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Opposites attract…

28 January 2013 No Comment

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North and south poles.  Positive and negative charges …..

These are all opposites – and supposedly they attract.  It’s true of north and south poles of a magnet and positive and negative charges (like rubbing a balloon and sticking it to the wall)  – this may be less true when my bank account is considered, where it seems all the charges are negative…

In what is termed ‘unit operations’ in chemical engineering then there are processes that can be considered opposites or reverses.  We have separation and its opposite, mixing.  We have size reduction processes (‘comminution’) and the opposite here is agglomeration.  Alternative words or process steps may be briquetting, tabletting, granulation, pelletization, pelleting, sintering etc……

We’ll note that there’s no particle size change with mixing and separation but this is certainly not the case with size reduction or agglomeration.   In cooking, we size reduce coffee beans to make freshly ground coffee.  We may agglomerate flour, egg, and sugar into a cookie…

In a webinar on January 31st, I’ll be considering comminution or size reduction mainly from the perspective of the energy expenditure – 1% of the word’s electrical energy is used in the size reduction processes in cement manufacture.  This is something I’ve looked at before in a presentation at Partec in Nürnberg  a few years back.  But this time I’ll also get the chance to explore agglomeration processes so that I can finally get to looking at light scattering from a peanut – which can be considered as the partial agglomeration of 2 touching spheres – important if you’re considering the sintering of metal particles to make products such as filters….

So hope to see you there and make all of you individual particles into a larger webinar conglomerate…..