Upvote:4
The Belgian mission in Atlanta is accredited as a "Consulate General". Accordingly, it is entitled to issue visas, including the Schengen Short-stay visa. This authority includes qualifying Chinese nationals, both with green card and without.
They advise...
We advise 3 weeks before the intended departure date.
...and
See Embassy and Consulates of Belgium in the United States and follow the appropriate links therein.