Osmium looks very unique compared to other metals which are almost all 'silvery' metallic color, expect for gold, copper.
How is it melted at excess 3000 C?
I know its an arc furnace but what powers it? Fuel? What contains the molten Os?
How are Osmium metal surfaces crystallized?
What is the price per gram? For metal Osmium
I've found various prices ranging from 400 per troy ounce in bulk (??)
Others 100$ for a gram in powder form
To 700$ for crystallized osmium per 1 gram http://www.osmium-rings.com/c/mid,30106,prices
[Edited on 25-10-2014 by nhindori]nhindori - 25-10-2014 at 05:42
Osmium crystallized dial by hublot
[Edited on 25-10-2014 by nhindori]
Dan Vizine - 25-10-2014 at 06:07
The sponge or compacted powder is melted by a DC current passing through it from a non-consumable W electrode or by melting an electrode made of crude
compacted osmium itself (the consumable electrode approach) in a vacuum and on a water-cooled copper hearth. You can go to Youtube and see videos of
the process.
Water-cooled copper hearths are AMAZING...you can melt any refractory metal on them with little to no contamination. In fact, unless the metal sticks
to the copper, you can expect almost zero copper pick up.
The only PGMs whose quoted price means anything in reality to you and me are gold, silver and (maybe) Pt.
The other prices are very capricious. A good example is Ru. It's at a low value right now, really low, but you won't see that reflected in the cost of
small Ru samples. For you and me, the price is whatever the seller decides. The only ones who pay the "spot" price are very large consumers, and even
then it's spot + x% so that the seller makes a profit, too.
The $700/g stuff must be prepared by the iodide, hot-wire route or (and this is a guess without research) or by vapor phase deposition in a quartz
tube ( roughly similar to the hot wire approach, really).
I'll leave the crystallization question for someone else. It's early and I'm still too tired to look it up.
[Edited on 25-10-2014 by Dan Vizine]MrHomeScientist - 27-10-2014 at 06:06
Good info Dan. I'll add that the price of Os greatly depends on what form it is in. It's incredibly high melting point and high hardness make working
with it extremely difficult. Powder form is 'cheap' because it's the easiest to make. A bead is much more expensive because it needs to be arc melted
in a special furnace. Crystalline specimens are even more expensive because the process to grow them is even more complex (vapor deposition), plus
they have high aesthetic value for collectors.j_sum1 - 27-10-2014 at 20:35
I'm going from memory here so please correct me if I am wrong.
My understanding is that osmium readily forms a toxic and volatile oxide OsO4. (Pretty much the highest oxidation state you are likely to see.) This
makes it rather problematic to handle.
It seems like a strange mix of properties to me. Densest element. High melting point. Tucked in the table surrounded by refractory metals. I am
assuming that it has reasonable refractory properties. But then liberating a smelly and toxic gas from its surface. And then having that cool bluish
tinge to it. (There are a multitude of grey metals, some with a gold/yellow tinge. But osmium is the only blue metal that I know.)
I think for me its price and the handling issues are likely to put it off limits. But it has always been one of those elements that I have found
interesting.
I think there is a thread around on the weirdest element. Perhaps osmium is a contender for the title. I would have nominated it but I don't know
too much in the way of specifics.violet sin - 27-10-2014 at 21:05
1g pellet Os 55$ free shipping j_sum1 - 27-10-2014 at 21:20
Aww. Now you're tempting me. That's cruel. I have already spent my budget for this week and so I can't do it. (And I should really sort out my Mo
and W order before I begin something new.)
At 20g/cm3, you don't get a very big pellet for a gram do you?diddi - 28-10-2014 at 03:44
the street price for Os lumps is around USD900 /troy oz. that is a bead about 14mm diameter. powder cheaper.Dan Vizine - 28-10-2014 at 04:42
I'm going from memory here so please correct me if I am wrong.
My understanding is that osmium readily forms a toxic and volatile oxide OsO4.
.
.
.
