making potassium (per) chlorate

[theodusta]

As to pH paper, it's tricky to use with the cell electrolyte because of the bleaching that occurs. What I've done is dipped the tip of the pH paper strip (cheap, but effective pH paper strips from China, purchased on eBay) and quickly observed the lead edge of the wet portion, where a hint of the color change exists for a moment before it bleaches out. It's not perfect, but it is an indication of where the pH is.

 

As Swede clearly says in his blogs, pH pens are quickly destroyed and the best pH sensors are slowly destroyed by exposure to the electrolyte. Due to the nature of the pH sensors, they tend to be "poisoned" by the electrolyte and rendered unusable. Swede explains all of this quite well in his blogs (if you haven't guessed yet, I recommend reading his blogs).

 

What type of pH paper are you using, Theo? If it's not the pH paper, maybe your technique can be modified so you can at least use it for an educated guess as to the pH your cell is running at.

 

Good luck.

 

WSM

 

I read the article about pH measurements from swede. He gave a lot of good tips, but I don't have a pH meter. A good one would cost here at least 220€ and I am looking for a way to measure the pH with strips, as my cell will not run the whole year ^^

 

I am using this pH paper: https://images-na.ssl-images-amazon.com/images/I/41LFfk9s%2BkL.jpg

 

It goes from 0 to 14. To obtain a moderately useful pH value I have to read out 4 colors at the same time this makes it tricky for me to read it out so fast with this strips. But it bleaches out anyway when it is getting in contact with the liquor sample.

 

Yesterday I have also tried this method taken from utahpayro's manual http://www.utahpyro.org/compositions/PreparingChlorates.pdf

 

"Measuring the pH of the solution can be done with common pH paper. However, if the paper is simply dipped directly into the electrolyte the hypochlorite present will usually bleach the paper making a measurement impossible. This problem can be overcome by boiling a sample of the solution for 5 minutes and measuring the pH of that. The boiling destroys the hypochlorite."

 

Without success. It's hard to boil a sample of 5 to 10ml for 5 minutes without evaporating it. It was done with a bunsen burner and a test tube. The only thing I got was a filthy hot plate and a pH strip which bleached out faster than before ^^

 

You have to use a ph meter for this... ph test strips won't work since as you said it bleaches out immediately. However what you can try is dilute them a bit and then use the test strip, but look at the color fringes rather than the wet strip...

 

Buying an expensive ph meter is out of the question for me but thank you for the hint with the dilution! I will give this a try. Do you have a ratio for diluting the sample with water?

 

 

 

I should mention, the blog section is set up to show the latest entry first. To read them chronologically, you may wish to go to the last entry and read them in reverse order. I find that starting on page 11 of Swede's blogs avoids the multiple postings of his excellent article on tubular leads.

 

Happy hunting!

 

WSM

 

Yes, I got a lot of very useful hints from swede and your blogs so far!

Edited November 13, 2016 by theodusta

[WSM]

I am using this pH paper: https://images-na.ssl-images-amazon.com/images/I/41LFfk9s%2BkL.jpg

It goes from 0 to 14. To obtain a moderately useful pH value I have to read out 4 colors at the same time this makes it tricky for me to read it out so fast with this strips. But it also bleaches out instantly when it is getting in contact with the liquor sample.

 

Ah, yes. I was afraid you were using those "high end" pH strips.

 

If you have access to the plain paper pH strips (which often come in a roll or pad and starts as an orange color), that aren't as specialized as the type you're currently using, maybe you'll have better results. If you can get some, let us know if you have better results with it.

 

WSM

Edited November 15, 2016 by WSM

[MrB]

It's hard to boil a sample of 5 to 10ml for 5 minutes without evaporating it. It was done with a bunsen burner and a test tube.

 

Use a larger sample? Also, a closed, recirculating system which returns the boiled of steam as a condensate to the sample, would limit the size of the sample needed somewhat.

I suppose a different tactic could be simply not to let it boil. If my understanding is right, it's the temperature that is significant, and in that case, sealing the sample, and tossing it with water in a pressure cocker, should do the trick? Since it effectively is water, the sample, and the water in the boiler would retain the same pressure, making it somewhat easy to maintain the integrity of the sample.But i guess that all boils down to if it's actually the temperature making the difference. And if so, what temperature is actually needed. Perhaps it doesn't have to boil at all? 60, 80c?

 

Diluting it with a source of water with the "wrong" pH would give misleading data, but i suppose adding two sources of data, one which is known, (test the supply your using to dilute with?) and doing some maths should give a reasonable estimate? Different chems buffers differently, so i dunno if it would be accurate. Mum, is the science head, i defer to him. WSM rocks to, so if he has no objections...

