Optical Frames Precision Parts
Challenge
Recoup precious metals and recycle precision parts from the consumer optical frame industry.
Deposition
Gold, Chromium, and Titanium
Substrates
Stainless Steel
Results
The demonstration went very well, and our client is currently considering the license of this technology from us, however, we are also open for any other firm who may be interested.
One of our clients, an European precision cleaning company, involved in cleaning precision parts, became interested in purchasing a license to our new technology, so that they could expand their business to serve customers who wanted to recoup precious metal depositions.
The client is skilled in cleaning precision parts, focused on non-precious metal depositions.
There were in-house orders from their customers, with precious metals deposited onto glass surface that were being cleaned by the client using a weaker aqua regia.
Once the deposition was dissolved by the weaker aqua regia, the client would send the solution to one of the major refineries for the rest of the steps necessary to recoup the precious metals.
The glass substrate was trashed after the cleaning.
While the weaker aqua regia is OK to be used for processing glass surfaces, it does not work for processing precious metals deposited onto other surfaces.
That was the case of our client’s new customer, a producer of eyewear products.
The shields and components from the producer’s thin film coating chambers were sent to our client for cleaning and recycling of the precision shields and to recoup the depositions of gold, chromium and titanium.
Our challenge was demonstrate how to clean the precision parts and separate, purify and smelt gold into gold bullions.
We considered the following state-of-the-art and available technologies:
• As explained in other case studies and our FAQs, the cyanides could not be used, because they would not dissolve the gold trapped underneath and\or between layers of titanium and chromium.
• The current aqua regia would dissolve the stainless steel shielding in minutes, so the customer would have to keep buying precision parts;
• Blasting by different blasting media would mean consequent extraction (dissolution of metals from the media in liquid chemicals) most probably by the aqua regia. Since (i) it was not possible to blast some of the precision parts, (ii) the refiner’s facilities were not equipped to carry out extractions of tens of tons of blasting media, (iii) and since the extractions cause huge losses of precious metals as well, we had ruled this possibility out.
• The weaker aqua regia, potassium iodide/iodine, thiourea/sulfuric acid/iron (III) sulfate and some other processes were ruled out too, because they would not serve reliably in large scale.
• We knew, we were ideally looking for a technology that would (i) dissolve most of the deposited metals, (ii) preserve the stainless steel chamber shielding precision parts, and was (iii) be robust and simple enough to scale-up, in remote locations if necessary and processed by a staff with little or no technical experience.
So our new patented solution was our no. 1 choice – the deposition (i) was not too thick, (ii) so we would meet the lead time to return the parts, (iii) the amount of chromium and titanium was standard and the (iv) chromium was not the first layer on the stainless steel precision parts.
We expected this new solution would dissolve titanium, gold and peel the chromium off.
It was also possible to make this new solution extremely strong to start attacking chromium, but that would hurt the stainless steel precision parts. So we had diminished this thought.
Our theoretical expectations were met with success and the separation of gold from “the other metals” was straightforward.
Since our client required no scale-up, the trial was carried out in a small scale.
We demonstrated this technology to our client, so that they could decide on whether they wanted to license the technology for use with their customer.