In this video I will be isolating chromium metal from stainless steel. I would also recover a nickel but to my surprise it wasn't there. I was looking for some straightforward guide at least on YouTube and I didn't find anything so... Here it is I guess. Anyway so first of all this is absolutely not cost effective. If it wasn't me I would rather buy some chromium powder and then process it into its sold or preferably my particular sold, of course. So here you can see that I'm already cooking some stainless steel tube in sulfuric acid with. A little bit of hydrochloric acid to speed things up. I'm doing this in huge as beaker and inside this beaker I have smaller beaker filled with water to condense the vapors. Kind of poor man's reflexing setup. Basically. Now a little bit of backstory. So I was about to machine this tube for my glass blowing lathe and I taught myself what if I used a seat and sponge and dropped the outside walls of this tube? Well it's basically an iron so it should be quite quick. Yeah and guess how that turned out. Exactly. Nonetheless the next day I was expecting this tube to be quite corroded basically because of hydrochloric acid. For example this kit of kitchenware it's stainless steel at least it says so. And what you can do is put a salty water there and in a few weeks it's mess. So in my eyes the corrosion resistance of stainless steel to chlorine ions seem to be very low. So at this point I was quite curious what the chromium and nickel content of this steel is. I was expecting something around I don't know 60% in reality it's yeah it's about 20% of chromium there and that's all. Ian maybe about 2% of copper for some reason. Okay so our tube is cooked and I'm going to transfer it to the beaker. I mean the leftover solution not the tube. Just in case I am filtering this through some coffee filter and there was no insoluble residue. Okay next step is to precipitate the hydroxides of the metals. From what I have read the chromium free hydroxide from the NXACWA complex in strongly alkaline solutions that means that it's soluble in a hydroxide basically. And that's not happening there so either it's chromium to hydroxide which properties I don't really know or I don't know. After the precipitate settled down I siphoned the remaining liquid into other container. Then I added some hydrogen peroxide to the liquid assuming that it contains only some sodium salts so nothing happens and that's true nothing has happened so good. Anyway the point is that I'm trying to dilute the hydrogen peroxide because in the next step I expect quite vigorous reaction. Okay so I slowly poured back the hydrogen peroxide solution and it wasn't that bad actually. And what we are doing here is that we are oxidizing iron to a hydroxide to iron free hydroxide or iron free oxy hydroxide or what it is and the chromium to hydroxide to chromium at oxidation state 6 so it forms sodium chromate. Iron will remain insoluble so it's easy to separate it from chromium by simple filtration. So once again I let things settle and siphoned sodium chromate. In case you miss the first boring don't touch this thing this is cancer. Then I transfer the sodium chromate into the huge esbicar and in the next step of reaction we will acidify the solution to form sodium dichromate so solution will change the color from yellow to orange. Now we want to reduce the oxidation state of the chromium to plus 3 so it's much safer to handle. Well we have quite a few options there. This could be done with primary alcohol such as ethanol, sulfide ions such as potassium or sodium sulfide or by sulfide as I am aware. I have tried both of these but it's quite messy at least with ethanol and quite smelly with by sulfide. Then you can bubble hydrogen through the solution and finally we can oxidize this even more to the oxidation state plus 7. Criminating this oxidation state is not stable in water solution and conveniently it will reduce itself to the oxidation state plus 3. This is way to go because otherwise you will have to boil away the hydrogen peroxide that's remaining there. I don't really understand how it can persist there because it is supposed to oxidize the chromium but I guess magic. Anyway so let's proceed. Immediately after addition of hydrogen peroxide the solution will change color from orange to well some darkish violet blue and then transition slowly to green. This camera is not 100% correct in the color representation but it's fairly close. Now in the smaller scale this reaction is quite fast. I was a little bit afraid to be fair. Okay so what we are left with is chromium-free sulfate, chloride or whatever I see you added in. And now that the solution is quite a little bit safer to handle we can remove hydrogen peroxide and this is usually done by boiling the solution so off to the hot plate. After about half an hour of boiling we can let this cool and proceed to the next step and that is precipitation and cleaning of the chromium salt. It seems that the chromium carbonate is only thing that is really practical and insoluble so we will go with that. You can precipitate it with sodium hydroxide or ammonia but you will eventually lose some chromium there. So I am adding sodium by carbonate to the solution. When the reaction is done large flakes of sodium carburet will start to form. You can simply filter this off and clean it and let's quite pure salt of chromium what you have there. Here I am filtering chromium carbonate through some coffee filters, nice grayish moldy color and originally I wanted to extract metalic chromium so I am going to read this off this in acid. I tried using electrolysis and displacement reaction. What you see here is displacement reaction and I am trying to displace chromium with aluminium. To my surprise aluminium does not seem to be reacting with chromium sulfate there. The only thing that happened is that the solution has changed the color because it has been reduced. On the other hand the electrolysis just oxidized the solution to this orange red color. I tried this with chromium sulfate and chloride and the result is the same. I was using positive carbon electrode and tried to deposit chromium on some copper plate. I have not tried what Wikipedia suggests and that is to suspend positive electrode in sulfuric acid with some membrane to prevent mixing the solution with sulfuric acid and that way to prevent oxidation of the chromium sulfate. That's quite all the work and I'm happy to give up right there because I don't really need chromium for anything. I'm just playing around with stuff. Okay so thanks for watching and have a nice day.