MattEx - 30-5-2005 at 03:05
So, what's the best way to prepare Barium Chloride from Barium Sulfate? I've made some BaCl2 from BaCO3, but now i've run out of that -
however, I have a rather large quantity of BaSO4. The sulfate i've found produces a rather lousy green flame, so that's why I want to
convert it. The chloride produces a very satisfactory green 
(bright neon green).
This is with Ammonium Perchlorate as the oxidizer in a urethane binder.
BromicAcid - 30-5-2005 at 05:39
Although it took a few minutes, google gave the result I was looking for on this site relating to this topic:
Okey Dokey.
AHHHHH! Barium
chloric1 - 30-5-2005 at 05:39
One of my favorite elements!
You use it to make chloric acid, periodic acid,
sodium dithionite etc.
Your problem has an easy solution if you are willing to work for it. And work hard you must. 
First get some activated charcoal then powder it fine like your barium sulfate. Put in a quality crucible. Heat the whole mess to orange heat for
about an hour or more with a large propane torch or forced air charcoal furnace and when you have a grey powder that smells of H2S you are ready to
dissolve in HCl(very dangerous-be careful with H2S) and filter out excess carbon with diatomaceous earth between two filter papers. Evaporation of
the resulting clear solution will give you the dihyrdate of barium chloride!
notagod - 30-5-2005 at 07:57
Take a look at my post in this thread:
http://www.sciencemadness.org/talk/viewthread.php?tid=1245
MattEx - 30-5-2005 at 17:00
Thanks for the reponses .
Ahh, HEAT the BaSO4 and Na2CO3 solution .
I put that together and puzzled over why it didn't react for quite awhile... then threw it out. Damn 
.
Then again, I was using NaHCO3 rather than Na2CO3 - this shouldn't make any real difference, should it? At least...
BaSO4 + Na2CO3 ->heat-> BaCO3 + Na2SO4
BaSO4 + 2NaHCO3 ->heat-> BaCO3 + Na2SO4 + CO2 + H2O
Doesn't seem to change much except the reaction products. Of course, just 'cause it balances, doesn't mean it works .
12AX7 - 30-5-2005 at 20:06
2NaHCO3 --heat--> Na2CO3 + H2CO3
H2CO3 = H2O + CO2 (carbonic acid)
As a matter of fact, you'll be boiling it for an extra twenty minutes because the above reaction is so endothermic (HCl + bicarb gets cold
despite the heat of neutralizing the acid!).
What I don't get is BaSO4 is far less soluble than BaCO3, what the heck makes it proceed?
Tim
notagod - 31-5-2005 at 09:05
I read this in a book and supposedly the high sodium carbonate concentration makes it work. Don't remember the details. I tried it a few times,
with good results.
MattEx - 31-5-2005 at 15:04
Purity is important to me, so am I right in saying that I should use an excess of Na2CO3 from stoichometric, to ensure all the BaSO4 is converted? Any
tips on how much excess, if so?
Also, is there a temperature I should be trying to get to, or just heat it until a reaction occurs (which i'm also unsure about, since no gaseous
products are produced so it'll be hard to tell if anything is happening... )?
BaSO4 and BaCO3 are both insoluble, so filtering them plenty to ensure shouldn't be a problem, correct ?
12AX7 - 31-5-2005 at 15:18
Yes, both insoluble. To seperate them, you can dissolve in HCl, filter and re-precipitate with Na2CO3.
Tim
notagod - 1-6-2005 at 10:58
MattEx
Yes, You should use an excess of Na2CO3. For the temperature, I don't know, but it's a concentrated boiling water solution of Na2CO3, so a
few degrees over 100 Celcius. For purity, rinse and repeat 2-3 times. You could test it by putting it in HCl and see if all dissolves.