Laser printer heating elements, ruthenium?

[qst42know]

Does anyone know if these heating elements from a laser printer might be ruthenium. Of the few laser printers I have taken apart some have been quartz lamps and others have been these ceramic strips.

Printed on one side of a thin piece of ceramic is this thick black compound. If I recall correctly ruthenium oxide can be used for this type of high temp resistor.

I there a quick test?

 

[qst42know]

In a test tube with hot AR I got a yellow solution full of needle like crystals.

Spot test with stannous was dark red brown, dilluted spot test shows green.

Any thoughts?

 

[qst42know]

Spot test after hot nitric showed dark brown.

The concentrated spot from the AR aged to dark green.

I'm guessing PD at this point but I don't have any DMG.


Anyone saving scrap laser printers?

 

[lazersteve]

I'm thinking it Pd also.

DMG would confirm this for you.

PM me and I'll see you get some.

Steve

 

[Harold_V]

Spot test with stannous was dark red brown, dilluted spot test shows green.

Any thoughts?

I like your style. Seeing that spot plate brought back some very pleasant memories.
I agree--it's likely palladium. It is the chameleon of the metals we encounter, and can manifest itself in many ways when testing. Do use DMG in such an instance. It tells no lies.

Harold

 

[qst42know]

Thanks Harold, I can't claim to use it exclusively but a spot plate is a very useful tool.

 

[Chumbawamba]

What printer model did that come out of? It doesn't look immediately familar but I might've reduced a laser printer to parts several moons ago and come across something like that, but I wouldn't remember any details.

Assuming it is Pd, how much do you reckon is there? I figure a gram or so?

 

[qst42know]

I don't know the printer model number. I think they were HP brand. Easy to locate in the printer as it's the only roller in the assembly that has a 12ga. wire attached to the end.

I haven't processed any for yield data but you might be able to estimate it. A 10"x.270x.025 piece of ceramic plus a coating thickness of .003 weighs a total of 4.6 grams. The trick would be guessing the type and density of ceramic.

 

[Irons]

I don't know the printer model number. I think they were HP brand. Easy to locate in the printer as it's the only roller in the assembly that has a 12ga. wire attached to the end.

I haven't processed any for yield data but you might be able to estimate it. A 10"x.270x.025 piece of ceramic plus a coating thickness of .003 weighs a total of 4.6 grams. The trick would be guessing the type and density of ceramic.

Here's some useful reading:

http://www.patentstorm.us/patents/6316752/description.html

 

[qst42know]

Well I tested this with DMG (thanks Steve) positive for Pd turned a bright lemon yellow.

These elements are something to watch for when scrapping laser or thermal printers. :mrgreen:

 

[Sodbuster]

Hello:
In a TV or PC monitor flyback coil with the two little adjuster knobs I have found a little white ceramic glasslike looking board with some of the same black baked on tracks and a fallower. It's used more like some kind of a reostat or potencheometer and not a heating element. The black contact ring and all the tracks look like glass and feels like glass if you try to score it with a knife
I was just wondering if anyone has ever tested these for Pd ?
I think It was an old auto ECM where I may have seen some of the same kind of stuff on the ceramic.
Just wondering
Ray

 

[DNIndustry]

i would like to go against the results and ask what color would tungsten or nichrome turn. PD oxides blue with heat, right?

 

[qst42know]

This I would assume is the patent for this particular application.

http://www.freepatentsonline.com/5732318.html

This paragraph was clipped from the patent.

"It is assumed that the heat generator provided on the surface of the ceramic substrate, which is in the form of either lines or a surface, is made of a complex containing at least one metal selected from a group consisting of noble metals such as silver, platinum, palladium and ruthenium and alloys thereof, or a complex containing at least one component selected from a group consisting of a carbide of Si, simple elements belonging to the groups IVa, va and iVa of the periodic table, and carbides, nitrides, borides and silicides of these elements, for example, so that the substrate can be uniformly heated by arranging the heat generator on a ceramic substrate mainly composed of aluminum nitride, for example. In this case, it is not necessary to control resistance every section of the heat generator, particularly when the heat generator is in the form of a surface. The former has such an advantage in manufacturing that the heat generator can be formed at a lower temperature as compared with the latter, while the latter advantageously attains heat resistance at a lower cost than the former."

I'm not 100% confident in my testing skills but from Hokes book on testing I have household ammonia and sodium thiosulfate. I will attempt the test again and post the result for ruthenium.

 

[qst42know]

From Testing Precious Metals by Hoke the solution is made alkaline by adding ammonia heated and then add a crystal of sodium thiosulfate. This is the result. The solution was at first a deep red and ended with a chocolate brown precipitate.

I'm not certain what I'm looking at, what do the chemists of the forum have to say?

Are there any other definitive or further tests?

 

[Chumbawamba]

Q42K, did you find out anything subsequently? Is that in fact Pd?

 

[Harold_V]

Q42K, did you find out anything subsequently? Is that in fact Pd?

To determine the presence of Pd, DMG is used. It tells no lies, and is impossible to confuse with anything.

Harold

 

[qst42know]

Yes, I tested with DMG and got a yellow precipitate confirming Pd. Some Palladium is certain but I didn't take a photo.

The brown precipitate is from following a procedure written by Hoke for detecting Ru in a Pt/Ru alloy. I think it confirms Ru but I was waiting for a confirmation from someone with Ru experience.

 

[sh3030]

So how could one process these on a large scale?

I ask because we have hundreds of these units.

 

[Chumbawamba]

You mean how to process the printers? One screw at a time, in my experience.

The larger operations would probably run the whole thing through an industrial grinder and use automated sorting techniques to separate the plastic and metal. The residual precious metals might be recovered at a later stage when most of the dross material (plastic/steel) is removed?

I plan to turn my attentions to scrapping the various laser printers I have stored up to determine how much time and trouble is involved. I had my guys working on some photocopiers yesterday but I didn't come across the heating element yet. I figure copiers should also have a similar heating element.

Any idea of the weight yield of the precious metal from one such heating element? Half a gram maybe?

 

[qst42know]

Any idea of the weight yield of the precious metal from one such heating element? Half a gram maybe?

The weight of two elements ceramic and all is about 10g I would expect the yield to be a small fraction of a gram. I found a repair parts outfit selling replacement fuser elements for $29. If you had a bucket full they may be worth processing.