6 replies to this topic

[frosty90]

Hi,

I recently extracted my first batch of K chlorate from my electrolytic cell. I filtered and re-crystalised once, to remove graphite. I did not boil the solution. Now that the stuff is dry I can notice two apparent crystal structures: There are 'flat sheets' which are certainly the potassium chlorate, but there are also a few long, thin needle like crystals. What are they? Could they be K hypochlorite? Should I boil the stuff in solution and re-crystalise? I'd take a picture, but I havnt got a good enough camera for such tiny things.

Cheers,
Jesse

[MDH]

That's potassium chloride. You haven't converted all of your chlorate. There is probably hypochlorite present as well.

[frosty90]

That's potassium chloride. You haven't converted all of your chlorate. There is probably hypochlorite present as well.

Ahh, your right. A quick search of the internet told me KCl crystals were cubic so I thought they must be something else, but I just crystalised some quickly in the freezer and what do you know: tiny needles. I cannot convert 'all' of the chloride in the cell; to save my graphite anode. I let it run for a while, then let it cool and settle, decant the liquid, and take the precipitated crystals, dissolve them in hot water, filter hot and re-crystalise, then rinse with ice water. I was under the impression that as the solution cooled, chlorate would precipitate out preferentially because it was much less soluble, and leave the chloride in solution? Is there a better technique?

Cheers,
Jesse

[Arthur Brown]

There are two major topics on SMDB currently running with all the interested hobbyist chlorate and perc producers contributing and researching literature. The old (now moved www) "cape canaveral" pages are linked in their new locations from there too.

[Bonny]

Ahh, your right. A quick search of the internet told me KCl crystals were cubic so I thought they must be something else, but I just crystalised some quickly in the freezer and what do you know: tiny needles. I cannot convert 'all' of the chloride in the cell; to save my graphite anode. I let it run for a while, then let it cool and settle, decant the liquid, and take the precipitated crystals, dissolve them in hot water, filter hot and re-crystalise, then rinse with ice water. I was under the impression that as the solution cooled, chlorate would precipitate out preferentially because it was much less soluble, and leave the chloride in solution? Is there a better technique?

Cheers,
Jesse

After harvesting the crystals, dump them into a bucket with a fine screen in the bottom (I use 200 mesh, but 100 would probably be fine).As they are draining, wash them several times with ice cold water.Make sure to stir as you wash to expose all the crystals to the cold water. This will remove most of the KCl. This water can be saved for recharging the cell. You can also do a final light wash with cold water/alcohol, which will speed drying (I've never done so though). You can then dissolve/filter/and recrystallize. Most of (any) remaining chloride will stay in the water. Give the crystals another cold water wash and the chloride level should be almost nil.

For more info check out the chemistry threads on apcforum.net

[frosty90]

After harvesting the crystals, dump them into a bucket with a fine screen in the bottom (I use 200 mesh, but 100 would probably be fine).As they are draining, wash them several times with ice cold water.Make sure to stir as you wash to expose all the crystals to the cold water. This will remove most of the KCl. This water can be saved for recharging the cell. You can also do a final light wash with cold water/alcohol, which will speed drying (I've never done so though). You can then dissolve/filter/and recrystallize. Most of (any) remaining chloride will stay in the water. Give the crystals another cold water wash and the chloride level should be almost nil.

For more info check out the chemistry threads on apcforum.net

Hi,

I did recrystalise and rinse with cold water, but only once. After two runs with graphite though Im sick of it, the finest particles cannot be filtered, even with good quality lab filters. I think I might now have a source of MMO anodes, if not Ive found some reasonably priced platinum, so I wont be bothering with chlorate again until I get these new anodes.

Cheers,
Jesse

[Bonny]

Hi,

I did recrystalise and rinse with cold water, but only once. After two runs with graphite though Im sick of it, the finest particles cannot be filtered, even with good quality lab filters. I think I might now have a source of MMO anodes, if not Ive found some reasonably priced platinum, so I wont be bothering with chlorate again until I get these new anodes.

Cheers,
Jesse

I never bothered with graphite only MMO. Check "The Agora" on apcforum.net, theres MMO anodes for sale there and they are great. I produced 20+ Kg's of (potassium) chlorate and the anode looks like new. DON'T use platinum for chlorate, only to convert chlorate to perc.