User blog comment:Inept Wiki User/Speculation: The other Celestial Spirits/@comment-203.87.139.100-20130612140759/@comment-7418318-20130612150843

I wonder about that.

Angel said she killed other celestial mages and took their keys.

We saw Loke summon his key somehow when he gave it to Lucy, so maybe spirits have the ability to move their key around magically if the situation allows it.

If that's the case, those keys might have been teleported away (either by the spirits themselfs, or by the Spirit King) rather than dissolving.