Sensors & Transducers


Detecting tramp metal on mine conveyors

March 2005 Sensors & Transducers

A new range of metal detection equipment on the South African market promises to assist local mining companies in eliminating the damage caused to machinery by tramp metal.

Tramp metal - pieces of unwanted metal that end up in expensive processing equipment such as crushers and mills - results in costly repairs and downtime. These pieces of metal usually originate from broken equipment, such as jaw-crusher teeth, screens or shoots; or from tools, such as wrenches and spanners - which accidentally land up in processing circuits where they cause damage.

Local engineering company, PJ Tech, of Phalaborwa, in Limpopo province, believes that it has the solution to most of the challenges faced by mining companies in detecting tramp metal. At the beginning of the year the firm was appointed as the exclusive southern African distributor of Tectron conveyor mounted metal-detection equipment, which is based in the US. It has since supplied two of these detectors to the Tati nickel-mine in Botswana, and is currently negotiating the sale of machines to a South African copper-mine, as well as platinum-mining companies.

PJ Tech MD, Peter Nowakowski, says that the technology employed in the Tectron range allows the equipment to accurately distinguish between ores with a high mineral content, which are highly conductive, and pieces of tramp metal on conveyor belts. According to Nowakowski, there are several ranges of other metal-detection equipment available locally. However, he maintains that the high mineral content of some of the ores mined locally makes it difficult for the equipment to differentiate between tramp metal and ore.

Nowakowski says that the Tectron range, on the other hand, overcomes this seemingly impossible challenge and can be programmed to ignore highly-conductive ores and steel cord belts while detecting magnetic, nonmagnetic, ferrous, and nonferrous tramp metal.

Operation

The equipment, which incorporates a pulsed eddy current design, generates a pulsed inductive field in a transmitter coil. A receiver coil, which is only active when the transmitter is inactive, monitors the field. An electric pulse energises the transmitter at regularly spaced intervals. As the transmitter coil's energy field collapses, it momentarily creates a strong electromagnetic field, which induces energy into any metal particle passing through the detector. When the energised particle discharges the energy, the receiver coil picks up the currents within the metal. The receiver electronics are set up to discriminate between the return signals. When tramp metal is detected, the conveyor belt stops and the alarm is activated.

Nowakowski says that besides its ability to operate in difficult product applications, another benefit of the system is the ease at which it can be installed. The transmitter and receiver antennas can be installed without cutting the belt or dismantling the conveyor. Similarly, the replacement of components does not require cutting or dismantling of the conveyor belt.

About Tectron

Founded in 1967, Tectron is located in Laguna Hills, in California, where it occupies an 11 000 m2 manufacturing facility. The company has more than 4000 metal detectors in service in the aggregate, mining, paper and pulp, wood products and recycling industries.

For more information contact PJ Tech, 082 377 9405, [email protected], www.pjtech.co.za



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Next-generation condition monitoring
Sensors & Transducers
The next generation Sitrans MS200 multisensor from Siemens is setting new standards in condition monitoring.

Read more...
Telco sensors for blocked/empty chute detection
Sensors & Transducers
Telco sensors overcome the problems of contaminated environments through powerful high-performance infrared sensors that ensure penetration of harsh pollution and guarantee reliable detectio

Read more...
Cleaning solutions for optical sensors
Endress+Hauser South Africa Sensors & Transducers
Achieving accurate and continuous process visibility requires reliable sensor performance, even in challenging media. Endress+Hauser’s CYR51 mechanical cleaning unit addresses these challenges by providing stable, automated cleaning of turbidity and UV-Vis absorption sensors.

Read more...
Next-generation gas meter module
Sensors & Transducers
Sensirion has launched its new gas meter module combining a low-power consumption mode, future-ready compatibility and seamless integration, all within the same compact form factor.

Read more...
Adjustable proximity sensor with five metre range
Gail Norton Instrumentation Sensors & Transducers
The Telco line of photo-electric eyes have the accuracy and reliability you need.

Read more...
Food safety – a matter of weight
Sensors & Transducers
Weighing systems play a key role in ensuring product quality in food production, complying with legal requirements and avoiding product recalls. The Minebea Intec MiNexx portfolio has been specially developed to meet these requirements.

Read more...
Telco sensors in the paper and pulp industry
Gail Norton Instrumentation Sensors & Transducers
The paper and pulp industry poses a major problem for most photoelectric sensors. Telco Sensors has overcome this with its powerful and high-performance photoelectric sensors, ensuring penetration of thick and harsh pollution while guaranteeing reliable detection.

Read more...
Leaders in sensor technology
Gail Norton Instrumentation Sensors & Transducers
A new addition to the Telco Sensors range is the adjustable Proximity sensor, with a range up to 5 metres.

Read more...
Cutting-edge sensor technology
Endress+Hauser South Africa Sensors & Transducers
The advantage of Endress+Hauser’s Memosens technology is that digitised measured values and sensor information are transmitted via a non-contact connection from the sensor to the cable, and as a digital signal to the transmitter.

Read more...
Miniature inductive sensors
ifm - South Africa Sensors & Transducers
The inductive IY/IZ type sensors from ifm are used in various industrial areas where space is limited.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved