Neutralizing Anhydrous Aluminium Chloride

[lesianatalia]

I have some anhydrous aluminium chloride (>99%) on site that I need to dispose of. The problem is that anhydrous aluminium chloride is extremely water reactive - giving off hydrogen chloride fumes on contact with water.

My facilities to deal with these fumes are limited, so I thought the best way to dispose of it would be to use a neutralizing agent like caustic soda first. Not quite sure if this is the most safe way.

Any suggestions?

 

[kenvlach]

Have you already dealt with this problem?

As you suggested, neutralize with NaOH (use a small excess) in a large volume of continuously stirred water. Rxn. is
AlCl3 + 3 NaOH(aq) = 3 NaCl(aq) + Al(OH)3(aq)

As FW AlCl3 is 133.35 & FW of NaOH is 40, I would an equal amount of NaOH predissolved in water & cooled [actually, I use twice as much 50 wt% NaOH solution, but still need to cool]. Suggest using at least 10 gallons of water+NaOH per pound of AlCl3 in order to absorb heat; that way can get rid of 50 lbs in a 500 gallon mixer.
Also, I would try to sprinkle the AlCl3 over the surface to avoid possible explosive boiling. If you have a large quantity, maybe put some fibergrate over the tank & then use a shovel to toss the AlCl3 over the grating. Of course, wear PPE.
If you have already neutralized, kindly post the method used & observations.
Ken