B!

[Visco]

Here's an update on the anodes, I had to open up a DHL import account to get a price on shipping. As soon as they issue my account number we should be on schedule to recieve a small test batch if all is well with quality the price should be around $20.00 to $25.00 depending on import shipping cost. That's allot better than the $50.00 from the first company.

[Arthur]

For those without access to perc, $25 or $50 it barely matters if this is the key to getting perc.

[WSM]

Here's an update on the anodes, I had to open up a DHL import account to get a price on shipping. As soon as they issue my account number we should be on schedule to recieve a small test batch if all is well with quality the price should be around $20.00 to $25.00 depending on import shipping cost. That's allot better than the $50.00 from the first company.

 

That's great news. I'd be happy to test one out, if you'd like. Let me know (and how much to send). Thanks.

 

WSM

Edited November 17, 2016 by WSM

[WSM]

For those without access to perc, $25 or $50 it barely matters if this is the key to getting perc.

 

That's true, but the lower the cost, the more people who'll be able to take advantage of the opportunity to make their own. This is a good thing.

 

WSM

[WSM]

Use a larger sample? Also, a closed, recirculating system which returns the boiled of steam as a condensate to the sample, would limit the size of the sample needed somewhat.

I suppose a different tactic could be simply not to let it boil. If my understanding is right, it's the temperature that is significant, and in that case, sealing the sample, and tossing it with water in a pressure cocker, should do the trick? Since it effectively is water, the sample, and the water in the boiler would retain the same pressure, making it somewhat easy to maintain the integrity of the sample.But i guess that all boils down to if it's actually the temperature making the difference. And if so, what temperature is actually needed. Perhaps it doesn't have to boil at all? 60, 80c?

Diluting it with a source of water with the "wrong" pH would give misleading data, but i suppose adding two sources of data, one which is known, (test the supply your using to dilute with?) and doing some maths should give a reasonable estimate? Different chems buffers differently, so i dunno if it would be accurate. Mum, is the science head, i defer to him. WSM rocks to, so if he has no objections...

B!

 

Hi MrB,

 

I'm not sure. I avoided the fancier pH papers so I could keep it simple. I find the 1-14 pH paper, though not specific enough for fine work, does allow a general indication of pH to the whole number. When I use it in a sample of electrolyte, I get maybe a 1 to 1.5 mm band of color at the lead edge of the wetness before it bleaches out. This has been enough to clue me as to the pH level the electrolyte is at.

 

I've not tried diluting or boiling the electrolyte for pH measurement, and I don't know how or if it would work; or even the accuracy of doing so.

 

Perhaps Mumbles has more information to offer on the topic.

 

WSM

[Mumbles]

There really isn't a good answer for this. Maybe get some cheap-o electric pH meter off of amazon? Ideally if sampling and immediately rinsing the lifetime would be okay. If not, they're only about $15-20. I have the following one for beer brewing. So far so good. I haven't checked against a good meter, but the readings are all about where I've expected so far.

 

https://www.amazon.com/Alkaline-Hydroponics-Calibration-0-00-14-00-Measurement/dp/B018J40IKU/ref=sr_1_5?ie=UTF8&qid=1479236119&sr=8-5&keywords=pH+meter

 

The real issue with some of the work arounds is that they don't accurately measure the pH of the cell in working conditions, which is what we really care about. Boiling destroys the hypochlorite by turning it into chlorate and chloride, but also will change the pH. Boiling it without boiling off the water shouldn't be hard by using a watch glass over a beaker or flask or even a cold paper towel around the top of a test tube, or you could just dilute with distilled water by the amount that will get boiled off. Hypochlorite is a basic material. It's actually also only really stable in basic conditions. I think this is partly what drives the increase in efficiency from regulating the pH. Additionally diluting will change the pH to some degree. If you know the dilution, you can possibly back out the "real" pH though. Dilution may slow the bleaching, but I don't think it will prevent it. I don't have an operational cell, so if that's a route you're looking into, you'd have to see if dilution works or helps.

[WSM]

Several months ago, Arthur shared a patent he found with me for producing sodium chlorate. In the patent (Circa 1962, when graphite anodes were state-of-the-art), it recommends switching to platinized titanium anodes and running at greatly increased temperatures (between 105^oC and 115^oC) so the water will evaporate as the cell runs, naturally concentrating the liquor so sodium chlorate levels will be high enough to harvest from the cell in greatly increased amounts. Another benefit is feeding the cell with purified brine and not dry salt, eliminating many extra steps.

