Jet Engine Turbine Scrap Discussion

I thought today would be as good a day as any to see what the general forum population knows about jet engine scrap and have a turbine scrap 'show and tell' of sorts.

To further this goal, I will be posting photos of my scrap and looking for others with photos and stories of jet engine scrap that they have personally encountered. I'm not looking for stock internet photos that anyone can Google up and post here, I'm looking for scrap you have come in contact with and your experiences with it. Depending on where this goes, I may even divulge more of my hard won knowledge on the subject. I'm even toying with the idea of a 'jet engine turbine' scrap contest where you can win some turbine scrap and get my personal assistance (privately of course) on recovery and refining of the scrap.

I want to specify up front that I treasure this knowledge above all of my refining experiences and for this reason I am placing watermarks in all of my photos so they don't become part of the internet fodder on the subject. We all know there are a hundred charlatans in the refining business for every one honest person you come across. This is why I have to watermark my photos, so please forgive me for this.

Make note of when this post is occurring and where you saw it first, because I'm sure it will become a 'hot topic' for the internet media craze. I'm not interested in seeing common patents on the subject. This thread is for your original information only.

If posts are made to this topic that are unrelated to the subject at hand, I will split them off and move them to another forum or to their own thread if they warrant such. I do not want this thread to devolve into another thread filled with 'internet chatter'. This is a chance for everyone to share what they know about jet engine turbine scrap. Only share what you feel is appropriate, as I will be doing the same. Hopefully this thread will remove some of the 'mystique' surrounding this form of scrap.

Without further ado I will start off with some general identification photos of jet turbine material:


Fuel Nozzles:



Tobi's and Stators



Stators, I also call these Vanes to distinguish them for the other type of stator pictured above



Blades




Who's next? If others will respond with their information I will share more information about the construction and controlled destruction of of these parts for purposes of precious metals recovery, complete with photos, processes, and videos.

Steve

Steve,

I'm so excited you have created this thread! I will be anxiously watching this thread throughout it's duration! Thank you, thank you, thank you. I would like to know what pm's are on those parts, in each of the pictures? They look like rusty, greasy parts to me.


Steven

They are rusty and greasy, but that comes with the territory. I'll post much more information as others contribute.

Steve

Steve, it's very nice of you to share this information with the Forum, I hope it doesn't impact your livelihood negatively. I wonder , are there PM's in fuel cells? Like as in fuel cells from jet airplanes? I know most cases are aluminum and there are some tubes and wires inside but I'm not sure what those tubes and wires would be made of. Any ideas? Also any PM's in other turbines that you know of? Thanks and good luck,I hope you get more business, Jonn.

John,

I have never had the opportunity to handle any fuel cells first hand so I have no clue if they contain values or not. The purpose of this thread is not to drum up business, but to expand and share knowledge with others who have not had the opportunity to deal with this scrap source. I consider this thread an educational venture, that is why I posted it in the 'Types of PM Scrap' section.

Hopefully this thread will bring out those knowledgeable in this form of scrap to share what they have learned for the benefit of everyone in the group.

Steve

The fan blades are titanium correct? As well as fuel lines,not to be confused with the fuel nozzels.

The core of the blades varies from several varieties of high temperature metals and alloys. Some blades will be made of titanium. Operating conditions, manufacturing quality, and function of the part determines what coatings, alloys, and base metals are present in a particular part. Many of these alloys are considered vital to the national security of nations and their exact compositions are kept secret. Others parts are made of more common base metal alloys. You will find a veritable zoo of metals in any given engine, the key to getting the precious metals is to know how the parts are assembled and where the precious metals are applied. Once you know where the metals live you can develop processes for recovering the precious metals from the base metal.

Many of the alloys used in these parts are more sought after than the precious metals. In fact, the precious metals are considered contaminates in the alloy trade industry. There are entire companies built on the buying and selling of the alloys alone. These businesses are very tight lipped and deal with a specific circle of buyers and sellers. There are still other companies that become middle men to the process and recover the precious metals then they sell the alloy (if the refiner knows how to leave it intact) for a profit. The alloy buyers in the end market have very tight guidelines on what they will purchase and how many 'contaminates' are allowed in the material they purchase.

I could type several more paragraphs on the subject of the alloys trade, but I don't want to bore anyone.

Steve

Stator fan blades can be 6Al4V titanium or can be an inconel series. If inconel, they are brazed with gold.
There is much information available about which brazes and of what kind they are. Often encountered is the Nioro 82/18 (AuNi). There are also a variety of Pd/Ag/Au, Pd/Au/Ni and Pd/Ag/Cd and Ag/Ni brazes. Generally speaking, stators are brazed by hand and the yield can be variable depending on who was brazing and what the application is. There are over 20 PM-containing items in the engine, from silver-plated SS316 delivery lines, to gold plated bushings/flanges, to HPT blades, stators, impeller shaft/compressor hub, etc.

In general, as you progress toward the hot end of the engine, PM-content increases. Most modern engines have multiple stages. More fuel efficient, higher performance engines will have more precious metal content and more valuable alloys.

The third picture Steve listed is vanes/buckets as they are called in this industry.

