[inaneQuestionsAll]

I have a dream. A dream were I can purify silicon dioxide pure enough for Chemical Vapor deposition, using only salt water and charcoal.

Just working some of the chemistry so far I have this:

- Electrolysis (Chlor-alkali Process) of salt water and water yeilds chlorine gass, hydrogen, and Sodium hydroxide.

- The chlorine is "cooked" with sand and carbon (to steal the oxygen from the silicon dioxide), forming co2, silicon tetrachloride plus impurities.

- The liquid silicon tetrachloride is distilled.

- Silicon tetrachloride is used in CVD, creating hydrogen chloride.

- The hydrogen chloride is bubbled through the sodium hydroxide in water solution made at the start, to yeild more water and salt.

- Some of the water would be distilled off to purity for the first step.

Is there an easier way? Would plain glassware be ok for the reactions?

[Wastrel]

It would help if you told us the bigger picture.  What are you trying to deposit, silicon or silicon dioxide?  What is the application?

At the moment it sounds very neat in theory, of the sort that comes crashing down the first time you try the first step.

Since glass is mostly silicon dioxide, I would say it wasn't suitable for most steps.

[inaneQuestionsAll]

The goal is pure silicon dioxide for MCVD into optical fiber preforms.
http://en.wikipedia.org/wiki/Optical_fiber#Manufacturing

As well as this colder deposition process:
http://www.nanoscribe.net/content/16/1/en/how-can-polymer-structures-be-shielded-from-thermal-or-chemical-post_treatment.html

I am also interested in other processes that would produce silica powder pure enough to avoid thermal shock damage during/after sintering. I would use a process similar to this for the sintering: http://www.markuskayser.com/work/solarsinter/
My system would need more light focused than his raw sand setup did, because of the bright white silica and higher melting temperature. I understand that sintered objects made this way would be frosted white and stronger than regular glass.

Ultimatly, I would like to take such a setup to a desert region and be able to build from sand into pure silica dioxide glass (fused quartz).
http://en.wikipedia.org/wiki/Fused_quartz


What type of containment would you suggest for the reactions needed in purification? Am I being realistic?

[inaneQuestionsAll]

Would it be better if I separated each of these reactions into individual topics?

[billnotgatez]

I do not think we need to do that

Would it be better if I separated each of these reactions into individual topics

Moderator: billnotgatez

[billnotgatez]

http://en.wikipedia.org/wiki/Silicon_dioxide
http://en.wikipedia.org/wiki/Silicon_tetrachloride

I put these links in for reference purposes