I have a large CRT monitor that, by the weight of the monitor, I estimate to contain over two pounds of lead. I want to know if the lead oxide is a mixture with the glass, or if it is chemically bonded to the glass.

I also want to know if there is any way (preferably extraction using heat) I can remove the lead in pure form or in oxide form. I know for sure you'd crush the glass.

I bring up heat extraction because chemicals are expensive, and I've heard of it being done that way on a large scale.

Edit: I'm not concerned about making a profit because I don't really have the setup to do so. I'm just curious about it because I've seen it done on an industrial scale using heat, so could it be replicated on home scale.

In what form would the lead be if you smelted it out? Does heating lead oxide reduce it to lead again? If so, would the lead melt out and flow to the bottom?

  • 5
    $\begingroup$ The lead in the face glass of the CRT would be a lead oxide glass. Smelting lead is nasty. There would be some lead oxide given off as dust which would contaminate the surroundings. Unless you already have a lead smelting setup, you could buy lead cheaper than you could recover it. $\endgroup$ – MaxW Feb 16 '16 at 3:47
  • 6
    $\begingroup$ You really do not want to try to extract the lead out of the glass. It will be a long, dangerous process that at best will give you and yours a big dose of lead fumes. Recycle it. $\endgroup$ – Jon Custer Feb 16 '16 at 15:10
  • 2
    $\begingroup$ The lead glass used in CRTs is not a mixture (at least not in any sense where a physical process could readily separate it): it is a glass that contains a high proportion of lead oxide in its structure. It is about as easy to extract from glass a aluminium would be from a high alumina glass (which is not easy at all). $\endgroup$ – matt_black Apr 3 '18 at 12:19

A simple Google search will find you a number of informative articles.

I went and looked at one of the links and it was an abstract which I will quote below in full. It looks like a possible method though I strongly advise against proceeding without a lot of forethought into pollution control measures. There will be various lead compounds formed and keeping the dust and products out of the air and environment will not be easy. As a business case this is going to be irrelevant soon as the number of CRT displays being recycled is decreasing continuously as 2nd generation LCD monitors have already reached end of life, only a small percentage of industrial control equipment still operates on CRT monitors and they will slowly be recycled over time, the big gold rush is over.

Here is a video from SWEEEP KUUSAKOSKI showing their industrial processing system, the method is not described but this started operation in 2013. The same time as the paper below was published.

Another video by Green Lyon describes a patented process to extract the lead from glass using an aqueous phase process at moderate temperatures with non-scary reagents. Not sure if this has been reproduced elsewhere, this video was also published in 2013, a good year for CRT glass.

Extraction of Metallic Lead from Cathode Ray Tube (CRT) Funnel Glass by Thermal Reduction with Metallic Iron
Xingwen Lu†, Kaimin Shih*†, Chengshuai Liu‡, and Fei Wang†
Environ. Sci. Technol., 2013, 47 (17), pp 9972–9978
DOI: 10.1021/es401674d
Publication Date (Web): August 5, 2013

"A novel and effective process of thermal reduction treatment with the addition of metallic iron (Fe(0)) to recover lead from cathode ray tube (CRT) funnel glass is introduced. The key technological breakthrough of this process is the use of a relatively lower temperature and an inexpensive reducing agent to extract the metallic lead. The influences of temperature, the reducing agent content, and the holding time for lead reduction were examined to determine the optimal extraction efficiency. The lead extraction efficiency first increased and then decreased with increasing temperature. The maximum lead extraction efficiency occurred at 700 °C. The growth of crystalline lead first increased significantly with an increase in the Fe content, reaching maximum growth at an Fe addition of 50 wt %. The most effective treatment time was determined to be 30 min, as the vitrification of lead back to the glass matrix occurred under longer treatment times. The experimentally derived results indicate that a 58 wt % lead extraction can be achieved with the optimized operational parameters (50 wt % Fe addition, heating at 700 °C for 30 min) in a single extraction operation."

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.