AR Fume Safety/Prevention/Treatment

[austexjwlry]

Ouch,,

If anyone has to go to the emergency room like my wife did on Jan. 17 this year with severe asthma like symptoms and running a fever. If your lungs are irritated and inflamed think twice about allowing them to treat you with a cortisone i.v. being pumped into your system to reduce inflamation as it can cause pulmonary edema, where your lungs start to fill up with your own fluids much like drowning. She reacted very badly to it. I almost lost her, 4 days in the hospital and well over $20,000. later she was able to come home. Respect these and all the fumes we produce!

You can buy quite a few fume hoods for the price of one emergency room visit! And no amount of money can replace a loved one!

Wayne

 

[ddrew]

:idea: This works great for 14 pound pentium chip batches...
using a 3/4 gallon poor or rich man's 'recipe'.

Using the lid from the 5 gallon drywall bucket, REMOVE RUBBER GASKET from inside the lid's edge, drill or carve hole for PVC pipe with elbows, to allow the pipe to angle downward into a plastic 24" deep bin 3/4 way full of water and wood ash mix, just gotta mix it up so it's like a THIN milkshake consistency since the fumes will come out of the pipe at pressure, you want the bubbles to travel freely from the end of that pipe, not clog like will happen as the ash settles, LOL, but anyways, you get the picture... You could try something liquid like premixed water and drano. Either way, an alkaline solution with the pipe near the bottom cuts the fumes down about 95%. Cover the bin with a wet towel and sprinkle the ash on top of that, might need some clamps to hold the towel in place. This traps/neutralizes the fumes that escape the alkaline liquid part. As with all reactions, when the bin bubbling stops, the reaction is nearing the end. Take the pipe out soon, as the reaction cools, it will suck up the water through the pipe and a possible nasty surprise could ensue. You'll notice that some fumes will stay in the bucket, as you remove the lid, hold your breath. The liquid on the underside of the lid is highly corrosive and should be rinsed into that bin. I use a quart or so of rain water. You'll also want to rinse down the inside of the bucket as the condensed liquid is highly corrosive.

There are some other methods that are FREE and work great too, I'll post them later. I think small batches are for the birds! LOL It is safe to say that I do this all without gloves or respirators.

some conditions affecting fumes: Humidity, wind direction/speed, air temp, etc... all true. If humid, use the neutralizer. If dry air and windy, just let it rip, using the lid with a vent hole a good 1000 feet from neighbors, wildlife, etc. Make sure the hole in lid is clear first though. You can also cover that with a cloth/ash to minimize the escape. As long as you don't seal the vent shut, you'll be OK. I've even trapped the fumes, cooled them into liquid then used them to dissolve more gold plated stuff. Either way, fumes are nasty, stay upwind and try to minimize them if possible. The garbage can upside down seems a bit archaic, but, to each their own, :lol:

AF 8)

I read this post with interest, and saw nothing to dispute it, or confirm it. Can anyone validate whether this is an effective method to use INSTEAD of a fume hood? If so, is this an accepted practice?

AquaFortis, you mentioned '... some other methods that are FREE and work great too, I'll post them later.' Did you put them in another post, or is there anything else you'd like to share with us??? Thanks for the great advice, everyone, and I look forward to learning TONS on this forum...

Have a great weekend, everyone.

 

[Anonymous]

I saw Noxx and goldsilverpro were interested in high(er) concentrations of H2O2. Just thought I would shed light on it. It can be found in 1 gallon jugs in a thick plastic bag. Non-Chlorine pool shock. Something like this http://www.archchemicals.com/Fed/BAQCIL/Products/coreProducts.htm . It claims 27%. It costs always less than 20USD. Remember, this ain't the stuff granny used to wash her mouth out with. It's the real deal. It will bleach any part of your body a brilliant white from the smallest droplet. Often unnoticed until you feel the wasp sting you! Be careful and have fun.

 

[Lou]

Yep, and it's been mentioned quite a few times elsewhere on the site!

There may even be a better source according to one member! Stay tuned!

 

[ddrew]

Yep, and it's been mentioned quite a few times elsewhere on the site!

There may even be a better source according to one member! Stay tuned!

I've been going through this scenario, and unfortunately I don't have a 1,000' clear zone (even though I have 10 acres of land), so that leads me to more conventional solutions.

I'm considering building a fume hood, using 1/4" tempered glass on the front, with plywood sides and pleated furnace air filters for particulate capture, and venting back and down into a 'Negative Air Machine', like a CRSI 2000. They're selling used on eBay in the $2-300 range, with another 200 for freight. These are commonly used industrial ventilation units used in a variety of applications. It has a HEPA filtration of 99.97%. The duct work would be aluminum, since the CRSI unit is also made of aluminum. I understand there are some corrosion issues with Aluminum and some of the fumes generated, and I'm curious if going to light gauge stainless for the ductwork and input side of the CRSI unit would be worth the investment?

Does anyone have any experience with this kind unit, and whether a HEPA filtration system is sufficient to control the fumes typically created in a gold & PGM refining operation?

That also leads to another question about disposal of the filters when they are full. Will burning the filters liberate the fumes (or underlying chemicals) and start the problems all over again?

 

[goldsilverpro]

You will have corrosion problems with ANY metal, including stainless.

 

[ddrew]

You will have corrosion problems with ANY metal, including stainless.

What is the 'Best Practice' currently used in industry for fume hood construction? I used to do EHS work in the Air Force, and really want to do this right, if I start doing this.

Thanks in advance for any and all suggestions.

 

[Lou]

Epoxy paint over stainless, or enamel over stainless is what is used for typical fume hoods, both have limitations. No HF with enamel or glass, but you can use perchloric and chlorine dioxide with enamel, but not with epoxy (but you can use HF with epoxy).

The ideal material is a fluoro polymer, like teflon.

http://www.scicominc.com/teflon_film.htm

For the duct work, I recommend PVC over stainless, aluminum, and anything else--for the price and easy of construction, it can not be beaten.

 

[ddrew]

Epoxy paint over stainless, or enamel over stainless is what is used for typical fume hoods, both have limitations. No HF with enamel or glass, but you can use perchloric and chlorine dioxide with enamel, but not with epoxy (but you can use HF with epoxy).

The ideal material is a fluoro polymer, like teflon.

http://www.scicominc.com/teflon_film.htm

For the duct work, I recommend PVC over stainless, aluminum, and anything else--for the price and easy of construction, it can not be beaten.

Thanks Lou, that's a great idea. Since this doesn't rely on a specific substrate, I think I'll use Plywood to build the hood, and then cover it with this. I can find better uses for the Aluminum or Stainless. I seem to remember that wood was discussed in another thread about fume hoods.

 

[ddrew]

While on the topic, I'm seriously looking at a 'Negative Air Machine' that will provide the filtration and airflow for my fume hood. It's a commercial unit used in Asbestos Abatement, and duct cleaning. It uses a HEPA filter and has two pre-filters. I plan on using a pleated filter for the first pre-filter, for capturing any airborne PM's, but am looking at using an Activated Carbon refillable secondary pre-filter to capture most of the fumes before getting to the more expensive HEPA cannister filter.

Is that worth the extra effort? I've read that Activated Carbon will capture a significant amount of the noxious fumes, and since that filter is refillable, I can change the carbon out more frequently (using an approved full face mask, of course). The HEPA Cannister Filter is costing almost as much as the Negative Air Machine itself (I'm buying it used from a house cleaning co), and I want to keep it functional as long as I can.

This Negative Air unit is a 'Dri-eaz DefendAir XL' and has 550 cfm of airflow at load, and 985 cfm free flow. It's a portable unit that will roll under my bench and seal it's air intake (on the top of the unit) under an airtight seal on the bottom of the fume hood. The working area of the fume hood will be 3' wide and 1 1/2' deep and 3' tall, with a 'slot type' opening in the back for exhaust down to the Negative Air Machine. I'll cover all the inside of the fume hood with the teflon film recommended in a prior post.

The books I've been reading on hood design give a design criteria of 120 cfm per sq ft of work area (using an open tank design). I think that is sufficient for a small scale 'recreational' refining operation.

My plan is to build a functional fume hood using repurposed materials and low cost used equipment (this machine was on craigslist - newer version on eBay for $385). I'll draw plans and provide them to the forum when I'm done.

I'd appreciate any and all critiques of my design and plans.

 

[Blacktoadd]

Having a fume hood is a minimun, I agree with that 100% You will also find that some fumes always get away from you. Some fumes go up, and some go down, from your fume hood you need a duct to the ceiling, and also one to the floor. Little note: Inside the fume hood a little shelf in fromt of the fan is a good place to place the flat pie plates from corning you get from Good will. the air going across them evaporates down any solutions you want very rapidly, and free. If shelf is close to fan, and a cover top and sides are added high velocity across the top of the surface of the pie plate evaporates nearly as quick as bunsen and beaker. All of the floating crystols that form will be in a pile on the far side of the plate, doing a little separation as well. I love free processes and stuff. Sometimes dilute liquids can be evaoporated for free, heat the acids off. everythng will be in bottom. a little cheap acid will remove base metals leaveing values behind, all separaded.

 

[Blacktoadd]

There is a nice product, PVC foam core with two shiny sides in board form. It can be bent simply by placing a 2x4 on each side of a bend line and heating the crack with a heat gun. When sofe bend and hold a few min. It can be solvent cemented or screwed together. It can he heated between two sheets of plywood or sheet rock or whatever and wrapped around anything to from cheap plastic duct of any size.

 

[viacin]

and when using AR you'll have Chlorine gas also.

Isn't that mustard gas?

 

[Lou]

No, that is bis(2-chloroethyl) sulfide. Please use a search engine next time.


Chlorine, a product of many of our processes was used as a war gas, but it was largely ineffective compared to other gases.

 

[viacin]

I did use a search engine. I'm not a scientists so

"The sulfur mustards, of which mustard gas (bis(2-chloroethyl) sulfide) is a member, are a class of related cytotoxic, vesicant chemical warfare agents" doesn't tell me much. Your no sufficed.

 

[Lou]

Relax, do not take offense.

I'm not trying to argue, it just seems like you said "isn't that [chlorine] mustard gas" only to say it.

I guess my point is that you don't need to be a scientist to figure out that chlorine is not a mustard agent based off this:
"The sulfur mustards, of which mustard gas (bis(2-chloroethyl) sulfide) is a member, are a class of related cytotoxic, vesicant chemical warfare agents"


As for the big words, just search them up or use common sense and figure them out contextually. Hopefully, you'll never need to know more about that compound anyway!

 

[viacin]

lol sorry lou. Took it the wrong way. And you're right, This is as mucha s I need to know about it

common sense isn't always my strongest point anyway, but I make up for it with book smarts 8)

 

[wop1969]

If the AR fumes could be moved thru water that is impregnated with say
agricultural lime (CaO), crushed limestone (CaCO3) or sodium bicarbonate (NaHCO3) would the NITROGEN DIOXIDE fume be nutralized?

Also is their any chance that the NITROGEN DIOXIDE fume could react to the water? I have read that it does not like water ???

 

[Noxx]

Yes part of it would be. But I'm not sure how much though.

 

[Anonymous]

If anyone is still looking for higher concentration H2O2, go to a health food store and ask if they have "food grade" hydrogen peroxide. It should be 35%. As with any other chemical read the MSDS first--this stuff will eat your skin!