Since the launch of environmental management company I-CAT Environmental Solutions’ retractable stockpile dust ring (R-SDR) system last year, market demand has increased greatly, says I-CAT technical manager Morne van Wyk.
This demand can be attributed to the R-SDR system having eliminated the need for numerous permits and reducing maintenance costs such as removing and/or moving stockpiles using front-end loaders, he adds.
Dust control systems help to reduce site emissions and to protect employees, Van Wyk point out. Dust produced by material processing operations and mining is a major source of airborne fumes – a leading contributor to environmental pollution.
He explains that dust suppression is also important in terms of health and safety. Dust that is not suppressed in areas where there are zinc, lead, coal and iron-ore projects in progress might lead to those working at or living near the projects contracting black-lung disease or silicosis.
The R-SDR system has a programmable logic controller (PLC) for automated control. The system consumes low amounts of water, and a booster pump can be added to increase water flow and pressure. Van Wyk says a hose can be supplied with the unit, which also comes with the option of being equipped with a two-way valve for manual control of water flow.
The PLC system works with two input signals. The first signal is from a “belt-run” switch which indicates if the conveyor is running or not. The second signal comes from a product sensor located above the conveyor belt, which indicates and confirms if there is actual material on the conveyor belt. Both signals are required for the system to start or stop automatically.
Once the conveyor belt starts, a signal from the product centre activates the R-SDR system, which, in turn, detects if there is a product on the belt. It then sends a second signal to the PLC unit that activates the solenoid valve (an electromechanically operated valve), which then allows the R-SDR system to start spraying automatically.
As a result of the variable-particle sizing technology, the R-SDR system also features a number of customisable options, such as the R-SDR system’s stainless steel misting ring, mounted at the end of the conveyer belt, which also allows for nozzles to be added, removed or replaced with different types and sizes to suit specific applications.
Van Wyk explains that the system creates a “virtual curtain” – material falls into the centre of the ring, which sprays mist on the outside where it forms a curtain around the stockpile – for significant particle containment. It completely suppresses the dust, providing simple, focused dust management that is well suited to continuous duty applications such as radial stackers.