Undesired metal detection in iron ore handling

Posted in: , on 26. Oct. 2005 - 02:04

Hi, everybody

quite often, we suffer damages or jams in some of our belt conveyors because of the presence of steel plates, rods or any other steel pieces together with the conveyed material.

Now we are thinking of installing some kind of magnetic separator or metal detector to solve this problem.

Since one of the bulk material that we are handling is iron ore, we are not sure about the existence of some system that is able to find the difference between the conveyed iron ore and the undesired steel piece;

we would like to know if anyone has experience dealing with metal detection in this kind of material in order to advice us regarding the most suitable detection system for our facility

Regards

pfrisk
(not verified)

Tramp Metal Detection - Thermo Electron

Posted on 26. Oct. 2005 - 03:46

The Thermo Electron Ramsey Oretronic III Tramp Metal Detector may be exactly what you need. Please visit our website at www.Thermo.com/bulk-handling for information on our Tramp Metal Detector System and contact us with additional application information. We look forward to working with you on this project.

donald seymour - Tectron, USA
(not verified)

Metal Detection And Magnetic Seperation

Posted on 26. Oct. 2005 - 10:07

Tectron Metal Detection Inc. has different models of metal detectors specific to the application. For an Iron Ore Mine (or Gold Mine with Iron Ore) we use our model 8600 to ignore the iron ore, and steel cord belt, and stop the belt when tramp metal is present.

Our model 8050 is designed to be used with a magnet. This model will ignore Iron Ore, steel cord belts, and and other magnetic ores. Typically it is installed before a magnet and can descriminate between Magnetic metal and Nonmagnetic metal. For Nonmagnetic metal it will fire an output to stop the conveyor. When a small piece of magnetic metal is detected, it will send a signal (with the optional Magnet Activation Circuit) to switch the magnet "ON and OFF". When a large piece of magnetic metal is detected, too large for the magnet to pull off the belt, it will fire an output to stop the belt.

Our model 6000 is designed to detect roof bolts to protect overland belts.

Please visit us at www.tectron.net

Re: Undesired Metal Detection In Iron Ore Handling

Posted on 27. Oct. 2005 - 07:54

Dear Mr. Pablonici,

The magnetic-separators experts have already replied giving specific type of the system. As a general rule, the presence of metal pieces can get distinguished because of concentration of magnetic flux density around such pure metallic objects according to their purity and size. It would be interesting to know from the experts if they can mention such basic principle.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916

Pablonici

Posted on 2. Dec. 2005 - 10:19

Estimado Sr. Pablonici,

Somos la empresa ALBOEX situada en Rubi (Barcelona) representantes de la firma alemana S+S dedicada a la deteccin de metales y que tiene acuerdo comercial con TECTRON en EEUU.

Deseariamos ponernos en contacto con usted por lo que agradeceremos nos haga llegar su direccin y telefono as como

correo electrnico.

Podemos darle una solucin, pero es necesario el contacto directo.

Atentamente.

Cristina Boadella

ALBOEX S.L.

Dear Mr. Pablonici,

We are ALBOEX placed in Rubi (Barcelona) representing the german company S+S that produces metal detectors and that

have a comercial agreement with TECTRON in USA.

We would like to contact you and we would apreciate that you give us your complete address and telephone so as the e-mail

address.

We can give you a solution, but it is necesary to have a direct contact.

Best regards

Cristina Boadella

ALBOEX S.L.

We are

donald seymour - Tectron, USA
(not verified)

Metal Detectors In Iron Ore Applications

Posted on 2. Dec. 2005 - 08:47

Dear Mr. Mulani,

I am an engineer with twenty two years experience designing and applying Tectron metal detectors for the mining and aggregate industries. Tectron is the oldest continuous manufacture of metal detectors using Pulse-Induction method of metal detection.

Tectron metal detectors work on the Pulse-Induction method of metal detection. This method uses a set of coils that acts as a transmitter antenna and a receiver antenna. The transmitter antenna will deliver a pulse of very high energy which induces eddy currents in the metal part to be detected. It also induces eddy currents into the product (iron ore). After the sudden deactivation of the transmitter pulse, the energy within the metal slowly dissipates and the energy within the product (Iron Ore, Copper Ore, Gold Ore, Nickel Ore, ect...) will dissipate more rapidly. For a short time after deactivation, the metal part still "emits" a small amount of energy where the iron ore's energy has completely dissipated. It is the small amount of energy, that the metal part still "emits", that is detected by the receiver antenna and causes the metal detector to trip. Other metal detector manufactures use the same principle; however their circuitry and technique will be different from ours.

Iron Ore mines have unique problems when using magnetic separation technique (Magnets). The first problem is that they use a manganese alloy for the digger teeth and wear plates because the host rock (typically magnetite) is very hard and abrasive. Manganese alloy is usually nonmagnetic and a magnet will not pull it from the burden. The second problem is that the host rock is magnetic in nature. The higher grade of ore, the more strongly it will be attracted to the magnet causing a loss of material.

There are a number of different combinations of using magnets and metal detectors to detect or separate unwanted metal from the burden:

1. Metal Detector, will detect both magnetic and nonmagnetic metals. This will insure protection to down stream equipment, however it can cause considerable down time and loss of production.

2. Magnet, will remove magnetic metals without any loss of production, however it will allow nonmagnetic metals to pass and damage downstream crushing equipment.

3. Metal Detector after a Magnet, will minimize the amount of down time and the metal detector will detect the nonmagnetic metals. This is the most widely used method.

4. Metal Detector before a Magnet, will allow the magnet to be controlled by the metal detector. This method allows for a minimum amount of ore loss with each piece of magnetic metal being extracted by the magnet. This combination is common when the ore body is magnetic.

The problem of nonmagnetic metals and highly magnetic ores caused Tectron to develop a metal detector with magnet activation circuits specifically to discriminate between magnetic and nonmagnetic metals in magnetic ores. The model 8050 is designed to be installed upstream of a magnet. It will stop the belt for nonmagnetic metals, it will provide a signal to operate a downstream magnet so it can remove magnetic metals (not stop the belt), and ignore magnetic ores.

If you have any questions, or comments, please do not hesitate to contact us.

Best Regards,

Donald Seymour

Senior Sales Engineer

Tectron Metal Detection Inc.

Re: Undesired Metal Detection In Iron Ore Handling

Posted on 12. Dec. 2005 - 11:23

>>The second problem is that the host rock is magnetic in nature. The higher grade of ore, the more strongly it will be attracted to the magnet causing a loss of material.

The magnetic susceptibility of the host rock will be dependent on the iron ore type. If there is magnetite or maghemite present then there may be a problem. Otherwise, haematite is not attracted to a magnet and will not be a problem.

In the iron ore industry in Western Australia there are many examples of static and cross belt magnetic separators as well as metal detectors. They function without major problems.

Process delays caused by belt stoppages to pick out metal objects can be a cause of frustration to operating personel and it is not uncommon for these to be de-tuned or even turned off.

If there is a lot of metal coming through from the pit to the primary ore treatment section, then it may be appropriate to discuss the issue between the two departments, to see if some simple measures can be agreed to reduce the level of metal coming forward in the process.

If the metal is coming from liners, then the liner fixment method may need attention.

The two measures above address the issue at source.

Peter Donecker Bulk Solids Modelling [url]www.bulksolidsmodelling.com.au[/url] [url]https://solidsflow.wordpress.com/[/url]