Sciencemadness Discussion Board

Anyone interested in purchasing rhodium or ruthenium sponge? Your budget is the limit!

Melgar - 23-11-2016 at 12:44

A friend of mine was having a hard time finding rhodium and ruthenium sponge in small quantities, so he went for very large quantities; much more than he needed in fact. Rhodium and ruthenium sponge rarely even show up on eBay. We haven't settled on a pricing model yet, but you guys would obviously get a discount that buyers on eBay would not. Prices would probably be based on the metals' spot prices plus a percent, plus shipping. Discounts would be available for larger orders. The first few buyers would get discounts too, assuming they're regular forum members and can vouch for the quality once they receive it.

For rhodium, it can be dissolved in either a NaHSO4 fused salt, or oleum. There are probably other ways too, but since rhodium sulfate is its most-used, most stable salt, most methods require oxidation with sulfur trioxide in some form.

Ruthenium can be dissolved in bleach, which causes it to form RuO4, similar to osmium. (It's right above Os on the periodic table) Since this stuff is toxic, and you probably don't want to lose it as a gas anyway, what I did when I was trying to isolate the finely-divided metal was to use bleach under a layer of cyclohexane, then add the ruthenium metal, which would sink to the bottom. RuO4 is heavy and nonpolar and so dissolves readily in nonpolar solvents, although its half-life isn't very long, so it would eventually form a black suspension in the cyclohexane. The suspension would eventually form clumps and settle back down to the bleach layer, where it would immediately be reoxidized due to its high surface area. So as long as there was active bleach in the bottom layer, the suspension would remain in the top layer. The whole system did give off bubbles, but we determined that they were most likely O2, as they did not form metallic coatings on glass like RuO4 did, and when collected, could cause a smouldering splint to relight. We also didn't notice any significant oxidation of aliphatic hydrocarbons as a solvent for RuO4, although we did learn that THF was a very poor solvent choice. I'm curious what that reaction product was (could very well have just been a reaction with the bleach), but it was heading quickly for thermal runaway, so we just quenched it with sodium thiosulfate and dumped it into the organic waste container.

Anyway, considering how much of a pain in the ass it was for him to get these metals, this could be quite an opportunity for those of you interested in the chemistry of these elements. Pricing would be by the gram, and at least at first, we'll just give out quotes until we establish a pricing formula. It'll be less than double the spot price for sure though.

Cryolite. - 23-11-2016 at 13:02

Ruthenium tetroxide is capable of oxidizing ethers to the corresponding diacids. In the case of THF, the product was likely succinic acid.

Seeing as these are both very expensive but very useful catalytic metals, I am interested in how the pricing of low quantities will be. How much would, say, 1 gram cost?

[Edited on 23-11-2016 by Cryolite.]

j_sum1 - 23-11-2016 at 13:04

Can it simply be ampouled and sold as an element sample?

careysub - 23-11-2016 at 18:35

Or simply put in a little jar and sold as an element sample?

As noble metals putting them in an ampoule is not too critical, I would be happy with cheaper, faster access sans ampoule.

Besides, if I want to do a little chemistry with a sample I would have to break the ampoule anyway.

Fleaker - 24-11-2016 at 08:30

Depending on the particle size of the sponge, it may go into refluxing HBr or HCl/Cl2 over the course of a week or two.

I should emphasize that RuO4 isn't formed by adding Ru to bleach--it's a mellow reaction. However, if one takes Ru sponge and dissolve it in hypochlorite, warm it and acidify that liquor, there certainly will be RuO4 formed because of the chlorine formed from the chlorate content in the bleach (especially after heating it). Brauer has a good discussion on RuO4. I've never had it explode on me and always attributed such claims to explosive chlorine-oxygen compounds if the ruthenate is prepared from hypochlorite.

Woelen has an outstanding page on the chemistry of ruthenium in aqueous solutions here:

http://woelen.homescience.net/science/chem/exps/ruthenium/in...

Melgar - 24-11-2016 at 20:22

Ruthenium will bubble pretty vigorously in swimming-pool 10% sodium hypochlorite solution, and if you don't use an inert organic solvent to trap the RuO4, it'll form a metallic layer all over the inside of the glass. I imagine the ruthenium probably catalyzes the decomposition of NaOCl to NaCl and O2 to an extent, but there is definitely a reaction that produces significant amounts of RuO4 without any external heat source, even with a solid ingot of ruthenium. The reaction is exothermic, but the ruthenium suspension becomes visible almost immediately, indicating RuO4 formation. According to this video, if the NaOH concentration isn't very high, RuO4 can form. Apparently this is the case with commercial hypochlorite solutions:

https://youtu.be/H7Ng4sOVkns

Woelen probably added the NaOH deliberately, to avoid this reaction happening, but using cyclohexane or heavy mineral oil (cheaper, and more viscous, so bubbles and metal stay suspended for longer) traps the RuO4 for long enough that it decomposes back to metallic Ru before it can escape into the air. I only ever did this reaction outside, but if someone did it indoors, obviously a fume hood would be necessary.

I didn't realize that the spot price of ruthenium is only like $40 an ounce, making it by far the cheapest platinum group metal. So I guess it doesn't make sense to sell it per gram. And with rhodium prices below platinum prices, now he's thinking of holding onto the rhodium as an investment. Still waiting to hear back from him as far as how (or if) he wants to sell it.

Fleaker - 27-11-2016 at 13:13

Have you personally seen this to be the case? I can't say that my experience with Ru in hypochlorite has been entirely the same.

For one, I have not seen any deposition of RuO2/Ru on any glassware when preparing Ru/Al2O3 catalyst samples for ICP-OES but admittedly I try and keep the glassware clean. The fizzling in the case of 50 g 5% Ru/Al2O3 into 200 mL 12.5% w/v NaOCl isn't that vigorous, but it is definitely exothermic. I just don't see much RuO4 being produced in alkaline conditions such as would be encountered with strong bleach. RuO4 has a pretty ozone-ish smell; I don't think RuO4 or OsO4 smell at all like chlorine or chlorine dioxide and I've never smelled either in alkaline situations, although all work I ever did with it has been under a good draft.

I believe almost all of the gaseous species produced is simple oxygen; it may be catalytically produced but it may also be produced by the production of sodium chlorate as the temperature rises. One of the first steps after reduction of any RuO2 to metal for a Ru/Al2O3 catalyst is to put it all into 1.5 M NaOH, stir, and run chlorine through it. After that's done, then it's filter pressed and boiled down before acidification. The boiling makes sodium chlorate out of the hypochlorite. When that concentrate is slowly acidified, the RuO4 distills with Cl2. At the end it needs boiled to get the last of the RuO4 out of solution.

I never noticed much difference in Ru concentrations on samples prepped with NaOCl vs KOH/KNO3 if the samples were properly pre-reduced to Ru with H2. If they weren't reduced, then the bleach would not recover the Ru effectively but the fusion would.


I do not know how much RuO4 could be formed in strong, alkaline hypochlorite solutions but I imagine while it might be possible, it probably isn't much. Maybe some RuO4 is formed at pH 8-9 in OCl- but I have never noticed it in practice and would be hesitant to say that it would be so much as to be analytically meaningful. As an aside, my: 12.5% w/v NaOCl has a pH of 12.5 per the meter (it bleaches papers, obviously).


It's been my experience that Os is much easier to oxidize than Ru (heat and with other oxidants).

And yes, Ru, Rh, even Pt, all are quite undervalued right now. Good time to acquire, in my honest opinion.


If your friend doesn't want to sell any, let me know and I can get you fixed up with whichever ones you want. Also, I can make them into salts for you if you desire, but there would be a minimum order on account of the tedium and time to set up tube furnaces and such.

careysub - 28-11-2016 at 08:44

Does anyone know of a source that sells ruthenium anywhere near the spot price?

Silver, gold, and platinum and palladium are available in "investment" form on eBay for example at not too large a mark-up from spot (165% of spot for platinum), but the cheapest ruthenium seems to be $15/g (1100% of spot). It is priced as if it was $300/troz Ruthenium "investment" items do not exist on eBay.

violet sin - 28-11-2016 at 09:36

Alibaba. I had an offer to get Ru @ 250g/970$US shipping included. Not a spectacular deal, but the best I had found. Could scare up the contact info if you like this evening. They were nice and courted a prospective buyer with patients.

careysub - 28-11-2016 at 13:03

Unfortunately I cannot afford to save that much money.

