46% Alumina content too high?

[skismeno]

Hello All,

Another South Australian here about to embark on the building of a wood oven.

As has been mentioned in this forum - firebricks here in SA cost around $5 each.

I have come across some free fire bricks (enough for the hearth - will use red brick for the dome) and am unsure if they are suitable for the oven.

I found the 'specs' for the bricks online and they are 50% Silica and 46% Alumina. I have a feeling the Alumina content is too high for this application - can anyone confirm.

Thanks heaps,

Peter