Lead recovery from CRTs lead glass

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kjavanb123

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All,

I have over 3 tons of lead glass from the funnel part of CRTs, it seems the lead monoxide is sprayed on the surface of glass, can I boil it in dilute nitric to form lead nitrate solution then drop lead by inserting iron to the nitrate solution?

Regards,
Kevin
 
If it would work for lead nitrate like for copper nitrate or copper sulfate, I would prefere to use an electrolysis of the lead nitrat, so you can reuse the HNO3. But I haven't tried yet and I couldn't find much info about it. Would be nice, if someone could validate this.
 
It won't work or everyone would do it.
The lead oxide is melted together with the glass, it is not at the surface.

Göran
 
then drop lead by inserting iron to the nitrate solution?
If it would work for lead nitrate like for copper nitrate or copper sulfate, I would prefere to use an electrolysis of the lead nitrat, so you can reuse the HNO3. But I haven't tried yet and I couldn't find much info about it. Would be nice, if someone could validate this.

It won't work or everyone would do it.


http://www.jce.divched.org/video/electrolysis-leadii-nitrate
http://answers.yahoo.com/question/index?qid=20121011125302AAtt7Aq
http://media.rsc.org/Classic Chem experiments/CCE-82.pdf
http://www.chemeddl.org/alfresco/se...deo.html?options=false&ID=vid:5859&guest=true

I am still not as sure as you are. Everything seems to look like there will form lead at the cathode and O2 and lead dioxide at the anode. Then there are H+'s at the cathode free to form HNO3 with the nitrate ions.

But your argument is plausible, too. The only reason I see, would be, if it is too slow or not effective enough for our purposes.
 
solar_plasma said:
I am still not as sure as you are. Everything seems to look like there will form lead at the cathode and O2 and lead dioxide at the anode. Then there are H+'s at the cathode free to form HNO3 with the nitrate ions.
I don't say anything about electrolysis of lead nitrate, the problem sits in the small fact that the lead oxide is buried inside the glass when it is melted together into a solid mass. It is shielded by the rest of the glass and you would have to use HF to get at it. That's why there is an abundance of lead glass from CRT:s and you have to pay for disposal.

Göran
 
Instead of making a big mess of poisonous lead salts and glass, why not do the responsible thing and send the CRT glass to the lead smelter?
 
Absolutely right. I focused one and only on the part about what to do with lead nitrate and I believed Göran refered to this.

Björn
 
This company recycles leaded glass. Link: http://www.nulifeglass.com/crt-recycling-services/safely-recycling-crts-tv-screen-computer-monitors.htm
 
Imran said:
This company recycles leaded glass. Link: http://www.nulifeglass.com/crt-recycling-services/safely-recycling-crts-tv-screen-computer-monitors.htm
Nice! But still, CRT's are an expense, nothing you can sell for profit.
www.nulifeglass.com said:
We charge a fee for our processing and recycling services.
They are melting it in a furnace with a special flux to separate it into lead and recyclable glass.

Göran
 
I know of only two (common) things that will dissolve glass. Molten sodium hydroxide counts as the safer of the two, turning the silicon dioxide into (water-soluble) sodium silicate and water (which at >318C will instantly boil off).

For the record, I wouldn't run that reaction even if you could recover silver from the glass. I might consider it for gold, but only after coming up with some means of doing it without me needing to occupy the same building as the molten lye. For lead? :shock: Pay the $5 per CRT to have someone else dispose of them properly.

Another promising reaction I can't seem to find much more than this quote about, "Glasses containing lead oxide as an ingredient are subject to reduction when exposed to flames of a carbonaceous nature. The carbon partially reduces the lead oxide to its metallic state, forming a black deposit.". I would presume that happens as purely a surface effect, though, so probably not all that useful as a practical recovery technique.

Overall, I'd consider lead recovery from glass, purely aside from the dangers of poisoning yourself, as one of those things you can only do profitably on a much larger scale than most of us can do in our garden sheds.
 
I have sent out a few samples to the biggest lead and zinc smelter in the country, awaiting for their results.

