Sciencemadness Discussion Board

Copper(II) Sulfate

guy - 22-11-2006 at 23:04

*NOTICE*
I know this is a very cheap and non-interesting compound that many take for granted but I remember when I couldn't get this and I was pretty happy when I figured out how to make it. So maybe this could be useful to someone, or not. Also I posted this before, but I just wanted to "officially" put it here.
-------------------------------------------------------------------------

<b>Copper(II) Sulfate</b>
CuSO4*5H2O


<b>Materials:</b>

Copper metal
Ammonia
Ammonium sulfate
Ethanol
Air bubbler/Aquatic pump
Bucket w/ cap
Filter paper
Heat source

<b>2Cu + O2 + 2NH3 + (NH4)2SO4 ----> [Cu(NH3)4]SO4 + 2H2O

[Cu(NH3)4]SO4 ----heat----> CuSO4 + 4NH3

CuSO4 + 5H2O -----> CuSO4*5H2O</b>


This method uses very cheap and common materials so it is good for larger scale productions.

Set up the bucket with air stones at the bottom and connect it to an air pump. Pour 187 g of 10% NH3 solution into the bucket. Add 73g of (NH4)2SO4 to water to make a saturated solution, and pour that into the bucket also. Place 70g of Cu on top of the air stones. Turn on the pump. Cover the bucket to lessen ammonia evaporating. After about 24 hours, most of the Cu should have dissolved leaving a dark blue solution.



After...


Add denatured alcohol to the solution until all the [Cu(NH3)4]SO4 precipitates. Filter the precipitate and add a little more alcohol to make it as free of water as possible. Water will cause the formation of copper(II) oxide when this is heated.

Heat the precipitate until all ammonia has evaporated, leaving the white, anhydrous copper sulfate.

To make the hydrate, add water and recrystallize.

Darkblade48 - 22-11-2006 at 23:35

Just wanted to add that an alternative method to make copper sulfate is to make the hydroxide (electrolysis of copper metal in an MgSO4 bath) followed by addition of sulfuric acid.

Same end result, different starting reagents :)

guy - 22-11-2006 at 23:37

Yeah, but that would be the easy way! Haha, really, when I wanted to make this, I had no access to any of those reagents. So this is like a poorman's version.
And Ive done the electrolysis method before with poor results. So I seeked a better way of doing this.

[Edited on 11/23/2006 by guy]

chromium - 23-11-2006 at 01:10

Good prep!

I have heard of people saying that this section should be only for trully advanced works. In my opinion this is not the case. Any finished and tested designs or synths ( no matter simple or complex ) that could be usefull for others should be placed here as otherwise these might well remain unnoticed in other forums that contain mostly discussions, ideas, propositions, references to scientific works most of which can probably never be used in home, etc.

Edited to make my thoughts intelligible.


[Edited on 23-11-2006 by chromium]

woelen - 23-11-2006 at 02:52

Quote:
Originally posted by chromium
In my opinion this is not too easy for Prepublications.

Isn't this tested? Guy provides a mechanism and provides pictures of the result. I think most people can reproduce this and the required chems and equipment are easy to obtain in almost every part of the world. Whether this is the most efficient, easy or optimal method is another discussion, but I think it does work and can be interesting.

Thanks for sharing this guy!

Baphomet - 23-11-2006 at 03:37

Nice one guy. I like your use of an (aquarium?) air pump which is something I too like to use for that little extra entropy.
Any technique that can help the amateur chemist acquire the raw materials for practise of their art is all good in my book.
By the way, some hardware shops sell CuSO4 as 'bluestone' for use as a fertilizer on citrus trees.

chromium - 23-11-2006 at 04:11

Quote:
Originally posted by woelen
Quote:
Originally posted by chromium
In my opinion this is not too easy for Prepublications.

Isn't this tested? Guy provides a mechanism and provides pictures of the result. I think most people can reproduce this and the required chems and equipment are easy to obtain in almost every part of the world. Whether this is the most efficient, easy or optimal method is another discussion, but I think it does work and can be interesting.

Thanks for sharing this guy!


Well, it seems that i did not express myself clearly. I think like you that this is good preparation and it's very well that guy put it up here.

I have always wonderd why so few members dare to write anything for prepublications while almost anyone of us has at least something to put up here. My post was in fact about that matter.

woelen - 23-11-2006 at 06:58

Sorry chromium, now I read your sentence correctly :). I first interpreted as if you wanted to tell that this synthesis is not easy enough for prepublication and that still a lot of issues have to be addressed before it is easy enough.

Mr. Wizard - 23-11-2006 at 08:22

Quote:
Originally posted by Baphomet
Nice one guy....snip....
By the way, some hardware shops sell CuSO4 as 'bluestone' for use as a fertilizer on citrus trees.


Most hardware store around here sell the CuSO4 'bluestone' KILL tree roots that invade sewer piping. Now I've learned it's also used to treat the soil for trace mineral deficiencies and to prevent many fungal diseases both in plants and animals.

This has been a very good thread for me. :)

The procedure is actually a net generator of Ammonia too, so the step that liberates the Ammonia could be used to reclaim the initial Ammonia and more.

I'm curious if it will work on US 5 cent coins "Nickels" which are 75% Cu and 25% Ni.

guy - 23-11-2006 at 13:10

Thanks everyone for your compliments!
Quote:
Originally posted by Mr. Wizard
Quote:
Originally posted by Baphomet
Nice one guy....snip....
By the way, some hardware shops sell CuSO4 as 'bluestone' for use as a fertilizer on citrus trees.


Most hardware store around here sell the CuSO4 'bluestone' KILL tree roots that invade sewer piping. Now I've learned it's also used to treat the soil for trace mineral deficiencies and to prevent many fungal diseases both in plants and animals.

This has been a very good thread for me. :)

The procedure is actually a net generator of Ammonia too, so the step that liberates the Ammonia could be used to reclaim the initial Ammonia and more.

I'm curious if it will work on US 5 cent coins "Nickels" which are 75% Cu and 25% Ni.


Yes it will work since I also have done it before to try and get nickel salts.

12AX7 - 23-11-2006 at 19:49

Ammonium sulfate is even easier to get than ammonia (well, I'm not sure of anywhere that doesn't sell janitorial (10%) strength ammonia, but maybe in terms of quantity or price or concentration it's true...*shrug*), you think it'd work that way too?

Let's see... 2(NH4)2SO4 + Cu + O = Cu(NH3)4(2+) + 2SO4(2-) + H2O... hmm needs excess base to proceed in that manner.

How about urea, another common source of nitrogen? (Heck, does urea complex with copper at any pH?) If nothing else, you can leave out a solution and it'll get some nitrogen-hungry things in it that'll (at least partially) turn it into ammonium carbonate, which should serve just as well for the above reaction.

Tim

guy - 23-11-2006 at 23:50

Yeah this uses a combination of ammonia and ammonium sulfate. The ammonia can be regenerated and reused so its a good deal.

12AX7 - 24-11-2006 at 13:12

Durr, blind me :o

How about urea?

Tim

guy - 11-12-2006 at 15:00

Quote:
Originally posted by guy
*NOTICE*
I know this is a very cheap and non-interesting compound that many take for granted but I remember when I couldn't get this and I was pretty happy when I figured out how to make it. So maybe this could be useful to someone, or not. Also I posted this before, but I just wanted to "officially" put it here.
-------------------------------------------------------------------------

<b>Copper(II) Sulfate</b>
CuSO4*5H2O


<b>Materials:</b>

Copper metal
Ammonia
Ammonium sulfate
Ethanol
Air bubbler/Aquatic pump
Bucket w/ cap
Filter paper
Heat source

<b>2Cu + O2 + 4NH3 + 2(NH4)2SO4 ----> 2[Cu(NH3)4]SO4 + 2H2O

[Cu(NH3)4]SO4 ----heat----> CuSO4 + 4NH3

CuSO4 + 5H2O -----> CuSO4*5H2O</b>


This method uses very cheap and common materials so it is good for larger scale productions.

Set up the bucket with air stones at the bottom and connect it to an air pump. Pour 187 g of 10% NH3 solution into the bucket. Add 73g of (NH4)2SO4 to water to make a saturated solution, and pour that into the bucket also. Place 70g of Cu on top of the air stones. Turn on the pump. Cover the bucket to lessen ammonia evaporating. After about 24 hours, most of the Cu should have dissolved leaving a dark blue solution.



After...


Add denatured alcohol to the solution until all the [Cu(NH3)4]SO4 precipitates. Filter the precipitate and add a little more alcohol to make it as free of water as possible. Water will cause the formation of copper(II) oxide when this is heated.

Heat the precipitate until all ammonia has evaporated, leaving the white, anhydrous copper sulfate.

To make the hydrate, add water and recrystallize.

12AX7 - 11-12-2006 at 16:01

Quote:
Originally posted by guy
...


Why did you quote yourself, plus the pictures, to add...nothing?

Tim

guy - 12-12-2006 at 17:40

oops! I meant to edit something! haha

UnintentionalChaos - 19-12-2006 at 18:11

Would an excess of ammonia have any negative affect on this reaction? I have some ammonia that was unlabeled as to it's concentration, but a quick calculation of density (even including huge error assumptions for the fairly innacurate postal scale) leads me to believe that it is only 2.5%, maybe as low as 2% :( I'll re-mass the stuff, but the first check left me with a density of 988 kg/m^3, just 3kg/m^3 less than 2% solution and 5 kg/m^3 more than 3%) I'm just wondering if assuming 2% for safety and adding extra ammonia will do anything to the final product. My gut instinct is that it will not, but I'd appreciate another opinion.

guy - 19-12-2006 at 18:28

No, an excess of ammonia would be even better.

Very confused...

UnintentionalChaos - 23-12-2006 at 20:33

I am getting some very weird results from this synth. I now have very well drained and washed tetraamminecopper sulfate (hopefully). When I heat it, it definetly lets off ammonia, but does not become white, off white, or even light green. Instead, it turns a medium green. When I add this to water, it turns blue, but refuses to dissolve to any visible concentration. I tried boiling it to make it dissolve and I get a color change to light "mint" green. No black CuO is formed. Anyone have any ideas/tests I could do to see what's going on?

PS: When I boil the un-heated material in water, it definetly turns to CuO (as expected).

[Edited on 25-12-2006 by UnintentionalChaos]

[Edited on 26-12-2006 by UnintentionalChaos]

guy - 26-12-2006 at 19:03

You didnt heat it long enough the tetramminecopper sulfate.

It turns from blue --> green --> white.

Try heating it longer until it turns white.

UnintentionalChaos - 27-12-2006 at 00:13

Roughly what temperature should I be at? It's definetly temperature, not time that seems to be my problem. I don't have the luxury of a hotplate, unfortunately. I've been using a homemade alcohol burner, which uses up my waste alcohol, since I'm still working on a still. It;s at least 420 C in the open flame because i can melt zinc chips, no problem. With a setup made of old cans and flower pot pieces, I can simulate a ringstand (though one is coming in the mail soon), but the temperature is probably significantly lower. That is enough to get it to green, but clearly not hot enough for white. Clearly, I can't exceed 650 C....Hmm...I may have to put this one on hold until I get a hotplate because I don't have much temperature control beyond hot and really hot...that is, the difference between alcohol stove and gas stove...and I've managed to burn copper sulfate in the gas stove all the way to CuO. :(

Thanks for your help guy!

[Edited on 27-12-2006 by UnintentionalChaos]

Aqua_Fortis_100% - 27-12-2006 at 12:17

Quote:
originally posted by UnintentionalChaos :

Would an excess of ammonia have any negative affect on this reaction? I have some ammonia that was unlabeled as to it's concentration, but a quick calculation of density (even including huge error assumptions for the fairly innacurate postal scale) leads me to believe that it is only 2.5%, maybe as low as 2% I'll re-mass the stuff, but the first check left me with a density of 988 kg/m^3, just 3kg/m^3 less than 2% solution and 5 kg/m^3 more than 3%) I'm just wondering if assuming 2% for safety and adding extra ammonia will do anything to the final product. My gut instinct is that it will not, but I'd appreciate another opinion.


