I am not a ceramist, therefore not an expert on your question, but I have not heard of firing tiles coated with liquid emulsion. I know that photographic images have been placed on ceramics with dichromated processes, but not liquid emulsion. The ag emulsion is silver in a gelatin base, so whatever will burn off gelatin will burn off the emulsion. From my understanding, it doesn't go through a fire because the burning point of gelatin is very low, but, in fact, is applied to an already fired and glazed tile.
The tile must be "subbed" with either a clear polyurethane glossy varnish, or with a gelatin layer. With the latter, use a packet of Knox gelatin in a cup of cold water, let dissolve, then heat to 140 degrees. At that point you have to add a hardener to the gelatin--Freestyle sells Black Magic hardener. This is "loosey-goosey", meaning just add drops of hardener to your gelatin, say, 12 drops to the cup of hot gelatin. Then you want to also add drops of the hardener to your liquid emulsion Ag product--about 5 drops per teaspoon of Ag+ That way your gelatin is hardened and so is your liquid emulsion and upon development they will not "frill" off the tile. Then when the tile is finished the development, fixing, and washing process, spray it with a layer of Krylon Crystal Clear acrylic varnish, or more of the polyeurethane to protect it.
I have done both of these methods with tiles. The biggest problem you will encounter is bubbling of the layer off the tile so watch for that. Good luck and treat the tiles as fragile when done.