Arthur Posted February 3, 2015 Posted February 3, 2015 (edited) Great to see you back. Swede's findings were that robust electrodes were very expensive, I wish you luck on that one. My suggestions included that we used Swede's estimate of acid demand per amphour so that we could do fewer pH tests -prolonging the life of the elecrodes. UPS supporting the cell current could be hard, you may as well go for solar power. A cheaper protection against power failure would be a means of lifting the electrodes (relay controlled falling weight??) or a relay controlled method of dumping the electrolyte into a holding tank. Having seen (and seen the figures for) solar arrays on boats I suspect a hobby cell could be run from solar cells in the summer. Now that would be FREE chlorate, maybe free perc too. Edited February 3, 2015 by Arthur
MrB Posted February 3, 2015 Posted February 3, 2015 3. Stirred electrolyte mechanism.Electromagnetic stirrers are everywhere these days. Shouldn't be that hard to implement to a cell. Just place the plate under the cell bucket, and drop the magic bean inside, and your done. The only thing i'm not entirely sure about... This stuff is quite caustic, and i'm not sure what the bean is made of, or rather, coated with. I bet there are more then one coating in use, finding a supplier that has a bean that will work with our stuff should be possible. And as a bonus, the beans come in all sorts of different sizes and shapes.(Apparently the proper name is "stir bar", or even "flea". Not sure why, we always called them "magic beans" due to the size and shape of the ones we were using...) The PH probing is a problem. The caustic stuff kills the probes quite fast, and when it's not in use it should be rinsed, and stored in a storage solution. I think the "guesstimate" method, and manual testing every now and then to tune the feed might be the best way. I'm not entirely certain, but the additives seam hard to come by "over here" so i haven't even looked in to it that much.B!
WSM Posted February 3, 2015 Posted February 3, 2015 Hi guys, I'm glad you did achieve so much experience and knowledge through these years.You've inspired me to (maybe) try something new - automated pH control. Part of something I would call the ultimate DIY chlorate cell.To build an automated pH control, the hardest part would be trying to find chemical resistant mechanical parts. Also, to find a reliable and not very expensive pH meter for constant immersion duty.Although I think if someone tweaks the constant of HCl flow by trial and error, there is no need of auto pH regulation. I did it in previous times.In my vision, the ultimate cell would be1. Yield more than enough to satisfy one's needs2. Efficient3. Stirred electrolyte mechanism. This would ensure better electrolyte uniformity and lesser trapped base/acid in the crystals. Are some of you familiar with the horrible smell when you crush KClO3 crystals? 4. Autonomous. This means also a safety mechanism when faulty mains happens. A UPS for example. Hi 50AE, What sort of stirring method are you considering? WSM
Arthur Posted February 3, 2015 Posted February 3, 2015 The better stirrer bars have a PTFE coating which should resist the solution. Personally with a reasonable tank volume for the current passed through the cell I suspect that good mixing can be achieved simply by the hydrogen lift, maybe to have the electrodes off centre, will help the whole tank full to stir well.
Mumbles Posted February 3, 2015 Posted February 3, 2015 PTFE is the standard stir bar/magic bean coating in my experience. You can also find glass coated ones for special applications, but PTFE is the way to go here. The football (american football) shaped ones are probably the best suited. They handle viscous solutions and heavy amounts of precipitate the best. Crystalline chlorate toward the end may sieze a stirbar of a different geometry. Just thinking out loud really. Is there maybe some way to detect or estimate the pH indirectly? The amphour thing is probably the simplest and already largely figured out. Perhaps if there was a way to detect chlorate buildup or chloride depletion or even solution conductivity it may offer another route.
Arthur Posted February 3, 2015 Posted February 3, 2015 We used to make stir bars by putting an inch of bike spoke in a glass tube then sealing the end in a flame (was a bike factory so we had lots of spokes!). I also like the idea of a motor driven glass stirrer with either a propeller or a pair of glass links at the bottom. Hard worked mag stir bars can go spinning off and risk trashing an electrode or pH electrode.