I also have the less concentrated amonia.. but i even not determine the conc since i haven't the right equipment for measure the density... and also have only a homemade alcohol burner.. :D
30 min ago , i tried to dissolve a small amount of my CuO(made last night! But as posted by other members can also be bought in some pottery and ceramics stores and supplies) in NH4OH/(NH4)2SO4 solution for make tetraamminecopper sulfate, but after the colour of solution stays clear with black suspension of unreacted CuO.. i still don't warm this.. maybe wait a little more can result in anything...
UnintentionalChaos,about the CuO , you give me a probably great idea!!!! THANKS!!THANKS!!!
Obviously the CuO is a basic substance.. if reacted with an acid gives a salt.. how about dilute H2SO4?!?

the method is easy and cheap... simple to you get your CuSO4 from you CuO: react it in dilute H2SO4...

my H2SO4 from old batteries is pratically *FREE*..simple go in any auto store and to order the (most) probably free and useless (for they)acid liquid from used batteries... filter the liquid (containig PbSO4 and other nasty stuffs), and ready!
actually, my only source of H2SO4 is this..

i also tried:
measured 30ml of this filtrated acid battery solution and pour in a small cup.. add two pinches of CuO and wait..the CuO starts to give small bubbles and then stired the solution ..after 1 or 2 minutes the clear solution becomes blue!!!!

just:
H2SO4 + CuO ---> CuSO4 + H2O (heat helps the speed of reaction...)

the advantages of this method,i think, are several:
*not required any other chemicals or equipments further the heat source, CuO(or other Cu II H2SO4 reactive compound) and the free dilute H2SO4...
*if CuO is used, not generates nasty fumes or vapour as the guy's method (NH3) or SO2 from standard method (conc H2SO4 and heat:
2H2SO4 + Cu ---> CuSO4 + 2H2O + SO2^
*cheap and easy!

the only problems, i think, maybe be:
*obtain a more impure CuSO4*5H2O (because of some of the lead salts which can stay in H2SO4 solution even after the filtration);

*the energy spent to evapore the water from solution;

*and the yield difficulty be 100% because is need a small excess of CuO to consume the H2SO4... and then filter this CuO..(however can be used in other batches!)...

(and sorry since i still not evapore this solution, because my stove for experiments stay in yard and is a homemade wood-charcoal stove, and now it's raining here..:mad: )

the funny part of my experimet it's which the my CuO was made from proper CuSO4*5H2O!!! hahaha because have some kilos of this in my home which i bought in a garden store as fertilizer.. cost about R$ 7,00 the Kg( ~ US$ 2,50)
i interested in synthesising my own and tried this.. but my original purpose with CuO was made thermite which worked almost perfectly (not all pile consumed..:( )

probably it's also a good method of home manufacture if one has some copper (II) salts or CuO ..
the Guy's method is also very interesting and has great merits because one don't need any copper salt, simple just the metallic Cu which is much more easy to find..
Thanks Guy, and nice picks!
one question about your method: how much faster the copper react if cutting or even grinding (to make a coarse Cu powder) the Cu things ???
again thanks .. i need try this one day...


[sorry about my very poor english..]

[Editado em 27-12-2006 por Aqua_Fortis_100%]

guy - 27-12-2006 at 15:56

Quote:
Originally posted by UnintentionalChaos
Roughly what temperature should I be at? It's definetly temperature, not time that seems to be my problem. I don't have the luxury of a hotplate, unfortunately. I've been using a homemade alcohol burner, which uses up my waste alcohol, since I'm still working on a still. It;s at least 420 C in the open flame because i can melt zinc chips, no problem. With a setup made of old cans and flower pot pieces, I can simulate a ringstand (though one is coming in the mail soon), but the temperature is probably significantly lower. That is enough to get it to green, but clearly not hot enough for white. Clearly, I can't exceed 650 C....Hmm...I may have to put this one on hold until I get a hotplate because I don't have much temperature control beyond hot and really hot...that is, the difference between alcohol stove and gas stove...and I've managed to burn copper sulfate in the gas stove all the way to CuO. :(

Thanks for your help guy!

[Edited on 27-12-2006 by UnintentionalChaos]


It doesnt need to get that hot, its just a matter of time since you need to remove 4 NH3 groups. Try heating a small amount until it turns white. Trust me it will! :)
Quote:
Aqua_Fortis_100%

30 min ago , i tried to dissolve a small amount of my CuO(made last night! But as posted by other members can also be bought in some pottery and ceramics stores and supplies) in NH4OH/(NH4)2SO4 solution for make tetraamminecopper sulfate, but after the colour of solution stays clear with black suspension of unreacted CuO.. i still don't warm this.. maybe wait a little more can result in anything...


CuO is very slow to react with ammonia or water. It has a more favorable structure where it is stabilized by the O2-. This is why CuO reacts very slowly with water.

Here's how I tested my method before I made it a large scale.

I took Cu wire, sodium percarbonate (realeases O2 in water) and (NH4)2SO4 and NH3. Immediatly a dark blue solution is obtained.
Quote:

one question about your method: how much faster the copper react if cutting or even grinding (to make a coarse Cu powder) the Cu things ???


Im sure it would definetly.

As for the H2SO4 method...Im quite aware of it but H2SO4 is hard for me to get because of parents....and I would probably not use it for large scale methods like this.

As you can see, my method is a "copycat" of the Gold leaching process with cyanide and its pretty efficent on large scale.

Aqua_Fortis_100% - 27-12-2006 at 19:27

Quote:
originally posted by guy :
CuO is very slow to react with ammonia or water. It has a more favorable structure where it is stabilized by the O2-. This is why CuO reacts very slowly with water.


Oh! Right!!! you are 100% sure!
about the CuO reacting with ammonia/(NH4)2SO4 , i wait two hours and the solution becomes blue ,but separed by two layers: the layer on top has a pale blue colour and most volume and the down thin layer has a dark blue colour... after some more hours it's totally dark blue... are there a catalist for this reaction? heat isn't good, i think, because of generation of NH3 gas...

Quote:
originally posted by guy :
Here's how I tested my method before I made it a large scale.

I took Cu wire, sodium percarbonate (realeases O2 in water) and (NH4)2SO4 and NH3. Immediatly a dark blue solution is obtained.


Wow, another great idea! thanks! i really need try this...
how about using others compounds to provide O2 (like perborate, etc)???

[Editado em 28-12-2006 por Aqua_Fortis_100%]

UnintentionalChaos - 27-12-2006 at 19:54

"I also have the less concentrated amonia.. but i even not determine the conc since i haven't the right equipment for measure the density"

Are you sure you dont? I did the calculation using the given volume of a container, a couple of cut off soda bottles, and a low capacity postal scale. Since I couldn't mass the whole gallon at once, i poured it off into the bottles on the scale and took down the individual weights. This site is amazing for conversion help..it does everything (this is the link for volume but they have mass/weight, and just about anything else you could need.)

http://www.convert-me.com/en/convert/volume

After the conversions, it is a simple mass/volume. To minimize error (since the postal scale isnt too accurate) I massed the whole gallon, where a few grams either way does nothing to the density calculation. Then just use google and search for density of ammonia solution or some similar wording and something will turn up. Use that to calculate concentration from density. :D

Aqua_Fortis_100% - 27-12-2006 at 20:58

Thanks for all, UnintentionalChaos.. (great link.. NOW put in my favourites )..
i searched some stuffs for made my own scale as Brainfever's page describes... about the table of density of NH4OH i just appreciate it...
there are a lot of things i still need make .. chemicals, equipments, etc....
thanks again.. tomorrow i start the plan.. :cool:
thanks again..

guy - 27-12-2006 at 21:12

Anything that provides oxygen can oxidize the Cu, aqua_fortis_100%

As I read from another post, it seems you made CuO from Cu(OH)2? If so, just use Cu(OH)2 because that will work MUCH faster.

Aqua_Fortis_100% - 27-12-2006 at 22:19

Wow, it's true..thanks...

Actually ,as i says, my CuO don't was made with the original purpose for make CuSO<sub>4</sub> (rather, my CuO comes from proper CuSO<sub>4</sub>...).... i tried the procedure only for experiment the theory...
in fact, you are 100% sure because hydroxides usually reacts faster than oxide... but thinking on this, almost gives in same, because the Cu(OH)2 has a lot of water in it and also using a dilute H<sub>2</sub>SO<sub>4</sub> will make which you must evaporate TONS of water in it...and (for me) is more easy handle the powdered CuO than provide space for enormous volume of Cu(OH)<sub>2</sub>..
how i cann't see it's before?!?!
i tried NOW your idea:
just spill Cu(OH)<sub>2</sub> in half of cup volume,about 100ml.. then i added 45ml of acid battery solution.. after about 4 seconds the black solution in my hand turns INSTANTLY clear green colour and this INSTANTLY converts to clear blue colour... some black particles of Cu(OH)<sub>2</sub> settle on bottom of the cup, but after some seconds it's just dissolved..
Thanks guy! tomorrow i re-edit my earlier post about H<sub>2</sub>SO<sub>4</sub> method..

