Low alumina content firebricks - are these ok?

[BrickOvenMike]

Agreed, I'm no expert (this oven is the first masonry work I've ever done), but I've been very pleased with the performance of my firebricks.

My oven takes between 3-4 hours to heat up (My construction is 4in firebrick + 4in concrete + 4in perlite), and holds the heat well enough to cook at least 3 batches of bread at a time, probably more, although I've never tried more than 2 batches at a time.

Pizza cooking is even better starting out at about 900F (500C) ... last month we hosted a large party and I cooked just over 100 pizzas in 2-1/2 hours ... the oven dropped from about 850F to just over 500F in that time, and TONS of thermal energy was transferred to all those pizzas ...

Once again, I'm using firebricks with only 16% alumina content, and they work great!

Thanks guys for all the advice and feedback you offer on this site!

[old wanderer]

Last year I bought 350 white used fire bricks from a kiln where they used to process coke. The I got sick and had an operation. Last week the person I bought them from called me and said...."I know I said you could keep them at my house until you wanted them, but it has been over a year....(I drove 60 miles Saturday, and loaded all 350 bricks into my PU).

I have been trying to find our the Alumina content of these, but like was pointed out, quit procrastinating and get the oven built.

The support base is set, the 1st vermiculite/cement 2" layer is poured, now ready to pour the 6" support slab for the real oven (as soon as it stops raining).

I found a retired mason that was selling his commercial quality tile/brick saw with a $300 diamond blade for the price of a new blade, so will take a few of the bricks with me when I go to pick it up on Tuesday, maybe he will know.

I am also shopping for some flag stone to cover the outside of the whole wretched mess, when I get it up.