50AE Posted February 3, 2015 Posted February 3, 2015 (edited) I was afraid that magnetic stirrer bars would be blocked from crystals at a point. More frequent cell emptying would be needed. If the stirring is powerful enough to keep the crystals away with the centrifugal forces, less worries then. Arthur, 5V at 30 A are 150W. Mains fault usually lasts to 30min - an average UPS should hold for this long. An alarm system with phone messaging would be a nice feature too. Edited February 3, 2015 by 50AE 1
Arthur Posted February 3, 2015 Posted February 3, 2015 Unless anyone comes up with a seriously robust pH electrode, pH readings are going to be by rapid interpretation of a fading piece of indicator paper.
Arthur Posted February 3, 2015 Posted February 3, 2015 I was wondering whether a 5v 30a output could be had from solar panels! OK that's 150w lets fit 500w of solar panels and charge a big battery and use the battery through a 12 - 5 smpsu to provide 30a all night as well as all day from solar energy
WSM Posted February 4, 2015 Posted February 4, 2015 (edited) I was wondering whether a 5v 30a output could be had from solar panels! OK that's 150w lets fit 500w of solar panels and charge a big battery and use the battery through a 12 - 5 smpsu to provide 30a all night as well as all day from solar energy If building them yourself, nearly any voltage/amperage combination is possible. Photovoltaic cells generally output 1/2 volt each and the current is based on the total surface area of each cell. By combining the multiple cells in series and parallel, your designed output is achieved. Next comes the battery backup and the maintenance of the whole system. It's all more trouble than I care to deal with. Now for (nearly) free power, the best bet is buy a piece of land with a stream that runs through it year round, build a water wheel and run an electric generator ! WSM Edited February 4, 2015 by WSM
WSM Posted February 4, 2015 Posted February 4, 2015 I was afraid that magnetic stirrer bars would be blocked from crystals at a point. More frequent cell emptying would be needed. If the stirring is powerful enough to keep the crystals away with the centrifugal forces, less worries then.Arthur, 5V at 30 A are 150W. Mains fault usually lasts to 30min - an average UPS should hold for this long. An alarm system with phone messaging would be a nice feature too. I like Mumbles suggestion of using an (American) football shaped, PTFE coated stirbar, which he says will resist bogging down when crystals start accumulating. If you're making sodium chlorate, any stirring scheme should work, but potassium chlorate crystals will get fairly thick on the bottom of the cell. WSM
ivars21 Posted February 4, 2015 Posted February 4, 2015 (edited) The problem with solar power is that you need some form of voltage regulator, as you cannot use it directly - unless you live in desert. If cloud shadows the panel, you have significant voltage drop. So if you design your panel to generate max 5V, then in direct sunshine you will get 5V, 80% of the time (if not tracked) you will get 4V or less even in sunny day, the current will not be linear either. Then there is a problem storing the energy at 5V, which is definitely not cost effective. It's just not worth it IMO, although the solar cell' prices have been dropping so fast past 5 years. Edited February 4, 2015 by ivars21
THEONE Posted February 6, 2015 Posted February 6, 2015 Lately i made a 3L cell with 660gr of NaCl with a homemade Mno2 anode and a SS cathode. The supply was from a computer power supply with 5v and 20Amp output. The cell was running for 5 days at a temperature of 50-55 oC. A lot of hypochlorite was made and the solution turn to deep green. After the run, i evaporate it down to 1L and i prepare some saturated solution of Kno3 for metathesis reaction. I want to mention that about 270gr of salt comes out during boiling process, and i though that that was Nacl. When i drop the kno3, a salt comes out. This salt it looks that it is pure sodium chlorate!! It looks than kno3 is not working for metathesis reaction. Also i Drop some drops of 35% HCl to the first 270gr and a reaction accures, so a presence of chlorate was there, but maybe not a lot. It looks the KCl is an one way road.
