printer friendly version
Case study: Mogale Gold
July 2010, Control Systems Design
Mine tailings are the crushed and milled rock residue that remains after mineral extraction. These tailings must be deposited for storage in a cost effective way that also meets environmental guidelines and mandates. Dams, dumps, and other types of surface piling are some of the more common tailings deposition methods used today. However, these all pose serious environmental concerns, as tailings often contain trace and sometimes substantial quantities of the metals found in the host ore, as well as certain amounts of chemicals and compounds used in the mining processes. As a result, establishing and maintaining tailings dumps represent a significant cost for mining companies.
A New Strategy: Tailing reprocessing
Historically, mineral separation processes have been somewhat inefficient because after the required crushing, grinding and metallurgical treatment, some amount of valuable metal is left behind in the residue. But recently, improved mining technologies and the ever-increasing price of gold in the marketplace have opened the opportunity for mining companies to purchase old mining dumps and treat the tailings in order to recover residual gold. South African miner Mintails is currently focused on exploring, evaluating, and processing hundreds of millions of tons of surface gold bearing tailings in the Witwatersrand area of South Africa. These types of gold reclamation efforts are never 100% efficient, and automation and control plays a significant role in improving the metallurgical processes. With the help of systems integrator Opto Controls, each month Mintails is collecting significant amounts of the valuable metal. In the process, the company is positively impacting the environment by clearing away mountainous, land consuming, and unsightly dumps.
Opto Controls has been a supplier and integrator of hardware and software for industrial automation, remote monitoring, and data acquisition applications for more than 10 years. Specialising in solutions utilising Opto 22 components and systems, Opto Controls’ broad project and industry expertise includes access control and security, print production monitoring, and factory automation. Company president Mike Harrison and process control and programming engineer Adam Carless, head a team contracted by Mintails to assemble and configure an automation system for Mintails’ Mogale Sands Plant This system connects to, monitors, controls and acquires data from a large assortment of field devices, equipment, and instrumentation and also manages the many mechanical and chemical processes used to remove the gold from the tailings.
The Opto Controls system’s key components are Opto 22 rack mount and standalone programmable automation controllers (PACs) and I/O housed in containers located at various areas of a processing plant situated between the gold mine and the dump. “Initially, these controllers were to be networked via fibre-optic cable, but Mintails management later decided to go with a wireless solution from MikroTik so as to avoid having to dig trenches and lay conduit for the cabling,” explains Harrison. The MikroTik platform features a Linux-based operating system, omnidirectional antennas, and wireless communication capabilities utilising all four of the 802.11 standards (a/b/g/n), as well as frequency ranges within the industrial, scientific and medical (ISM) radio bands. The system also has meshing capabilities, data transfer speed of up to 350 Mbps, and a range that easily bridges the average distance (about 150 metres) between the Mogale site controllers.
Readers wanting to find out more about the Opto Controls solution architecture for the Tailings Processing System can visit: http://instrumentation.co.za/+C14002
For more information contact Mike Harrison, Opto Controls, +27 (0)11 792 5232, email@example.com, www.opto.co.za
- Rockwell Automation delivers control solution at Impala
January 2015, Rockwell Automation, Control Systems Design
PlantPAx system extended to reduce refrigeration costs and improve efficiency.
- Force monitoring for manual presses
December 2014, ASSTech Process Electronics + Instrumentation , Control Systems Design
German instrumentation specialist, Burster, has introduced its new ForceMaster 9110 to monitor both complex and simple manual press operations in manufacturing and assembly processes.
The device monitors ...
- Case History 139: The importance of measurements and dynamics.
November 2014, Michael Brown Control Engineering, Control Systems Design
One of the first laws of process control states that you cannot control what you cannot measure. However, although instrument practitioners all know this they very often forget it.
I think this is largely ...
- Pervasive sensing changes the fundamentals of automation
November 2014, Emerson Process Management SA, Control Systems Design
Wireless technology coupled with a reduction in the cost of sensor technology is driving a new era in industrial automation.
- Rockwell Automation’s high-pressure mist fire suppression
November 2014, Rockwell Automation, Control Systems Design
The Rockwell Automation installations of automation instrumentation for controlling conveyor belt speed and sequencing can include a fire suppression system in the form of a Fogtec high-pressure water ...
- PlantStruxure PES solution for Tshwane wastewater plant
October 2014, Control Systems Design
Artiflex Engineering and Schneider Electric help the metro to standardise its process control architecture.
- PlantStruxure PES shines at Xperience Efficiency
October 2014, Schneider Electric South Africa, Control Systems Design
Schneider Electric combines control applications, supervision and field devices under one integrated software platform.
- Case History 138: Bad actors.
September 2014, Michael Brown Control Engineering, Control Systems Design
Alarm management has become a subject of interest in many plants. With the advent of computerised control and HMI systems, it has become extremely easy to put alarms onto control loops. Nowadays operators ...
- Omniflex replaces annunciator system for Shell
September 2014, Omniflex Automation Products, Control Systems Design
When Shell Lubricants in the UK needed to replace an ageing process alarm system with SIL certified technology, it chose Omniflex to engineer a replacement solution based on the state-of-the-art Omni16R ...
- Automation of the brewing process
August 2014, Endress+Hauser, Control Systems Design
Instrumentation from Endress+Hauser optimises every step of the way.
- Case History 137: The cycling pressure loop.
July 2014, Michael Brown Control Engineering, Control Systems Design
I have written much in the past about the peculiar problems inherent to integrating processes. The most commonly found of these are level controls, but some pressure control loops, particularly those ...
- PC-based control
July 2014, Beckhoff Automation, Control Systems Design
Beckhoff’s Scientific Automation integrates robotics, measurement technology and condition monitoring into the standard control platform alongside PLC, motion control and safety technology. TwinCAT utilises ...