This has been a very interesting discussion thread. Several widely disparate themes have been articulated and I wish to add one more:

As near as I can tell this is a CHEMISTRY list and participants are (to varying degrees) CHEMISTS (this means chemistry knowledgeable) and the thread is (among other purposes) intended to share chemistry knowledge and educate as many as wish to be educated.

Now and here, a difficult technical and chemical-based problem has been posed - how to get rid of an old, sizable piece of instrumentation which contains a significant quantity of a chemical with some highly undesirable properties. And to perform this in a modern, responsible and economical fashion.

One particularly easy yet not very helpful answer to this question (in a technical list) is "hire a contractor to take it away and do the job for you." Thanks loads people - I needed a chemistry list for this answer.

This type of answer also begs an important question: "I, as a contractor, have now taken on the task of safely, responsibly and economically decommissioning and disposing of this beast." The technical question remains the only difference is who is answering the question. Here is the heart of the matter.

It is helpful sharing, in this forum, the names of technical entities that (the list participants) have been judged capable of handling this sort of task and this ought to be encouraged vigorously. Guesses are less significant than hard experience. Fear responses are not helpful and really ought to be discouraged. They do not help the chemical profession and technical discussions. Technical cautions (you know what I mean here, right?) are totally important and helpful.

Back to the task. There is interesting and important chemistry that needs to take place to accomplish the stated task. I extend SINCERE and HEARTY thanks to those (you know who I am addressing - Rob and several others) for talking technical. Please keep up the technical talk. I, for one, love learning more chemistry and practical matters. (This is why I am here - others may have other interests and those ought to be respected - in the most efficacious places.)

Joseph

On Tue, 19 Apr 2022 2:11 PM, Info wrote:
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> When I first read the description, I was afraid this was a classic Bercaw (CalTech) design in which the pump was integrated into a single bench-long (or multi bench) piece of glass, in which case you'd need advanced techniques to deal with it. I have seen work done on a pump on a design like that once in my lifetime. The glassblower used a Nichrome wire to cut the pump from the line. And, of course, not many schools have that capability anymore in which case the next best way to cut it out would be to score the line with a carbide tool or file, wet the line, and then apply a glob of hot glass which, ideally, would cause a clean break. But I see that this one is modular, so none of this is a concern here.
>
> That said, that's a BEAST of a pump. Let's get the most easily-addressed concern out of the way first:
>
> 1. There's a decent chance that's an asbestos board the diffusion pump heater is attached to and it looks rather friable. Check with your local/state authorities and or waste contractor. The amount is small, so depending on the applicable regs, this is likely to å be a do it yourself (or EHS folks) project should you choose to do so. In theory, it could be easy as respirator up, cut the wires, double bag and tape it up securely. Don't mess with trying to unscrew the heater from the base. But again, don't think about it without official guidance. It may not be asbestos, but I assume the cost of a test is probably about the same as disposing of it so it's easiest just to treat it as such.
>
> 2. That is a huge sucker, but at least it comes off as one piece. The best/easiest bet is what someone else suggested - see if your waste contractor will take it whole kit and kaboodle without emptying it.
>
> 3. If you do want to remove the mercury from it, you are going to need to plan that carefully. REALLY carefully. It will involve **pouring it out** either the side arm or the top and that opaque tape-covered bulb (which I am assuming is a cryogenic Dewar of some kind) is going to make that a challenge. I see many ways that could go south or worse given the length of the pump, the various crannies, and the shifting weight of the mercury. The splashing and spilling would be a big concern, so you'd want to put a plastic tarp down on the floor where you're working AND use a huge flat containment tray AND be wearing full Tyvek including booties AND have the receiving flask securely clamped - just as starters. å If I was tasked with this, my approach would be to set up secondary containment and use the score/hot glass method to cut the thing in half at the neck below the taped-up bulb. å That would let your pour it out much more easily. å But that's just a thought based on!
my own
> personal comfort/experience working with these kinds of systems and it's not something a novice should attempt.
>
> 4. Assuming you did remove the mercury successfully, you are still left with the question - dispose of the contaminated pieces as solid waste or clean the pieces with dilute nitric acid (as discussed by others in this thread). å The later is doable, but you are going to generate a couple liters of nitric/mercury waste in the process. Not a biggie in itself, but compare that cost (and effort, time, risk) to trashing the glass as solid waste and I suspect solid wasting is the way to go.
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> Honestly, unless someone there has experience working with these things, the most economical answer is to outsource the whole project even though that will seem like a lot of money.
>
> But if you are inspired enough to tackle this on your own, here's my writeup on mercury in the laboratory which is worth a read first: http://www.ilpi.com/safety/mercury.html <https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ilpi.com%2Fsafety%2Fmercury.html&data=05%7C01%7Cjoseph.diverdi%40COLOSTATE.EDU%7Cabcc9944744d45b7088c08da224bdc5b%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C637860007218785408%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000%7C%7C%7C&sdata=C%2BZpaDu6TZstD%2FHCIF%2FJKXsd9rwROHxphkoZC9qNlmA%3D&reserved=0>
>
> Please feel free to follow up with additional questions/comments.
>
> Rob Toreki
>
>> On Apr 18, 2022, at 4:59 PM, Todd Melgreen > wrote:
>>
>> Hello All-
>>
>> I was hoping that someone on this e-mail list may have some answers to a few questions regarding a mercury diffusion pump.
>>
>> We would like to remove the mercury from the diffusion pump.å Once the mercury is removed we would like to dispose of the remaining glass diffusion pump properly,å I am wondering if anyone has any experience or has attempted to do this previously that we could learn from.
>>
>> Questions are:
>> What is the easiestå way to remove the mercury from the diffusion pump?
>> Are there vendors who deal with disposing of mercury contaminated glass?
>>
>> I appreciateå any insight or help that can be provided.å Thanks.å I do have photos of the pump but they can't be sent to this list serve.å So if seeing these would help you please email me directly and I can send them your way.å Thanks again for your help in advance?
>>
>> Regards,
>>
>> Todd A. Melgreen, ASP
>> Chemical Hygiene Officer & Chemistry Lab/Stockroom Manager
>>
>> Chemistry Department
>> Willamette University
>> Salem, OR 97301
>>

--
Joseph A. DiVerdi, Ph.D., M.B.A.
Associate Professor of Chemistry
Colorado State University, Fort Collins, CO, USA
+1.970.980.5868 - /diverdi.colostate.edu/
/us02web.zoom.us/j/9460709393

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