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Irons

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Has anyone studied the formation of Hydrazine when adding Urea to AR? The production of Hydrazine by reacting Urea with Chlorine Bleach has been discussed before. I would think that the Chlorine in AR would do the same.

Comments?
 
That reaction (oxidation) is very finicky and requires careful temperature control. Also, transition metals tend to decompose hydrazine hence the use of EDTA or gelatine in the urea+OCl- method.


There is a thread on sciencemadness about the synthesis of hydrazine from urea and I highly recommend reading it Irons*. It actually is a better procedure than anything in the patents or literature (in terms of optimization--he who made that method was very good at what he did).


Lou
 
Lou said:
That reaction (oxidation) is very finicky and requires careful temperature control. Also, transition metals tend to decompose hydrazine hence the use of EDTA or gelatine in the urea+OCl- method.


There is a thread on sciencemadness about the synthesis of hydrazine from urea and I highly recommend it. It actually is a better procedure than anything in the patents or literature (in terms of optimization--he who made that method was very good at what he did).


Lou

I wasn't proposing this as a method to produce Hydrazine but as a concern for safety by the possible emission of Hydrazine fumes from the use of Urea in AR, that's why I put it in the safety section.
 
I don't understand how the subject of making your own hydrazine ever came up. I once worked for a large refinery that used liquid hydrazine to drop their gold. This was proposed by the egg-headed PhD chemist that ran the lab. It was dangerous, violent, stupid, and worthless.

I don't think these types of chemicals have any place on this forum. This isn't Science Madness, thank God. IMHO, we should stick to the basics. Tried and true refining chemistry is pretty cut and dried. Re-inventing the wheel, in this case, is absurd. The science should never overshadow the art.
 
goldsilverpro said:
I don't understand how the subject of making your own hydrazine ever came up. I once worked for a large refinery that used liquid hydrazine to drop their gold. This was proposed by the egg-headed PhD chemist that ran the lab. It was dangerous, violent, stupid, and worthless.

I don't think these types of chemicals have any place on this forum. This isn't Science Madness, thank God. IMHO, we should stick to the basics. Tried and true refining chemistry is pretty cut and dried. Re-inventing the wheel, in this case, is absurd. The science should never overshadow the art.

I agree. I have used Hydrazine in the past and it's a very nasty chemical. My concern is that it might be produced inadvertently from the use of Urea to neutralize the Nitric Acid in AR and that people might unknowingly be poisoned by it.
 
That is highly unlikely Irons--any hydrazine formed would certainly be destroyed by all of the metal ions in solution.


I have to disagree with your saying there is no place for those chemicals on this forum. I know hydrazine and its salts are useful for refining especially within the platinum group as it is an excellent reducing agent that quickly and quantitatively drops out a sponge. If you've ever done anything with Pt, Pd, or Rh black you will understand why a sponge is much preferred.


And GSP I didn't mean "I highly recommend you make your own hydrazine" but rather that you read the thread if you're interested in reactions that produce hydazine solutions. I will edit so as to clear any confusion. I am not telling people to make their own hydrazine.
 
Hydrazine works well, perhaps too well.

If you're precipitating Platinum Sponge from solutions without contaminants, that's one thing.

For solutions of mixed metals with many contaminants, it works too well.

I recovered my first PGM in 1969 (Ruthenium) and I still don't consider myself to be very well versed in the subject. I learn something new every day.

For folks with little chemistry training, little safety equipment and skills in dealing with hazardous materials, there may be better choices for reducing agents.

On edit: I had to think hard about when I first used Hydrazine as a reducing agent. It was in 1972 when I used it to make Gold sols (colloidal Gold suspensions).
 
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