Darkonez Posted March 11 Posted March 11 Hi guys, I’ve got my new shiny PBO2 Anode and a proper power supply and have made a beautiful batch of sodium perchlorate. Before I do the magic of turning it into KCLO4 I wanted to make sure I have no chlorate left in solution, I’ve followed some great advice from here and online resources but I can’t find a detailed description of using HCL to scrub the Chlorate out. I know you add HCL to the solution and boil to remove the unwanted which leaves as a gas that’s dangerous to breathe but the instructions I have don’t mention the amount of HCL per Litre or how long to boil ??? any advice please?
mx5kevin Posted March 11 Posted March 11 1 hour ago, Darkonez said: Hi guys, I’ve got my new shiny PBO2 Anode and a proper power supply and have made a beautiful batch of sodium perchlorate. Before I do the magic of turning it into KCLO4 I wanted to make sure I have no chlorate left in solution, I’ve followed some great advice from here and online resources but I can’t find a detailed description of using HCL to scrub the Chlorate out. I know you add HCL to the solution and boil to remove the unwanted which leaves as a gas that’s dangerous to breathe but the instructions I have don’t mention the amount of HCL per Litre or how long to boil ??? any advice please? HCl by itself is worthless. Hydrochloric acid in presence of sodium or potassium metabisulfide proportionally dosed when the solution boiled to generate SO2 gas are necessary. sodium or potassium metabisulfide without HCl is worthless too. Destroying the chlorate are the best with KClO4. The test to see if all the chlorates have been neutralized is simple. A little KClO4 needs to be crystallized and test it with 30% HCl, if does not have yellowish color change the product are chlorate free. The NaCl can be recovered in the chlorate cell. In the perchlorate cell not possible to get absolutely chlorate free product. If the PbO2 anode is running in very pure perchlorate, the layer will start to wear off slightly. The runtime must be experienced, it will always be the same. Further purification of KClO4: Rinse from the crystal the acid solution with clean water. Neutralize the acid with potassium or sodium bicarbonate, mixed thoroughly in alkaline water. Than was it whit mixing it pure ice cold water. Recrystall the KClO4 in hot water and wash again the crystalls in ice cold water, recrystall the KClO4 again and wash it again, now you get pure KClO4, dry it in a oven or gas stove. You will get purity close to analytical reagent grade KClO4. This will be purer than technical grade, and much more purer than the chinese anticake shit. Use a beaker what are resistant from acidic solution whit a heat shield Wire Gauze ceramic center what protect the beaker from cracking this is important. And boil it outdoor using airtight closed safety glasses and a M3 mask with chlorine filter Gas Cartridge.
mx5kevin Posted March 11 Posted March 11 (edited) To start, measure out a 5-10% metabisulfite, make from it a solution, measaured from KClO4 crystals and make it with HCl the solution under pH3 (example every 100g KClO4, 5-10g metabisulfide). Then you proportionally add the two in liquid form in small doses until all the chlorate disappears when the perchlorate solution are boiling. It should always be added slowly to the bottom of the hot solution and never poured on top. I usually do this with a syringe and a straw. Metabisulfide should not be added in powder form. The acidic solution can be used repeatedly, sulfate or metabisulfite will not precipitate easily because they are very soluble in the acidic solution. But unfortunately, this solution must be discarded later because it cannot be recycled into the process. Unless you have a distillation apparatus. The water does not need to be evaporated very much in the acidic solution, the KClO4 crystals should be added to the hot water until they dissolve. When it is ready to recrystallize in clean water, it must be some of the water evaporated. The process is labor-intensive, but the results are well worth it. Edited March 12 by mx5kevin
Arthur Posted March 12 Posted March 12 Part of the purification IS the conversion to the Potassium salt. (Almost) all sodium salts are soluble, but potassium salts MUCH less so. As you add KCl the insoluble KClO4 will ppt out as assorted sizes of crystals, but lots of the unwanted comps are still in solution. SO first get any unwanted solids out of the liquor then ppt out the perc and then filter off the liquor and wash it gently with a little water and dry it in warm air. At this point the cell liquor can be returned for reuse and the purity of the dry product assessed.
Darkonez Posted March 13 Author Posted March 13 Thank you guys! I have my first little batch of kclo4!!!! beautiful pure white crystals with a almost glittering effect.
mx5kevin Posted March 14 Posted March 14 (edited) On 3/13/2025 at 9:19 AM, Darkonez said: Thank you guys! I have my first little batch of kclo4!!!! beautiful pure white crystals with a almost glittering effect. Take a few of those crystals and test them with 30% hydrochloric acid. If they remain completely white, the product is chlorate-free. Use a a heat shield Wire Gauze ceramic center through the beaker and the hotplate otherwise your beaker will crack from uneven heat distribution. Crystallize it twice with clean water completely dissolved the KClO4 and after this wash it with clean ice cold water. You should not skimp on cleaning the product. If this is crystallization in pure water, the product cannot be acidic. Edited March 14 by mx5kevin
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