[sorry about my poor english...i try to improve]

[Editado em 28-12-2006 por Aqua_Fortis_100%]

Aqua_Fortis_100% - 28-12-2006 at 20:49

Quote:
I took Cu wire, sodium percarbonate (realeases O2 in water) and (NH4)2SO4 and NH3. Immediatly a dark blue solution is obtained.


today i just tried your method, but with a slight modification: i replace the sodium perborate by H<sub>2</sub>O<sub>2</sub> ...
put some thick wires and 1 cents coins (as described by other member) in a 500ml PET bottle, then put some ammonium sulfate in it (unfortunately this is the impure farm grade...but very cheap).. then added 50ml of household ammonia...nothing happened.. but when added 100ml of 3% H<sub>2</sub>O<sub>2</sub> , the solution after 2 or 3 seconds starts to bubble, and the bubbles staying located in copper things..some fast seconds after this becomes to clear to deep blue!!!unfortunately the Cu things not was all eat (actually, small amounts in surface of these which in fact be are eated by solution) and the H<sub>2</sub>O<sub>2</sub> was consumed quickly(probably releases O<sub>2</sub> too fast because of the copper ion which catalyses the decomposition). About this, can you help me about how i can improve the O<sub>2</sub> generation (or how i can let the H<sub>2</sub>O<sub>2</sub> releasing the O<sub>2</sub> for more, much more time) H<sub>2</sub>O<sub>2</sub> or other oxodizing substance???


one idea about this: if one gets many (old) very thin wires, cut all in small pieces with a pair of scissors and put in a blender with water and turn this on (almost as Al foil method), and turn on , and off , with care (wait some minutes after each time turned on, to not overheating the motor), to make many VERY small pieces and/or even maybe a coarser Cu powder, and make the tetraamminecopper sulfate route H<sub>2</sub>O<sub>2</sub>/(NH<sub>4</sub>;)<sub>2</sub>SO<sub>4</sub>/NH<sub>4</sub>OH or by ...(because , as you in an earlier post said,about the small pieces "eat the copper MUCH faster" )... and after make the CuSO<sub>4</sub>*5H<sub>2</sub>O ..
using H<sub>2</sub>O<sub>2</sub> as a O2 source, has a advantage which the H<sub>2</sub>O<sub>2</sub> finish to decompose in water which help to keep the final product more pure .. but the disadvantage is which decomposes too fast what do the solution need more O<sub>2</sub>...one care is to use LOW concentrations of hydrogen peroxide, because higher conc. gives TOO VIOLENTS reactions ( i tried put 5 - 10ml of 50% hydrogen peroxide, and the reaction was just violent,with jets and clouds of hot NH3 given off almost instantly the H<sub>2</sub>O<sub>2</sub> was added and the PET bottle also turned very hot in my hands in 2 seconds...fortunately i was used goggles and to be in outside)...

But if a air bubbler or aquatic pump is used (as in your original idea),will be faster because of greater superficial area of small Cu things.. and the yield will be much better without hydrogen peroxide addition...and without hazards of H<sub>2</sub>O<sub>2</sub> or another thing...
(i have just mentioned the H<sub>2</sub>O<sub>2</sub> because is quite cheap here.. a liter of hazardous 50% cost R$ 6,00 (about US$ 2,50 ) in some cleaning stores..so one can dilute this in a very weak H<sub>2</sub>O<sub>2</sub> solution)


[sorry by not finish the experiment because, also of my parents (my mom today, give me a great told off because i was made some experiments which accidently releases a strange tear odor when i washed in the paper filter , just when she go in my direction...), i cann't filter and boil the solution at the moment... :(
but tomorrow i try boil it ...if my mom to calm..]

[sorry about my poor english and any fool thought]

[Editado em 29-12-2006 por Aqua_Fortis_100%]

guy - 28-12-2006 at 21:32

Hmm..Ive never used perborate. Does it release O2 on contact with water?

