ZINC RECOVERY FROM ITS ACIDIC SOLUTION

I am working on environmental pollution control specially removal of heavy metals from an aqueous solution. If some one has any idea of zinc recovery from its acidic solution. please send me the methodology.

The short answer is you just bring the pH up to about 10 and the zinc precipitates and settles, Dr. Singh. But a treatability study may indicate the need to destroy ammonia, or break other complexes, or to use co-precipitant/coagulants to drive the zinc out of solution, and a final sulfide treatment to reach low discharge limits. On the dewatering side, you may need polyelectrolytes and possibly organic coagulants. In my own estimation zinc recovery from this precipitate is not economically practical today, based on the many claims that it was, followed by the failure to actually be implemented. This practicality issue depends to an extent on where you are in the disposal chain, though. Here in the USA some platers reduced the amount of zinc in their sludge sufficiently that the recyclers/refiners they had lined up would no longer take it, which left them in the lurch.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey