Rhodium?

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Slaughlin79

Well-known member
Joined
Dec 25, 2017
Messages
84
Location
Southeast,Texas
As there is no way to test if this is rhodium,at least not for the home refiner,does this look like rhodium? I couldn’t get the color the same but it’s somewhay close to the picture. I don’t know what else it could be because it was precipitated with zinc and when i redissolved all my cement from leach solution this is what is left. This is just a small amount. I still have probably 8 times this but not sure what a weight would be.DA4C4AC9-D7AD-46DE-8094-1B528506C6AC.jpegA318EFAA-99E5-48D7-9EF7-634DD3E1D01C.jpeg3597C6BA-6091-4534-A472-4B7D7D528E56.jpegF0D3E081-7D08-4D59-B1DC-93B2703E826D.jpeg
 
fuse this grey powder with sodium bisulfate--for2hours----them dissolve this fusion in hot water--if a red solution of rh bisulfate is formed--them probably ,the grey powder is rh---another way:boil some grams of this powder with h2so4(concentrated) for 2 hours---if a red solution is formed----it is rhbisulfate --(rh2(so4)3----let it cool and cement with zinc powder----the cemented material is passed in dilute hcl,to eliminate any zinc that remained----then ,you have rh
 
Right,this is a good technique for determining rhodium metal!
Anyway I personally use my own technique which I actually don't really recommend( :lol: )-but it seems to work in some cases!I simply when have a good quantity of unknown PGMs sponge I just immediately do the following:put it into a crucible right as is,sprinkle some borax for it not to fly all over the place and simply melt it down to a bead!So while melting I quite precisely determine the melting point of the metal by the time required to heat it to melt and also by the intensity of the glow from the metal when I see it solidifies..And in addition to that when it solidifies it looks different for different groups of PGMs:the group 8 metals ruthenium and osmium are immediately determined by the stench of ruthenium tetraoxide,resembling ozone stench and osmium tetraoxide resembling chlorine gas stench,for group 9 which is my favourite:Rh and iridium you will struggle to melt both but anyway you will almost never have any loss of iridium metal even if you melt it from the sponge under open air(obviously if you do that in such manor that no sponge flies all over the place but stays in the melting dish;by the way never ever use graphite anything close to any melting PGMs because it will lead to a real disaster for your metal in all cases if graphite in any amount touches the surface of molten PGMs and in some cases even for your health and life!)-and almost the same for rhodium,and both these metals will not spit like crazy when they solidify if you don't let any graphite touch them!And for group 10,palladium and platinum you have to be a bit careful(yes,almost forgot to say:in your picture that is evident that this sponge does not contain any ruthenium,osmium and palladium!That is for sure!)-they like to absorb oxygen while molten but they both don't react with it while molten so it stays dispersed in the metal where it is liquid and so as they both still don't react with it when their temperature falls below melting point,but when it does so they can no longer sustain oxygen in their lattice so they expell it in quite a nasty way!So you most likely would determine them by their spitting at around solidifying,which again,is not shown by neither rhodium metal nor iridium metal..

Something like that is what I use if I don't really need a huge degree of precision and don't have any mixed PGMs with none of them being at least 85-90% of the material by weight!
 
I know that I sometimes come across as an old fart when it comes to safety however let me present a few facts. Not feelings - plain facts.

Permissable workplace limits for Osmium Tetroxide is 0.0002ppm.
Permissable workplace limits for Hydrogen cyanide gas is 1ppm

This means that Osmium Textroxide is deemed to be five thousand times more toxic than Hydrogen Cyanide gas.

At concentrations where you can smell it I would suggest that the concentration is in excess of those limits. Most people run for the hills screaming when the word Cyanide is mentioned so so do these facts put things into perspective for those people thinking of doing this?

.
 
anachronism said:
I know that I sometimes come across as an old fart when it comes to safety however let me present a few facts. Not feelings - plain facts.

Permissable workplace limits for Osmium Tetroxide is 0.0002ppm.
Permissable workplace limits for Hydrogen cyanide gas is 1ppm

This means that Osmium Textroxide is deemed to be five thousand times more toxic than Hydrogen Cyanide gas.

At concentrations where you can smell it I would suggest that the concentration is in excess of those limits. Most people run for the hills screaming when the word Cyanide is mentioned so so do these facts put things into perspective for those people thinking of doing this?

.
Life is more precious than metal. Thanks for the info...

Sent from my LG-H872 using Tapatalk

 
anachronism said:
I know that I sometimes come across as an old fart when it comes to safety however let me present a few facts. Not feelings - plain facts.

Permissable workplace limits for Osmium Tetroxide is 0.0002ppm.
Permissable workplace limits for Hydrogen cyanide gas is 1ppm

This means that Osmium Textroxide is deemed to be five thousand times more toxic than Hydrogen Cyanide gas.

At concentrations where you can smell it I would suggest that the concentration is in excess of those limits. Most people run for the hills screaming when the word Cyanide is mentioned so so do these facts put things into perspective for those people thinking of doing this?

.


At least there is an antidote for cyanide poisoning, if taken quickly after exposure. Os...no such thing.
 
Lou said:
anachronism said:
I know that I sometimes come across as an old fart when it comes to safety however let me present a few facts. Not feelings - plain facts.

Permissable workplace limits for Osmium Tetroxide is 0.0002ppm.
Permissable workplace limits for Hydrogen cyanide gas is 1ppm

This means that Osmium Textroxide is deemed to be five thousand times more toxic than Hydrogen Cyanide gas.

At concentrations where you can smell it I would suggest that the concentration is in excess of those limits. Most people run for the hills screaming when the word Cyanide is mentioned so so do these facts put things into perspective for those people thinking of doing this?

.


At least there is an antidote for cyanide poisoning, if taken quickly after exposure. Os...no such thing.
Sounds like the juice may not be worth the squeeze!

Sent from my LG-H872 using Tapatalk

 
Lou said:
anachronism said:
I know that I sometimes come across as an old fart when it comes to safety however let me present a few facts. Not feelings - plain facts.

Permissable workplace limits for Osmium Tetroxide is 0.0002ppm.
Permissable workplace limits for Hydrogen cyanide gas is 1ppm

This means that Osmium Textroxide is deemed to be five thousand times more toxic than Hydrogen Cyanide gas.

At concentrations where you can smell it I would suggest that the concentration is in excess of those limits. Most people run for the hills screaming when the word Cyanide is mentioned so so do these facts put things into perspective for those people thinking of doing this?

.


At least there is an antidote for cyanide poisoning, if taken quickly after exposure. Os...no such thing.

As you told me...permissable exposure time "how long can you hold your breath?"
 
One reason osmium tetroxide is so dangerous is.... don't hold your breath, it won't help... it attacks the eyes! It will deposit a thin layer of metal on the eyes and that is impossible to remove. It will build up over the years until your eyesight is lost.

Göran
 
Back
Top