I'm thinking a cell made with PVDF polymer can operate up to 121^oC, so with the average boiling point of sodium chlorate cell liquor (a mixture of NaCl and NaClO₃) being between 105^oC and 115^oC (average 110^oC), this could work. Another option would be a borosilicate (Pyrex) beaker. There are many hurdles to overcome but I think it's at least possible and bears further investigation.

WSM

 

A few years ago I found a company on eBay selling 16 foot lengths of 90 mm OD PVDF pipe with a 2.7 mm thick wall. I asked whether they would cut one to 4 four-foot lengths (to lower the shipping costs) and they agreed, plus they accepted my ridiculously low offer. They had many of these lengths of pipe which weren't selling, partially because at the full length they'd have to be truck freighted at great expense.

 

 

A trial cell between 12" and 15" in length could be made up to test the idea of a high temperature sodium chlorate cell. With such a thin wall, compatible outer insulation would be called for. I have some heavy duty 90 mm PVDF pipe caps that could be press fitted onto this pipe for a bottom closure and the whole thing set up to test the idea and determine whether it's viable.

 

The plan would involve larger MMO and titanium electrodes running with high current and much hotter than normal (the goal is between 105^oC and 110^oC). At that temperature, the water will boil off during the run (and a larger vent would be necessary) plus the electrolyte will concentrate the chlorate where decent yields can result at room temperature (rather than refrigerated, saving even more expense and effort). The other great plus is that dried, purified salt won't be required, just the purified brine (which will save lots of energy and effort in the preparation of the starting material), and make for a cleaner setup.

 

We'll see...

 

WSM

Edited November 19, 2016 by WSM

[WSM]

A few years ago I found a company on eBay selling a 16 foot length of 90 mm OD PVDF pipe with a 2.7 mm thick wall. I asked whether they would cut it to four 4 foot lengths (to lower the shipping costs) and they agreed, plus they accepted my ridiculously low offer. They had many of these lengths of pipe which weren't moving, and at the full length they'd have to be truck freighted at great expense.

IMGP7478.JPG IMGP7479.JPG

A trial cell between 12" and 15" in length could be made up to test the idea of a high temperature sodium chlorate cell. With such a thin wall, compatible outer insulation would be called for. I have some heavy duty 90 mm PVDF pipe caps that could be press fitted onto this pipe for a bottom closure and the whole thing set up to test the idea and determine whether it's viable.

The plan would involve larger MMO and titanium electrodes running with high current and much hotter than normal (the goal is between 105^oC and 110^oC). At that temperature, the water will boil off during the run (and a larger vent would be necessary) plus the electrolyte will concentrate the chlorate where decent yields can result at room temperature (rather than refrigerated, saving even more expense and effort). The other great plus is that dried, purified salt won't be required, just the purified brine (which will save lots of energy and effort in the preparation of the starting material), and make for a cleaner setup.

We'll see...

WSM

 

The question in my mind right now is if I could design the cell to be self-heating (to about 105^oC or slightly more) with just oversized electrodes or whether I'd have to add a compatible immersion heater? I believe it can be done with just the large electrodes but it needs to be tested.

 

If this proves to be a workable design, the problem will be the expense if trying to scale up the process. If it does work as described in that old patent, and I'm able to scale it up, making respectable amounts of sodium chlorate; from which could be made sodium perchlorate (and then other desirable perchlorates) will be a practical reality and not just a laboratory curiosity.

 

I think it's worth the effort to test the theory. Wouldn't it be nice to be self-sufficient for pyrotechnics grade potassium perchlorate?

 

WSM

 

Edit: My idea is to modify the design by substituting MMO for the platinized titanium and use CP titanium for the cathodes.

Edited November 18, 2016 by WSM

[WSM]

The patent I'm referring to is US3043757. It was applied for in 1959 and awarded in 1962.

 

US3043757 Enhanced Sodium Chlorate Process 6-16-15.pdf

 

I'm planning on building a small prototype high temperature NaClO₃ cell and see how it runs. One major difference is I plan to use MMO instead of platinized titanium.

 

If this works as well as I hope it will, It'll mean a major change in the way I approach sodium chlorate production (simplifying the steps).

 

Thanks to Arthur for finding and sharing it with me.

 

WSM

[taiwanluthiers]

Has there been any words on lead dioxide anodes?

 

It appears those things are commercially manufactured for waste water treatment, so I wonder if we can go that direction as far as obtaining an anode?

