Bürkert’s digital valve positioners can help modernise infrastructure and improve efficiency at Australian mine sites.
Process valves play a crucial role on mine sites. Why? They’re used to control the flow of fluids such as water, slurry, chemicals, air and gas throughout various stages of mining and mineral processing operations.
Without them, mine sites simply cannot run.
They are essential in managing everything from ore processing to waste management, and help with the overall safety and efficiency of a site, as well as its environmental compliance.
“The advantage of these valves is that we can maintain tight control over a given process by ensuring that just enough of the controlled media is available,” Bürkert SideCONTROL expert David Ray told Mining. “That way, all manner of on-site applications can be completed without wasting extra product or time.”
Process valves can typically be found around flotation tanks and various flushing applications.
Flotation tanks separate valuable minerals from the crushed ore through a process that uses chemicals and air bubbles to selectively attach the mineral to the bubble, enabling the separation and recovery of the high-quality concentrate.
Flushing is also crucial on mine sites – especially in underground drilling operations – for removing drill cuttings, improving drilling performance, ensuring rock drill reliability and optimising rock tool life.
It also plays a vital role in water management, mine safety, fire suppression, dewatering and environmental protection.
Mines can of course be dirty and dusty environments where valves are subjected to all manner of abrasive and corrosive conditions. They are also often located in hard-to-reach areas, making them a potential safety risk when it comes to maintenance.
As well as reducing maintenance hazards and associated costs, today’s mine sites are also concerned with minimising energy consumption wherever possible.
This is where Bürkert’s SideCONTROL range of digital valve positioners with inbuilt proportional-integral-derivative (PID) controllers for all valve types can offer an advantage.
“Bürkert ensures our products are aligned with digital networked technology and meets industry requirements,” Ray said. “This is also the case with our digital positioners, available in a number of ethernet options.”
Bürkert’s SideCONTROL valve positioners are ideal for mineral processing applications because they can be used in a wet and dirty environment where operators need remote access.
In areas where it is not ideal for someone to service the valve directly, the side positioner can be used with a remote mount, away from the actual valve. They are also more tolerant of contaminated air supply, further reducing maintenance costs.
SideCONTROL positioners are 24-volt (v) direct current (DC)-powered and include a built-in PID controller to provide a standalone control loop where necessary, which can aid in reducing cabling and infrastructure costs.
“The Bürkert 8793 process controller option is a stand-alone control system without the need for a programmable logic controller (PLC), but can still provide feedback to the main control system in the plant,” Ray said.
“It can be used for a pressure, flow and temperature control loop with ease of setting up PID values via the automatic ‘P TUNE’ function.”
A feature helping operators see energy savings is the positioner’s pneumatics, which don’t bleed air when the valve is in a hold position, meaning there is zero air consumption in a hold state.
While other positioners consume compressed air at rates of anything between 65–100 litres per hour while stationary, the Bürkert SideCONTROL positioner can provide significant savings on compressed air usage.
“Using our ‘feed and bleed’ principle of operation means the positioner does not have any compressed air requirement in steady state of operation,” Ray said.
“Bürkert’s side positioner with the feed and bleed principle uses poppet solenoid valves, unique to their range, meaning they are less vulnerable to contaminated compressed air issues. Because of these stopgaps, the valve continues to have a trouble-free lifecycle.”
Supporting modern industrial ethernet protocols, the SideCONTROL positioner also provides simple operation through a graphical display and keypad or via a Bürkert communicator device, with fast start-up functions.
Retrofitting can be done in situ while preserving existing valve hardware, with SideCONTROL compatible with all common pneumatic valve actuators, both single or double-acting types.
Upgrading valve positioners with digital connectivity in brownfield mineral processing sites can help to modernise the infrastructure and enhance efficiency and safety.
“The Bürkert positioner is easy to install and commission as an added bonus to using no air in steady state, providing significant energy savings of the life of the valve,” Ray said.
“It doesn’t require instrument quality air, hence is less vulnerable to contaminated compressed air supply and with ability to characterise the input to the percentage opening, Bürkert can linearise the process to be give better control.
“Bürkert has the latest in digital communications as well, including Profinet, Ethernet IP, IO-Link and Modbus TCP.”
This article appeared in the Winter edition of Mining Magazine.
