Loading [MathJax]/jax/output/HTML-CSS/fonts/TeX/fontdata.js
Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: SiO2 + Na thermite reaction?
Rainwater
National Hazard
****




Posts: 987
Registered: 22-12-2021
Member Is Offline

Mood: Break'n glass & kick'n a's

[*] posted on 11-2-2025 at 12:52


Not really intrested in silicon or thermite, just curious to if the OP reaction would take place.
When thermodynamic calculations are so close to the 45 unit margin, I have noticed the reaction can go ether way.
This is due to errors/non-linearity in the listed values or reaction conditions.
Being a value of 100, and something i was easily able to do at the time.
I have another datapoint for my margin of error dataset




"You can't do that" - challenge accepted
View user's profile View All Posts By User
teodor
International Hazard
*****




Posts: 1001
Registered: 28-6-2019
Location: Netherlands
Member Is Offline


[*] posted on 11-2-2025 at 13:24


It's definitely will take place but the math is wrong because it can take place only on excess of cold alkali metal reacting with a small piece of 2200C amorphous SiO2. There is no experimental evidence that the reaction can start on a lower temperature and I think it is the main reason why the practical way was to react fluoride with Na/K.

[Edited on 11-2-2025 by teodor]
View user's profile View All Posts By User
Acetyl
Harmless
*




Posts: 2
Registered: 15-1-2024
Location: Poland
Member Is Offline

Mood: discoverer, student, scientist

[*] posted on 11-2-2025 at 14:34


Recently I carried out a reduction of SiO2 using Mg.
The amount of Mg used for the reaction was a few percent higher than it would result from stoichiometry. Among the products you can see inclusions of a white substance, most likely unreacted SiO2. The SiO2 came from fuses.

Sil2.jpg - 574kB Sil1.jpg - 1MB

I confirm that we will not get pure Si using this method. The thermite reaction is pretty for show: it proceeds calmly, shining with a strong white light. A lot smoke is generated.

I purified the post-reaction mixture in diluted HCl and washed it several times with water.

I show what I got in the photo. Among the reaction products was magnesium silicide: when pouring Si into the acid, you could hear a lot of shots and sparks above the solution.

The reaction of magnesium silicide with HCl was identical to that in the article:
https://en.wikipedia.org/wiki/Magnesium_silicide

View user's profile View All Posts By User
 Pages:  1  2

  Go To Top