Please confirm adress details of this enquiry.

Thanks in advance for your answer.

Best regards,

RUSSELL FINEX NV

Tel. +32 15 275919

E-mail : info@russellfinex.com ■

We often have similar problems when we screen aggregates, with some clay and moisture. At that condition we can screen without big difficulties so fine as 6 mm (1/4")

We solved it running with high frecuency screens (1200-1500 rpm), but anytime with Harp screen pannels, slotted parallel to the screen lenght.

Did you try this type of screen panels?

You can see them in an article wrote in spanish language at

http://www.eralgroup.com/pdf/CalculoSuperfCribado.pdf

In pages 11 and 18 you will find pictures of these panels

jlbouso@eralgroup.com ■

Dear Shri A K Srivastava,

The screens for sticky and small sized materials generally have high frequency and high acceleration values for deck.

The screen you are mentioning has deck acceleration of about 3.0 g.

There are screens, which have much higher magnitude of acceleration. A particular type has screen panels, which are relaxed and stretched like bow-string effect, imparting very high acceleration forces to material. The panel aperture dimensional variations at operating frequency also resist the material build-up. There are also other types of screens.

Suggest you to refer to screen designers / manufacturers for solution.

Regards,

Ishwar G Mulani.

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

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear A.K. SRIVASTAVA,

At 1/4" stroke and 950 RPM your screen is running at 3.2g. As a horizontal unit it probably runs at 45DEG drive inclination. In this case only 2.3g are acting vertically to the screening surface. A vibrating screen usually operates sufficient if the vertical acceleration exceed 3.3g (point of statistical resonance). A horizontal unit therefore has to run at around 5g.

We suggest that you contact the vendor of your screen and explore options to increase the overall acceleration.

Should the blinding problem remain we recommend the use of harp wire sections rather then PUR media.

Best regards

W.S. TYLER CANADA LTD.

TYCAN VIBRATING SCREEN DIVISION



Dr.-Ing. Rudiger Heinrich

DIVISION MANAGER



Phone: (905) 688-2644 Ext. 420, Fax: (905) 688-6940

225 Ontario Street, St. Catharines, Ontario, L2R 7B6

www.wstyler.com ■

I believe your problem is due to the fact that you are working in the 'sticky range' for your ore. The more energy you put into this ore, the worse the situation will become regardless of what machine you employ.

I can only but wonder how you manage to get the feed to the screen. Do all your chutes block regularly? Do the operators hose out the chutes to clear them? How much ' rogue water ' is entering your system?

In my opinion you need to decide which side of the sticky range you wish to operate in. This may vary according to the time of year.

If you wish to operate on the lower side, then you need to monitor your water input rigorously, with regular audits, inspections and meetings of all departments involved in ore handling. This can be difficult, as some departments will not have any direct problems if they provide wet ore to the next operation. Just one excursion above the lower limit can clog your plant. It is important that your operating practice does not mean that this will pass large amounts of water to the next stage of the process.

If you decide to operate on the wet side of the sticky ore range, then you will need to decide at which point you wish to raise the moisture content (estimate >18%) and then examine what design changes that will require.

30 mm iron ore is a dense abrasive material, as you will no doubt be aware. The consequences of this should not be underestimated when considering alternatives.

So in summary if we consider the 4 major factors: design, materials, operation and maintenance, I suggest that your primary problem lies in operation. ■

I can offer some suggestions here:

1. Please advise manufacturer's OPEN AREA percentage for the polyurethane 9x9mm aperture SNAP in panel. This is critical.

It will probably not exceed 25-30% open area....indicating larger screen size would be needed. Was a sizing formula given?

107.25 sq ft actual according to screen dimensions - with a load tph yielding media.......and CLAY....makes it pretty tough screening

2. The screen area is 2mx5m or nominal 6.5 feet wide x 16.5 feet long or 107.25 square feet total. (6x16) + -

At this square footage we are asking the screen to pass nominal 1.538 tons per square foot available. This is asking the screen to do wonders on this speed stroke setup....especially if on poly.

3. This is very special, TOUGH screening, especially with the clay content.

4. Accelerating force equals 3.2 G's NOT ENOUGH accelerating force ........especially if using POLY.....you would like about 4 g's miniumum to activate.......the poly.......vs wirecloth.

5.MEDIAS TRIED so far: You have silently been solving your problem by process of elimination. Poly DID NOT WORK, Long slot DID NOT WORK, Perf plate DID NOT WORK,

So........by process of elimination.......I believe you have proven the media is not the prob.........the screen setup is the culprit....it is not right.

SPECIFIC QUESTIONS asked:

1.Design of a new panel.......is not the answer in my opinion. The speed stroke is not clearing the apertures....and you have no flexibility to adjust..........always bad....as we can not help ourselves.....by stroke adjustment.

2. You have a special situtation, requiring a special solution.

................................

I would recommend doing a factory demo........really.....you need to see it work.........and have some comfort level.......PROVEN....that it does actually screen and keep the deck openings clear.This a NON BLINDING screener MEANT for difficult jobs.

The deck and the deck only on this screener......runs at 50 G's and is on a slight incline of about 10 degrees.....and has panels that SNAP......open and relax......totally different than your present setup........and is meant for NASTY, NON conventional screening applications that are not working by normal choices.

Send me a private email........if you desire for more information.

Sincerely, George Baker - Moderator ■

Dear Mr. Shrivastava,

We request you to visit the below websection for your screening solutions.

http://www.eurogomma.com/animation.html

Best Regards,

Charles Christy Raj ■

Dear Mr. Srivastava,

we see your problems with the clay iron ore. In my opion the available screen not enough acceleration.

We tested our flip-flow screen Trampolin with clay magnetite ore and had good results by aperture 6x6 and 10x10 mm.

For more information see our homepage

www.joest.com

Best regards,

Frank Saager ■

Dear Sir

Abon Engineering in Melbourne Australia, have developed a roller screen suitable for sticky materials. They have had some success with the tar sands in Canada.

They may struggle at this time with 8mm size, but worth the question to Abon

Try http://www.abon.com.au/

Best Regards

Gary James ■

how about using a scrap magnet to remove the iron ore from the ROP feed and or using high pressure water to break the mud clumps as they form and using magnetics to separate the mud from the iron fines. ■

I have inquiry for iron ore single deck vibrating screener, 400tph to screen out -3mm (10%max), and requested manganese steel at required mesh size for this purpose. Anyone have experience in using manganese steel at 3mm aperture for vibrating screener? ■

Dear Mr. Srivastava,

for screening sticky iron ore we have used mogensen sizer with 5 decks with in built washing arrangement. the results were excellent. with this kind of screen the power requirement is comparitively less compared to conventional vibrating screens.

you may try this.

regards

subba rao ■

Kroosh Technologies, knows exactly how to deal with your problem.

For maximum efficiency with short ROI, please contact me:

mandil@kroosh.com

You are invited to check our site:

http://www.kroosh.com

Thank you ■