Sciencemadness Discussion Board

Making H2SO4 from gypsum and silica ?

metalresearcher - 23-8-2020 at 22:01

Quote:
On wiki I found
https://en.wikipedia.org/wiki/Calcium_sulfate#Other_uses

[quote=wikipedia]
Up to the 1970s, commercial quantities of sulfuric acid were produced in Whitehaven (Cumbria, UK) from anhydrous calcium sulfate. Upon being mixed with shale or marl, and roasted, the sulfate liberates sulfur trioxide gas, a precursor in sulfuric acid production, the reaction also produces calcium silicate, a mineral phase essential in cement clinker production.[14]

CaSO4 + SiO2 → CaSiO3 + SO3

Can we as amateurs make SO3 that way by just heating ordinart CaSO4 (e.g. crushed drywall) and silica sand ?

Maurice VD 37 - 24-8-2020 at 01:05

You may try. But the reaction occurs at a temperature that is usually not possible to get by amateurs (~1500°C).

macckone - 24-8-2020 at 07:08

You will get SO2 not SO3, SO3 decomposes at the temperature required.

Edit: the table on page 6 provides the partial pressures of SO2 and SO3 at various temperatures.
Attachment: Decomposition of Calcium Sulfate.pdf (3.3MB)
This file has been downloaded 314 times

[Edited on 24-8-2020 by macckone]