Regards
Kevin
 
I can see why the charge money to recover the lead from the glass, it would be expensive to recover the lead from glass, I would be willing to bet you would spend much more money on that lead trying to recover it yourself, they have the capital already invested in the equipment they understand the process, and can process it cheaper than you would be able to, spending the few dollars per CRT seems fairly cheap to me, at the prices of fuel nowadays.

phosphor coating CRT can contain toxic metals such as cadmium barium or other metals (Zn.Al,Y.Mg):
http://en.wikipedia.org/wiki/Phosphor
http://firecontrolman.tpub.com/14098/css/14098_56.htm

From wiki:
Toxicity

Older color and monochrome CRTs may contain toxic substances, such as cadmium, in the phosphors.[49][50][51] The rear glass tube of modern CRTs may be made from leaded glass, which represent an environmental hazard if disposed of improperly.[52] By the time personal computers were produced, glass in the front panel (the viewable portion of the CRT) used barium rather than lead, though the rear of the CRT was still produced from leaded glass. Monochrome CRTs typically do not contain enough leaded glass to fail EPA TCLP tests. While the TCLP process grinds the glass into fine particles in order to expose them to weak acids to test for leachate, intact CRT glass does not leache (The lead is vitrified, contained inside the glass itself, similar to leaded glass crystalware).

In October 2001, the United States Environmental Protection Agency created rules stating that CRTs must be brought to special recycling facilities. In November 2002, the EPA began fining companies that disposed of CRTs through landfills or incineration. Regulatory agencies, local and statewide, monitor the disposal of CRTs and other computer equipment.[53]

In Europe, disposal of CRT televisions and monitors is covered by the WEEE Directive.[54]
 
solar_plasma said:
If it would work for lead nitrate like for copper nitrate or copper sulfate, I would prefere to use an electrolysis of the lead nitrat, so you can reuse the HNO3. But I haven't tried yet and I couldn't find much info about it. Would be nice, if someone could validate this.

Björn,
I found it.
Here you suggest being able to re-use the HNO3 from copper nitrate or copper sulfate from an electrolysis process.
Can this be done in a way that can yield usable HNO3 that will dissolve more copper ???
Or can you explain what process you are talking about better ???

Thanks
 
solar_plasma wrote:If it would work for lead nitrate like for copper nitrate or copper sulfate, I would prefere to use an electrolysis of the lead nitrat, so you can reuse the HNO3. But I haven't tried yet and I couldn't find much info about it. Would be nice, if someone could validate this.


Björn,
I found it.
Here you suggest being able to re-use the HNO3 from copper nitrate or copper sulfate from an electrolysis process.
Can this be done in a way that can yield usable HNO3 that will dissolve more copper ???
Or can you explain what process you are talking about better ???

Thanks

I meant simple electrolysis of Cu(NO3)2 with graphite electrodes to gain Cu at the cathode, H+ and NO3- are left in solution. And electrolysis of CuSO4 with graphite electrodes to gain Cu at the cathode, H+ and SO4-- are left in solution. I have seen infos about it on the forum, too, just have to find it again. If I remember right and if I didn't had some hallucinations, some of the moderators wrote about it and told, that the acid not will be pure, but usable for many purposes.

Just as an example: http://www.google.de/imgres?q=elect...w=187&start=0&ndsp=32&ved=1t:429,r:0,s:0,i:80

Theoretically there is only H+ and SO4-- left back, in real I would expect, that some copper will be redissolved again, that the process will get ineffective at a point, when there is not enough CuSO4 left back and other processes like the electrolysis of H2O will take over.
 
Found it:

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=5410

lazersteve wrote:
Copper nitrate solution (6 molar or less) can also be converted to nitric acid via electrolysis. The anode and cathode are inert materials (graphite) and the copper metal is removed form the cell as it accumulates at the negative terminal. The nitric produced will not be 100% free of base metals, but will be usable in further dissolving reactions to remove more base metal.
 
Not to mention the cesium presence...electrons ......and so on....thorium is another element to be consider,if is only an oxide....

Lead glass is recycled by use of gravity and silicium dioxide(aka sand)...they studied this long time ago....not trying to reinvent the wheel
 
I would like to resurrect this thread, if I may, since it is almost four years old now, and I am wondering if any new information might have been discovered. I do just your everyday scrapping to sell to scrapyards. In the past, I have been able to find places that would take my gutted televisions without charging me a fee, and life was good. But those sources have dried up, and now I have a pile of TV carcasses that I cannot legally dispose of without paying more than the scrap I got from them is worth. I saw a video on youtube from a big company that recycles the glass to get the lead from it, which would be great for me because I also cast fishing jigs. Now, to watch the video, it appears that the process is nothing more than melting down the glass, and letting gravity do the work of separating the lead from the glass, but I can't believe it is actually that simple, so I have been trying (unsuccessfully) to find more information on it. Has anyone here heard anything on it?
 
Good luck. There are multi million dollar corparations going under because of the total collapse of the CRT glass market.
 
I sold my 3 metric tons of CRT glass to a glass recycler, but I strongly believe with our existing lead smelting equipments we might be able to recover lead from CRT glasses.

Havent had the chance to try it, but I will, and results will be here.
 
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