Melting metals in a domestic microwave

I am looking to try and melt metals in a domestic microwave for this I need to use a ceramic mould which can absorb microwaves. I just
wondered whether anyone can tell me which ceramics are best at absorbing microwaves and whether anyone has any ideas as to what the composition of the mould should be in order to achieve this.
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http://home.c2i.net/metaphor/mvpage.html shows how to make small melts to 1,000 c.
Gordon
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Interesting Web page ! - you are a brave soul ! I watched others try to sinter ceramics in domestic microwaves - from a safe distance - the stuff that doesn't work can be very entertaining Magnetite - alumina refractoriness that I saw tested had a tendency to runaway with spectacular results. (small portions would melt right through the microwave bottom and the counter top and the cupboard bottom) They did a lot of work on microwave sintering of ceramics at ORNL - let me know if you want references. The susceptibility of SiC decreases with temperature - it makes for nice controlled heating. Yittria stabilized zirconia is a good suseptor once it's heated and it's commonly used for induction heating applications. Zirconia can certainly take the heat and corrosion of melts - maybe an SiC crucible with a ZrO2 (YSZ) liner might work? (be careful of thermal expansion differences and thermal shock to the zirconia) Gregg
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to
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With an old microwave oven sitting out side viewing though the door with a mirror and binoculars it sure a lot safer than many things I do everyday like driving to coffee in a college town.
The save distance part is the key to anything you do. My neighbor made substantial amounts of nitro glycerin in the 50's using mechanically remote controlled mixing in 55 gallon barrels of ice water from behind an earthen berm. The mistakes were spectacular but harmless. I drove by the farm he was did it on a couple of weeks ago and most of the evidence is grown over now.
Gordon Couger Stillwater, OK www.couger.com/gcouger
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Funny you should mention what it takes to be safe I wish you were around when I was in grad school - to lecture some of the students. There is nothing so reassuring as walking into a lab and being surprised by a brightly glowing microwave on the other side of the door. Or running to a room because a grad student is screaming at another student who is about to pour 20% HF in a sink to clean glass ware. On the other end of the spectrum - I just had a go around at work about safety - I have to hook a CO2 cylinder up to a piece of equipment. I wanted to hook up a flow regulator (small flows 10 liters an hour at ~ < 5psi pressure) - no problem right? - 5 minute job right? The safety engineer (I use that term loosely) said a flow regulator and two pressure relief valves were not enough We needed a line capable of holding 700psi from the tank to the equipment - in case the regulator and safety valves failed (and I was the one who had to insist on a portable CO2 monitor)- now this line runs into tygon tubing ??? If - and I mean if -the regulator and the pressure relief valves fail all at once - the line will blow up in the operator's face instead of back at the tank - 10ft away. This job will cost $1000's and it's been a couple of months so far and I'm still waiting. (by the way this is an A priority project) Dilbert lives, Gregg
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They give the job of safety engineer to someone that is incapable of doing anything else after he has been brain washed to makes sure all common sense he might have had has been erased.
Write up the safety engineer as prescribing an unsafe installation. Tell the distraction that you will not assume any liability for a installation that you know to be unsafe because of faulty design and will require all people working in the lab to sign a wavier informing them of the unsafe installation. The safety engineer is not untouchable. To keep from making him look like the fool his is make a short run of high pressure tubing and put in a T to dump the pressure into a safe area.
I don't know what the fallout of being right is over this but you can beat city hall the price may be more than you are willing to pay.
Actually an orifice on the high pressure side slightly larger than will allow you maxim flow and pressure will make the whole thing fail safe so no high pressure can escape through failed controls.
I see people that want to put a cut off valve on a rubber people line at the burner on a furnace instead of the tank. If anything ever happens and they cut off the valve at the burner and the hose burns thought the fire is between them and the tank. If the only cutoff valve and regulator is at the tank they will be at the tank to regulate the flame and shut down the valve in case of a problem and there will be no risk of a fire from a broken hose at all. How every they can not see it that way.
With the background today's students have they are dangerous with a feather duster. Very few have any experience at all. Many don't know what work is they have never seen any. And they have never done any thing that involves safety. Schools have sanitize there programs to the point that the rough spots in the sidewalks are inspected once a week so the poor darlings don't stump their toe.
Gordon

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You certainly gave food for thought- I'm torn between starting a pissing match (which can cause delays) or waiting until the next Delbertish thing comes along that isn't as important. I'll definitely show your response to several co-workers who have had problems with him. Thanks, Gregg

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You seem to know a lot about YSZ.....so a probably stupid question for you. Leaving aside all the cost questions, oculd there be any advantage to using scandia stabilised zirconia instead of yttria ?
Tim Worstall

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