taiwanluthiers Posted July 17, 2014 Posted July 17, 2014 (edited) The platinum did not dissolve, it simply flaked off, There was a bunch of crud at the bottom of the cell. I used tap water, and aside from chlorate and water I only added some potassium dichromate. I do not know the chloride content of the cell... I doubt the tap water had chloride in it at all, most the ions in it was carbonate. Starting stock was potassium chlorate I just wonder if it was due to the very low amp draw at 5 volts, or too low of a voltage. I could get a higher amp draw at 12 volts but it's like way too high, so high that when I tried it I let the blue magic smoke out of the computer power supply... so it's dead. I just wish there was a way to get a voltage in between... I tried rigging it to get 7v out of it but no matter what the power supply will NOT turn on. Edited July 17, 2014 by taiwanluthiers
pyroChile Posted July 17, 2014 Posted July 17, 2014 (edited) Nothing good... I ran the cell longer and ALL the platinum eroded from the anode. I do not know why, but I was using a computer power supply at 5 volts, and the amp was really low. No idea what was the deal here. It does not look like any perchlorate formed at all. I tried again using the old LD anode, and a KNOWN pure chlorate sample (reagent grade) to see if it was due to small amount of chloride contamination, and ran it at 12 volts, then the power supply died like within 30 minutes. It was pulling 20 amps before that. I don't know where to get a real power supply, because with a computer power supply it was either 5 volts or 12 volts, and nothing in between. The only real power supply I can find is only capable up to 3 amps so if I want to run it at 15 amps I'd have to get like 10 of those... Hello. How much electrolyte? ( for platinum plated, max 2 amp per 100 ml) What kind anode? ( 100 microinch, is recommended) It is important to control the pH 6.8 to 7.0 (where the HClO and ClO ^ - are in a 2:1 ratio) for conversion to chlorate, due to a high ph (which is what tends to rise, because chloride escapes) will generate all the HClO dissociate in ClO-, preventing can generate ClO3 from the HClO + ClO- then the only way to generate is having contact with the anode, which results in more power would be needed (9 e) in that if there equilibrium with HClO and ClO-, needing 6e. Further more hypochlorous ion and chlorate is reduced at the cathode and oxygen at the anode occurs escaping. Occur first chlorate and then perchlorate... After ensuring the production of chlorate, it can raise the alkaline pH to produce perchlorate. (ClO3)ad + OH- --> ClO4- + H+ +e- Oxygen production is eroding the anode, so you have to control pH at the beginning (calculate time for chlorate.. 106 Amph per mole), because if there is no oxygen, it occurs at the anode. Ph is controlling with acid perchloric. Not acid hydrochloric. Best regards, =) pd: sorry for may bad english (google translator) Edited July 17, 2014 by pyroChile
taiwanluthiers Posted July 17, 2014 Posted July 17, 2014 I don't use platinum to make chlorate, especially when MMO does the job cheaper and more efficient.
pyroChile Posted July 17, 2014 Posted July 17, 2014 (edited) I don't use platinum to make chlorate, especially when MMO does the job cheaper and more efficient. What I told you is what occurs in a cell for perchlorate with platinum anode. Chemical reactions occurring in this way, first the chlorate is generated in the cell and chlorate solution then is oxidised to perchlorate. So as a tip I tell you to start controls the pH with perchloric acid, while chlorate is formed in the cell (calculated the approximate time) with this you make sure enough chlorate ions in the electrolyte (remember that there must be a minimum concentration of 50 grams per liter of ClO3 in the electrolyte, to prevent erosion of the anode) and then elevate to an alkaline pH to continue the process of oxidation perchlorate. Best, =) Edited July 17, 2014 by pyroChile
taiwanluthiers Posted July 17, 2014 Posted July 17, 2014 first of all, if I had to use perchloric acid to control the PH, I might as well just buy expensive lab grade perchlorate, the perchloric acid is more expensive than the perchlorate itself. Also I wasn't sure if ph control is absolutely necessary, I thought it was just for efficiency.
WSM Posted July 17, 2014 Posted July 17, 2014 The platinum did not dissolve, it simply flaked off, There was a bunch of crud at the bottom of the cell.I used tap water, and aside from chlorate and water I only added some potassium dichromate. I do not know the chloride content of the cell...I doubt the tap water had chloride in it at all, most the ions in it was carbonate. Starting stock was potassium chlorateI just wonder if it was due to the very low amp draw at 5 volts, or too low of a voltage. I could get a higher amp draw at 12 volts but it's like way too high, so high that when I tried it I let the blue magic smoke out of the computer power supply... so it's dead. I just wish there was a way to get a voltage in between... I tried rigging it to get 7v out of it but no matter what the power supply will NOT turn on. Chloride negatively affects the platinum plate, but it's not the only thing. If your anode is platinum plated titanium, the titanium substrate may also be attacked. For example, if your tap water is fluoridated, fluorine may be attacking the titanium causing a separation of the platinum and the whole process being accelerated by the current. Is your chlorate sodium chlorate or potassium chlorate? Is your power supply regulated (most converted computer power supplies aren't)? We don't yet have enough information about your setup to determine the cause of your problem with any degree of certainty, and can only guess. Help us help you. WSM
taiwanluthiers Posted July 17, 2014 Posted July 17, 2014 (edited) I said a million times, I am using potassium chlorate solution I don't think my water supply is flouridated, but I have no way to be sure. However if it was the flouride destroying the anode the MMO anode I use to make chlorate would have surely been damaged as well, but they have made a lot of chlorate and remained as good as new. I'm not using a "regulated" power supply, just a computer PSU. I do not know where to get regulated power supply that can supply more than 3 amps. Edited July 17, 2014 by taiwanluthiers
WSM Posted July 17, 2014 Posted July 17, 2014 Hello.How much electrolyte? ( for platinum plated, max 2 amp per 100 ml)What kind anode? ( 100 microinch, is recommended)It is important to control the pH 6.8 to 7.0 (where the HClO and ClO ^ - are in a 2:1 ratio) for conversion to chlorate, due to a high ph (which is what tends to rise, because chloride escapes) will generate all the HClO dissociate in ClO-, preventing can generate ClO3 from the HClO + ClO- then the only way to generate is having contact with the anode, which results in more power would be needed (9 e) in that if there equilibrium with HClO and ClO-, needing 6e. Further more hypochlorous ion and chlorate is reduced at the cathode and oxygen at the anode occurs escaping. Occur first chlorate and then perchlorate... After ensuring the production of chlorate, it can raise the alkaline pH to produce perchlorate.(ClO3)ad + OH- --> ClO4- + H+ +e-Oxygen production is eroding the anode, so you have to control pH at the beginning (calculate time for chlorate.. 106 Amph per mole), because if there is no oxygen, it occurs at the anode. Ph is controlling with acid perchloric. Not acid hydrochloric.Best regards,=)pd: sorry for may bad english (google translator) Hi pyroChile, Your description looks like the chlorate and not the perchlorate cell reactions. Correct me if I'm wrong (and please site references so we can be on the same page). I'm aware of one source from India, where they set up a cell to run directly from sodium chloride to sodium perchlorate, but that setup was unique and depended on the lead dioxide over graphite anode they made, plus the addition of sodium fluoride to the cell (and the other parameters tightly controlled). That type of setup will quickly run into incompatibility problems with anodes that have a titanium base, but for their particular setup it worked. WSM
WSM Posted July 17, 2014 Posted July 17, 2014 I said a million times, I am using potassium chlorate solutionI don't think my water supply is flouridated, but I have no way to be sure. However if it was the flouride destroying the anode the MMO anode I use to make chlorate would have surely been damaged as well, but they have made a lot of chlorate and remained as good as new.I'm not using a "regulated" power supply, just a computer PSU. I do not know where to get regulated power supply that can supply more than 3 amps. I wonder if your setup would work better with sodium chlorate. I have an inexpensive platinum coated titanium anode I'll try with distilled water, sodium chlorate and a small regulated power supply. I'll let you know if it works. The country of origin for my small regulated supply is China (the PRC). Can you get eBay items from there? WSM
taiwanluthiers Posted July 17, 2014 Posted July 17, 2014 I'm not sure how to deal with Chinese suppliers. A lot of them don't deal with individuals at all. I have one more platinum anode.
