D4RR3N - 5-6-2008 at 10:18
I can purchase Yttrium metal in lump form relatively cheaply but the prices I have been quoted for Yttrium powder are six times higher then the price
of lump yttrium. Firstly I cant understand why its so expensive as its not as rare as other elements which are much cheaper. Secondly I was wondering
if I purchased a few kgs of yttrium in lump form dose anyone know if I could get it milled somewhere, strange question I know but has anyone here ever
got a solid metal milled into a powder form?
Edit by C: Spelling- Yttrium, not Yuttrium
[Edited on 6-6-2008 by chemoleo]
12AX7 - 5-6-2008 at 10:36
Yttrium?
I imagine it has to be milled under inert gas.
What powder size, what for, etc.?
Tim
D4RR3N - 5-6-2008 at 12:50
Sorry, Yttrium (Y) metal, I can purchase it for under $300 per kg in lump form but I received a quote from China today at $2000 per kg powder 
First I thought it was a typing mistake but then I was told the prise was extra high to help the earthquake victims. Thats about seven times more
expensive then lump yttrium
Particle size is not critical but the finer the better. Not sure how its milled, vacuum, inert gas or fluid?
jokull - 5-6-2008 at 14:20
What you need is a Ball Milling machine.
I don´t know if you can gain access to such a thing. Anyway, the atmosphere for milling depends on the metal itself. For example, if it is pyrophoric
you may need nitrogen or argon.
How fine your powder will be depends on the balls' ratio, i.e. the ratio of ball diameter over initial particle diameter.
There are many other methods for particle attrition but I am not familiar with.
chemoleo - 5-6-2008 at 16:45
What is the supplier, if I may ask?
chemrox - 5-6-2008 at 17:54
What about grinding it up under a liquid?
JohnWW - 5-6-2008 at 20:32
It is quite a reactive metal, and it would react, possibly burn in, nitrogen, if it was ground in nitrogen, to form YN. It may also react with CO2, so
the only gas that it could be ground under would be argon.
D4RR3N - 6-6-2008 at 05:11
jokull,
I thought a ball mill was only used to reduce brittle substances to a powder, metal?
If its as I think it consists of a tube with two heavy balls which are free to slide up and down the length of the tube. The tube is capped at both
ends and a ball is inserted, then the material you want to reduce to powder, then the second ball is inserted and the whole assembly rotated.
I have never seen the machinery used to mill metals but I had visualised it as a circular wheel with a file like surface (think of an enlarged version
of the wheel used in a cigarette lighter) I think it would be milled under liquid because the process would produce heat.
chemoleo ,
The supplier that gave me that quote was TJ Technologies & Materials
http://www.tjtminc.com
I could understand the price of Yttrium powder being higher then in lump form but seven times the price
jokull - 6-6-2008 at 09:27
There are many other methods for the production of metal powders.
Here is the link to download "Metal Powders" book:
http://mihd.net/h7worp/
Therein you will find a brief description of general methods used for obtaining different sizes of a given metal. It seems there is no an specific
description for yttrium but it may give you some clues to dive deep into your subject.
JohnWW - 6-6-2008 at 15:39
Thanks, Jokull. In grinding a reactive metal to a powder under a liquid, there would be the added problem and expense of drying or otherwise removing
the liquid afterwards. Reactive metals which could form hydroxides (this would include yttrium) obviously cannot be safely ground under water.
Grinding under lube oil poses the problem of removing the oil by solvent extraction (e.g. with benzene, toluene, petroleum ether, or hexane)
afterwards.
BTW As I remember, it took someone quite some time to devise a satisfactory method of grinding brass to a powder, for use as the pigment in imitation
"gold" paint. It was a trade secret for many years.
D4RR3N - 7-6-2008 at 13:14
jokull , When I click on that link I dont see anything about metals?
Guess a stream of refrigerated inert gas could be used to grind metals and remove the heat generated.
Waffles - 9-6-2008 at 19:38
Don't bother with chinese or any company not in North America or Europe for metals, chemicals, or other pure material type- you will be screwed. You
will not be successful in creating your own yttrium powder- grinding a relatively hard metal to powder is a silly idea, and I doubt you want to go to
the trouble to make a contraption to melt the stuff in an inert atmosphere and spray out the pressurized metal (also into inert atmosphere) which is
really your only other option for making powder. Try A.D. Mackay- they are a GOOD company, and I would expect them to help an individual such as
yourself, and they will not bullshit you.
D4RR3N - 12-6-2008 at 03:46
I was not going to go to the bother of constructing a machine to reduce the metal to powder, I thought I might be able to get it milled somewhere. You
are right about Chinese company's though, there is no set price, they just see how much they can get from you.