Ammonium Perchlorate 2x failed. Why?

[cornz]

OK, beginner here, so be gentle.

Made myself a MMO+ and Titanium- electroylosis cell.

Used Potassium chloride and made pot chlorate. Thermally decomposed to potassium perchlorate.

All well and good.

 

Decided to try Ammonium perch.

Had two attempts using sodium chloride then planning to displacing with ammonium chloride to precipitate ammonium perchlorate out.

Took 500g of non iodised halite and a platinum anode. Anode from same guy as the MMO one which works for kci03.

Ran for several DAYS at 6-7v dc at 28 amps.

Ran in a water jacket for temp control.

Periodically tested for perchlorates with methylene blue, no perchlorates present (i was expecting some). Tested my ethylene blue with my home made pot perch and it reacts as it should.

So, if i am understanding the process correctly, there should be perchlorates present in my liquid that has undergone the electrolysis.

I'm wondering if my cathode is buggered, can stainless steel be used as a suitable cathode with my platinum anode?

 

My first attempt using store bought table salt had much the same result. No detectable perchlorate.

 

Half of my wants to dump my ammonium chloride into the solution and see if anything does fall out but i understand ammonium chlorate is far too unstable for safe use. I'm only wanting a few ounce to play with. Anyone care to suggest what i could be doing wrong?

 

 

 

 

 

 

[Thothermes21021]

For producing perchlorates you need lead dioxide or platinum anodes. If you use MMO electrodes you wound only produce chlorates. The most affordable electrodes are the lead dioxide ones. You can buy them or make them by yourself. Personally I tried to make them but because I used a carbon rod instead of graphite so the film of lead dioxide when doing the electrolysis would just fall of. So at the end I just bought it.

Once you have the right electrodes you have to control de pH at around 6.5. You could do that by small additions of HCl from time to time or using potassium or sodium persulfate at a concentration of 2g/L.

[cmjlab]

Seems it would be safer if you have pure KCL04 to do a double displacement with Ammonium Chloride to make AP? Then you wouldn't have to worry about the possibility of Ammonium Chlorate formation.

Fair warning, I've not made it this way personally, as it's easier for me to purchase.

[Thothermes21021]

KP is less soluble than AP, so a double displacement reaction won't work. To avoid formation of Ammonium Chlorate you have first to destroy the remaining chlorates present in the solution. By adding sodium or potassium metabisulfite you would destroy the chlorates presents. Then for eliminating the sulphates the solution is treated with barium carbonate and filtered. Now you can do the double displacement reaction with ammonium chloride.

[cmjlab]

I agree that it is less soluble at lower temperatures, which is why it requires heat input to exploit the increased solubility at 100 degrees Celsius.

 

I admit I'm not a chemist, but several parents related to making AP from Potassium Perchlorate and Ammonia Chloride exist, as well as several videos demonstrating the process. So to outright dismiss it as a viable solution seems a little premature.

 

However, it was simply a suggestion to the OP, who will need to take everyone's input and do the research themself to determine what is the safest, most appropriate route for materials on hand, and accept the remaining risk (or not).