# will this work for a fume hood



## Rickthenewb (Jul 28, 2010)

I have recently moved into a warehouse where I plan using the cyanide leaching method in very small amounts (80 grams at a time), I have a small warehouse with only a window so I planed on building my own fume hood. My question is do you think its ok to have a fume hood with a fan on the wall rather than above. I have included an attachment of what I want to build. On a side note, should I get a respirator suit or will cartridges be ok? thank you in advance.


----------



## 4metals (Jul 28, 2010)

The opening will require a 2200 cfm fan if you go by general rules for exhaust, a typical window fan won't cut it.

Do you plan on adding any removable plexiglass panels to close off the size of the opening while reactions are going on? A respirator for you will be fine but what are the odds the person walking past the window will be wearing one? Can you direct the airflow upward once out the window? 

Before you begin I suggest you discuss your plans on treatment of your waste cyanide, your hood design screams of lack of funding, I hope your plans for the cyanide wastes is better funded.

You're opening the door here to get yourself in a world of trouble, there are people on this board who have worked with cyanide, myself included, do yourself a favor and openly discuss your plans. I know it's a bitter pill to swallow but better to go in with your eyes wide open to all the potential issues you will face.


----------



## joem (Jul 28, 2010)

could you not jus use a stove fan with plexi wall and door?
joe


----------



## Rickthenewb (Jul 29, 2010)

I plan on working at night when no other businesses are open, right after posting this i decided to just do the cyanide part of my reaction outside, its safer for both other people and myself, I don't plan on working with cyanide a lot, just enough to get to know what its like working with it and to improve my familiarity. As far as disposal I have a waste company in order. I am going to use the fume hood for my any other reactions. As far as the Plexiglas, yes I plan on putting in two sliding doors. Let me know what else you think.


----------



## joem (Jul 29, 2010)

I thinking a range hood fan
4 2x2 legs
plexi screwed on 3 sides
Plexi hinged on the front for a door
your scubber/filter attached to vent
You can't get it with an online classified request


----------



## 4metals (Jul 29, 2010)

If you are using a waste hauler for cyanide you will need an EPA ID# and you will have to manifest the waste, which includes reporting to the state. When they see cyanide they will b e in to see you and you will have some serious hoops to jump through.

If you are only experimenting, don't go down a road that the EPA will never forget. Do your experimenting, neutralize the cyanide yourself, properly, and haul it with your other wastes, never mentioning its existence because it has been completely destroyed by that time. 

Cyanide is a valuable tool for refining, but as anything worth doing it has an associated cost.


----------



## Rickthenewb (Jul 29, 2010)

I should have my EPA number by next week, I am doing very small amounts of cyanide use (less than 15 pounds a year) I have a letter from the DEP saying that I do not need any permits at this time so I think I will be ok for the time being. I just want to see how well this works and if it does, I have a lot more money to pour into this. As for treating it myself, I would if it was legal but I can't. I just want to do enough small experiments to see how much gold I can get off of different types of media, once I know what I can get I will then apply for more permits, get a different warehouse and much better equipment. I really appreciate all of your comments and I welcome more because I want to make sure I am not missing anything.


----------



## 4metals (Jul 29, 2010)

If you have a pH meter and an ORP meter you can treat the cyanide in a 2 step reduction. Considering the small quantities you're talking over the course of a year you should be able to accomplish this as your monthly waste solution generated will be low and you will have the time to completely reduce the cyanide to cyanate and then to a carbonate and nitrogen gas. 

If you are planning to get into the refining business from a chemical standpoint, you'll always have need for a pH and ORP meter. Even if you stick to acid refining.


----------



## gmiller (Jul 29, 2010)

If you are going to produce ANY type or amount of acidic fumes, the range hood and fan will quickly be reduced to useless scrap.

I speak frome personal experiance.

Wishing you the best from your endeavers.

G. Miller


----------



## joem (Jul 29, 2010)

ok of course
thats why the pickle jar lid lost all the paint when just sitting loosly on my jar of fermenting cpu and hcl test.
Yeah thinking the paint would gone on the fan as well
ignore my previous idea my wife does.


----------



## HAuCl4 (Jul 30, 2010)

4metals said:


> If you have a pH meter and an ORP meter you can treat the cyanide in a 2 step reduction. Considering the small quantities you're talking over the course of a year you should be able to accomplish this as your monthly waste solution generated will be low and you will have the time to completely reduce the cyanide to cyanate and then to a carbonate and nitrogen gas.
> 
> If you are planning to get into the refining business from a chemical standpoint, you'll always have need for a pH and ORP meter. Even if you stick to acid refining.



What gadgets would you recommend 4metals?. I saw this one in a swimming pool shop, I think it does both pH and ORP:


----------



## 4metals (Jul 31, 2010)

That tester reads a strip you put into the liquid, giving you the value at that point in time. For treatment purposes a pH unit with a probe so you can watch the values either rise or descend with your chemical additions is advisable. This thing would quickly consume all of the strips in your inventory. 

The same is true with ORP, it is a millivolt readout and it is difficult to predict what the readout will be because different chemical combinations have different ORP readings. In cyanide destruction we look for a specified pH and ORP reading, where the waste has to sit for a while then it is brought to another ORP level for complete destruction.


----------



## 4metals (Jul 31, 2010)

I guess it would be helpful if I gave you the parameters.

Raise the pH of the solution with liquid sodium hydroxide and maintain the pH at 11.5 while adding the bleach.

Add sodium hypochlorite under ORP control until +300 mv is achieved, and maintained for 30 minutes while mixing.

Using dilute sulfuric acid lower the pH to 8 and maintain while adding more bleach.

Add sodium hypochlorite under ORP control until +700 mv is achieved, and maintained for 45 minutes while mixing.

The first step oxidizes the cyanide to cyanate, the second oxidizes the cyanate to carbon dioxide and nitrogen.

These are the guidelines for a batch treatment, a continuous flow system gets more complicated requiring flow restrictions to maintain retention times. Do yourself a favor and stick with batch treatment.


----------



## 4metals (Aug 1, 2010)

To test if your destruction of the cyanide was complete a quick and easy method is to use cyantesmo test papers. They are a very sensitive test for hydrocyanic acid which is generated in a test tube by acidifying a small sample. If you're going to dabble in cyanide, get the test papers.

http://www.mn-net.com/tabid/10435/default.aspx

By the way the same company sells pH papers which are excellent for colored solutions called Pehanon test papers. If you're buying the cyanide papers there are good to have on hand as well.


----------



## saadat68 (Jun 12, 2021)

Hi 
Is there any easier method when cyanide solution is low? for example 100 millilitre solution with one gram sodium/potassium cyanide?
Does boiling and completely evaporating solution decompose cyanide? Is it safe?
https://orchid.ganoksin.com/t/boiling-cyanide/41561

In step 2, We can use bleach instead of water and evaporate again! :idea:


----------



## Yggdrasil (Jun 12, 2021)

I'm scratching my head a bit here.
Should you not have explored and researched this, 
before you started your Cyanide endeavours?


----------



## saadat68 (Jun 13, 2021)

I don't start anything sir.
Is there any book that explains cyanide destruction methods with details? 
I searched many on google, but sounds like all the sites explain methods for mines and high volumes and also without enough details! 
So how labs or small plating workshops destroy their cyanide?


----------



## Ray Gun (Aug 31, 2021)

Why are all the fume hoods fundamental? I see them as very limited for space and tough to work in ... never mind the size of a free-standing fume hood.
A friend of mine has a son at university doing his PhD in chemistry and his son told me for acid reactions using heat all you need to remove dangerous fumes are Polypropylene wall-mounted Fume Extractors like the one in the pic.
Is he wrong or missing something?


----------



## notehunter494 (Aug 31, 2021)

Hello Ray Gun
I believe removing dangerous fumes from running reactions for college chemistry to prove theory etc. and any kind of digestion of metals in quantity are two totally different things. If you ever saw the cloud, the BFRC, that is given off by even a small digestion, say 5 ounces, of karat gold in boiling concentrated nitric acid you would understand why an inclosed fume hood is a must. School is not industrial production. There is a channel on YouTube by screetips that you might check out. He makes it look easy but he is a pro., and a Forum Member. Smelling, and that is what is properly done in school reactions, is not inhaling. If you inhale the reaction gases in refining you will die if you are lucky because if you survive your quality of life will be so poor you will wish death instead. That is why more of this Forum is about fume hoods and scrubbers and flow rates than chemistry. The chemistry is quite simple, with a lot of nuance, like in cooking, to get it just right. There really is a clear path with the chemistry but getting there safely, that is a mine field.