Percarbonate (Na2CO3*H2O2) also sold as Oxiclean realeases huge amounts of O2 in water.

Anyways. that was just a confirmation test to see if the theory checks out.

ANd dont worry about your english its pretty good.

UnintentionalChaos - 28-12-2006 at 22:24

Farm grade ammonium sulfate....you mean browish junk from (probably) iron impurities? I've unfortunately got the same stuff. If you have some time on your hands, its not too hard to clean up somewhat. Dissolve in water (it is extremely soluble), run through some kind of filter (I used cheap paper towels quadrupled over) a few times until the paper stops turning brownish-gray. The solution should be tan now (Probbaly started out quite brown). Microwave or boil off about half the liquid (assuming you started with a saturated solution) and filter it. These crystals are fairly clean (this was what I used for the synth). A quick wash with alcohol or acetone might get a bit more iron stained solution off ( I didn't bother). Halve it again and repeat the above process. The rest is quite contaminated. If you have blueberry bushes or conifers, I should think they would enjoy the last bit of it. (If you're working with a larger batch, obviously continue to boil off water until only a small amount remains) Alternately, you might be able to let it crystallize with evaporation, but I would think it's hygroscopic nature might interfere. On second thought, you could probably booze the stuff out by adding alcohol to a saturated solution until the salt precipitates out. I'll have to try this now...

PS: Alcohol works like a charm. You just have to wring out the ppt very well and almost all of the iron goes with it. The only thought I had, though, is that due to ammonium sulfate's immense solubility, youd lose a huge amount of salt and a whole lot of alcohol if you tried this with the whole batch. I'd just use this method for what I called unsalvageable up a bit. I had saved that stuff and just cleaned it using this method a minute ago.

[Edited on 12-29-06 by UnintentionalChaos]

12AX7 - 28-12-2006 at 22:37

The ammonium sulfate I have (I assume it isn't an alum or anything) seems to be rather easy to crystallize. Every time I dissolve and evaporate it, I can't help but get chunky, white to transparent (not necessarily well-formed) crystals from it.

Seems to me the brown crud should settle out quite easily, after maybe a week tops. pH up or down might help if it's a soluble thing, and recrystallization once or twice should be sufficient for the stingiest use.

Tim

Aqua_Fortis_100% - 28-12-2006 at 22:45

Oh, sorry guy!!! i almost always make troubles with the words perBORATE and perCARBONATE :( at the start of post i wanted said which "i replace the sodium percarbonate by H2O2 " , but i wrotes "i replace the sodium perborate by H2O2 "..i'm ashamed...
----------
about the perborate, even if you used this instead of percarbonate probably the same effect was obtained..(like the percarbonate, the perborate in contact with water undergoes hydrolisis giving (in these case) borate and H<sub>2</sub>O<sub>2</sub> ),i heard which is also used like "oxiclean" or in other laundry bleaches, etc , but i never find this here in supermarket, only the percarbonate which is quite expensive.... my only worry about using this percompounds is if the impurities generated by sodium carbonate or borate ...what about? more details on your procedure using perborate? thanks .

tomorrow, i (try) to go on city center to buy some percarbonate (because there is much more cheap..) and try all about...
---
[thanks again for to think which my english is regular...if my nice english teacher to think it's , i will be happy! haha actually mine is a primitive type "from dictionary" because i dont know too right how use the "would", "does" and others verbs...]

[Editado em 30-12-2006 por Aqua_Fortis_100%]

UnintentionalChaos - 28-12-2006 at 22:47

Of course, that's if you're quite patient or plan well in advance. :P
You can do the heating/alcohol to get a much improved, if not perfect product in under an hour and in the microwave. Definetly not wise for mass production though...electricity drain + ethanol waste = $ouchmywallet$
For use in this synth though, a crudely filtered product should be fine (to keep large particles out of the filters at the end), because part of the process (At least the original post) is to ppt with alcohol anyway and the impurities will just be left in solution. :D

"I assume it isn't an alum or anything"
So test it by heating. Ammonium Aluminum Sulfate or ammonium alum, the stuff I assume you're referring to, as well as potassium alum both melt at temperatures below the boiling point of water. Ammonium sulfate requires high temperatures to decompose into a lovely plume of ammonia, SOx, and/or NOx. I realize just how close I was to doing that when drying the salts in the oven :o

