239 posts
TimePosted 09/09/2009 08:13:45
xxxx says

### blending

what is the minimum & maximum blending ration from a staker - reclaimer in cement for coal as well as for limestone piles.how it is calculated.what is the normal range & methods of improvements

rajesh

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29 posts
TimePosted 10/09/2009 21:25:52
vinayak says

### Re: blending

Hi

The blending efficiency is ratio between the standard deviation of input to the standard deviation of output. Samples are collected in the input of the stacker and analysd for the interested parameters like LSF or SM etc and the Std DEV is calculated. Similarly when the same material is reclaimed after blending the samples are collected and analysed for the same parameters and the Std Dev is calculated. The ratio between the two is the blending eff. Normally it is around 10:1

It can be improved by increasing the number of layers by increasing the stacker speed. Reducing the input varaition will naturally reduce the output varaition which would help the plant operation.

Circular piles are having lesser initial cost and occupies lesser space compared to longtitudinal piles.But as it is a continuously operating/moving pile, mild variation in the output qulaitycis inevitable.

Vinayak

537 posts
TimePosted 11/09/2009 04:46:00

### Re: blending

vinayak:

It can be improved by increasing the number of layers by increasing the stacker speed.

Yes, but be carefull not to increase the number of layers excessively. If the number of layers is so great that the thickness of each layer is less than the upper particle size of the material being stacked, you could actually increase the end-cone segregation in linear stockpiles.

vinayak:

Circular piles are having lesser initial cost and occupies lesser space compared to longtitudinal piles.But as it is a continuously operating/moving pile, mild variation in the output qulaitycis inevitable.

Yes, the main advantage of a circular blending pile is that there are no end cones, and hence less variability due to segregation at the ends. However, with respect to blending performance, a circular pile is a compromise and in my experience does not perform quite as well as a longitudinal chevron-stacked pile.