I've been playing around with microwave ovens, looking for several things, one of which is a practical way to fire clay. I still haven't found one, but have made a little progress. I bought about 20 lbs. of aluminum oxide sand blasting media from Harbor Freight the other day, thinking it might work pretty well. I've read that aluminum oxide is a good microwave attracter. It did not work, and I couldn't get it to heat at all unless I mixed it with something else that would. It was black.
Oh, well, I thought, I'll mak it into Aluminum hydroxide and use it for chromatography. I wasn't sure how to go about it, but thought I had a pretty good idea. I washed it several times with water, then added some HCl. It began to liberate HS, so I flushed it and set it up again in a flask with an exhaust tube running into some NaOH. That worked well, and I kept adding HCl in small amounts until there was no more reaction
As I had it planned, the result of this was supposed to be AlCl3 in solution, and I hoped that most of the impurities would stay behind. Not sure about that, but after filtering I added NaOH with the idea that Al(OH)3 would fall out of solution. I got a hell of a precipitate, but something looked wrong. CRC said that Al(OH)3 is white, but this was dark green, and thick, almost like a colloid. Even though my original mass of aluminum oxide was small, every time I added more base there was more of the green precipitate formed, until the whole beaker was filled with it.
I washed this material with water over and over, but it retained the bulky, colloidal property. I decanted off most of the liquid, and then noticed that as it began to dry the material changed from dark, spinach green to reddish brown, not unlike rust. When completely dry it lightened, and now the color appears too light to be rust but I may be wrong. It does seem to have the ability to attract microwaves, but not so much so that it would make a good material for that purpose.
I looked it up in CRC and found that it matches the description given for ferric oxide, Fe2O3-2H2O. I had already noted that heating it with a propane torch drives out water, because the water would condense on the anvil part of my vise when I heated the red-orange powder with a propane torch. The material darkens, but then returns to the original state after some time.
I don't know what I did that caused this particular product to be produced.
A prologue to the story is that there was still some material from the original aluminum oxide that was not affected by the HCl. It's black and looks somewhat crystalline in the light. This must be the real aluminum oxide, because it does seem to attract microwaves well, and appears unchanged after getting it hot enough to melt a ceramic pot and a bit of aluminum. It remains a loose powder. The only trouble is that it should be a white powder, not black.
I posted this here to see if there are any comments. All are welcome.
PP
Oh, well, I thought, I'll mak it into Aluminum hydroxide and use it for chromatography. I wasn't sure how to go about it, but thought I had a pretty good idea. I washed it several times with water, then added some HCl. It began to liberate HS, so I flushed it and set it up again in a flask with an exhaust tube running into some NaOH. That worked well, and I kept adding HCl in small amounts until there was no more reaction
As I had it planned, the result of this was supposed to be AlCl3 in solution, and I hoped that most of the impurities would stay behind. Not sure about that, but after filtering I added NaOH with the idea that Al(OH)3 would fall out of solution. I got a hell of a precipitate, but something looked wrong. CRC said that Al(OH)3 is white, but this was dark green, and thick, almost like a colloid. Even though my original mass of aluminum oxide was small, every time I added more base there was more of the green precipitate formed, until the whole beaker was filled with it.
I washed this material with water over and over, but it retained the bulky, colloidal property. I decanted off most of the liquid, and then noticed that as it began to dry the material changed from dark, spinach green to reddish brown, not unlike rust. When completely dry it lightened, and now the color appears too light to be rust but I may be wrong. It does seem to have the ability to attract microwaves, but not so much so that it would make a good material for that purpose.
I looked it up in CRC and found that it matches the description given for ferric oxide, Fe2O3-2H2O. I had already noted that heating it with a propane torch drives out water, because the water would condense on the anvil part of my vise when I heated the red-orange powder with a propane torch. The material darkens, but then returns to the original state after some time.
I don't know what I did that caused this particular product to be produced.
A prologue to the story is that there was still some material from the original aluminum oxide that was not affected by the HCl. It's black and looks somewhat crystalline in the light. This must be the real aluminum oxide, because it does seem to attract microwaves well, and appears unchanged after getting it hot enough to melt a ceramic pot and a bit of aluminum. It remains a loose powder. The only trouble is that it should be a white powder, not black.
I posted this here to see if there are any comments. All are welcome.
PP
