Home made castable concrete recipe?

[Stone Mason1]

Hi all, im venturing into the world of pizza oven construction and fire places/BBQ's as a part of my small stone masonry buisness.

Im looking for a recipe for casting the inner layer of the pizza ovens.

Heres what i know... A standard fire brick i can purchase contains this:

Al2O3 (alumina)
SiO2 (Silicon dioxide, Silica, Quartz)
FE2O3 - (Iron Oxide)

And the extra ingredient in a refractory cement is:
CaO (Calcium oxide,quicklime or burnt lime)

I have sources for Iron oxide, silica sand and calcium oxide.

Im just not to sure about alumina and the drying time of using calcium oxide.

Is it possible to make a mix using:

Portland cement 30%
Silica sand 40%
Quartz 10mm pebbles 28%
Iron oxide 2%

What would the cons be not having the alumina content?
Also info on where alumina would be able to be sourced would be nice.
Any help on this would be great...

[dmun]

Re: Home made castable concrete recipe?

Portland cement 30%
Silica sand 40%
Quartz 10mm pebbles 28%
Iron oxide 2%

This looks like ordinary concrete, with fancy aggregates, and a bit of red colorant. I'm certain that this will fall right apart in contact with direct flame.

[david s]

Re: Home made castable concrete recipe?

Alumina is not like a material you buy. It is found mostly in clays which are composed of varying proportions of alumina and silica along with all kinds of other, sometimes undesirable, fluxing materials like iron oxide. You can trial lots of materials and combinations, but I think you are better off sticking to a proprietary castable.