Chemistry Talk

Guest

Hello - I'm interested in making large quantities of Aluminum
Hydroxide [Al(OH)3]. It is a compound that decomposes at 300C, which
is perfect as a heating buffer-medium in a personal project. That is,
I wish to use an arbitrary heat source applied directly to the
Aluminum Hydroxide within a metal container to ensure the temperature
inside the container doesn't exceed approx. 300C (while enough
Aluminum Hydroxide hasn't decomposed, the temp. should stay in that
range). That way, the Aluminum Hydroxide acts as a natural temperature
controller.

I'm aware that the interaction of water and a base like Sodium
Hydroxide NaOH will create Aluminates, which also make some
hydroxides. I'm ionterested in pure hydroxides but have little to no
experience with using these materials. I also don't really have a way
to probe the temperature directly. As far as I understand, when using
say NaOH, H2O and Al, the interaction does two things. One rips the
oxide layer off the Al and exposes the H2O directly to the Al and
forms the hydroxide I need. However, the Na cation remains in solution
along with the Al(OH)4 anion.

Since Aluminum Hydroxide is insoluble in water, after reacting say Al
foil with NaOH in distilled water solution, any remaining white
material in the solution should be fairly pure Aluminum Hydroxide,
correct? I can then take the liquid portion and pour it off and boil
the soaked hydroxide at a temperature just around water's boiling
point to get hydroxide? Hopefully this works and seems to be the most
cost effective (I need a LOT of Aluminum Hydroxide). I am concerned
about the temperature of the Aluminum Hydroxide boiling/decomposing at
300C - this is the most important aspect.

Other methods through replacement reactions (such as Ammonia
Hydroxide, Magnesium Sulfate, and Alum for example) do not seem cost
effective although seemingly quite pure.

My questions are thus: is using a base like NaOH in sol an adequate
way to meet what I need? Is there a better way to get Aluminum
Hydroxide? If I use NaOH method, what about the Na+ anion affecting
the boiling/decomposition temperature of the Aluminum Hydroxide?

Thank you so much,
parlous

number6 · Guest

On Jul 17, 11:46 am, parlous2...@gmail.com wrote:

Guest

Thanks for your reply and suggestions. I think I may make a bunch via
NaOH and then try stick some sort of thermometer on it, monitor how is
behaves.