schroedinger Posted February 6, 2015 Posted February 6, 2015 Lately i made a 3L cell with 660gr of NaCl with a homemade Mno2 anode and a SS cathode. The supply was from a computer power supply with 5v and 20Amp output. The cell was running for 5 days at a temperature of 50-55 oC. A lot of hypochlorite was made and the solution turn to deep green. After the run, i evaporate it down to 1L and i prepare some saturated solution of Kno3 for metathesis reaction. I want to mention that about 270gr of salt comes out during boiling process, and i though that that was Nacl. When i drop the kno3, a salt comes out. This salt it looks that it is pure sodium chlorate!! It looks than kno3 is not working for metathesis reaction. Also i Drop some drops of 35% HCl to the first 270gr and a reaction accures, so a presence of chlorate was there, but maybe not a lot. It looks the KCl is an one way road.Sounds nice. If you want KClO3 There is no reason to boil down the liquid. It is near to insoluble, just cool the solution down to 0ºC and you get the precipate. Also for chlorate like you allready mentioned KCl is a lot easier to process.
WSM Posted February 7, 2015 Posted February 7, 2015 Sounds nice. If you want KClO3 There is no reason to boil down the liquid. It is near to insoluble, just cool the solution down to 0ºC and you get the precipate.Also for chlorate like you allready mentioned KCl is a lot easier to process. I'd recommend only cooling the solution down to 5oC or sodium chloride may drop out as well. WSM
WSM Posted February 7, 2015 Posted February 7, 2015 Lately i made a 3L cell with 660gr of NaCl with a homemade Mno2 anode and a SS cathode. The supply was from a computer power supply with 5v and 20Amp output. The cell was running for 5 days at a temperature of 50-55 oC. A lot of hypochlorite was made and the solution turn to deep green. After the run, i evaporate it down to 1L and i prepare some saturated solution of Kno3 for metathesis reaction. I want to mention that about 270gr of salt comes out during boiling process, and i though that that was Nacl. When i drop the kno3, a salt comes out. This salt it looks that it is pure sodium chlorate!! It looks than kno3 is not working for metathesis reaction. Also i Drop some drops of 35% HCl to the first 270gr and a reaction accures, so a presence of chlorate was there, but maybe not a lot. It looks the KCl is an one way road. Deep green? I wonder what that is? Do you think some manganese compound is present in the chlorate? WSM
WSM Posted February 7, 2015 Posted February 7, 2015 Last November I wrote a comment in the Bucket Cell thread regarding making potassium perchlorate via the sodium perchlorate method: "I wonder if our concerns about sodium contamination in the final product are overblown? I did a calculation based on the relative solubilities of sodium perchlorate and potassium perchlorate; I believe the potassium salt is about one percent (1%) the solubility of the sodium salt. At that rate, a simple wash with cold distilled water after vacuum filtering the KClO4, should leave the final product pure enough to use, as is, when dried and powdered. When used, I expect there'll be no sodium contamination to speak of." WSM
THEONE Posted February 7, 2015 Posted February 7, 2015 (edited) Deep green? I wonder what that is? Do you think some manganese compound is present in the chlorate? WSM Yes. I read in wikipedia that this is hypochlorite, and it forms at low temps. Chlorate says that they will form at higher temps, like 80-90. So i guess it is hypochlorite. Also some permanganate formed due to the pink color of the solution but this go off with some H202. Also with more H202 the green color go off and the liquid was clear. Also i saw in wikipedia that hypochlorite react with H202 to form oxygen, so that is why i believe that i had a lot of hypochlorite for some reason. I am thinking to increase the Amps to get the solution more hot, to see if hypochlorite will be formed again. I have seen other videos that ther solution was clear, not yellow - green like mine. The efficiency also was not very good, i guess this is because of the formation of hypochlorite Edited February 7, 2015 by THEONE
Arthur Posted February 7, 2015 Posted February 7, 2015 It's certain that manganese compounds are strongly coloured, and green is one of them. Whether you produced a green Mn compound I can't say. Having determined here that Laserred supplies good MMO I see little reason for working with other compounds for electrodes.
