Passivating means, surface treatment means, surface treatment spray means and method for treating metallic surfaces of work pieces or cast molds

1. A passivating agent for metallic surfaces of workpieces or casting molds, the passivating agent consisting of:

5% to 50% by weight of orthophosphates;

0.1% to 5% by weight of a gelatin; and

water,

wherein a redox potential of the gelatin is set so that a gold number of the gelatin is smaller than 50 μmol Au/g of gelatin.

2. The passivating agent as recited in claim 1 , wherein the orthophosphates comprise at least one of the compounds zinc phosphate, aluminum phosphate, manganese phosphate, titanium phosphate, calcium phosphate, boron phosphate and iron phosphate.