Dissolving Titanium

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Fournines

Well-known member
Joined
Mar 9, 2009
Messages
228
Location
New York City
Does anyone here have any experience dissolving titanium?

I've heard that HCL and NaF will do it? I was reading that a 4:1 mixture of HF and HNO3 can also attack Ti. Another source says H2SO4 and HNO3.

Any thoughts?
 
When I worked in the chemical plant we used some titanium impellers. They were eaten away after a month or 2 but not sure which acid ate them up. About the only acid that we used there that we don't use here is hydrobromic(sp) acid. Don't know if that will help you find a path or not.
 
Fournines,

Not sure if this is your requirement but it's an interesting article none the less. http://www.woelen.nl/chem/Ti+F/Ti+F.htm
 
Fournines not sure if my thoughts help but if your refining titanium jewellery with gold inlays why not use AR it will dissolve the gold even if it doesn't attack the titanium.
If it's rings you can try an old ring stretcher as used by jewellers as the inlays are normally lasered together and split very easily allowing you to remove them by hand.
 
HCl will dissolve titanium but the oxide layer dissolves quite slowly so ... nothing happens for the first 30 minutes in hot 32% HCl and then the Titanium dissolves quite rapidly.
Hope this helps
Allen
 
fournines: I meant to ask you this in the past, but forgot.

How do you verify that the final products in your refinery achieve the 9999 standard?. In other words, what's the nature of the quality control method that you use with some details?.

TIA.
 
HAuCl4 said:
fournines: I meant to ask you this in the past, but forgot.

How do you verify that the final products in your refinery achieve the 9999 standard?. In other words, what's the nature of the quality control method that you use with some details?.

TIA.

In a nutshell:

We take a sample of our material, dissolve it in AR and run it in our Inductively Coupled Plasma-Optical Emission Spectrograph (ICP-OES). The ICP is calibrated using standards that are traceable to NIST, and is capable of reporting trace values into the parts-per-billion.

It does a quantative analysis of the the entire spectrum. The ICP runs the impurities and reports the purity by difference.

The assayer who runs our lab used to own a lab that did assays for COMEX. The same COMEX approved procedures are used by our assayers to test our material and ensure quality.
 
Sodium flouride in an Hydrochloric matrix will digest titanium. But Nick is right, if you're running those titanium rings which have been circulating for quite some time now, they can be run in aqua regia and give the customer back the undissolved shanks. Otherwise the customer will think there is more gold due to him, the rings are gents rings and rather bulky, the gold contained is minimal compared to the overall weight. Give back the undissolved shanks and save yourself the aggravation.
 
4metals said:
Give back the undissolved shanks and save yourself the aggravation.
I agree 100%!

That goes a long ways towards establishing credibility with the owner of the material. If you return nothing, questions are often raised. Pretty hard to refute the yield when the waste is returned and it's still identifiable.

Harold
 
Yes there is gold, but the rings are also filled with diamonds which the customers need back. Most are set in Au, so a boil in AR will dissolve the settings allowing the diamonds to easily fall out.

Sometimes it is still not enough to loosen the stones, and some of the rings have diamonds in channel settings. Those then need to be taken out by hand. It is not a big problem if it is only a few dozen rings, but when it is hundreds and hundreds of them it becomes much more labor intensive.

I was just trying to figure out if there was a way we could build greater efficiencies into the process. After talking it over internally, at this point I don't think we want to deal with the extra waste that dissolving the Ti would create.
 
The most important thing you have to consider is the effect the flourides in solution will have on the glass electrodes in your waste treatment system. Even diluted with your waste stream flourides etch and eat glass electrodes. The same is true with your HF waste if you're etching the CZ's for your customers.
 
Fournines try the channel set rings in hot Hcl, they only need to have a thin strip of the titanium dissolved and the stones should loosen nicely after a short soak, you might have to mess with them a little to remove the stones but it should work well enough to remove them easily. I'm sure I did this with some titanium rings with small diamonds in rub over settings and it worked fairly well.
 
allenp said:
HCl will dissolve titanium but the oxide layer dissolves quite slowly so ... nothing happens for the first 30 minutes in hot 32% HCl and then the Titanium dissolves quite rapidly.
Hope this helps
Allen

Sorry... But is this true?
 
Does anyone here have any experience dissolving titanium?

I've heard that HCL and NaF will do it? I was reading that a 4:1 mixture of HF and HNO3 can also attack Ti. Another source says H2SO4 and HNO3.

Any thoughts?
I am still looking myself for a method to dissolve Titanium without dissolving any noble metals, or myself. So let me know how you get on. Unless you can control your environment very well, be careful with HNO3 and Ti, as they go pyrophoric (explode) at minor temps. I found this article helpful:

https://www.azom.com/article.aspx?ArticleID=1240
 
I am still looking myself for a method to dissolve Titanium without dissolving any noble metals, or myself. So let me know how you get on. Unless you can control your environment very well, be careful with HNO3 and Ti, as they go pyrophoric (explode) at minor temps. I found this article helpful:

https://www.azom.com/article.aspx?ArticleID=1240
Did you read the thread?
It says Titanium is dissolved in hot HCl.
 
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