I think for me its price and the handling issues are likely to put it off limits. But it has always been one of those elements that I have found
interesting.
Your recollection is correct. Osmium tetroxide is a useful oxidant for certain organic transformations.
My understand is that the powder is hazardous (high surface area), the sponge less so and the bulk metal is considered relatively safe because the
gaseous OsO4 emissions are quite low.MrHomeScientist - 28-10-2014 at 05:41
Correct! An arc-melted bead of Os is quite safe. Similar to how beryllium powder is dangerous but the bulk form you can handle reasonably safely.
I have a 5 gram bead of Os that I purchased from the RGB company, a well-known supplier of good quality elements. I'll have to post a picture of it
when I get home. The density is really amazing to feel in your hand.j_sum1 - 28-10-2014 at 14:14
Nice to know that by brain recalls some things correctly.
Are there any other bluish elements? I can't really think of any.
(I love the colour of caesium by the way.)Dan Vizine - 28-10-2014 at 15:05
Osmium is generally considered to be the only metal to look bluish.
Aww. Now you're tempting me. That's cruel. I have already spent my budget for this week and so I can't do it. (And I should really sort out my Mo
and W order before I begin something new.)
At 20g/cm3, you don't get a very big pellet for a gram do you?
It would be small but when you consider it's chemically isolated from platinum ore as residue and every pellet no matter the size was melted at 3000 C
The blue color is truely blue and notably different from other metals
Depending on where you live packages shipped are in customs agents control they might tax you or they might not.
Oh and cesium is alkali which does not go well with travel trough airports
Chlorine bromine are all categorized as hazardous materials nhindori - 28-10-2014 at 16:26
Taper bore rifles firing Osmium-Iridium alloy needles, carried through bore by Teflon sabots...
Shoulder fired kinetic anti armor weapon. Would not want to use, personally!
Can shaped charge bullets be far behind?quantumcorespacealchemyst - 30-10-2014 at 05:30
so as far as chemistry, it seems heating under oxygen is required for it's oxidation to OsO4 and depending on the reactivity of the powder, maybe only
air or noble gas with an amount of oxygen? if that works then condensing the flow seems nessesary to get the OsO4 out of the gas phase? and to get
OsHalogens, reactions with a hydroX acid? with Cl there seems to be the ability to form the IV chloride from Cl2 gas. http://en.wikipedia.org/wiki/Osmium%28IV%29_chloride .
i wonder about Os in acid forms like Au and Pt.
induction heater around an Os pellet in a quartz tube, the outlet rigged to connect to a water cooled condenser, or through a water cooled condenser
to a flask of HCl with air being pulled at an appropriate rate out through a vacuum take of valve.
[Edited on 30-10-2014 by quantumcorespacealchemyst]quantumcorespacealchemyst - 15-11-2014 at 22:43
i meant for the conversion of an amount, i realize that it oxidises on it's own. i wonder is h2o2 will work, although it may need to be heated. i
found that with selenium it doesn't react by only mixing, although weirdly osmium may be more prone to oxidation than selenium as i don't know if
powdered selenium oxidizes to any degree as osmium does. . maybe h2o2
and an acid will work for it like hno3 or h2so4 or h2seo4? i am most interested in H2O2 + H2SeO4 + OsNotBismuth - 10-3-2020 at 23:49
Just wondering as Os is brittle wld the flakes simply oxidise to the tetroxide @RTP like the powder? thks! :]
sciece nerd - 11-3-2020 at 06:01
Well, zinc is also somewhat blueish.Boffis - 11-3-2020 at 08:53
Crystalline flakes do not oxidize at room temperature.
Has anyone ever tried to dissolve fused osmium in alkaline oxidizing agents? Like say bleach or KOH + H2O2?nezza - 19-3-2020 at 10:57
Potassium has a bluish tinge to me. The alkali metals have subtly different colours to my eyes.
Lithium - pure grey
Sodium - Silvery with a faint pink tinge at times
Potassium - Pale Bluish
Rubidium - Very pale yellowish gold
Caesium - Pale gold
