What is ammonium zincate

From: Qi Wang (wang_iq_at_hotmail.com)
Date: 12/29/04 

Date: Wed, 29 Dec 2004 10:26:06 +0800

Hello,

I read United States Patent 5,349,074 describing a process to purify
different biliary acids from hog biles, and encountered the following
sentence:

"The biliary acids solution is treated with an ammonium zincate aqueous
solution to precipitate the zinc salts of the same biliary acids."

The meaning istself is clear but I don't what "ammonium zincate" is, as I
cannot find any info with Google, nor from any reagent catalogues.

Any ideas? I am not a good chemist.

Thanks in advance.

Qi Wang