Tongon Gold Mine benefits from Systems Anywhere’s scada and Expert System.
Randgold Resources is an African focused gold mining and exploration company with listings on the London Stock Exchange and Nasdaq. Major discoveries to date include the 4 million ounce Tongon deposit in the Côte d’Ivoire.
Systems Anywhere was approached by Randgold Resources to supply the scada system for the new mills at the Tongon Gold Mine Phase I and worked closely with another company responsible for the programming of the Allen Bradley PLCs. “Commissioning started in September 2010, and the first gold was produced by the facility in November,” says Systems Anywhere MD, Andre Vuilleumier. The first phases of the project have now been completed, both mills are running efficiently. Phase II is in progress.
The prerequisite for Systems Anywhere was to achieve the following:
* Application of the corporate standard to facilitate the roll-out of future projects and reduce engineering costs.
* Standardisation of control philosophy – operators moving between mines will be using a system they already know and understand.
* Improvement of alarming – dealing with the flood of alarms by filtering and prioritising them.
* History of production data – for trend and cause analyses.
* Reporting on a real-time and scheduled basis – for the provision of information based on current realities.
* Improving production – achieved by implementing an Expert System based on fuzzy rules to reduce process variation and improve production.
* Consistent maintenance and support – once again, the portability and predictability of processes was a key requirement.
In order to meet these goals, Systems Anywhere made use of Wonderware’s Suite of Software including the ArchestrA-based System Platform, Historian, InTouch (Scada/HMI) and Wonderware Information Server.
Systems Anywhere gives its clients the opportunity for input by providing a ‘Thin Slice’ demonstration ahead of the roll out of the scada screens. This gave Randgold the opportunity to contribute towards the graphical elements. “Once approval was obtained, ArchestrA technology, smart thinking and intelligent templates made deployment easy,” says Vuilleumier.
The Tongon scada system covers more than 2000 instances, 92 templates and 8500 active I/Os. There are three global pop-ups with dynamic population and a ‘go to’ function, 11 system screens and 70 process screens, including the Expert Operator.
All the alarming and alarm groups are automatically selected and no engineering is required thanks to ArchestrA’s built-in alarm facilities and tree structure. “There is no longer a need for separate coding at the HMI level,” explains Vuilleumier. “Alarm Pareto diagrams mean that operators are not swamped and can focus on the top five alarms at the time. Fixing the top five alarms every day improves plant availability very rapidly. We went further and showed all the interlocks to the alarmed device so that operators can identify the cause at a glance.
Wonderware Information Server is used for scheduled reports per shift, per day etc, and it makes provision for manual data entry. This is especially valuable for trending purposes because the time that the sample is taken is the time that is entered into the Historian with its result. This means that the trend reports are reflective of the correct times. The reports can also be generated to show data aggregation, up-time of equipment, time-weighted averages and KPIs.
In order to maximise efficient production, Randgold made use of Systems Anywhere’s ‘Expert System’. The expert system monitors the mill load, mill feed, power consumption, trends and then takes a decision on whether to increase or decrease the input feed rate. This is a multivariable control system which is quite different from the standard PID configuration.
“The Expert System takes over the responsibility of changing the set points from the operator and brings the mill to peak performance. The benefits of this approach are transparency and simplicity,” says Vuilleumier. “Complicated mathematics could be difficult to manage at site level whereas the fuzzy-based rules are more easily traced so that operators can understand the control philosophy of the system.” The Systems Anywhere Expert solution increases productivity and facilitates an automation-based result, as opposed to control based on human input.
Randgold now has a proven optimal system that can be replicated and deployed to its other assets with minimal cost and re-engineering and maximum confidence.
For more information contact Andre Vuilleumier, Systems Anywhere, +27 (0)11 704 6253, [email protected], www.systemsanywhere.com
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