Sciencemadness Discussion Board

From the Wiki: CaSO4 + SiO2 -> SO3 + CaSiO3. Does this actually work?

Merryp - 20-1-2020 at 15:11


http://www.sciencemadness.org/smwiki/index.php/Sulfur_trioxi...

Temperatures aside, this seems pretty straightforward, and doesn't require gas phase oxidation with a catalyst at elevated pressure.

Given the very limited citations, both here and on wikipedia, the question remains whether that process actually works as described.

Are there any better sources available on that matter?

annaandherdad - 20-1-2020 at 16:48

This was done at Whitehaven in the UK, google on it plus "sulphuric acid" you'll get lots of hits. They produced lots of H2SO4 there by this process until 1992.

rockyit98 - 20-1-2020 at 17:02

Quote: Originally posted by Merryp  

http://www.sciencemadness.org/smwiki/index.php/Sulfur_trioxi...

Temperatures aside, this seems pretty straightforward, and doesn't require gas phase oxidation with a catalyst at elevated pressure.

Given the very limited citations, both here and on wikipedia, the question remains whether that process actually works as described.

Are there any better sources available on that matter?

yes https://d28rz98at9flks.cloudfront.net/9554/Rec1949_044.pdf
SO3 is very toxic. and heating to 1000C isn't easy. a much better way is to heat MgSO4.6H2O-------(slow heating)-----MgO+H2SO4 +5H2O more information needed

Merryp - 20-1-2020 at 17:26

Quote: Originally posted by rockyit98  

yes https://d28rz98at9flks.cloudfront.net/9554/Rec1949_044.pdf
SO3 is very toxic. and heating to 1000C isn't easy.


Neat. That one's still going via the contact process/SO2, though.

Yes, I'm aware of the inherent difficulties and dangers, I'm interested in it from a "chemistry from scratch" point of view, historical production, that kind of stuff is what I find most interesting.

[Edited on 21-1-2020 by Merryp]

[Edited on 21-1-2020 by Merryp]

Merryp - 20-1-2020 at 17:43

Quote: Originally posted by annaandherdad  
This was done at Whitehaven in the UK, google on it plus "sulphuric acid" you'll get lots of hits. They produced lots of H2SO4 there by this process until 1992.


Well, wikipedia contradicts itself on that matter. On the page for SO2, it claims the opposite:

"sulfur dioxide can also be a byproduct in the manufacture of calcium silicate cement; CaSO4 is heated with coke and sand in this process:
2 CaSO4 + 2 SiO2 + C → 2 CaSiO3 + 2 SO2 + CO2
Until the 1970s, commercial quantities of sulfuric acid and cement were produced by this process in Whitehaven, England. "

[Edited on 21-1-2020 by Merryp]

[Edited on 21-1-2020 by Merryp]

draculic acid69 - 20-1-2020 at 23:12

If it requires heating to 1000'c it's useless considering that mgso4 or na2so4 heated to 650'c lead to so3 as well.im guessing that caso4 would follow suit at a lower temperature.i read somewhere that ammonium persulfate heated to 180'c gives off so3.hobby electronic stores will have it in pure form.