22 replies to this topic

[Gary]

Hi all,

Recently, I made a batch of potassium perchlorate by electrolysis. However, it is heavily contaminated with chlorate, which means that I will not be able to use it in pyro formulas containing the ammonium ion (there's the potential for the formation of the dangerously unstable ammonium chlorate), copper, or sulphur.
Could I use iron(2) sulphate to destroy the chlorate? I assume that the iron 2+ will be oxidised by chlorate to iron 3+, and that the chlorate will be reduced to chloride. To remove the sulphate ion, I might be able to use barium chloride, to precipitate as insoluble barium sulphate. I will use potassium hydroxide to keep the solution slightly alkaline, to prevent the formation of the highly unstable chloric acid, and also to precipitate the iron as the insoluble hydroxide, which can be removed from solution by filtration.

[Bonny]

Here are some links that might help:

http://www.wfvisser....el_purification

http://www.geocities...te/destroy.html

[wjames]

i'll be honest, i have no idea what-so-ever.




But, what i do know.....is you want to be wearing gloves what ever you do !!!!

[MDH]

Sodium Metabisulfite is both widely available, and frequently used in the destruction of chlorates into chloride.

As mentioned in the previous link, ferrous sulfate will also work excellently - and it's also used to manipulate black powder speed.

[knackers]

thermal decomposition is a process you could use,, it will oxidise the chlorate to perchlorate and it will also reduce some of the chlorate to chloride,

it is similar to auto oxidation but alot quicker

[MDH]

The yield of such a process is very poor.

[knackers]

maybe so, but i am only offering another option, and besides....he already has perchlorate so that won't change, and you don't lose anything,, you still have your chloride to go again and your pechlorate for whatever

http://www.freepyroi...rchlorate_1.pdf

Edited by phill 63, 30 October 2008 - 09:39 AM.

[Arthur Brown]

BEFORE you try to make perc you need to have all the analysis methods and reagents sorted our to do proper analysis of the product.

Electrolysis IS the industrial method of perc production, but they have all the lab kit ready for the analysis.

[knackers]

MDH, on Oct 30 2008, 03:26 PM, said:

Sodium Metabisulfite is both widely available, and frequently used in the destruction of chlorates into chloride.

As mentioned in the previous link, ferrous sulfate will also work excellently - and it's also used to manipulate black powder speed.

you state in your previous reply, Quote..." the yield of such a process is poor " (thermal decomposition )

can you tell me if perchlorate will be made with sodium metabisulphite destruction to chloride ?

Edited by phill 63, 30 October 2008 - 10:46 AM.

[Bonny]

phill 63, on Oct 30 2008, 10:45 AM, said:

you state in your previous reply, Quote..." the yield of such a process is poor " (thermal decomposition )

can you tell me if perchlorate will be made with sodium metabisulphite destruction to chloride ?

If I understand it correctly, the metabisulphite will only detroy the residual chlorate without affecting the perchlorate.

[Gary]

MDH, on Oct 30 2008, 04:26 AM, said:

Sodium Metabisulfite is both widely available, and frequently used in the destruction of chlorates into chloride.

As mentioned in the previous link, ferrous sulfate will also work excellently - and it's also used to manipulate black powder speed.

I've had a look at Visser's site and found it to be very useful. However, he does'nt mention how sulphate should be removed from the perchlorate solution once all the chlorate has been destroyed. My guess is to add barium chloride solution until no more clouds of white precipitate (BaSO4) are produced, then filter-off the insoluble barium sulphate.
During electrolysis, I added a small amount (5g/L) of sodium dichromate to prevent reduction of the perchlorate. Incidentally, barium chloride will remove the chromate ion from solution, by precipitating it as the insoluble barium chromate, which can be filtered-off.

[Gary]

wjames, on Oct 30 2008, 01:17 AM, said:

i'll be honest, i have no idea what-so-ever.




But, what i do know.....is you want to be wearing gloves what ever you do !!!!

Do'nt worry- I'm very safety-concsious. I know what I'm doing! I am fully aware of the hazards chemicals pose. In fact, I carry-out my own risk assessments before embarking on any pyro experimentation.

[Arthur Brown]

Have you done any analysis of the product? You should have a good amount of Perc and demonstrably little Chlorate before you bother with the destruction and purification.

Perc is available from reputable pyro suppliers in the UK (inc one in Guildford!) at commercial purity. Good perc costs �10 - 20 a Kilo fingers eyes and face - priceless

http://www.pyrosocie...p?showtopic=426 is a huge thread giving LOTS of detail read it right through.

It's far too easy to make chlorate but not so easy to get a good yield of perchlorate and prove it is chlorate free. You really do need to produce a solution containing well less than 1% solids as chlorate the rest as good perc. can you not electrolyse down to a proven low ppm of chlorate.

If you have a ClO3 ClO4 mix and you destroy the ClO3 then you could be destroying half of the electrolysis you have done, or MORE.

[knackers]

.

Edited by phill 63, 31 October 2008 - 08:23 AM.

[Gary]

Arthur Brown, on Oct 30 2008, 08:36 PM, said:

Have you done any analysis of the product? You should have a good amount of Perc and demonstrably little Chlorate before you bother with the destruction and purification.

Perc is available from reputable pyro suppliers in the UK (inc one in Guildford!) at commercial purity. Good perc costs �10 - 20 a Kilo fingers eyes and face - priceless

http://www.pyrosocie...p?showtopic=426 is a huge thread giving LOTS of detail read it right through.

It's far too easy to make chlorate but not so easy to get a good yield of perchlorate and prove it is chlorate free. You really do need to produce a solution containing well less than 1% solids as chlorate the rest as good perc. can you not electrolyse down to a proven low ppm of chlorate.

If you have a ClO3 ClO4 mix and you destroy the ClO3 then you could be destroying half of the electrolysis you have done, or MORE.

I done a qualitative analysis on my 'perchlorate' product: the conc. sulphuric acid-sugar method. I have no doubt that a substantial amount of chlorate is present in my product, but ther's no reason why there should'nt be any perchlorate present- I used a platinum (wire) anode (Pt has a high oxygen overpotential), stainless steel cathode, and a small amount of dichromate additive to prevent reduction of any perchlorate formed during electrolysis. By the way, I am talking about sodium perchlorate- I have not converted it to the potassium salt yet.

I find the price of perc to be a tad expensive- I'd rather make my own. I actually enjoy making my own pyro chems, especially those 'hard to find' chems- there are no UK pyro websites selling barium compounds for pyrotechnic greens.
I certainly do'nt have a cavalier attitude towards chemical safety, but owing to the health and safety 'Nanny state' and overly repressive safety legislation, chemical companies are no longer able to supply even moderately hazardous chemicals to amateur chemistry and pyro enthusiasts: so what do I do?-I put my chemistry knowledge into action and make my own! Safely, of course.

Edited by Gary, 31 October 2008 - 10:23 PM.