Maroboduus - 28-11-2016 at 16:22

Quote: Originally posted by careysub  
Does anyone know of a source that sells ruthenium anywhere near the spot price?

Silver, gold, and platinum and palladium are available in "investment" form on eBay for example at not too large a mark-up from spot (165% of spot for platinum), but the cheapest ruthenium seems to be $15/g (1100% of spot). It is priced as if it was $300/troz Ruthenium "investment" items do not exist on eBay.


Yes, as a matter of fact I DO know somebody who sells it at a most reasonable markup from the spot price.

Melgar - 29-11-2016 at 10:39

Quote: Originally posted by Fleaker  
Have you personally seen this to be the case? I can't say that my experience with Ru in hypochlorite has been entirely the same.

Yes. My friend put a ruthenium ingot directly into bleach, and it coated the inside of his flask with a metallic layer. Then he put a beaker over the flask, and it coated the inside of that with a metallic layer too, as well as part of the table. This was before I got there, otherwise I would have advised against doing that, but I did see the metallic coating all over his glass. When I did it, I put a nonpolar layer on top of the bleach, then added the ingot. There was a lot of bubbling, the hypochlorite layer became bright yellow, and soon, a black, finely-divided particulate appeared in the nonpolar layer. As the reaction proceeded, the particulate gradually formed loose clumps, then slowly sank to the bottom of the nonpolar layer. The hypochlorite layer eventually lost its yellow color, at which point the metal particulate would start drifting back into the aqueous layer, and the bubbling would stop.

Since this was a ruthenium ingot, not sponge, my best guess as to what happened is that the reaction of NaOH with ruthenium used up the NaOH in some localized areas near the ingot, causing the pH to drop in those areas enough to allow some RuO4 formation. The metallic layer on his glass was not thick, and not much ruthenium would need to be deposited to make a metallic layer visible. When I captured the gas in a nonpolar layer, it made the entire layer black, but the amount of metal that was actually suspended in that layer was very small.

Does that seem like a plausible explanation?

As far as sourcing these metals for close to their spot price, my friend said he got his through Crystal Bay Trading, formerly pm-connect.com, now located at https://platinumtradingonline.com/. You have to call them to arrange a purchase though, presumably because of the massive amount of attempted fraud in the precious metals and jewelry industries.

careysub - 29-11-2016 at 12:18

Quote: Originally posted by Melgar  

...
The metallic layer on his glass was not thick, and not much ruthenium would need to be deposited to make a metallic layer visible.


Indeed not. The "absorption" (i.e. not transmission) path, reducing transmission by a factor of 1/e (to 36.7%) in a metal is about 4 nm, a high quality aluminum mirror coating, much thicker than necessary to reflect efficiently for long service life, is 100 nm. A 10 nm layer would look like a mirror.

Your proposed mechanism (I gather) formation of volatile RuO4, that gets reduced on surfaces it contacts, looks like a convincing mechanism to me.

I never heard of this phenomenon before, but it is interesting to me as an amateur telescope maker.

People use the Brashear process (with tin salt pre-treatment) to silver mirrors at home. A benzotriazole over-coating is often used to protect the short-lived silver coating.

Aluminizing requires expensive vacuum chamber set-ups (but I know people working on that too). Ruthenium coating using RuO4 vapor is something I have never heard proposed. I wonder how it would fair with benzotriazole coating.

I did a little Googling on ruthenium tetroxide toxicity, since it is similar to the well know very toxic and volatile osmium tetroxide, but apparently there is little information on toxicity. Since ruthenium is produced in much larger quantities than osmium, and is much cheaper, I wonder if that is an indicator that it is considerably less toxic, since otherwise reports of toxic incidents would be in the literature.