----------



## Ray Gun (Sep 1, 2021)

notehunter494 said:


> Hello Ray Gun
> I believe removing dangerous fumes from running reactions for college chemistry to prove theory etc. and any kind of digestion of metals in quantity are two totally different things. If you ever saw the cloud, the BFRC, that is given off by even small digestion, say 5 ounces, of karat gold in boiling concentrated nitric acid you would understand why an inclosed fume hood is a must. School is not industrial production. There is a channel on YouTube by screetips ...


I am here posting because of Streetips and yes I have seen the reactions (and vapour cloud) from various refining techniques. I have watched well over 30 hours of his content in the least month alone. I am posting here to learn all I can before setting up.

A student completing his PhD in chemistry at the University of Sydney is not your local college my good man.
I am not trying to be a dick (I assure you) as I can come over that way to some people.

Videos of Streetips doing karat scrap gold refining (over 1 kg of scrap) were sent to Abhishek (PhD in chemistry) and he asked "why would you need a fume hood for such small reactions?"
"You have a one-ring hot plate and 200 ml of acid going into a 3000ml receptacle whats with the full-on fume hood?"

The company I reached out to clearly defined the extraction capabilities of the product they are providing and it was clearly defined as rated to remove Nitric/Hydroclori and sulfuric acid fumes from reactions on base metals ... I asked specifically. The fans are rated for corrosive fumes as is all the ducting they supply.
You are welcome to contact them.
https://www.spotextractor.com/wall-mounted-fume-extractors.html
The Whatsapp contact is +91 99130 00626

The safety aspects of refining metals with acids can not be underestimated but making it sound like you are working in a BSL4 lab is just blatant over-dramatisation.
Rule NO.1 extract all the emissions = check.
Rule NO.2 do not get 78% Nitric acid on your skin or in your eyes (wear safety gloves/glasses) = check.
Rule NO.3 do not get 1,064 °C molten gold on your trouser leg = check.
Rule NO.4 do not sprinkle sodium metabisulfite on your corn-flakes = check.

Would I recommend that some of the people I have seen posting here (in need of fast-buck) mess around with these products and techniques? Nope!
Is it safe if you follow rules 1 through 4 ... absolutely 100% 

So my contention is that a free-standing fume hood (which is bulky and a pain in the arse to work in) is not compulsory and even overrated and outdated. Your objective is to remove fumes so that you do not get gold fever and potentially die from hyper-toxicity ... once that has been accomplished there is nothing left to discuss.
Feel free to tell me if I have missed anything?

Also calling Sreetips a master chef is just pure comedy gold ...
I think Steve aka Kadriver is a top man as the content he has provided is the best you will find (that I have seen). But to call him a PhD in theoretical physics is stretching the limits of credibility.

When you watch him adding nitric acid to Aqua regia boiling sessions and he then says "oh why not" and puts in another 3 ml (that is not precision). He is precise where he needs to be ... inquartation figures for gold with silver or copper - he will get out his calculator and a pad but the rest is by eye and feel. This is why I have ripped all the good tutorials to MP4 - because you can see how much at each step he adds to the receptacle.
When you watch as much of his content a month as I have (I have ripped the good tutorials to MP4) you will see that if there is one thing it lacks - it is a formula that is carved in marble.
If you follow the exact methodology you see in a Streetips video you would need to be a shaved monkey to get it wrong. I will not even bother with testing the gold in the solution with some filter paper because if you have followed the exact methodology ... of course that 156 gm of gold is in solution ... it is not interdimensional physics FFS!

My grandmother used to make some of the best chocolate gateau you will ever taste and she could do it every time without fail. But she did not have an IQ of 167 and was lecturing at the Imperial College London at the weekends ...
I am going to watch some more Streetips content.

Ray Gun ...


----------



## Ray Gun (Sep 1, 2021)

*Usage *Laboratories, Chemical Industry Pharmaceutical unit

We are instrumental in offering Polypropylene Wall Mounted Fume Extractor. Our engineers have precisely designed this product to meet the needs of *varied industry applications*. These are manufactured from supreme grade components in compliance with the set industry standards. Moreover, clients can avail this product from us in different specifications as per their exact needs.
We bring forth for our clients an array of Wall Mounted Fume Extractor, which is used to ventilate the contaminated air. This helps in keeping the workplace and user safe from harmful fumes. Our range of Wall Mounted extractors is appreciated for its high performance, durability & perfect finish and finds usage in laboratories, pharmaceutical units, *and production environments*.

https://www.spotextractor.com/wall-mounted-fume-extractors.html


----------

