Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: george on 18/09/2004 11:08:24

Title: What happens when a pot is 'fired'
Post by: george on 18/09/2004 11:08:24

When you make something out of clay and dry it, it goes hard, but easily falls apart if you make it wet again. But if you put it in a kiln and bake it, the pot becomes hard and water-resistant.

My question is, what happens when you 'fire' (bake in a kiln) an item of pottery to make these changes occur ?

Title: Re: What happens when a pot is 'fired'
Post by: Ylide on 19/09/2004 20:27:09

It has to do with the hydrated minerals in the clay having the water driven off.  I don't mean just the adhsive water that sits in the pores but the water that is actually part of the crystalline structure.  A quick search garnered a really good website that explains the whole process in depth.  I knew the chemistry of it but I wasn't sure what kind of minerals are used in clay...this gives better examples than I could.

http://www.digitalfire.ab.ca/cermat/education/200.html



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