The challenge
One of the world’s largest copper producers, Codelco needed to optimise the water recovery process of the thickener pools at its Norte mine in Chile. Water used in mineral processing is recovered for reuse and the thickeners need to gauge the levels with accuracy as well as communicate the information from the field to the central control room. Without that data, the multivariate predictive application based on Honeywell’s Profit Controller could not optimise the water recovery process. Therefore, issues of gauging the level of several thickeners, the ability of communicating data and process optimisation required a reliable and cost-effective solution.
With a huge amount of precipitation in the pools, to process recovered water and to send residuals to the tailing was problematic, as Codelco could not retrieve accurate or timely water levels of both the dark (untreated) and recovered (clean treated) water of the pool. If clear water levels are too low, then not enough water is recovered. Plus, the pools were suddenly empty because there was no way to measure levels except manually. In addition, the topography of the region presented many obstacles including climate and distance challenges.
“The inability to gauge online and the high cost of maintaining the traditional wired network (frequently broken by heavy trucks and machinery) caused very low availability of measurement,” said Guillermo Cortés, concentrator automation leader, Codelco.
The solution
Codelco chose Honeywell’s OneWireless network to connect new field devices in the mine to the existing Honeywell TPS control system. The OneWireless network is used to connect Siemens S7 300 PLCs to the Honeywell infrastructure. The PLCs are then used to manage equipment and instruments installed at each tank and pool. Since installing the system, the use of water is much more efficient because the level of water in the thickeners can be accurately gauged in real-time.
“We chose the OneWireless system because it offered the most dependable solution for both our complex operation and the advanced control application, since it provides a higher capacity to support real-time gauging and instrumentation,” said Cortés. “Our desert zone has many challenges including topography, the long distance between the thickeners and control room, and the extreme environment conditions of radiation, wind and temperatures. We are very pleased with the reliability of the Honeywell solution.”
There are seven OneWireless multinodes covering the site. One gateway is used to send the Modbus data collected from the PLC to the Honeywell TPS. With the installation of OneWireless, operators in the control room can call information from the PLCs under the Honeywell TPS control system. This information can be fed into the Profit Controller application to optimise process control of the facility.
The benefits
After the successful implementation of the network to support PLCs, Codelco decided to install Honeywell XYR 6000 high level analogue input transmitters to monitor the level of the clear and dark water using ultrasonic transmitters. The information is automatically transmitted to operators who can make sure water levels remain accurate.
“OneWireless has given us meaningful benefits. We can now gauge and remotely transmit multiple variables with high availability in real-time. We can now gauge and manage the thickeners’ levels and flows and the efficiency of the whole process has greatly improved,” said Cortés.
The Honeywell OneWireless solution provides a communications network and protects investments by integrating Honeywell and other third-party products. In addition, these solutions are guaranteed to migrate to emerging wireless standards. Much more than just avoiding the cost of wire, the breakthrough value lies in the ability to integrate valuable data into existing control systems and advanced applications, while also sharing that data with other networked applications.
For more information contact Boni Magudulela, Honeywell Southern Africa, +27 (0)11 695 8000, [email protected], www.honeywellprocess.com
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