hashashan Posted December 20, 2007 Posted December 20, 2007 jacob:Not very sensitive, I dont have any problems with chlorate. I always use chlorate due to its cooler flame. However you do need perchlorate in mixtures containing sulfur or ammonium. mumbles: and what if you want to make some AP from it? thats why i need ti very pure. tentacles: what was the problem? my current density was about 20-30 mA-cm^2
WarezWally Posted December 20, 2007 Posted December 20, 2007 Using chlorate with sulfur and sulfur compounds is fine aslong as you use it within a short period and they are both nice and dry. Potassium chlorate was mixed with sulfur and charcoal for years and was used in firecrackers without many issues. A lot of people make out that if any sulfur comes into contact it will cause the mixture to explode / ignite. That is pretty much bullshit but over time it gets more and more sensitive and that generally leads to issues. Look up old compositions from about 50 years ago, sulfur and chlorate were commonly mixed.
hashashan Posted December 23, 2007 Posted December 23, 2007 I know that usually nothing happens, I once used a nice blue that was had both chlorate and sulfur. But still those compositions are considered not safe.
tentacles Posted December 26, 2007 Posted December 26, 2007 hashashan: the PbO2 only plated on the corners of the Ti sheet, and on the back where the NC had peeled off the Ti - it actually stuck really damn good on the back. I'm making more PbNO3 and going to make some Pb acetate. Last time I plated Pb, I did so at two current densities and it worked MUCH better at the lower density, as in smoother plating. I plan on making up like 2L of 400g/l solution for my next try, and etching the Ti right before I begin.
hashashan Posted December 26, 2007 Posted December 26, 2007 Did you clean the Ti from the oxide? That could cause a problem. Dont etch it(it wont etch if its not clean) and you shouldnt etch if you want to peel it off. Just sand the Ti so it will have a shiny surface. sand the corners so that they will be smooth abnd not sharp(this should prevent overgrowth on the corners)
tentacles Posted December 28, 2007 Posted December 28, 2007 Just wanted to post a couple of pics, I've been filtering and boiling down some lead nitrate solution to determine the approximate concentration.. I turned off my hotplate last night, and had it on low heat all night. This morning I had a clear solution at about 32C, and check out what I came home to in my 2L tall form beaker. That's a 2 1/2" stir bar. There's about 830ml of solution in the beaker, at 26C. That makes the lead nitrate concentration right around 60g/100ml, or about 498g of lead nitrate in solution. The crystals (once fished out) weigh 27g. The solution was a bit supersaturated still, as it started crystallizing out when I poured it into a graduated cylinder to measure. The ppt was dissolved in a slight amount of water to saturation. I dissolved the 27g of crystals in about 47ml of water, coming up to about 880ml of saturated PbNO3 soln. http://www.apcforum.net/files/DSCN1.JPG http://www.apcforum.net/files/DSCN2.JPG For the uncropped (warning: 2mb each!) pics: http://www.apcforum.net/files/DSCN6772.JPG http://www.apcforum.net/files/DSCN6775.JPG
Draco_Aster Posted December 29, 2007 Posted December 29, 2007 Has anybody ever thought of using a pool chlorinator for chlorate production? Essentially thats what it IS! I had an old one lying about (new ones are a bit exy ) and used it for a few hours in a jar of KCl soln. with no visible signs of erosion or contamination. I got the idea from my father who said the electrodes are Pt 'substrate' plated or something along that line....
BPinthemorning Posted December 29, 2007 Posted December 29, 2007 If this is true, that would be briliant. Please post after you finish some tests.
tentacles Posted December 29, 2007 Posted December 29, 2007 Pool chlorinator anodes are usually MMO (mixed metal oxide) coated over Ti. I've heard that some are actually platinized Ti. Someone on scimadness has a pool chlorinator anode, I can't remember if he has actually tried it yet or not. There has been a lot of experimentation making MMO coatings as a precursor to plating with PbO2. Someone had a DTO (doped tin oxide) coating last over 200 hours in a NaCl -> perchlorate cell with no visible wear. The coatings themselves don't seem terribly difficult to prepare, but do require SnCl4 and SbCl2. There has also been some experimentation with spinel cobalt coatings, these don't seem to last quite so well.
WarezWally Posted December 30, 2007 Posted December 30, 2007 Ive got a MMO anode, waiting for some grade 2 Ti tubing.
