|Monthly Tech-Tip |
Alternate Names: Imco 400
A milled and air floated Lincoln fireclay. An all purpose clay with high strength and plasticity.
It is not clear why the chemistry for this is different than for IMCO 800 if they are both airfloated Lincoln fireclays.
In our tests we found it to be very smooth, plastic and has a kaolinish feel. It has high alumina like a kaolin. Although it fires straw-colored at cone 6, it turns to greenish at cone 7 and becomes very dense by 9. It is still stable at cone 11 and cone 10R is not bloating or expanding either. It has some light brownish scumming on the 8+ bars at the edges (but this covers most of the surface on the 10R bar). This is not really a fireclay, it is vitreous at cone 10.
Cone 10R top, 11 oxidation and downward below that. This material, although called a "fireclay", is more fine grained and much more vitreous than what would normally be considered a refractory fireclay. Is it similar to Lincoln Fireclay (from California).
|Materials||Imco 800 Fireclay|
|Materials||Lincoln 60 Fireclay|
|Materials||APG Missouri Fireclay|
IMCO information on their mined clays
Fireclays are non-kaolin non-ball clay materials similar to stoneware clays but lacking fluxing oxides. Many fireclays have a PCE of 28 or more.
|Drying Shrinkage||5% @ 27% water|
|Firing Shrinkage||Cone 6: 7.7% Cone 7: 8.2 Cone 8: 8.7 Cone 9: 8.5 Cone 10: 8.0|
|Sieve Analysis Dry||+65: 0.1 +100: 0.1 +150: 0.2 +200: 0.4 +325: 0.5|
|Water absorption||Cone 6: 4% Cone 7: 1% Cone 8: 0.1% Cone 10: 0%|