pyroChile Posted July 17, 2014 Posted July 17, 2014 Hello. first of all, if I had to use perchloric acid to control the PH, I might as well just buy expensive lab grade perchlorate, the perchloric acid is more expensive than the perchlorate itself. Also I wasn't sure if ph control is absolutely necessary, I thought it was just for efficiency. Seen in this way ... then I have read that you can control the pH with sulfuric acid, gives better results than with hydrochloric acid. Hydrochloric acid added chloride ions. I said a million times, I am using potassium chlorate solution I don't think my water supply is flouridated, but I have no way to be sure. However if it was the flouride destroying the anode the MMO anode I use to make chlorate would have surely been damaged as well, but they have made a lot of chlorate and remained as good as new. I'm not using a "regulated" power supply, just a computer PSU. I do not know where to get regulated power supply that can supply more than 3 amps. Is not possible to synthesise potassium perchlorate, from potassium chlorate. Best, =)
pyroChile Posted July 17, 2014 Posted July 17, 2014 Hi pyroChile, Your description looks like the chlorate and not the perchlorate cell reactions. Correct me if I'm wrong (and please site references so we can be on the same page). I'm aware of one source from India, where they set up a cell to run directly from sodium chloride to sodium perchlorate, but that setup was unique and depended on the lead dioxide over graphite anode they made, plus the addition of sodium fluoride to the cell (and the other parameters tightly controlled). That type of setup will quickly run into incompatibility problems with anodes that have a titanium base, but for their particular setup it worked. WSM Hello WSM! Here is reaction: http://s25.postimg.org/6f5qjd9pn/Screen_Shot314.jpg http://s25.postimg.org/6t72iytt7/Screen_Shot315.jpg Here is source: http://www.typhoonguitars.com/oxidizer/chlorate/reaction.html Best regards, =)
WSM Posted July 18, 2014 Posted July 18, 2014 Hello.Seen in this way ... then I have read that you can control the pH with sulfuric acid, gives better results than with hydrochloric acid. Hydrochloric acid added chloride ions.Is not possible to synthesise potassium perchlorate, from potassium chlorate.Best,=) Hi pyroChile, This statement is not true as written. Swede succeeded in converting potassium chlorate to potassium perchlorate with a platinized titanium anode, and detailed the process in his blog. To say it's not practical may be more accurate. The notion of it being impossible is common, and even Dr. Shimizu states it in his book, Fireworks, the Art, Science and Technique. WSM
WSM Posted July 18, 2014 Posted July 18, 2014 (edited) Hello WSM!Here is reaction: http://s25.postimg.org/6f5qjd9pn/Screen_Shot314.jpg http://s25.postimg.org/6t72iytt7/Screen_Shot315.jpgHere is source:http://www.typhoonguitars.com/oxidizer/chlorate/reaction.htmlBest regards,=) I have no argument with the parts quoted for perchlorate production. I believe I saw that several parts of the chlorate process were quoted in your earlier post, where the discussion was perchlorates. I'm not throwing stones, but I like to keep the two processes (chlorate and perchlorate) separate in my mind, for clarity. Thanks for sharing the source. The author has put in a tremendous amount of good research there. WSM Edited July 18, 2014 by WSM
WSM Posted July 19, 2014 Posted July 19, 2014 (edited) I'm not sure how to deal with Chinese suppliers. A lot of them don't deal with individuals at all. I have one more platinum anode. I'm referring to eBay purchases (not big industrial suppliers). Here in the US, we can get a wide variety of items on eBay from all over the world (I don't know if that's true in Taiwan). Some sellers of LD anodes must buy a predetermined quantity from China and then sell them individually on eBay. I believe the LD anodes I've gotten on eBay were originally manufactured in China and then sold by individuals in the US. I still need to modify one with a filled, tubular titanium lead and do a test run in a small cell (sodium chlorate to perchlorate). I'll report the results when I do. Again, I suspect sodium chlorate will be easier on the anode than potassium, probably due (at least in part) to the solubilities involved. WSM Edited July 20, 2014 by WSM
WSM Posted July 19, 2014 Posted July 19, 2014 I'm not using a "regulated" power supply, just a computer PSU. I do not know where to get regulated power supply that can supply more than 3 amps. Check out eBay item: 171123409781 or 181213696935 These are only examples. There is likely something more suited to your needs. You just need to keep searching. WSM
taiwanluthiers Posted July 20, 2014 Posted July 20, 2014 I have seen power supplies like this sold in stores in Taiwan, but wasn't sure if they would be right... Problem is at 5v the current draw is very low yet at 12v the current draw is too high. I just wish I can get something in between. I still rather do potassium chlorate simply because purifying potassium chlorate is 100 times easier than sodium chlorate. I was thinking I had to get one of those lab power supplies where you can easily change the voltage or amp draw, but those power supplies are expensive and can handle 3 amps at the most.
