Originally Posted by mvallaba

Dear All,

We are currently developing the raw material yard requried for a blast furnace. In this raw material yard blending of iron ore is done by slewing stacker and portal reclaimers.

How can we determine the efficiency of the blending process? and is there any formula for checking the blending process?

regards,

mvallaba

I am not a metallurgist but would not the weight of the ores and the percentage of iron and other minerals be the measure to follow for weight and blending a charge? ■

Dear Mr. M. Vallala,

It is purely statical calculation. Please read chapter written by A.W. Gerstel in the book " Stacking, blending & reclaiming".

Regards.

A.Banerjee ■

not sure why you are digging up a bunch of old threads Mr. Banerjee - 4th one today. ■

Hello,

The subject you are referring is too complex to explain here in such forum. You are likely to get better information easily from competent supplier of stockyard machines, as a collateral information. However some basic information is as below:

1) Blending (homogenisation) effort is combination of blending ratio and batch size.

2) Blending ratio is defined as (Standard deviation input) ÷ (Standard deviation output).

The smaller the batch size, the more will be the blending (mixing) effort. Also, more blending ratio means more is the blending effort. The total blending effort is sum effect of these two. Its total is not simple sum, but will increase geometrically.

3) You (concerned authority) will get the batch size from blast furnace functional designer (chemical engineer) from supplier of the blast furnace.

4) You will also get the permitted variation of specific property of material, from blast furnace functional designer (chemical engineer) from supplier of the blast furnace.

5) You will have the permitted variation in this property for incoming material.

6) Above will enable you to decide the blending ratio.

7) Your requirement for material handling equipment and system would be get aforesaid blending ratio in conjunction with the batch size. This is to be fulfilled by the supplier of the bulk material handling equipment and system. Please note that system and its operational logic also plays important role (how you form stockpile, how is the reclaiming action, etc.).

The TransTech publication book ‘Stacking Blending Reclaiming of Bulk Materials’ provides certain information. This book is now out of circulation.

It is clarified that my professional career did not have the opportunity (scope) to involve in some of the points. The knowledgeable persons can add some more information if they like.

Regards,

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Gary said some time ago and I will say similar...there is an increasing tendency for some individuals to flood the forums with useless irrelevant replies to long expired threads.

For myself the only reason for reviewing these threads is to recognise the boring repetition, inconclusive content and misinformation (this book is out of print...etc). ■

Originally Posted by I G Mulani

Hello,

The subject you are referring is too complex to explain here in such forum. You are likely to get better information easily from competent supplier of stockyard machines, as a collateral information. However some basic information is as below:

1) Blending (homogenisation) effort is combination of blending ratio and batch size.

2) Blending ratio is defined as (Standard deviation input) ÷ (Standard deviation output).

The smaller the batch size, the more will be the blending (mixing) effort. Also, more blending ratio means more is the blending effort. The total blending effort is sum effect of these two. Its total is not simple sum, but will increase geometrically.

3) You (concerned authority) will get the batch size from blast furnace functional designer (chemical engineer) from supplier of the blast furnace.

4) You will also get the permitted variation of specific property of material, from blast furnace functional designer (chemical engineer) from supplier of the blast furnace.

5) You will have the permitted variation in this property for incoming material.

6) Above will enable you to decide the blending ratio.

7) Your requirement for material handling equipment and system would be get aforesaid blending ratio in conjunction with the batch size. This is to be fulfilled by the supplier of the bulk material handling equipment and system. Please note that system and its operational logic also plays important role (how you form stockpile, how is the reclaiming action, etc.).

The TransTech publication book ‘Stacking Blending Reclaiming of Bulk Materials’ provides certain information. This book is now out of circulation.

It is clarified that my professional career did not have the opportunity (scope) to involve in some of the points. The knowledgeable persons can add some more information if they like.

Regards,

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com

Thank you Sir for sharing your knowledge.

Regards, ■