[skumar1]

I am trying to granulate a natural/artifical graphite with the help of a phenolic binder in a high shear granulator and then crush/grind a bit to make it comfortable for pressing. But what is happening is the agglomeration is taking place in the shear granulator, but on crushing in a cross beater/hammer mill the powder is getting to finer sizes. can some one suggest the best machine(s) for the above work so that I get a granulated mixture slightly coarser than the starting mixture suitable for flowing and compaction in a press?

[eugenedakin]

Hello skumar1,

My first question is, 'what type of phenolic binder are you using'.  Some phenolic binders are very potent (completely dissolve graphite) and some are a very poor binder (cause graphite to precipitate).

This is only a suggestion (I am not sure if you are set up for this type of modification to your process):  Use a phenolic dissolver that slightly dissolves the graphite near the beginning of your process, when you reach the portion of your process that requires a larger granulated form of graphite, add a precipitator/binder.  This will combine the graphite particles to larger size.

Another set of possibilities is to lower the speed of the granulator or lower the volume of binder used.  You could also lower the amount of crushing/grinding time.

Before you make any changes to a process, perform small laboratory trials first.

Sincerely,

Eugene

[skumar1]

I use phenol formaldehyde type resin which is a solid binder that has to be dissolved in methanol first. This solution I am adding to the graphite powder. I am surprised that the binder dissolves the graphite powder.
Ok. I will try to follow the steps.
Yes I can reduce the speed of the mixer.
But binder solution if I decrease may be detrimental to aggolmerating pattens.
I hope you are aware the granulation starts with nucleation, followed by compaction and then coalescence and finally layering and then brekage according to the modles/theories of granulation.
I feel something is going wrong in these steps.

[eugenedakin]

Try it in a beaker first...

[gregpawin]

You know, just when I think I gotta hold on this chemistry thing, there's questions like this that make me think that I know nothing whatsoever.

[eugenedakin]

gregpawin,

Are you kidding around... or are you serious?

Eugene