AdmiralDonSnider Posted August 6, 2009 Posted August 6, 2009 (edited) Sulphates, especially those from strontium and barium, are vital for a variety of effects e.g. as a delay agent in firefly stars or as color producing agents in AP based strobes. Some more exotic red stars also employ strontium sulphate. However, sulphates seem to be hard to find in the stocks of (european) pyro suppliers. I wondered if there is a simple way to make them your own. (I´m not the genius chemist, so...please forgive me in case I asked for something very common... ) Edited August 6, 2009 by AdmiralDonSnider
andyboy Posted August 6, 2009 Posted August 6, 2009 Sulphates, especially those from strontium and barium, are vital for a variety of effects e.g. as a delay agent in firefly stars or as color producing agents in AP based strobes. Some more exotic red stars also employ strontium sulphate. However, sulphates seem to be hard to find in the stocks of (european) pyro suppliers. I wondered if there is a simple way to make them your own. (I´m not the genius chemist, so...please forgive me in case I asked for something very common... ) They are abundant and cheap at ceramics suppliers though. I've made Strontium and Barium Bensoate with most of my stack, works great.
Arthur Posted August 6, 2009 Posted August 6, 2009 Good white plaster (plaster of Paris in the UK) is pure calcium sulphate!
Mumbles Posted August 7, 2009 Posted August 7, 2009 One of the easiest ways would be to dissolve the carbonates in dilute sulfuric acid. I would preference to dissolve it into HCl(faster), and crash out the corresponding sulfate with an excess of potassium sulfate. Potassium sulfate is sold in most garden supply stores as "sulfate of potash". The same can be done whle starrting with the corresponding nitrate or sulfate. Watch out for sulfide contamination while dissolving the carbonate. It won't smell nice.
AdmiralDonSnider Posted August 10, 2009 Author Posted August 10, 2009 Thanks. If sulphuric acid is used for the synthesis: wouldn´t any traces present a major hazard in combination with chlorates? (Firefly formulas are nitrate based anyway) Are there possible ways without H2SO4? Could you further describe the equation and the process, you know, kind of a how to?
WSM Posted August 20, 2009 Posted August 20, 2009 Thanks. If sulphuric acid is used for the synthesis: wouldn´t any traces present a major hazard in combination with chlorates? (Firefly formulas are nitrate based anyway) Are there possible ways without H2SO4? Could you further describe the equation and the process, you know, kind of a how to? Hi All, When I wanted to make strontium sulfate and had strontium nitrate on hand, I combined strontium nitrate solution with Epsom salts solution (magnesium sulfate) and the strontium sulfate dropped out, leaving the hygroscopic magnesium nitrate in solution to be washed out. The magnesium nitrate solution can be thrown into the garden as fertilizer without concern. Barium nitrate also works for making barium sulfate using this process.
Ralph Posted August 20, 2009 Posted August 20, 2009 (edited) One of the easiest ways would be to dissolve the carbonates in dilute sulfuric acid. I would preference to dissolve it into HCl(faster), and crash out the corresponding sulfate with an excess of potassium sulfate. Potassium sulfate is sold in most garden supply stores as "sulfate of potash". The same can be done whle starrting with the corresponding nitrate or sulfate. Watch out for sulfide contamination while dissolving the carbonate. It won't smell nice. (any soluble sulfate will work (so long as the chloride is also soluble) though potasium or magnesium sulfate would be best(sodium and ammonium sulfate which are both common will work but sodium impurities will ruin your colour and ammonia isn't compatible with chlorates) BaCO3(s) + 2HCl(aq) ---> BaCl2(aq) + CO2(g) + H2O(l) BaCl2(aq) + K2SO4(aq) ----> BaSO4(s) + 2KCl(aq) or alternatively BaCO3(s) + H2SO4(aq) ----> BaSO4(s) + CO2(g) + H2O(l) the first one (like mumbles said) is better as all of the barium carb will convert and it will happen quickly with sulfuric acid it will be slow and will require mixing to gt a full reaction to occur Edited August 20, 2009 by Ralph
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