Eventually I'll make those rubies

[KWyant]

Hello Folks,
I'm Karl Wyant hailing from Duluth, MN. About 10 years ago I got it in my head to make a few synthetic rubies. Bought most of the equipment. I've got 3 electric ni-chrome wire furnaces, etc. Anyway, I never bought the platinum crucibles. Got interviewed recently and was asked what project have I failed to accomplish and this started eating away at me again. Looked up the price of platinum and decided there was no way I was going to buy 1 or more crucibles. I've always been interested in doing things myself. Even make my own hydroponic fertilizer from 50lb bags I buy at local fertilizer store. Using gram scales and such because it is a rip off buying those premade solutions. Yes, all of my hydroponic endeavors are for wholesome endeavors, lettuce, tomatoes, peppers, and melons.

Anyway, I started thinking maybe I could recover my own platinum and put it to use. I knew there was platinum in catalytic converters and disk drives, both of which I have just laying around so I am in the process of learning about it. I now know there are at least 2 ways to go about it 1) Hot Aqua Regia followed by ammonium chloride and 2) HCL + Clorox followed by ammonium chloride. I found my way here after finding Lazersteve's videos. Thanks Lazersteve, you'll probably see an order from me soon.

I still need to learn how to turn that precipitate into platinum. Not sure if I simply melt it or not. I've learned I can melt platinum with an oxy-acetalyne torch set to an oxidising flame, but better a hydrogen torch. I doubt my kilns will melt the platinum. I've got books on lost wax casting and am considering that as a way of casting the crucible, but still some time to that. Years ago there was an ebay ad for a guy with 4 platinum crucibles and a crucible mould for reforming them. I am still looking for a platinum mould, but haven't found one yet.

Once I get the platinum mould going, Making the rubies themselves will be fun. The best recipe I know currently requires the use of Lead Fluoride as a flux together with aluminum oxide and chromium, but I would love to know a safer flux than lead fluoride. That is some nasty stuff.

Enough about me for now. All, thanks in advance for any help. I'll post pics as I go and maybe my stumbling can help others who are interested in similar things.

Karl Wyant

 

[turtlesteve]

Hey Karl,

Sounds like a fun project, I've even considered trying it myself (I cut gems, and it would be nice to say I made one "from scratch"). There are tons of ways to grow synthetic rubies, even some without requirement of platinum crucibles. However if it's flux growth I think Pt may be necessary. Flame synthesis is most commonly used industrially, and doesn't require Pt (more complex furnace setup, however). Also hydrothermal growth gives excellent results but is more dangerous to perform (the reaction vessel is called a "bomb" for good reason). For flux growth, MoO3 has also been reported in at least one paper. It's not as toxic but is also volatile (you'd be growing via flux evaporation, not cooling - I assume this is what you intended for the PbO as well.) Also grows beautiful bi-pyramidal crystals instead of thin platelets.

Good luck
Steve

 

[turtlesteve]

Oh - another comment:

I have made one crucible so far, and have started on a 2nd. This was not for me, but for my research group as we didn't have funds available for re-making what we wanted. I melted the platinum (calcined, from ammonium chloroplatinate) using a hydrogen torch, to make a round ingot. The ingot was rolled into a sheet, and the sheet was hammered into a cup shape. The hammering technique (called "raising") is not trivial and you would need to practice a lot on say, copper, before starting.

Casting platinum would be more difficult.

Steve