[Edited on 29-11-2016 by careysub]

Melgar - 29-11-2016 at 13:48

Ruthenium tetroxide is supposed to be pretty hazardous, but it's hard to get it into that state, and it doesn't stay like that for long. IIRC, osmium oxidizes more readily, which is what makes it more dangerous. Considering they use nickel carbonyl in industry, I can't imagine ruthenium tetroxide is worse than that. If it's any help, the layer was quite dark and not extremely uniform; more the color of iron or lead than silver. The precipitate in the nonpolar layer was even darker (but then, so are silver nitrate stains). It was pretty hard to get off though, so I guess that's good news! The particles might not be a good size for forming a reflective coating, and I'd imagine that a gas is less easy to control than a liquid. But it would be a whole lot heavier than air, so you could use that to your advantage. I wonder if you could apply a static charge to the glass, or if that would do anything useful? Presumably the RuO4 goes through a few steps as it decomposes, possibly forming ions?

careysub - 29-11-2016 at 14:03

I found a paper on the reflectivity of ruthenium, and while it is good in the IR spectrum it is not outstanding in the visual range, about 70%.

This is about the same as the reflectivity of fresh speculum metal that preceded to the use of silvered glass (invented by Liebig). Both silver and speculum metal tarnished terribly, so if ruthenium is more resistant, it might have a long term advantage.

One would expect an actual coating process to be carefully controlled, using an enclosed coating chamber with still air and appropriate geometry. Vapor deposition is after all how aluminum coating works, though in a vacuum.

But the poor initial reflectivity takes the wind out of sails on this idea.

Fleaker - 29-11-2016 at 23:07

Quote: Originally posted by Melgar  
Quote: Originally posted by Fleaker  
Have you personally seen this to be the case? I can't say that my experience with Ru in hypochlorite has been entirely the same.

Yes. My friend put a ruthenium ingot directly into bleach, and it coated the inside of his flask with a metallic layer. Then he put a beaker over the flask, and it coated the inside of that with a metallic layer too, as well as part of the table. This was before I got there, otherwise I would have advised against doing that, but I did see the metallic coating all over his glass. When I did it, I put a nonpolar layer on top of the bleach, then added the ingot. There was a lot of bubbling, the hypochlorite layer became bright yellow, and soon, a black, finely-divided particulate appeared in the nonpolar layer. As the reaction proceeded, the particulate gradually formed loose clumps, then slowly sank to the bottom of the nonpolar layer. The hypochlorite layer eventually lost its yellow color, at which point the metal particulate would start drifting back into the aqueous layer, and the bubbling would stop.

Since this was a ruthenium ingot, not sponge, my best guess as to what happened is that the reaction of NaOH with ruthenium used up the NaOH in some localized areas near the ingot, causing the pH to drop in those areas enough to allow some RuO4 formation. The metallic layer on his glass was not thick, and not much ruthenium would need to be deposited to make a metallic layer visible. When I captured the gas in a nonpolar layer, it made the entire layer black, but the amount of metal that was actually suspended in that layer was very small.

Does that seem like a plausible explanation?

As far as sourcing these metals for close to their spot price, my friend said he got his through Crystal Bay Trading, formerly pm-connect.com, now located at https://platinumtradingonline.com/. You have to call them to arrange a purchase though, presumably because of the massive amount of attempted fraud in the precious metals and jewelry industries.


Seems plausible to me but I don't have any Ru ingot that I'd do that to (my pieces are ebeam pieces and were gifts). I do have a bunch of sponge but that might not work due to surface area phenomena like you advised. I never observed anything like that in my experience with strong, fresh bleach in the lab so I assume it's not possible or I'd be dead by now. In process, when recovering from a supported catalyst, usually just keep the whole reactor cold and open up a cylinder of chlorine while it stirs.

I can't remember if I ever put up a photo of the "Bubble Wrap of Death". I had some few hundred milligrams of OsO4 that someone in their infinite wisdom decided to put into a screw top bottle. Even electrical-taped shut, the inside of the safe and the bubble wrap it was in it (as well as bottle label) were coated with a shiny metallic black sheen. I disposed of it upon seeing that. It's very nasty. Both of them are. The sheening and mirroring of glass is something every PGM has done for me in one fashion or the other when reducing them in solution.