I did not think about the coatings, but the braze processes crossed my mind. I work in close proximity to this type of scrap though it is rareer than pins and connectors. I will be more cognizant and see what I come up with.

lazersteve said:

The core of the blades varies from several varieties of high temperature metals and alloys. Some blades will be made of titanium. Operating conditions, manufacturing quality, and function of the part determines what coatings, alloys, and base metals are present in a particular part. Many of these alloys are considered vital to the national security of nations and their exact compositions are kept secret. Others parts are made of more common base metal alloys. You will find a veritable zoo of metals in any given engine, the key to getting the precious metals is to know how the parts are assembled and where the precious metals are applied. Once you know where the metals live you can develop processes for recovering the precious metals from the base metal.

Many of the alloys used in these parts are more sought after than the precious metals. In fact, the precious metals are considered contaminates in the alloy trade industry. There are entire companies built on the buying and selling of the alloys alone. These businesses are very tight lipped and deal with a specific circle of buyers and sellers. There are still other companies that become middle men to the process and recover the precious metals then they sell the alloy (if the refiner knows how to leave it intact) for a profit. The alloy buyers in the end market have very tight guidelines on what they will purchase and how many 'contaminates' are allowed in the material they purchase.

I could type several more paragraphs on the subject of the alloys trade, but I don't want to bore anyone.

Steve

Click to expand...

Breath of fresh air Steve, great subject matter. I find it interesting in that metallurgy has advanced to the point industry is able to manufacture turbine blades as single crystal pieces.

It would be interesting to see a cross section under an electron microscope.

Here's some SEM micrographs of a directionally solidified blade with the Pt and after I removed it.

Note the directionality of the piece--adds strength.



Also see a gold-brazed stator that was etched to show the gold.

Here's an exploded view I created for a fuel nozzle customer to confirm the exact location of the gold in the part:



and a 55 gallon batch of gold brazed stators before the gold is extracted:



and the braze is stripped



Steve

Here's an exploded view I created for a fuel nozzle customer to confirm the exact location of the gold in the part:

Click to expand...

Can you explain where the gold was located on the fuel nozzle assembly? I ask so that I can better familiarize myself of the locations pm's can be found on military equipment, etc.

I'm trying to give others a chance to ante up there contributions before I go further into the rabbit hole. As more people in the know loosen their grip on the information, I'll loosen mine. I have literally hundreds of photos of all facets of this type of scrap and it's processing. I'll release more information as others do the same. Lou has generously provided some great photos (I love the SEM images), but I'm certain there must be others that can contribute some knowledge on the subject. Thank you Lou.

Maybe one of you military guys out there has worked on building the engines and can shed some light on what you know about the interior of the engines and how they are fabricated, repaired, and/or tested? I like to learn just as much as the next guy.

Be patient and I'll post more as others participate. Comments on the photos provided are also welcome and may even spark new submissions on my part.

Steve

Steve. When the braze is stripped do the stators fall apart or is some bonding material left behind?

Steve, I don't have anything to add to the discussion (this stuff right now is outta my league), but I do have a question. I've noticed on your pictures (and the videos on your site) some pixel-ed squares. What are those? Just curious.

Rusty

lazersteve said:

John,

I have never had the opportunity to handle any fuel cells first hand so I have no clue if they contain values or not. The purpose of this thread is not to drum up business, but to expand and share knowledge with others who have not had the opportunity to deal with this scrap source. I consider this thread an educational venture, that is why I posted it in the 'Types of PM Scrap' section.

Hopefully this thread will bring out those knowledgeable in this form of scrap to share what they have learned for the benefit of everyone in the group.

Steve

Click to expand...

for what it is worth, fuel cells could potentially have pm in the reaction membrane.... it has been a long time since i have dealt with them, but when i was doing research work platinum was used in the membrane that the reaction too place at... It was my understanding at the time that it was 'the thing' that all the research was looking into. something about being a catalyst for the reaction... however, this may be out of date seeing as it was 15 years ago when i was in the lab. just my two cents for what its worth.

qst42know said:

Steve. When the braze is stripped do the stators fall apart or is some bonding material left behind?

Click to expand...

Most of the stators have tack welds along the connections between the 'vanes' or 'blades' and the inner and outer rings. Typically every fourth or fifth blade is tack welded in one or two spots to the outer ring. In some cases every blade is welded.



This said the two inner and outer rings will separate after the gold is removed if the welds are broken. Every type of stator is slightly different with respect to the welds and how the inner and outer rings are joined together.



Steve

rewalston said:

Steve, I don't have anything to add to the discussion (this stuff right now is outta my league), but I do have a question. I've noticed on your pictures (and the videos on your site) some pixel-ed squares. What are those? Just curious.

Rusty

Click to expand...

These are embedded watermarks. The group of blocks is called a 'Data Matrix', aka 2D bar code, and requires a license to use without having the words 'DEMO' embedded with your encoded text in the 2D bar code. I bought my license to use these types of bar codes in my software and photos several years back. I paid $699 for the licensed version of the 2D bar code generator and try to embed these symbols in all of my copyrighted images, software, and videos. The license allows me to use bar code software to write any text I want into a form which generates the data matrix which contains the encoded text I choose without the word DEMO being included in the matrix text.

The data matrix can contain over 2000 ASCII characters and can be decoded with the proper software and hardware. The text in these 2D bar codes can also be executed by custom software to execute program functions in programs and databases attached to the reader device. I have copyrighted one such custom software used to track the issue, return, and inventory of tools used at various locations. I figure, since I paid so much for the license, I might as well use the Data Matrix where ever I can to get the most for my money.

Steve

Thank you Steve for the explanation. I figured it was something like that.

Rusty