[Arthur]

One of the things we must consider with old patents and literature searches is that all parts of the process will have changed and improved over the years. Carbon electrodes have gone! Platinum electrodes have largely been replaced by lead dioxide etc we still can learn but we have a lot of catching up to do to be where the industry was 50 years ago.

[Visco]

Yes I have a small batch of lead dioxide anodes being made as we speak. Should be in my hands within 10 to 12 days. Price should be $20 to $25 each depending on what all the shipping racks up don't have an exact figure yet. I'll keep everyone updated.

[memo]

I have some interest in getting one

 

memo

[taiwanluthiers]

I'd like to get one assuming it becomes available. Shipping from China is cheap, oddly the same price as domestic shipping in the US. I bought stuff on ebay coming from China, and other than it taking longer to arrive the shipping cost is about the same.

[WSM]

Yes I have a small batch of lead dioxide anodes being made as we speak. Should be in my hands within 10 to 12 days. Price should be $20 to $25 each depending on what all the shipping racks up don't have an exact figure yet. I'll keep everyone updated.

 

I'd be interested in buying at least two (if you get enough to support that many to one person). I'd like to see how they compare to the others I've bought and used.

 

After we get a good source for LD on titanium anodes, it would be wonderful to have a commercial source for LD on graphite anodes.

 

These are exciting times .

 

WSM

Edited November 20, 2016 by WSM

[WSM]

One of the things we must consider with old patents and literature searches is that all parts of the process will have changed and improved over the years. Carbon electrodes have gone! Platinum electrodes have largely been replaced by lead dioxide etc we still can learn but we have a lot of catching up to do to be where the industry was 50 years ago.

 

That's true, but remember; in these days of developing hypersonic aircraft and missiles, we're still making black powder rockets for entertainment. So making our own oxidizers using techniques many decades older than state-of-the-art for today is far closer to current methods than that. Why, we're downright modern by comparison.

 

There are many types of anodes with a high enough oxygen over-potential, which can be used to convert sodium chlorate to sodium perchlorate, but they aren't available to us at an affordable price, so the point is moot. When I wrote about making perchlorates in the blogs, I limited my discussion of anodes to things I could get my hands on. Anything else (if unavailable to us) serves no practical purpose.

 

WSM

Edited November 21, 2016 by WSM

[WSM]

I'd like to get one assuming it becomes available. Shipping from China is cheap, oddly the same price as domestic shipping in the US. I bought stuff on ebay coming from China, and other than it taking longer to arrive the shipping cost is about the same.

 

I've had similar experiences buying things from China (on eBay). Most come in 7 to 10 days, especially light weight things. I did order a machine once, weighing about 15 kilos and it took a full month to arrive; but I'm very glad to have it (it was worth the wait).

 

The difficult part will be shipping the anodes inexpensively after they arrive here in the US, especially internationally (Ouch!).

 

WSM

Edited November 20, 2016 by WSM

[Visco]

I don't know exactly what shipping will be but it is somewhat expensive! The only way this company will ship is DHL express air which is not cheep. This is a small sample batch but if the quality is good I will turn around and place a larger order. We'll just have to see how these turn out.

[taiwanluthiers]

Why won't they ship China mail? It's cheap and it works. Is it an issue of the thing being fragile or is there something else at play? You need to negotiate with them more... I know one thing about Chinese is they are always open to negotiation, they love money more than they love God.

[WSM]

Why won't they ship China mail? It's cheap and it works. Is it an issue of the thing being fragile or is there something else at play? You need to negotiate with them more... I know one thing about Chinese is they are always open to negotiation, they love money more than they love God.

 

It may have to do with a shipper who'll ship hazardous materials with few restrictions. Folks who handle package shipping on our end tend to go nuts if lead (Pb) or other toxic materials are involved; justified or not.

 

Let's see how this turns out and if the anodes are up to the task.

 

WSM

Edited November 21, 2016 by WSM

[Arthur]

The Chinese must use a lot of perc, and I'm guessing that they do NOT pay US or Europe prices for it, so they must be able to make it and have the electrodes available, sadly no-one really wants an electrode metres square.

[patsroom]

Update. I have found a new supplier for anodes and the prices look good. As long as shipping doesn't become a problem we may be able to make this thing work. I'll let everyone know as I get the full quote and details.

I travel that very same road. Oh, the girl on the other end said all the right things to me. Told me that the anodes will last years,hold up to fifty ampes and make all the prechlorates I could use if IIRC. Had to buy alot of them at a time. Did it twice lost alot of money, worse was that others here on the forum lost as will because I was not able to test them before I released a few of them. I still have quite afew left as alot were chipped and cracked from shipping. But if you do better than me, I'm in and would like one that's for sure!............Pat