what is the procedure for the deflocculation test on clays carried out in labortory?

Question

the purpose is to check the effect of deflocculant on the slip(ceramic).

Answer 1

I love that word... DEFLOCCULANT! It's almost as fun as 'defenestration'. But that's another subject. ( :

Usually if you want to test the effect of a deflocculant on a slip, you measure its specific gravity. If you want to do this accurately, you weigh a defined volume of slip (say, 100 mL) and the same volume of water. Divide the weight of the slip by the water, and the result will be the density in g/mL (assuming you're weighing in grams, that is). Around 1.8 is a good density for a slip, lower usually means its too watery, and higher means too solid, of course!

Of course, if you have enough money, you can use a viscometer, which tells you EXACTLY what's going on - it tells you the ratio by weight of clay to water and the viscosity. But I don't expect most people have those lying around.

A lot of people determine if they've got the right amount of deflocculant by eye as they're mixing (it takes hours anyway!). But that's more of an art than a science, really.

Below's a pretty good resource you might wish to check out as well.

Answer 2

With the new first response deflocculation test kit you can get clear and easy answers just by urinating on the clay and waiting five minutes. Two stripes means you the effect of the deflocculation on the slip was successfu! Congratulations on the new addition to the family!

Answer 3

One qualitative method would be to measure the degree of settling that occurs after a centrifuging the samples or allowing them to rest for a very long time, both with and without the deflocculant. Flocculation causes the particles to pack less densely, because their shape does not allow for maximum packing density. The denser the sedimentation, the more effective the deflocculant.