The mere mention of a barrel suggests you need a modicum of blending.

So.

Barrel reclaimers have been an endangered species for many years because of cost and restricted utilisation.

Any bridge machine is captive in any failure situation.

Your best bet is the twin wheel job ...if you must. All you new lads are asked to blend on reclaim and told to forget about blending on stacking. If there's a hard way to do a job somebody will find it.

Find out what your punter really wants, what his previous troubles were and then flog him a bucket wheel stacker reclaimer...the maid of all stockyard work! ■

Kind attn. : Mr. Usman,

You have listed 3 points for comparison viz. equipment price, maintenance cost and service weight.

You have not mentioned very important consideration i.e. functional requirement. It seems the machines you are referring are for reclaiming together with blending. In case of simple reclaiming bucket wheel on slewing luffing boom is more convenient for operation compared to the machines you are mentioning.

Inferring from this, your functional requirement is for blending also. The simple comparison of price of the machine is not the right approach. Suppose barrel reclaimer is more expensive compared to others. But if it is likely to result into other economic benefits then this is to be also counted in the comparison. The iron ore so blended and reclaimed is for commercial use or for further process. If higher blended iron ore is to fetch more price in the market then it might be still preferable and economical to have it, in spite of its more price of the machine. Similarly if better blended iron ore is going to improve / increase the output of the steel then same is also taken into consideration.

Use of type of machine is a complex decision where various departments of the organization are involved to make an optimum decision. Generally such decision can not be implemented without analyzing the consequences in the function of the industry.

Regarding quality of blending; it is defined by blending ratio with reference to batch size. The smaller the batch size and higher the blending ratio implies more thorough mixing of the material. For easy to understand and as a lighter example, suppose a medicine tablet is of 5 gm. It is made up of two materials in certain proportion. Therefore for this typical case the batch size will be 5 gm and in this batch the said materials have to be in specific proportion because functionally consumption of this tablet is in one piece and that batch should provide the particular quantity of material while consuming. Well, this example is only for general understanding and not exactly matching to tonnes of material you are to deal with.

Apart from blending one also see the fluctuation rate in reclaiming operation. It seems the fluctuation margin will be in descending order with reference to serial number of your list. As far as efficient blending, this blending will be of superior grade with reference to the order in the list (i.e. single bucket wheel will have less efficient blending and barrel reclaimer will have most efficient blending).

The single bucket wheel will have least price, double wheel will have a higher price and barrel reclaimer will have highest price. This is to be treated as a probable comparison.

Regards,

Ishwar Mulani

Author book - Engineering Science and Appication Design for Belt Conveyors

Author book - Belt Feeder Design and Hopper Bin Silo

Tel. No. : 0091 (0)20 2587 1916

Email : parimul@pn2.vsnl.net.in ■

Dear Mr. U S Man,

If blending is prime objective ,please go for barrel reclaimer. Bridge reclaimer is maintenance prone equipment.

Cost of barrel is Rs. 15.00 Crs.& that of bridge is Rs. 12.0 Crs. The weight of Barrel is 520 ton & that of bridge is 465 ton.

The cost indicated in INDIAN RUPEE & weight is based on INDIAN supplyer.

Regards.

A.Banerjee ■

Dear Mr Usman,

I assume that this project has decided which way to go so I will be brief.

I would go with louispanjang's answer despite the fact that he is not really up to date on engineering service costs around the world. I believe that he is right!

A drum/barrel reclaimer is way too expensive for 1500t/h. Blending should be carried out through the use of the stacker, not the reclaimer. Anyone that claims that you can blend properly with a reclaimer did not pass their first year minerals processing course.

Hope it all went well. ■