making potassium (per) chlorate

[WSM]

I've added two more blog entries, to add to what's already been posted. I have more to add later when I can make the time.

 

The saga continues...

 

WSM

Edited April 2, 2017 by WSM

[greenlight]

Very good read! Thankyou for uploading those entries as I will need that information in the end and I was not quite sure how to perform the chlorate destruction.

Thankyou...

[WSM]

In an effort to make pure sodium chlorate as feedstock for perchlorate manufacture, the need for purifying the salt used to make a pure brine became apparent. The result of research and experimentation toward that effort lead me to develop this simple, one page note:

 

Salt Purification

 

Mined salt is often refined in the production of table salt; it is dissolved in water, purified via precipitation of other minerals out of solution, and re-evaporated. –Wikipedia

 

Commercial chlor-alkali plants are known to purify their raw brine by treatment with sodium hydroxide and sodium carbonate to remove calcium and magnesium contaminants by filtration, leaving pure sodium chloride solution.

 

MgCl₂ + 2NaOH → Mg(OH)₂↓ + 2NaCl

95.205 79.9938 58.3188 116.88

 

CaCl₂ + Na₂CO₃ → CaCO₃↓ + 2NaCl

110.978 105.988 100.086 116.88

 

In raw brine solutions treated with sodium carbonate and sodium hydroxide, calcium carbonate and magnesium hydroxide are the flocculant precipitates that drop out and are removed by filtration.

 

Sodium carbonate, decahydrate (washing soda) - Na₂CO₃.10H₂O

Solubility: Cold H₂O - 21.52g/100ml H₂O Hot H₂O - 421g/100ml H₂O

 

Sodium hydroxide (lye, caustic soda) - NaOH

Solubility: Cold H₂O - 42g/100ml H₂O Hot H₂O - 347g/100ml H₂O

 

After the precipitates are removed, as a final step, any residual alkalinity in the brine may be neutralized with hydrochloric acid, resulting in more brine.

 

NaOH + HCl → NaCl + H₂O

Na₂CO₃ + 2HCl → 2NaCl + CO₂↑ + H₂O

 

When the brine is neutral (or slightly acid) it’s ready for use.

 

 

I hope you find this information is useful.

 

WSM

[Mumbles]

WSM, what are some average amounts you need to use to purify your brine? I assume this would be more necessary with NaCl sources such as rock salt or water softener salt.

[WSM]

WSM, what are some average amounts you need to use to purify your brine? I assume this would be more necessary with NaCl sources such as rock salt or water softener salt.

 

A correct assumption.

 

With a 4 gallon batch of brine (made from the water softener salt shown in Homegrown Oxidizers Part Eleven) in a new 5 gallon bucket, took about 350 ml of a 1M solution of sodium carbonate. The brine turned milky and by the next day the precipitate had dropped to the bottom of the bucket.

 

After stirring the brine, I filtered the precipitate from the brine using a large scale Buchner funnel and slow lab grade filter paper. The ultra-fine ppt was removed and the filtrate was left alkaline. The brine was next treated with dilute HCl till it was neutral to slightly acid and then run in the first sodium chlorate cell.

 

It appears that a solution of sodium carbonate works quite nicely to remove both calcium and magnesium contaminants in the brine.

 

WSM

[WSM]

As in purifying NaCl brine, I've wondered if KCl brine can be purified similarly? Some research is called for.

 

I've noticed dark spots in the KCl water softening pellets and suppose it's rust scale similar to that found in the sodium water softener salt. It remains to be seen what other contamination may be found, and hopefully removed by some means, to make a purer end-product.

 

I'll report whatever I learn on the subject.

 

WSM

[Mumbles]

I was under the impression that either calcium or magnesium carbonate were more soluble than they are. You learn something new every day I suppose.

 

I don't see any reason that KCl could not be purified in the same manner to remove calcium or magnesium. Carbonate should remove any soluble iron contaminants as well as either iron (II) carbonate or iron oxides under reasonable pH conditions. Iron (III) carbonate does not exist and will form rust or magnetite.

[WSM]

I was under the impression that either calcium or magnesium carbonate were more soluble than they are. You learn something new every day I suppose.

I don't see any reason that KCl could not be purified in the same manner to remove calcium or magnesium. Carbonate should remove any soluble iron contaminants as well as either iron (II) carbonate or iron oxides under reasonable pH conditions. Iron (III) carbonate does not exist and will form rust or magnetite.

 

In a neutral or alkaline brine they're not so soluble as in an acid environment. It also explains why so much sodium carbonate is used in laundry soap, where it acts to "soften" the water by the removal of "hardeners" such as calcium and magnesium (by precipitation).

 

It's my understanding that when sodium carbonate is dissolved in water, some is converted to sodium hydroxide; which helps explain why I succeeded in purifying my NaCl brine with carbonate solution alone, without adding any additional hydroxide. I think the reaction is exothermic, as well, which adds to the effect.

 

I hadn't thought of any iron solutions in there, but it makes sense since there were large bits of rust scale in the original salt. It appears the purification of the brine with sodium carbonate/hydroxide solution(s) is a wise first step in producing pure sodium chlorate.

 

Doing the same with potassium salts may be an excellent idea to consider, for safety as well as the quality of the final product (potassium chloride or chlorate).

 

WSM

Edited April 7, 2017 by WSM

[WSM]

It appears the purification of the brine with sodium carbonate/hydroxide solution(s) is a wise first step in producing pure sodium chlorate.

Doing the same with potassium salts may be an excellent idea to consider, for safety if not the quality of the final product (potassium chloride or chlorate).

WSM

 

With that in mind, I searched eBay for potassium carbonate.

 

Amongst all the high priced food and wine additives, I noticed a fiber drum of K₂CO₃ for $300 OBO plus $40 shipping. I figured; nothing ventured, nothing gained; so I offered $60 for it. They countered at $100 plus the shipping price.

 

When I carefully viewed their listing, I realized it was 25 Kilos (about 55 Lbs) of anhydrous ASC reagent grade potassium carbonate, and I could have it for the bulk technical grade price! To boot, I had a credit to apply which covered most of the shipping fee .

 

I made the purchase and am waiting for it to be delivered to my door.

 

I plan to keep it in reserve for various experiments, not the least of which is the purification of my water softener grade potassium chloride salt (preparatory to using it for high purity oxidizer experiments).

 

Yesterday was a good day.

 

WSM

Edited April 6, 2017 by WSM

[cyimforeu]

I am a newbie but would not think this is for amateurs. Cost of set-up and the "chance" it will turn out good odds aren't great. Also I wanted to respond to a member asking voltage for his cell. No more than 6v from my understanding.

[WSM]

I am a newbie but would not think this is for amateurs. Cost of set-up and the "chance" it will turn out good odds aren't great. Also I wanted to respond to a member asking voltage for his cell. No more than 6v from my understanding.

 

To get the big picture, try reading the blog section titled Homegrown Oxidizers, starting with part one and progress through them at your own pace.

 

Some of the discussions here are advanced, but we can talk about whatever you're interested in (and at whatever level).

 

Most amateurs run their cell at between 2.5 Vdc and 5.5 Vdc. Very much higher or lower voltages create problems for the electrodes. Remember, voltage only applies "electrical pressure" for the reaction, the main power component is the current, which feeds the required "volume" of electrons to drive the reaction.

 

WSM

[eb666]

 

A device like below would be great if you can afford it for you cell as it measures coulomb's.

 

http://www.ebay.co.uk/itm/120V-50A-DC-Wireless-DC-Voltmeter-Ammeter-Power-Meter-Capacity-Coulomb-Counter-/252497442774?hash=item3aca0537d6:g:j0MAAOSwIgNXrXa7

 

EB

[WSM]

 

A device like below would be great if you can afford it for you cell as it measures coulomb's.

http://www.ebay.co.uk/itm/120V-50A-DC-Wireless-DC-Voltmeter-Ammeter-Power-Meter-Capacity-Coulomb-Counter-/252497442774?hash=item3aca0537d6:g:j0MAAOSwIgNXrXa7

EB

Looks interesting. I'll study it more carefully later (I'm working some long hours now, all this week).

 

WSM

[Arthur]

Coulombs is useful but it's only Ampseconds.

[WSM]

Coulombs is useful but it's only Ampseconds.

So you have to divide the reading by 3,600 to make it useful (amp-hours)?

 

WSM

[Arthur]

Just have a list to hand of what some selected numbers mean. Or see what else the meter can display. A quick calculation should indicate what number of amp seconds is needed to convert a gram/mole of chloride. Extend the calculation to a saturated litre of solution needs nn,nnn coulombs to completion (assuming 100% CE). So once that value nn.nnn of coulombs has flowed, a litre of saturated brine is electrolysed to the CE %age, and some more chloride needs adding, Then when that chloride is electrolysed the first harvest can be taken out by cooling, and the process restarted.

[WSM]

Just have a list to hand of what some selected numbers mean. Or see what else the meter can display. A quick calculation should indicate what number of amp seconds is needed to convert a gram/mole of chloride. Extend the calculation to a saturated litre of solution needs nn,nnn coulombs to completion (assuming 100% CE). So once that value nn.nnn of coulombs has flowed, a litre of saturated brine is electrolysed to the CE %age, and some more chloride needs adding, Then when that chloride is electrolysed the first harvest can be taken out by cooling, and the process restarted.

 

I see your point. Depending on this meter will require experience with it and confidence in it's performance.

 

Assuming 100% efficiency is quite an assumption. I used 54% for my calculations, but I ran without pH control. Even with pH control, I'd estimate no more than 90% CE, just to keep things on the conservative side. Industry works very hard to get anywhere near 95% CE.

 

WSM

[Arthur]

Once you have a meter for coulombs or amphours you need a lot of guesses for working end point. I start by calculating, using 100% CE knowing that CE must be less than that. This means that there should never be much chance of driving the cell to a low chloride level that would harm an electrode. Probably a realistic estimate is more like 50% CE for an amateur cell.

[WSM]

Once you have a meter for coulombs or amphours you need a lot of guesses for working end point. I start by calculating, using 100% CE knowing that CE must be less than that. This means that there should never be much chance of driving the cell to a low chloride level that would harm an electrode. Probably a realistic estimate is more like 50% CE for an amateur cell.

That sounds reasonable.

 

By using a high temperature system as in the patent we've been discussing (for sodium chlorate), the end of the run is when the electrolyte level reaches about 50% of the starting volume.

 

The next part is crystal recovery at room temperature, plus recharging the depleted electrolyte with brine (rather than purified and dried salt).

 

I'm looking forward to trying this system out for myself. If the run time is shorter than the standard methods, every aspect of the hot system will show it to be the more desirable approach.

 

WSM

Edited April 17, 2017 by WSM

[WSM]

I got the anhydrous, ACS reagent grade potassium carbonate and plan to try a solution of it for purifying my water softener grade potassium chloride solution.

 

For confirmation, I put a little in a test tube, added some purified water to dissolve it and did a flame test, which showed the lavender potassium flame. Next I added a little 3M HCl and got vigorous bubbling (CO₂), indicating the label is accurate.

If I make and use purified potash brine, my finished products will be that much higher quality (whether chlorate or perchlorate).

WSM

Edited April 14, 2017 by WSM

[WSM]

I just donated a modest amount to the APC fund. I strongly encourage everyone to donate something to this worthy cause, so we can keep this site from going commercial (with all the annoying SPAM that would follow).

 

It doesn't have to be a large amount (though that would not be refused), but we can all afford something. Please hop off the fence and act soon so this site can remain free to all.

 

Thanks (stepping off the soapbox now).

 

WSM

[WSM]

WSM, what are some average amounts you need to use to purify your brine? I assume this would be more necessary with NaCl sources such as rock salt or water softener salt.

It appears that the best way to determine how much alkali (sodium carbonate solution in this case) is needed to purify the NaCl brine, is to titrate a known volume sample of the raw brine with the sodium carbonate solution (made up to a known Molar concentration) till no more "hardness" precipitates are formed.

 

By doing this and carefully measuring the amounts required to completely remove the contaminants, we can mathematically determine the quantity of unwanted compounds in our given volume of brine.

 

Once we know how much contaminant is dissolved in our brine sample, we can know two things:

• the percentage of contaminants present
• how much Na₂CO₃ solution is required to remove those contaminants by precipitation

"Knowledge is Power", and it's demonstrated in this case; where when we know, or have proven by scientific method, the concentration of the contaminants in our raw sodium chloride brine, we are enabled to remove them with a measured amount of alkaline sodium carbonate solution to prepare a pure brine which can be electrolyzed to a more pure end product.

 

In my case, the desired "end product" is pure sodium chlorate crystals, which can be electrolyzed further to sodium perchlorate solution, which (after removal of residual chlorates) can be converted by metathesis to potassium perchlorate.

 

It's occurred to me that a similar process to purify the potassium chloride brine should work to yield potassium chlor-alkali salts as pure or better than the commercial salts we can buy. I hope to demonstrate this in my research and share it here.

 

WSM

Edited May 3, 2017 by WSM

[WSM]

My progress has slowed lately due to a heavy work schedule (12 hour days, six days a week). This is becoming the norm and may continue until Summer (I hope not, but we'll see).

 

In the meantime, I'm trying to get things going with the high temperature sodium chlorate experimental cell. I've disassembled the cell and will repair the leaky electrode lead.

 

After the repair and reassembly, testing will prove whether it's ready to operate.

 

More to follow...

 

WSM

[WSM]

This morning, I tried to add a few more blogs on the Homegrown Oxidizers series in the blog section. I got a few done but suddenly my system crashes whenever I try to add Photo files to the blog.

 

This is frustrating .

 

Anyway, enjoy the ones that got put in correctly, and I apologize for Part Fourteen as I'm stuck.

 

WSM

 

Edit: The new blogs are beginning to detail my efforts in making sodium chlorate.

Edited May 8, 2017 by WSM

[greenlight]

Good stuff WSM I will need that blog soon especially for the processing of the electrolyte. Well hopefully soon.

 

I installed the 200 amp shunt today after finally receiving it. Instead of 297 amps which the last one was reading, it now reads 111 amps which is still wrong considering the power supply is only 20 amp.

It is wired correctly too and I have no idea what the problem is.

Edited May 19, 2017 by greenlight