ok i got too study that aspect difference. time too call my ceramic store man, he sells what ever i need and builds kilns, forges, what ever there called, Thanks i will repost if i learn anything extra.
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You can buy aluminum oxide sandblasting, but most of it I see is black, and aluminum oxide itself is white. I canāt find a msds for the black stuff.
I just realized aluminum oxide would be in the dross from aluminum smelting.
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Black beauty is what was used in the old days for sandblasting it was coal dust. I donāt think you will find a MSDS sheet for it.
They also use walnut shells I think the walnut shells are easier on think metal. Either way they wouldnāt make good fire bricks.
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yes i seen that, i wonder what the white aluminum oxide blasting sand is made from, i see there is white now allso. ? its powderd aluminum oxide.We will have too experiment too check for gains in temp rateing, with out cracks from cooling.I bought some 2" 8# ceramic blanket, from cera matereal for 80.bucks out the door after calling and ask for slitely damage discount, 24"Ć12-1/2 feet long. that will nicly do the burn chamber in the wood heater with enough left too build another motor gasifier. And enough scrap too chop up too make insulated fire brick mix.
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All the white or tan ones I pulled up, were like 97% aluminum oxide, with other trace stuff like titanium oxide and silicone oxide. I just havenāt found an msds for the black stuff. You get a layer of black stuff if you treat aluminum with vinegar.
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i looked up aluminum oxide from china, and it says the stuff they sell is used for blasting media, and other stuff including refactory, i heard that the finer the better for the fire brick alumina powder, not sure yet how fine, then as you said there are different puritys that might need checking at some point, if the bricks crack, i might try a mixture too make some 1/2 " thick plates for the hot face, maybe hold up with ss plate strips, and use as heat holder experiment.
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In that link I posted, it mentions ground glass being added in certain mixes. That might be a component of the silicon oxide? Quartzite (quartz blasting sand, or even diatomaceous earth, ie, kitty litter / Sorb-all, are basically pure silica).
And, just to add confusion, I thought clays are largely aluminum compoundsā¦
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Not sure about the aluminum silicate, but the clays all have different percents aluminum oxides, i think the red art i bought is only 15 too 18 percent aluminum oxide, the better fire clay cost more because it has higher percent aluminum oxides, as menchened earlyer, i heard that up too just under 40 percent aluminum oxide is most can be gained from that addition.All i really need now is a good proven refactory cement too add some ceramic fibers or and metal shavings too make the hot face, too put in front of the ceramic blanket.
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menards has castable refactory cement 25 lb pail 28 bucks, then i see they have 50 pound bag of refactory morter, though the mortor is few dollar cheaper per pound, it only works will small space in between the fire bricks, so not made too be used as the cement is made. I think the cement may need lots of fillers too keep shrinkage down, not exactly sure about the refactory cement may need mixing, probly on the bag maybe.??
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It looks like the grit for aluminum oxide refactory powder is between 600 too 1200 grit, or thats what a chineese co. was selling as refactory alumina by the ton from alibaba. if i new how too transfer the links i would. Not FOR SURE YET ON THE MESH OR GRIT GRAIN SIZE.
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ask if they know the source or the % aluminum oxide. They do use dross from aluminum casting as part of some refractories, and I would assume blasting sand. Dross itself contains like 30% aluminum oxide, like 10% aluminum, then other things like zinc or magnesium, and stuff left from the fluxes. But then they use a rotary kiln to get the last bit of aluminum out.
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Hi the aluminum oxide for blasting media and or refactory substance, says about 95 too 99 .9 percent pure alumina short for aluminum oxide, allso i notice they use that term alumina for aluminum silica or the other ingreediant mechened earlyer.I think the main difference between blasting with aluminum oxide and casting refactory aluminum oxide is the grain size or fine enough for refactory, i am not sure of the finess difference Yet.but it may have too be ground fine in a machine before it will acheeve the chemicle reaction in reasonable time, from what i read so far.
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allso i read that real marble is good for supper high heat sheild if one has an old marble table too laying around, for bricks or too use for filler, smashed down for filler agigate,too mix in with the binders.
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Old firebricks are used as well. It is called grog in the ceramics circles. Or you bake it, then crush it and add it to a new mix. But I think the trick is what to use for the binder especially the more you add.
Holy cow. I just found this with lots of info:
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Ya grog i couldent flash the word. lots of variety of casting and refactorys, the most comon with fire bricks must be plain old aluminum oxide, for clay brick mixes anyway, they probbly not as high temp as the silica alumina mixes, when one ingreediant changes, they all have too be compatable chemicle speeking is the other thing too watch for. Quite confuzeing if trying too learn it all.For now i am just trying too get one good clay brick mix good, still dont have a kiln too fire the bricks in, think i might try putting a brick under my gasifier bottom chamber, on my wood heater.Thanks for shareing the knowlege,s. i see they sell ceramic door seal rope too and with wire mesh outer if wanted. the rope with out the mesh runs .87c foot if buy 100 feet. At cera-matereal company.
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firebricks, come in two varieties. The heavy ones, which are made out of fireclay, and light ones which are refractory and typically have a high aluminum content.
I think as near as I can tell the difference between the black aluminum oxide and the white stuff, is possibly the black stuff comes from reprocessed Dross from aluminum melting. You take the dross whihc is white then, separate it, and remelt it to extract more aluminum out of it, and the black stuff is the dross from the second time around.
Now to add confusion, I believe alumina or aluminum oxide can have sodium aluminate in it, but I am kind of unclear what is going on exactly.
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Now you have me wondering if there is a way to do something with aluminum cans we all have kicking around.
Well that is what I was wondering. I have been picking them up to do some casting, which got me started on looking at this in more detail. The aluminum is worth more as aluminum, but the dross of course has the aluminum oxide naturally as aluminum automatically forms the oxide coating on the outside in oxygen which comes up as dross/slag in the melting process. In otherwords, once I get the first furnace built, I will have some of it no matter what anyway. Because of the high surface area of an aluminum can, you actually get a significant portion of dross. I canāt find much of anything on isolating the oxide from the dross yet though.
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Well here is the good stuff 12 1/2 feet by 24" 2" thick 8# 2300 f ceramic fiber blanket, 80.00$ too my door. The clay bricks can be a learning experiment after i put this around the dome of the lower burn chamber,on my wood heating gasifier type too be.Fairly heavy roll with all the little air space in between the fibers, probbly better than the brick for insulate.
Think i will build a 1/8" thick steel shed too hold it up in place snug, then plaster the inside of the shed with high temp cement concrete mix for holding the heat in the area. All ceramic blanket mounting i will be wareing a full painters breather mask due too the dust that flotes everyware while working with the ceramics.j
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Off that site you posted, they have some stuff to go on top of steel.
I have a couple of small projects I want to try but other then that, it is most likely kids art projects and they may be more interested in pottery then metals. So I am trying to avoid spending any money. This gets expensive fastā¦ 
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