LGM Posted December 30, 2007 Posted December 30, 2007 Has anyone here tried bubbling chlorine gas through a hydroxide solution? This method was used up to WWI and is probably not as efficient or safe as electrolysis. However, I am having trouble with the electrolytic method and I'm looking for an alternative if I can't find or make a better setup.
tentacles Posted December 30, 2007 Posted December 30, 2007 I kicked my ass into gear today and am trying another plating session. I sanded the Ti strip with P220 sandpaper, and then used my dremel to round the edges nicely, wet sanded (EtOH) with 1000 grit SiC paper, and then painted the side that I hope to not plate with some cheap black spray paint. I covered the edges with hot melt glue, making sure to heat the Ti up so it would stick, and also covered the painted side with more hot melt glue. I then sanded the working side again with 1000 grit paper, then tacked on the scotch brite. I prepared 2L of solution as my bath: 250g/l of Pb(NO3)21.65g/l of NaF15g/l of Cu(NO3)22.2g/l of 50/50 200/325 mesh SiO210ml/l of 80% HNO3 I'm running it at 52C on my hotplate, with the stir bar running.Current density is 15ma/cm2, running off 3.3v on my new (and cheap) ATX PSU. PbO2 started plating immediately when I turned on the power. edit: Came home last night and it was pulling 845ma, which was a bit high for my liking - I know it's in the acceptable plating current range, but I bumped the voltage down to 1.7V (5.0v - 3.3v). It's pulling ~5ma/cm2. Plating continues.
Mumbles Posted December 31, 2007 Posted December 31, 2007 Chlorine into hyroxide produces hypochlorite, which is then decomposed by heat: Cl2 + OH- ---> ClO- + HCl If you are thinking about doing this, you might as well save yourself the time and trouble of dealing with chlorine and HCl gas, and buy bleach.
LGM Posted January 2, 2008 Posted January 2, 2008 Would it be worth it to spend about $40 on an MMO titanium substrate anode? I found a supplier and would like to buy it soon.
tentacles Posted January 2, 2008 Posted January 2, 2008 Is it made for chlorate/perchlorate production? Otherwise it's a crapshoot whether it will work at all, or very long. If it's reasonable size, then it may be worth it simply as a substrate to make your own if that's your bag.
LGM Posted January 2, 2008 Posted January 2, 2008 Apparently it's used in most commercial setups, I think that I'll get one eventually.
tentacles Posted January 2, 2008 Posted January 2, 2008 Just keep in mind that most commercial setups use a continuous system to keep chloride levels from falling too low. You should be fine if you let some chlorate ppt out, scoop it out, and then add saturated chloride to the solution. This type of setup would work best using potassium chloride, as the chlorate would precipitate much more readily.
tentacles Posted January 4, 2008 Posted January 4, 2008 Always with the double posting, I know... Anyways I decided to stop plating this anode, weird things were starting to happen.. I peeled it off the Ti, which wasn't so much peeling as breaking off a few little bits to release it.. It actually curved while plating, which is very strange. After I got it off, it was somewhat broken, so I lassoed it with some wire and dunked it in to plate it back together.. The result.. 168.7g of very ugly PbO2. I doped the plating solution with NaF, the resulting PbO2 is smooth, and shimmers. http://www.apcforum.net/files/DSCN6808.JPG http://www.apcforum.net/files/DSCN6803.JPG http://www.apcforum.net/files/DSCN6800.JPG http://www.apcforum.net/files/DSCN6798.JPG
WarezWally Posted January 4, 2008 Posted January 4, 2008 http://cgi.ebay.com/MMO-COATED-TITANIUM-AN...oQQcmdZViewItem Could you plate LD on that?
tentacles Posted January 4, 2008 Posted January 4, 2008 quite likely; the research on scimadness with spinel cobalt and doped tin oxide (DTO/ATO) coatings are actually progress towards a long lasting, quality PbO2 anode. It's a combination of providing a substrate that doesn't passivate (from both anodic action and the PbO2 itself) and that has a higher oxygen potential so that the PbO2 is the active anode surface. Also, something that you can get PbO2 to stick to well. I will silver and copper plate an end of the anode tomorrow, then I will try and find some gouging rods/graphite locally. In the mean time I will probably try a small test run with KCl. I admit the bulk capacities of using NaCl are tempting, but in a 4L cell you can dissolve a good amount of KClO3 and the separation of KClO4 is automatic.
Bonny Posted January 4, 2008 Posted January 4, 2008 I will silver and copper plate an end of the anode tomorrow, then I will try and find some gouging rods/graphite locally. There are several welding supply stores in town,(Welders Supply, Praxair, Liquid Air) and all will most likely carry gouging rods.
WarezWally Posted January 29, 2008 Posted January 29, 2008 I finally got a nice titanium mesh cathode With my MMO anode (0.5"x6") it can work at 10+A according to the manufactures data but the maximum I can get with it is around 3A @5v due to its small surface area. To get this it has to be nearly on top of the cathode. Will there be any problems running it at 12v? This will allow me to get 10A easily and It wont have to be too close to the cathode.
hashashan Posted January 29, 2008 Posted January 29, 2008 You want to make chlorate or perch? And try it slowly because too high current density can kill your anode
WarezWally Posted January 29, 2008 Posted January 29, 2008 According to the specs, I calculated my anode is good for 30A but I have no intention of testing that. 10A is good enough for the time being. Chlorate, I don't think MMO can make perc (what happens if the chloride conc reaches zero?)
Recommended Posts