Barium/Strontium nitrate synthesis

[schroedinger]

Hi

 

I just had a couple thoughs about the synthesis of Ba/Sr Nitrate.

As both carbonates are nearly insoluble in water, i thought about 2 different ways to prepare them, does someone have experience with them?

All this methods are based on amonia nitrate as the nitrate source.

 

First would be to add the carbonate and the aminia nitrate in water to a flask, stir it and heat to boiling. This works e.g. for pottasium nitrate, as the amonia can be evaporated by thermolysis of amonia carbonate, but the solubillty of both carbonates is quite small what could be a problem.

 

The other thing i thought about was to first react the carbonate with acetic acid to get the soluble acetate, and boil this with amonia nitrate. This way amonia acetat would get formed and get destroyed at 90º C, yielding amonia gas and acetic acid. This waymit should even be possible to stay below 110ºC to prevent the acetic acid from being driven off, and make it into a one pot synthesis, by adding the carbonte to the flask, add 100 to 200 ml of acetic acid, and add amonia nitrate solution untill nearly all carbonate is gone. Then heat to drive off all acetic acid and dry everything.

[Mumbles]

You should probably learn the difference between ammonia and ammonium, which are not the same.

 

Neither of those methods will probably be all that efficient time-wise. I have a feeling that the first route will be slow for the reasons you mentioned. Ammonium acetate does not decompose as readily as ammonium carbonate at elevated temperatures. Additionally, evaporating acetic acid entirely is not the easiest thing to do either. You'll also want to look into which way the equilibrium will lie in that reaction. Perhaps something like HCl could be used instead. The resulting ammonium chloride will likely decompose more easily, or be able to be sublimed out of the solid products.

[schroedinger]

Ammonia = NH3 ammonium = NH4+

 

I also thougt about using HCl but ammonium chloride needs 338ºC to dissiciate (it doesn't really sublimate, it recombines in the air).

 

As you will find both this reactions are based on shifting the equilibrium by removing the ammonia.

[schroedinger]

But given the solubilitys of Barium nitrate, maybe it would be better to make a solution of Barium chloride and Pottasium nitrate and precipate the nitrate from this solution. This has been done industrially with sodium nitrate, but maybe it works with pottasium nitrate too, as small residues of pottasium are not causing such a trouble compared to sodium.

[a_bab]

About the only feasable way to make barium/strontium nitrate is thir carbonates + nitric acid reaction.

But, the pottery grade carbonates will contain quite some amounts of insoluble sulfates and even sulphides since the Ba/Sr carbonates are made from the natural sulphates roasted wih coal.

Once filtered the final product will be a solution of the Sr/Ba nitrate, but while pure in theory the dried product would be very hygroscopical, a proof it's far from pure, being contaminated must likely with chlorides. Lots of crystalization cycles are needed for a usable product, and giving the current price of these salts I guess it's not worth it.

 

You shouldn't be able to get nitric acid anymore, so your best bet would be:

 

SrCO3+2NH4NO3--->Sr(NO3)2+2NH3+H2O+CO2

 

Some did it (there's an article in one of the BAFN collections).

You will more likely atract attention with a huge cloud of ammonia, then ordering some of these while you can.

 

As about your Ba chloride/K nitrate, it would be difficult to separate the two salts without lengthy fractional crystalizations.

Still, I guess it would be the best way though, but you will loose lots of Ba/Sr ions.

You can determine the looses with some sulphate, which will precipitate them as insoluble sulphates.

 

[schroedinger]

Well just found a thread on the uk forum about this, with a nice solution for this task: http://www.pyrosociety.org.uk/forum/topic/1061-barium-carbonate-barium-nitrate/

[Arthur]

It's easy to get a nitrate from another salt, but always easier to buy the nitrate. Chose the starting materials well as they will determine how difficult and dangerous the process is. Remember that soluble barium salts are poisons..