WSM Posted February 7, 2015 Posted February 7, 2015 Yes. I read in wikipedia that this is hypochlorite, and it forms at low temps. Chlorate says that they will form at higher temps, like 80-90. So i guess it is hypochlorite. Also some permanganate formed due to the pink color of the solution but this go off with some H202. Also with more H202 the green color go off and the liquid was clear. Also i saw in wikipedia that hypochlorite react with H202 to form oxygen, so that is why i believe that i had a lot of hypochlorite for some reason. I am thinking to increase the Amps to get the solution more hot, to see if hypochlorite will be formed again. I have seen other videos that ther solution was clear, not yellow - green like mine. The efficiency also was not very good, i guess this is because of the formation of hypochlorite I have seen the pale yellow-green tint of hypochlorite in my chlorate cell, but not what I'd call deep green. Hypochlorites are part of the process in making chlorates and our cells make a very strong solution of it. From a simple view of what happens in our cells, first the electrodes break down the water to hydrogen and oxygen ions. The oxygen ions combine with the chloride ions to form hypochlorite, hypochlorous and chlorate ions. The hydrogen ions form hydrogen gas which bubbles out of our cells. The whole process is much more complex than this, in reality. WSM
WSM Posted February 7, 2015 Posted February 7, 2015 It's certain that manganese compounds are strongly coloured, and green is one of them. Whether you produced a green Mn compound I can't say.Having determined here that Laserred supplies good MMO I see little reason for working with other compounds for electrodes. I agree. If you have access to MMO electrodes, that saves a lot of effort in the pursuit of useful pyrotechnics oxidizers. But, if you don't have access to MMO, and making your own is your only option, then the manganese dioxide coated CP titanium anode sounds like an attractive means to the end, if it works. WSM
WSM Posted February 7, 2015 Posted February 7, 2015 It looks the KCl is an one way road. My discovery of potassium chloride water softening salt at the local hardware superstore (many years ago) got me started on the path to discovering how to make my own oxidizers. I've made a lot of progress, but I confess, I'm more wrapped up in the engineering of it than pushing forward to complete it. I'm currently working on a small continuous system. I'd like it to have all the bells and whistles, and make a tidy job of it. We'll see in the end whether I've succeeded. WSM
WSM Posted February 7, 2015 Posted February 7, 2015 Yes. I read in wikipedia that this is hypochlorite, and it forms at low temps. Chlorate says that they will form at higher temps, like 80-90. So i guess it is hypochlorite. Also some permanganate formed due to the pink color of the solution but this go off with some H202. Also with more H202 the green color go off and the liquid was clear. Also i saw in wikipedia that hypochlorite react with H202 to form oxygen, so that is why i believe that i had a lot of hypochlorite for some reason. I am thinking to increase the Amps to get the solution more hot, to see if hypochlorite will be formed again. I have seen other videos that ther solution was clear, not yellow - green like mine. The efficiency also was not very good, i guess this is because of the formation of hypochlorite Another possibility for green coloration may be chromium compounds from the cathode you're using. Not likely when the system is running, but if the electrodes sit in the electrolyte with the power off, it's a possibility. With the power on, the stainless steel is protected by an effect called cathodic protection. Just a thought... WSM
THEONE Posted February 7, 2015 Posted February 7, 2015 (edited) A small part of the SS was out of the electrolite and this part was a little beat eaten by the solution. Maybe this will be the reason. It is a little difficult to me to find some KCL but i will see what can i do... Edited February 7, 2015 by THEONE
WSM Posted February 7, 2015 Posted February 7, 2015 A small part of the SS was out of the electrolite and this part was a little beat eaten by the solution. Maybe this will be the reason. It is a little difficult to me to find some KCL but i will see what can i do... Maybe so. Some of the most common sources for KCl are 1) water softening salt, 2) agricultural supplement (muriate of potash) or 3) dietary supplement (salt substitute). The agricultural grades are usually impure or have unwanted additives. If you're planning to use agricultural grade, it's best to dissolve it in water, filter it and recrystallize it before use in a cell. This technique will usually purify it enough to be servicable for our purpose. Where in the world are you? Different countries vary as to the materials available to the public. WSM
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