[Edited on 12-29-06 by UnintentionalChaos]

Aqua_Fortis_100% - 29-12-2006 at 19:36

Quote:
originally posted by UnintentionalChaos :
Farm grade ammonium sulfate....you mean browish junk from (probably) iron impurities? I've unfortunately got the same stuff. If you have some time on your hands, its not too hard to clean up somewhat. Dissolve in water (it is extremely soluble), run through some kind of filter (I used cheap paper towels quadrupled over) a few times until the paper stops turning brownish-gray. The solution should be tan now (Probbaly started out quite brown). Microwave or boil off about half the liquid (assuming you started with a saturated solution) and filter it. These crystals are fairly clean (this was what I used for the synth). A quick wash with alcohol or acetone might get a bit more iron stained solution off ( I didn't bother). Halve it again and repeat the above process. The rest is quite contaminated. If you have blueberry bushes or conifers, I should think they would enjoy the last bit of it. (If you're working with a larger batch, obviously continue to boil off water until only a small amount remains) Alternately, you might be able to let it crystallize with evaporation, but I would think it's hygroscopic nature might interfere. On second thought, you could probably booze the stuff out by adding alcohol to a saturated solution until the salt precipitates out. I'll have to try this now...

PS: Alcohol works like a charm. You just have to wring out the ppt very well and almost all of the iron goes with it. The only thought I had, though, is that due to ammonium sulfate's immense solubility, youd lose a huge amount of salt and a whole lot of alcohol if you tried this with the whole batch. I'd just use this method for what I called unsalvageable up a bit. I had saved that stuff and just cleaned it using this method a minute ago.

[Edited on 12-29-06 by UnintentionalChaos]

yes, mine ammonium sulfate is same thing you has...
about the purification of (NH<sub> 4</sub> )<sub> 2</sub> SO<sub> 4</sub> , my stupidity has no limite :
one year ago i would rather to feel lazy for do clean up this compound...this almost resulted in serious accident: i needed at occasion , some HMTD and no have ammonia (for hexamine), when i followed one "alternative" synth from KIBC book: ammonium sulfate, formaldehyde and 3% hydrogen peroxide.. like i never have success with too weak H<sub>2</sub>O<sub>2</sub>,then i tried dissolve some ml of 50% H<sub>2</sub>O<sub>2</sub> in water and added in fitered brownish solution (this shit brown impure (NH<sub> 4</sub> )<sub> 2</sub> SO<sub> 4</sub> and some CH<sub>2</sub>O .. about this, i remember what when added the CH<sub>2</sub>O to ammonium sulfate this generate some heat and in one point formed some "chunks" of a gelatinous substance (paraformaldehyde? think which probably formalin was polymerized to paraformaldehyde due presence of formed H<sub>2</sub>SO<sub>4</sub> from sulfate ))..anycase the temperature was the normal..(25°C -30°C) and when i added the hydrogen peroxide instantly the solution turned cloudy white and warms a little.. then i put the bottle with the mixture stand in my room for get more yield..but some time after..(2 or 3 hours),when i stays in kitchen, i feel a nasty smell from my room.. quickly i run and can seen which the bottle was hot, boiling and giving off formalin vapours .. the hot solution destroyed fast the small cristals of presumed HMTD as same facility as formed...then discarded immediately the solution in a manual sink there outside... this give me a basic and important lesson about which ALL chemicals are treacherous (some more than others..) if not treated with respective respect... today i'm less insane,but still ignorant...
Thanks for all, UnintentionalChaos and Tim, i have about 10 Kg of this (NH<sub> 4</sub> )<sub> 2</sub> SO<sub> 4</sub> and plan to purify it after new year's eve ...

[sorry about any grammar error and bad english]

[Editado em 30-12-2006 por Aqua_Fortis_100%]

Cesium Fluoride - 31-3-2007 at 21:37

I'm trying this method right now and it's working wonderfully. Thanks! One thing I noticed however is that the equation given initially is balanced incorrectly. It should be

2 Cu + O2 + 4 NH3 + 2 (NH4)2SO4 --> 2 Cu(NH3)4SO4 + 2 H2O

which means that 35g of Cu is only needed in the given recipe.

[Edited on 31-3-2007 by Cesium Fluoride]