Industry: Mining

Supervising the supervisory system at Exxaro’s Grootgeluk coal mine

Goals

  • Expert, remote supervision of the mine’s industrial automation infrastructure
  • Detection of system issues before they can cause major downtime
  • Automatic notification of potential problems
  • Maintain system health and performance
  • Management of software updates and patches

Solutions and Products

  • Sentinel Services
  • System Platform
  • Historian
  • Information Server
  • InTouch

Challenges

  • Accepting the concept of remote system supervision without jeopardising security

Results

  • 24/7/365 proactive system monitoring
  • 82% reduction in monthly system issues
  • Improved system availability
  • Availability of expert resources
  • System software is always current
  • Maximised asset ROI
  • Documented reasons for system improvement
  • Peace of mind

Lephalale, Limpopo Province, South Africa – Apart from capable
personnel at all levels, Exxaro’s extensive Grootegeluk coal mine relies
on a large industrial automation infrastructure to look after and
control its complex coal beneficiation processes. But who’s looking
after that vital infrastructure?

Background

The complexity and sophistication of supervisory and control systems is growing at a steady rate to keep up with the need for production information and efficiency. At the same time, these systems need access to sensors and instrumentation through equally sophisticated PLCs so that they can log, measure and control events in real time. So we can say without exaggeration that industrial automation and industrial IT is not for the faint-hearted. In fact, a “data processing manager” of the latter half of last century would pale when considering what instrumentation engineers, production managers and others have to deal with today – because even he wouldn’t know what was going on.

That’s why it’s become vital to find people that could integrate production knowledge with system knowledge – such a person is Jacques Jansen, Solution Analyst, Automation, Exxaro Grootegeluk. He makes a point that, although they have a great knowledge of their industrial automation infrastructure (Exxaro implemented their systems with minimal assistance from system integrators), their expertise lies in coal beneficiation and not in the quirks of the latest operating system or monitoring scan overruns.

“One of the biggest problems we have in the automation environment has to do with changes,” says Jansen. “While everything seems to be operating well with a stable system, someone could have justifiably changed a system parameter whose effect isn’t immediately obvious but that eventually results in a problem over time. We don’t have the resources and skills on site to deal with such problems.”

Another change is the issue of system updates where IT personnel would update existing operating systems without regard as to what updates and patches were in place.

“All these changes would slow down the systems and even cause expensive downtime leaving the operators to ask for help,” says Jansen. “We’re looking to expand our operations in the Waterberg but with skills and resources becoming scarcer and technicians stretched to their limit looking after the plant, we decided to look for a proactive system monitoring tool that could detect issues before they cause downtime.”

Implementation

The implementation took place between January and February 2013 and included installing monitoring agents at each key node of the system. The first priority was to establish secure Internet remote access through a dedicated port with only one-way traffic. Next on the agenda was a system assessment which included a system health audit followed by recommendations from Wonderware Southern Africa and a stabilisation project.

“The system assessment revealed a number of issues such as excessive disc and CPU usage, scan overruns, exceeding best-practice thresholds and several other problems which first had to be addressed before routine monitoring could begin,” says Jansen. “Apart from the real-time alerts from Wonderware, we also meet once a month to go through an extensive report not only to discuss what happened but also to look at developments and recommendations as to where we should be heading. This is a very thorough report. We saw problems with the number of alarms operators were required to handle and we even detected an error in the configuration on a virtual machine that caused things to slow down unacceptably. These meetings help us to optimise the software life cycle, upgrade our roadmap for the future and review our alarming and security philosophies.”

About Exxaro’s Grootegeluk coal mine

Situated 25 km from Lephalale in South Africa’s Limpopo province, this openpit mine employs 2100 people and produces 18,8 Mtpa final coal products, using a conventional truck and shovel operation. This mine has an estimated minable coal reserve of 2800Mt and a total measured coal resource of 4600Mt, from which semi-soft coking coal, thermal coal and metallurgical coal can be produced.

Grootegeluk has the world’s largest beneficiation complex where 8000 tonnes per hour of run-of-mine coal is upgraded in eight different plants.

About 14,8Mt of annual production is power station coal, transported directly to Eskom’s Matimba power station on a 7 km conveyor belt in terms of the existing supply contract. An additional 1,5Mtpa of metallurgical coal is sold domestically to the metals and other industries on short-term contracts. Grootegeluk produces 2,5Mtpa of semi-soft coking coal, the bulk of which is railed directly to Mittal SA under a long-term supply agreement. Approximately 1Mtpa of semisoft coking coal and thermal coal is exported through Richards Bay Coal Terminal or sold domestically.