Aluminum Corrosion in Pebble Lime Plants.

[ibf]

Can you give guidance on aluminum corrosion in pebble lime plants? The literature suggests good performance of aluminum in the presence of lime but we are experiencing corrosion in this environment. The aluminum is outdoors and will be covered with CaCO3 and CaO (which will turn to Ca(OH)2 with humidity and rain). Would this combination attack the aluminum or is something else in the environment causing the corrosion.



Thanks for your help.

 

[rnd2]

According to my copy of Philip A. Schweitzers'Corrosion Tables,
Aluminium is unsatisfactory against saturated Ca(OH)2

 

[ibf]

Thank you very much for your prompt reply rnd2.

 

[ibf]

rnd2 - Is it possible for you to send me the complete name , author and latest edition of that book where you found the answer to my question ?

Thank you.

 

[kenvlach]

ibf,
Re "The literature suggests good performance of aluminum in the presence of lime." -- What literature? I suggest that this is true only in a totally anhydrous atmosphere, e.g., on the surface of the Moon.

Lime absorbs moisture from the air, creating hydrated lime with a pH of 12.4, which caustically attacks the aluminum. This is the same reaction as Al with fresh concrete.

The attack of Al by alkalies is well-known:
At pH > 10,

Al(OH)₃ (solid) + OH^- ---> Al(OH)₄^- (aqueous)

 

[rnd2]

Corrosion Resistance Tables, 5th edition, 4-Volume Set edited by ...
edited by Philip A. Schweitzer. Invested with state-of-the-art research on
mechanisms of corrosion and advancements in corrosion resistance, ...

http://www.chipsbooks.com/corresis.htm

- 5k - Cached - Similar pages
Ain't cheap.