Os and Ru will darken the distilling tube, flask, and receiver, and even finger prints on the flask, if the glassware wasn't cleaned very well with something strong (caro's acid, then follow with ammonia and water). Concentrated sulfuric acid serves as the joint lubricant. If it stays clear with sulfuric, usually that means no organics and the oxides are fine. They all smell very strongly. The carbonyl I think is much worse.

I know Alan at Crystal Bay. Good guy and he could probably provide any of those materials (particularly the Ru :P ), really knows his stuff. I imagine his son is running it now though. I haven't talked to him in a year or two but last I recall he was taking it easy.

Mind you, I can also provide Ru sponge to you. I don't refine much of it as it's not worth the time at this time. Os occasionally but it's more expedient to buy it when needed for a customer. Usually I get Ru from Ru/Al2O3 catalysts or from it on titanium or niobium anodes. Last catalyst I saw was 5% Ru/Al2O3 and was about 5500 lbs dry. Unless it's practically given away for free, it's just not worth it at 40/oz.

Careysub, there are people who use weird Ru-Os alloy targets for some sort of sputtering application! I know a lot of people don't like to ebeam melt Os because it gets all over the melt chamber and stinks it up when it's opened!

I do not know what they form when they deposit on dirty surfaces but I think the reduction product is most likely the dioxide not the metal.

careysub - 5-12-2016 at 14:32

Apparently Crystal Bay has a 50 troy oz minimum for purchasing ruthenium. I am sure the price is good, but you need to tie up a couple of thousand dollars in ruthenium.

Fleaker - 28-11-2017 at 12:10

I would be willing to distribute smaller quantities to members of pure Ru sponge.

I am in the process of converting my accumulated Ru into Ru sponge now that the market is rapidly moving.

Joram - 28-3-2019 at 08:04

Fleaker Hello. I hope you can guide me and give me solutions. I am processing ore, it has been assayed by 3 places all with close to same findings. Ag,Au,Pd,Pt&Rh. I have never done any of this. I have tried everything with bad or little results. I finally have gone with AR[aqua regia]. The 1 assay place said the reason I am getting a matte in smelts is the pgm's and propane forge not hot enough. The reason no drops from AR with SB or Ammonium chloride is I have sulfur in my concentrates. To use zinc or Aluminum foil. They did not say anything else on how. Will this process work? AR hot few drops sulfuric, until no reaction, filter, denox twice add HCl then water, filter away crystals, double amount with water then stir in zinc or aluminum, filter precip, take precip into HCl hot over night, rinse real good, filter/decant put precip into hot nitric/water[50/50] over night, filter solids and melt with a oxi/acetylene torch. I dont care about any silver loss. I want the Au,Pd,Pt&RH. By putting the zinc precip into HCl then nitric I want to remove all other metals and leave me only gold & pgm's in a metal form, that I can now go back to AR and use SMB and AC then zinc drop the RH last from AR solution. I can not go buy any more chemicals. I have SMB, borax, soda, I make ammonium chloride and I have ammonia, sodium cyanide. I was told I can use cyanide to drop the palladium from the hot nitric/water soak. Some how the last nitric/water soak gold got in there also. Stannous test dark brown/black. So I tried SMB, something dropped tan. I filtered then rinsed the precip with ammonia. The precip went brown after dry it went dark brown with green coating like iron or copper. As rinsing with ammonia the ammonia went into the nitric/water solution and next morning there is a yellow precip in the bottom. I think I did not rinse the HCl precip well enough and some HCl carried over which made a low grade AR instead of just nitric/water. This is probably how gold got there. I just found out the exchange here will accept the mixed metal buttons, but no junk metals, only Ag,Au,Pd,Pt&Rh. So zinc/aluminum precipitates all metals in AR, now going to HCl soak then Nitric/water soak should remove all junk and leave me the gold & pgm's in the final precip, correct? Does SMB only precipitate gold with a little trace of other metals, but ammonia soak remove those? I dont care about silver loss, but I want the Pd. Does ammonia or ammonia and HCl or cyanide precipitate the palladium from nitric/water soak? and if I put the zinc precipitate into HCl and nitric soaks remove everything and leave the gold & pgm's? I understand this may not be the best way, but will it work? I have no choice but to deal with what I have on hand. Thanks Joe

Fleaker - 28-3-2019 at 10:53

How rich is it?