WSM Posted July 20, 2014 Posted July 20, 2014 I have seen power supplies like this sold in stores in Taiwan, but wasn't sure if they would be right... Problem is at 5v the current draw is very low yet at 12v the current draw is too high. I just wish I can get something in between. I still rather do potassium chlorate simply because purifying potassium chlorate is 100 times easier than sodium chlorate. I was thinking I had to get one of those lab power supplies where you can easily change the voltage or amp draw, but those power supplies are expensive and can handle 3 amps at the most. Then try eBay item 170431341946, though I believe the 5Vdc supply would work just fine (you did read the specs, right?). Commercial potassium perchlorate is made from sodium perchlorate. How much sodium contamination is found in the commercial product? Not enough to be an issue! Again the solubility of KClO4 is so low that washing ANY sodium salt out with chilled distilled water is trivial with a vacuum filtration setup (look up Buchner funnel with a google search, to see what I mean). I think the best proceedure involves first making sodium perchlorate, then treating it while still in solution with sodium metabisulfite to break down any leftover chlorate. Next do a double exchange with KCl, filter and wash the fine KClO4 crystals, dry and store them. Crystallization is nature's purification method. I think we can do a decent job of it, if we pay attention to the details. WSM
WSM Posted July 20, 2014 Posted July 20, 2014 Just try sodium clorate.Works much easy er. I agree. Plus, I believe the process with sodium may be easier on the LD anode (just a guess on my part). WSM
Arthur Posted July 20, 2014 Posted July 20, 2014 Because the sodium salts are much more soluble the electrodes have an easier life in a sodium salt cell than in a potassium cell. With Sodium salts you can later make KClO4 OR any of the other perchlorates, AP is trivially easy. With potassium salts that's where you stop KClO4 If you ever want to use a platinum electrode then give it the best chance or buy several. If you ever want to recycle the electrolyte then keep it clean! using HCl to do pH control ensures that there are only chloride reactions present, other acids have other ions and may produce persulphates or other contamination
WSM Posted July 20, 2014 Posted July 20, 2014 Because the sodium salts are much more soluble the electrodes have an easier life in a sodium salt cell than in a potassium cell. With Sodium salts you can later make KClO4 OR any of the other perchlorates, AP is trivially easy. With potassium salts that's where you stop KClO4 If you ever want to use a platinum electrode then give it the best chance or buy several. If you ever want to recycle the electrolyte then keep it clean! using HCl to do pH control ensures that there are only chloride reactions present, other acids have other ions and may produce persulphates or other contamination Hi Arthur, I agree with your statements, but I'm not sure about pH control for perchlorate cells. Some commercial system decriptions list the pH as a wide range (3 to 11 if memory serves, and maybe it doesn't in this case) or otherwise not as important as in chlorate cells. Older articles use the same pH as optimized chlorate cells, but the newer ones seem to indicate pH isn't as critical as in chlorate cells. I may need to study this facet of perchlorate manufacture more carefully. WSM
Arthur Posted July 20, 2014 Posted July 20, 2014 My point being that if you do the pH control in the chlorate cell with HCl then the chloride is just used in the reaction. If you use sulphuric acid you are adding a contaminant that will electrolyse to something that you need to remove. Another thing I've heard is that the platinum electrodes need a smooth voltage with little ripple, too much ripple and the electrode can erode.
WSM Posted July 21, 2014 Posted July 21, 2014 (edited) Another thing I've heard is that the platinum electrodes need a smooth voltage with little ripple, too much ripple and the electrode can erode. I hadn't thought about ripple (an AC element in the DC output; not a good thing) and that makes sense. I can see AC ripple being a problem for a platinized anode; sort of a "de-plater", if you will (at least for half the cycles). WSM Edited July 21, 2014 by WSM
WSM Posted July 21, 2014 Posted July 21, 2014 My point being that if you do the pH control in the chlorate cell with HCl then the chloride is just used in the reaction. If you use sulphuric acid you are adding a contaminant that will electrolyse to something that you need to remove. Also, that's a good point about not adding anything not already in the cell. Why pollute it with things foreign to the original mother liquor?! WSM
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