Thoughts on incineration and e-scrap.

[Anonymous]

I've been thinking long and hard about some safety issues with e-scrap that don't apply to jewellery.

Cadmium isn't a pleasant material regardless of the form it's in. Neither is Beryllium or Beryllium Oxide.

Both of these are present in a range of e-scrap. Joints, alloys, contacts, and white heat spreaders to name a few. Following the logic of how we recover precious metals and process them there can be situations where the filter papers, and recovered materials can and do contain these elements. It's well documented that both of these materials are at their "worst" when airborne i.e. Beryllium oxide fumes and Cadmium "webs" so should we be taking this into account more when either incinerating e-scrap or e-scrap filter papers?

This all occurred to me whilst planning a job with some specific 75/25 Silver/Cadmium last week, with particular reference to the particular steps I took in refining the product because of the Cadmium presence. As I was working through the steps I realised that just because I knew the Cadmium was present in this material I was treating it differently, which was wrong.

Your thoughts gents?

Jon

Edited for clarity on filter papers.

 

[nickvc]

You raise some interesting points as to personal safety as well as environmental damage potential.
Perhaps some of our scientists could issue some advice on dealing with these hazardous materials safely and responsibly.
Question one is do these materials become volatile and hence dangerous during incineration?
Question two at what point during heating do they pose a risk ?
Question three should we be doing this at all if the risks really are there?

Someone knows the answers to these questions so I'm hoping we get the answers to these concerns.

 

[necromancer]

some extensive information.

pdf file: TOXICOLOGICAL PROFILE FOR CADMIUM

by: U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health Service
Agency for Toxic Substances and Disease Registry

published: September 2012

http://www.atsdr.cdc.gov/toxprofiles/tp5.pdf


TOXICOLOGICAL PROFILE FOR BERYLLIUM (2002)

http://www.atsdr.cdc.gov/toxprofiles/tp4.pdf


papers like this will be a good read for anyone that recovers from e-waste

 

[solar_plasma]

Cadmium oxide is sublimating at 700°C, cadmium metal's boiling point is at 765°C. Nothing I would like to incinerate. I think this is something someone has to decide for himself. I wouldn't process anything like this knowingly, though I try to treat all more or less unknown metal compositions just as if they contained all the possible bad guys I can think of.

I would forget about those few 1/10 grams of silver in the filter papers and treat them as hazardous waste.

 

[kurtak]

Cadmium isn't a pleasant material regardless of the form it's in. Neither is Beryllium or Beryllium Oxide.

Both of these are present in a range of e-scrap. Joints, alloys, contacts, and white heat spreaders to name a few. Following the logic of how we recover precious metals and process them there can be situations where the filter papers, and recovered materials can and do contain these elements. It's well documented that both of these materials are at their "worst" when airborne i.e. Beryllium oxide fumes and Cadmium "webs" so should we be taking this into account more when either incinerating e-scrap or e-scrap filter papers?

.

Jon

You bring up a very good point here & its not just Be & Cd that is a concern here - to some degree most all metals can be of concern when it comes to exposure to metal fumes when heat is applied to metals &/or there salts & this even includes the essential/dietary/trace elements like zinc, iron, etc. & when "over exposed" to the fumes from welding, cutting (torch or plasma) melting, smelting, incinerating can/will lead to the condition of "metal fume fever"

As much as this can be a problem even with the essential dietary elements (when over exposed) the real concern is with elements that are not essential & therefore considered "toxic" & the fumes created from when heat is applied to them - & the potential for metal fuming is made greater when the metals are finely divided &/or contain traces of acids

When over exposed to essential element metal fumes the body will "generally" clear its self of the problem - though you will still suffer the effects of metal fume fever for the course of time for the body to do so

On the other hand when it comes to the toxic metals the body does not do so good at self clearing them & rather they tend to build up &/or accumulate in the body so these metals pose a problem in not only can they show symptoms soon after exposure (if the dose is large enough) but can go quite some time before symptoms show if the dosing is small &/or continued over time --- & its not just the fumes from applying heat to these metals - it is the dust from the finely divided powders of these metals that need to be considered as well

In the case of fume exposure these toxins - if done "soon" after exposure - for the most part - can be removed by the use of chelation agents such as EDTA --- If heavy metal toxins are not removed shortly after exposure they tend to create other conditions that can not be cured, only treated - chelation therapy does not work well on dust exposure because the toxins are not actually in the blood stream but rather particles in the nose, throat & lungs

Besides lead, mercury, cadmium & beryllium which are the common heard of toxic metals - "some" others to be aware of are copper, arsenic, nickel, all common in electronic --- & there are others like chromium (if you cut & weld a lot of SS)

It should be mentioned here that some of these metals are used in the form of there oxides as the filers in the epoxy resins of IC chips (BeO in particular) so the dust when handling incinerated IC chip ash is a real concern

The bottom line here being that yes - there are real hazards in not just the chem work of processing e-scrap but also in melting, smelting &/or incineration &/or milling processes - so these things should actually be done preferably in a fume hood but at least out side & I highly recommend that you also wear a "good" cartridge type respirator

More about metal toxicity :arrow: http://en.wikipedia.org/wiki/Metal_toxicity

Metal fume fever :arrow: http://en.wikipedia.org/wiki/Metal_fume_fever

Chelation therapy :arrow: http://en.wikipedia.org/wiki/Chelation_therapy

Kurt

 

[nickvc]

Good informative post Kurt well done.