soxhlet assisted base metal separation

[kronix]

Hi everyone!
I was wondering whether or not it would be feasible to use a soxhlet extractor with HCL to continuously drip conc HCL onto fibre CPU pins leaching out base metals? I do realise this would take some time, but it was just a thought I had.
Would the HCL condense properly?
It just seemed it may eliminate base metals from cementing back out onto pins as the condensate would be unadulterated.
thanks in advance!

 

[kronix]

Once I move at the end of the month I will be setting up my lab, I guess I'll just give it a try, I doubt I can lose any values in a closed system, if anything it will be a waste of time. Before anyone gets mad at me for not following standard procedure, I just have this labware and would like to use my new toy haha. I do realize that the proper way to do this is to boil in hcl until all base metals are dissolved followed with proper wash procedure, then on to dissolution with your oxidizer of choice followed with precipitation and cleaning powder via more washes. I have read a ton of material from this site and learned lots over the time I've been here and am very thankful to the contributors of this site.

 

[butcher]

Well I had to Google what you were talking about using, that looks like a very nice piece of lab equipment, and would have several uses in a lab.

I see no advantage in using it as you describe here, if it were me I would pack it up so it would not get broken put it in a box in a safe place, for use latter when I had a reason to use it.

A mason jar, old plastic bucket, second hand crock-pot, or other apparatus is what I would use, I do not cry too long when I break one of those.

 

[Sucho]

Soxhlet extractor is primary made for continuous organic extraction (organic solvent is evaporated, condensed and drops into patrone with for example tobacco for nicotine extraction).this labware helps to extract organics much faster and more efficient than batch type extraction(in fact, with soxhlet you do hundreds of batch type extractions in one take).

Hcl isnt a good liquid phase for soxhlet, because it is solubilized gas in H2O, so during evaporation hcl gas will go off the the water with very uneffective resorption to water in condenser(hcl gas solubility in water raises with lowering temperature and decreases with higher temperature,same as pressure effect, but in opposite manner)

In conclusion, your soxhlet operation would be HIGHLY uneffective with high hcl consumption and final liquid products will be water with a little chlorides of iron group metals inside

 

[freechemist]

And what about the azeotropic mixture of HCl and H₂O, with a constant high boiling point of 109^oC, containing 20.2% HCl?

 

[Sucho]

freechemist, your post is true and shows the only way how to use soxhlet and HCl as liquid phase in soxhlet.

on the other hand ( if you ever used soxhlet), idea of soxhlet usage with HCl liquid phase to dissolve kovar and iron based plated stuff is too laborous and very time consuming for me with low effectivity (if it is used not in the right way )

also soxhlet needs a lot of another labstuff such as heating nest, water circuit for cooler and hood


i have two soxhlets at my stock, but dont use them.maybe i will try something when i will retire :lol:

 

[freechemist]

Sucho, you're absolutely right with what you say about base-metal dissolution, using a soxhlet. However, a soxhlet can be quite useful, even to an inorganic chemist. Hopefully, you will not forget your two soxhlets completely until your retirement, and give the right things an eventual try, when it's time has come.

 

[kronix]

Well thanks for all the info guys. I have a heating mantle, a water pump, and all the other associated hardware except a fume hood which I plan on building when I move at the end of the month.
Once my lab is fully operational I think I may give it a go, if it works good I'll post a tutorial on how I did it, of course it will be open to suggestions and improvements as I am not a very experienced chemist. I will however pay close attention to safety as that is the most important aspect of any process dealing with harmful chemicals.
I do realize that it will take considerably longer for the reaction to finish, but I'm not worried about time, I have lots on my hands. Like I said earlier I have the equipment so I might as we'll have some fun and use it. I also have all the stands and Keck clips so I highly doubt I will break it if I'm careful.

Does anyone have any suggestions on the process? Should I distill my HCL before I use it to have a more concentrated acid? I would be using muriatic acid from the hardware store. Is it OK to use cotton balls instead of a thimble? Should I use ice water or a coolant/water mixture? Is there any danger of explosion at any tempurature?

Thanks!

 

[Marcel]

Hi everyone!
I was wondering whether or not it would be feasible to use a soxhlet extractor with HCL to continuously drip conc HCL onto fibre CPU pins leaching out base metals? I do realise this would take some time, but it was just a thought I had.
Would the HCL condense properly?
It just seemed it may eliminate base metals from cementing back out onto pins as the condensate would be unadulterated.
thanks in advance!

Dripping instead of dipping acid is very well known in PCB production. It is not exactly the procedure you discribed, there is no condensing effekt and therefor no condensing problems. The idea is a different one:
The drips have a large surface, surrounded by air. So we take the oxygen from the air und substitute the oxidizer that way. I think I remeber that this effect doubles or triples the efficency over dipping in acid. As for recovery, I think you have a point about cementing. As the drips roll down the surface of the material more they become very well agitated and are likely to drip down underneath the material where they can rets without cementing.
The next step after dripping acids was to spray them. This further enhanced the efficency (I think by up to 10 times or so). The drips are ven smaller and the surface compared to their volume even bigger. I was once even thinking of buying a PCB spray etch machine on ebay. But it is also a question of quantities you are dealing with.

http://www.megauk.com/spray_etching_machines.php
I am planning to build myself such a device for testing. But acid sprays are no child´s play. You must ensure, they cannot escape the cabinet or they will slowly but steadyly eat up your whole house )

Nice selfmade project here:
[youtube]http://www.youtube.com/watch?v=BaSWDJBhp-0[/youtube]




Marcel

 

[kronix]

Would this process work better with nitric acid, or is it pointless as you could just dissolve pins in a beaker anyways?

 

[butcher]

Man has been trying to re-invent the wheel since the cave man rolled that log down the hill, guess what is it is still round.

Sometimes the simple things that work are better than the complicated thing that may not work.

Thousands of years of expierimentation trials and error's to develop and prove that the simple method works, why would we want try and complicate things with some fancy gadget, when the simple method works so well.