemens SCADA system. Stop starting as well as full operational measurement and control is carried out from this central point. This includes full automatic control of the conveying systems, winders and the 18 MW ammonia based refrigeration plant. To this end some of the top technical skills in the country are utilized in this section.
Technical services department
The Department provides specialist technical services to the Underground Operations as well as the whole company. There are 34 employees working in five sections:
1. Cave Management: accountable for the most profitable and safe extraction of the ore reserve. It provides short, medium and long term production plans to the operations. In their work, the section utilizes modern cave management systems and software packages.
2. Rock Mechanics: ensures that the underground infrastructure is safe and stable throughout the life of the mine. Their responsibilities include stress change modelling and monitoring, design of the tunnel support, testing of new support products and support installation quality control. The section also provides training in rock hazard awareness and MQA training for the new mining supervisory personnel.
3. Geotechnical: the custodian of the ore reserve model (Block model). Their scope of work covers all the geological aspects, including sampling of ore in the production draw points, mapping of the geological structures and monitoring of ore grades. They are also responsible for the monitoring of the deformation processes in the Open Pit and the pit surrounding areas as well as the ground water flow balances
4. Ventilation: set up to ensure that the ventilation and occupational hygiene standards are reinforced in line with the legal requirements and Rio Tinto standards.
5. Survey: provides measuring and monitoring service to the whole business.
2005 was very productive year for the team. The following major projects were undertaken and successfully worked on:
- Implementation of PCBC and CMS block cave planning and scheduling packages. This allows to improve the cave management and do life of mine planning
- Further development and implementation of the Dispatch System. The entire production fleet is on the system and information is available for the operational decision making and performance management
- Implementation of the REBOP software package in understanding of the material flow parameters in the cave
- Construction of the block cave physical model in 1:100 scale. This allows to simulate dilution propagation in the cave as well as to simulate other draw parameters. It is envisaged that the model will be used in the block cave training of the junior mining engineers and production personnel
- Installation and implementation of the tunnel convergence monitoring system. This consists of more than a hundred stations installed in the production cross cuts and measured daily. The obtained information is used in assessment of the stability of the underground excavations and making adjustments to the draw schedules
- The draw point braw support went through the process of improvement, trial and implementation
- The Tunnel Support Code of Practice and QC document were updated
- Installation of the GPS real time monitoring station to control deformations taking place in the Open Pit
- Implementation of the systems of monitoring ore fragmentation in the cave, dolerite content and migration, ground water flow and migration. The mud rush potential assessment was conducted with the external experts
- The draw point sampling started in September
- Some exploration drilling took place on the Western side of the open pit to verify geological contacts and assess stability of the FOSCOR's ZBS plant
- The coarse stockpiles instrumentation was put in place to refine the Mine-Mill monthly reconciliation in line with the SOX requirements
Further improvement of the environmental conditions underground (dust, noise, air flow distribution).