plante1999
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Registered: 27-12-2010
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Leblanc process for potassium carbonate
Today I tried a variant of the original process that make sodium carbonate. Instead I attempted to make potassium carbonate from potassium chloride.
(All stochiometric ratio respected)
First I added the potassium chloride to sulphuric acid to make HCl (gas) which I recovered and potassium sulphate. The mixture was heated to drive of
HCl and when the mixture stopped to make HCl I stopped heating, washed my sulphate with methanol and filtered. The product was dried.
I make a mixture of Calcium hydroxide(from seashell, see prepubication tread for more information), potassium sulphate and carbon, all the chemicals
where coarse. The mixture was heated dry at 1000 degree to make the reaction go to completition (Even against vent It smelled strongly sulphur
dioxide, When I made my process I did not tough that hydroxide would make water... Turning all sulphide to dangerous hydrogen sulphide, which probably
burned to make the SO2( I was far away from the reaction so I don't think I respired much H2S)) Then I placed the melt in the water, the melt crumbled
and I filtered the solution to test it.
I added universal indicator that turned pink and do not want to change color even with strong base or strong acid.
Actual question;
Why the dye was altered and by what?
Conclusion: I should never use hydroxide with sulphide at high temperature and next time I try much finer reactant are needed.
I never asked for this.
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blogfast25
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That process ruined entire pockets of the English landscape (around Widness for instance) for decades during the so-called 'soda wars'. Bweurk!
See here for some juicy details:
http://developing-your-web-presence.blogspot.co.uk/2008/04/g...
[Edited on 22-6-2012 by blogfast25]
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plante1999
International Hazard
Posts: 1936
Registered: 27-12-2010
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Mood: Mad as a hatter
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I knew these but to make potassium carbonate it was the only process I found in bonus It give highly valuable RG HCl 30% Sol. and CaS. Next time I
will use CaCO3 instead of the hydroxide.
For those that are wondering, yes i'm actually making a Prepublication pdf about this process.
I never asked for this.
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