Strange metal with gold

[wessanator]

I have been processing some cell phone boards in strong AP and got some gold in solution so tryed to drop with BiSuf with no joy so I dropped in some copper strip and got a good bonding to the strip and so I reacted out the solution. After washing I melted and got a nice puddle in the bottom of my crucible so I pored it onto a plate of steel to cool but what I had was a ball of dark grey stuf that when I taped it with a small hammer it shattered leaving a nice shot of gold. I melt with oxy/ace and I pushed the puddle around on the bottom of the crucible and it reacted like a metal not a form of ceramic the strange thing is it did not aloy wth the gold.

Can anyone tell me what this dark silvery grey stuff is?

The cell phone chips have little gold wires in them and I processed them with HC / Bleach and got the same results about 3 x as much dark grey as gold.

 

[Anonymous]

I have been processing some cell phone boards in strong AP and got some gold in solution so tryed to drop with BiSuf with no joy so I dropped in some copper strip and got a good bonding to the strip and so I reacted out the solution. After washing I melted and got a nice puddle in the bottom of my crucible so I pored it onto a plate of steel to cool but what I had was a ball of dark grey stuf that when I taped it with a small hammer it shattered leaving a nice shot of gold. I melt with oxy/ace and I pushed the puddle around on the bottom of the crucible and it reacted like a metal not a form of ceramic the strange thing is it did not aloy wth the gold.

Can anyone tell me what this dark silvery grey stuff is?

The cell phone chips have little gold wires in them and I processed them with HC / Bleach and got the same results about 3 x as much dark grey as gold.

You have been told a thousand times on this forum not to melt using acetylene, keep all carbon sources away from your melted gold.

Use a propane , natural gas or hydrogen fueled torch to avoid carbon. Or an Electric furnace.

 

[wessanator]

Work in a steel shop and we don't have any other gasses and how is that relivent?

 

[Harold_V]

Work in a steel shop and we don't have any other gasses and how is that relivent?

It isn't relevant, not for gold. In this case, Gustavus is not correct in his assessment. He could be spot on when working with the platinum metals, however. They can form carbides easily.

Would you describe the silver gray material you created as being similar to cast iron? If so, that's a sulfide that has formed in the melting process. It can bear values. In order for the sulfide to return anything you may wish to keep, it is common to place a piece of steel in while heating. Iron will replace anything of value, yielding a similar material, but with a finer grain structure. Pouring such material to a cone mold will allow for stratification, with the values at the bottom, the center layer the sulfides, and the flux the top layer. Properly done, there will be a clean separation.

Don't pour recovered values on a sheet of metal. The surface of a mold should be coated with a layer of carbon to prevent any soldering of values to the metal. If you must use a sheet, soot it well with an acetylene torch first. Best, however, is to coat the surface of your choice of a mold with prepared lamp black coating, which can be obtained from foundry supplies. I would suggest that be used in all cases except for when pouring final ingots, at which time I'd rely on a smoky acetylene torch.

Harold

 

[Irons]

Work in a steel shop and we don't have any other gasses and how is that relivent?

Your regulator will fit a 20 lb propane tank. Use oxy-propane. It should only take a few minutes to switch over.

 

[wessanator]

The material is nonmagnetic and very dence it has a similar weight to gold and it has a grain like carbide or slate but can be shatered with a plier with good force. It is a silver/blue gray and definitely metalic looking the only other thing I have seen similar is oil refinery coke from the inside the main reactor of a cat cracker. I am melting in a graphite crucible with a oxidising flame and the steel plate is a 1 1/4" thick table just for quick chill.

 

[wessanator]

The grain is very fine and it almost has fracture plains like slate. I have saved it and now have about an once on the off chance it may be worth some thing or refined into something worth while. One more thing I had to add more oxidiser to my solutions as they would stall and darken up turning a blackish color, after adding a little more bleach or peroxide they would clarify and continue to take on metal.

 

[qst42know]

Not all acetylene hoses are compatible with propane. Not all O-rings will be either if your torch uses them.

Grade "T" hose can be used for acetylene or propane.

 

[goldsilverpro]

Like Harold said. Acetylene/O2 is fine for gold. Done it a zillion times.

 

[Harold_V]

The material is nonmagnetic and very dence it has a similar weight to gold and it has a grain like carbide or slate but can be shatered with a plier with good force. It is a silver/blue gray and definitely metalic looking the only other thing I have seen similar is oil refinery coke from the inside the main reactor of a cat cracker.

I'm still inclined to think it is a sulfide. The description you provided tends to fit. If you have a curiosity that warrants the time, melt it in a crucible, and add some scrap steel. If there are any values, they will be liberated, and some of the steel will have been absorbed. The nature of the material will change, with a finer grain structure, assuming it had values included in the first place. Pay attention to my comments about fluxing, below, and to the use of a cone mold.

By PM you asked about the possibility of the material containing one of the platinum group metals (osmium, if memory serves). It is my opinion that there is little to no chance. It's entirely possible you could refine for years and never encounter any osmium, or if you did, the amount is likely to be so small as to be insignificant.

One of the things that can help you make a decision is to use some common sense. Is there any reason for osmium to be found in cell phone boards? If not, it would be unreasonable to expect a recovery. Remember, the functions we perform here are not alchemy, they are well recognized chemical reactions, reactions that, when followed appropriately, will yield desirable results.

I am melting in a graphite crucible with a oxidising flame

I melted a lot of metal by that method, but I also had a couple melting furnaces. There are times when a prolonged soak at a high temperature is desirable. Recovering values from sulfides is a good example. You may enjoy success using a torch, but I am of the opinion you'll get tired of the operation before it might be successful. Do keep in mind, whey you are attempting to recover values from sulfides, a flux covering is very desirable. I used to use a mixture of soda ash (which will reduce silver chloride to elemental silver) and borax.

I tend to not agree with torch melting with a crucible. They are built wrong for that kind of heat application. I suggest you investigate melting dishes.

and the steel plate is a 1 1/4" thick table just for quick chill.

As long as you isolate the values from direct contact, and your work area is quite clean, no problem, but if you deal with more than a small sample, that's not an acceptable method. What you don't want to happen is to pour molten metal on a surface and have it run off, hitting the floor. I strongly advise you investigate a small cone mold (commonly used by assayers) and a larger one for greater volumes. They are a tool that will get used endlessly. I had three different sizes and used them regularly.

Harold