Single Process for Ammonia, Lead Nitrate/Nitric Acid/Lead (II) Oxide, With Separation of Scrap Lead / Chemistry / Forums

Forums

4hv.org :: Forums :: Chemistry

« Previous topic | Next topic »

Single Process for Ammonia, Lead Nitrate/Nitric Acid/Lead (II) Oxide, With Separation of Scrap Lead

Move Thread

LAN_403

Chris

Mon Aug 04 2008, 06:21AM

Registered Member #8 Joined: Thu Feb 02 2006, 04:34AM
Location: Harlowton, MT, United States
Posts: 214

By using DC electrolysis of scrap lead electrodes in an electrolyte of concentrated ammonium nitrate, I was able to prepare lead nitrate while dissolving the anode at an alarming rate. Ammonia is given off at the cathode but not surprisingly only comes out at a somewhat low rate and high cell temperature. Heating the cell is no problem; all you have to do is not cool it and let the electrolysis current do the work. Later I will experiment with using membrane cells, AC electrolysis, or reversing the DC polarity every few minutes or so, and come up with a system to better remove ammonia with a closed cell top and possibly vacuum. Anode removal exceeded 1/8" per hour with the cell at 3V in this experiment. This is tens or hundreds of times faster than the electrode removal in my electrolytic sulfate production method. Spongy lead that collects at the cathode and settles to the bottom of the cell may need recycled by melting/oxidizing (it oxidizes quite readily though which is nice), but this remains to be seen. With AC electrolysis this problem may be more or less eliminated, but at the same time the ammonia may be oxidized. Some sort of trade-off may be needed such as reversing the cell polarity repeatedly at a certain rate. A membrane cell would probably be even better, if it can minimize the amount of lead that ends up in the cathode chamber. I will try that out too if I get around to setting up a suitable membrane cell, and eventually a large battery of them.

The lead nitrate can then be separated by crystallization and decomposed at relatively low temperature (300-470Â°C according to online sources) to yield nitric acid (4NO2 + O2 rather, just add water). By washing the remaining PbO in a conservative amount of sulfuric acid it should be easy to then separate antimony and tin sulfates from the lead, as only they are soluble. I'm not sure if only enough acid to leech out the tin and antimony will be needed, or if most of all of the lead oxide will be sulfated as well. In any case the lead sulfate or lead oxide can then be smelted, as well as the other metal sulfates, to recover the pure metals and nitric acid.

It may also be quite practical to simply take the lead oxide left over from the nitrate decomposition step (after the lead has been purified and re-cast to electrodes) and react it with ammonium nitrate with liberation of ammonia, to skip smelting and electrolysis from then on out. It is a slow reaction driven by the removal of ammonia. I did a small experiment last night with adding PbO to ammonium nitrate solution and indeed it did give off some ammonia smell, but to be practical some external heating or possibly boiling would be required.

quicksilver

Sun Aug 24 2008, 04:43PM

Registered Member #1408 Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679

Lead nitrate is getting more expensive and this sounds like a winner (for killing two birds with one stone). What's the yield? What level of current was used?

Ocean Waves

Thu Nov 03 2011, 06:06PM

Registered Member #4181 Joined: Thu Nov 03 2011, 02:39PM
Location:
Posts: 42

this is an old thread but I been noticing that ammonium nitrate is getting very rare these days even as cold packs has been all but phased out, here in the us now one can buy ammonium sulfate by the 50 lb sack at the local big box stores. Maybe this may be a more useful route to cheap sulfuric acid, which could be distilled or concentrated in a 55 gallon drum by long term spurging with a regenerative blower and a mist tower, the remaining ammonium sulfate would recrystallize for another go at the dry cell not sure one could dissolve the lead though as it would passivate with PbO, this would however allow one to collect ammonium gas and sulfuric acid relatively pure with a simple dry cell using a membrane like uncoated rip stop nylon, a lead anode and an SS cathode.

I have been actually making my lead nitrate with NO2 and Ozone over water with lead chips in the bottom lately. The ozone is required or you just get significant contamination bright yellow lead nitrite, of course you could always add the ammonium gas steam from the aforementioned dry cell to the NO2 Ozone stream to produce in one step ammonium nitrate, just adjust the current out put on the dry cell to match the NOx reactor, I actually have several dry cell circuits planned for my laboratory, for the generation of salts, hydroxides, carbonates and acids using off the shelf precursors that i need for a personal extractive mineral processing plant intened to keep me working at my rural home while paying the bills, from my mining claim which according to local code is legal upto 55 gallon drums which is more than i need uasly.

So far I have only finished a NOx plant and an electro-dialysis plant still have a few more dry cells to construct. The amount of trouble you have to go through to get reagents here in the US is very bothersome when you need them in quantity and supply, while the agents are not classified as controlled substances I have come to the conclusion that is is much more practical to manufacture them in quantity on location. However easier said than done sometimes, but once in place seems to work well.

However I have yet to crack the code on concentrating the agents from the dilute solutions rendered by some of the processes, currently I'm thinking about using commonly available reverse osmosis membranes as a means of making dilute high purity solutions convert to concentrated high purity solutions ready for crystallization while at the same time yielding large amounts of pure water my main problem is finding a way to pressurize the solutions in-order to force them though the membranes on my budget. Chem resistant pumps and pressure accumulators capable of 120 psi are not cheap to buy or operate.

You can see where this is going if we want chems we are going to have to develop more and more accessible and practical lab scale processes to produce them in quantity, however I find this to be along the line of an old saying

â€œif you don't give them the powder they are going to build the bombâ€

as far as public danger goes I believe it would be a lot safer to the general pubic if one could just buy the chems in the first place, the act of direct purchase creates a paper trail that can arouse suspicion, with lab production comes a lack of a paper trail and the danger of undetectable pilots increases by a huge magnitude, this thought would make me feel very uneasy if i where to live in a populated area

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob