Method for guiding a moulding material in a moulding material cycle comprising two or more cycles

A method of guiding a molding material in a molding material cycle comprising two or more loops, comprising the following steps:

• in an earlier loop of said two or more loops of the molding material cycle, casting in a mold comprising the smectite-containing clay-bound molding material,
• processing the molding material that has been used for casting so as to result in a first processed molding material,
• in a later loop of said two or more loops of the molding material cycle, producing a molding material comprising:
• (i) first processed molding material,
• and
• (ii) aggregates comprising
• an additive containing at least one dehydratable inorganic compound that eliminates water at a temperature of 150° C. or more,
• one or more raw materials from the group consisting of
• mold base material,
• a second processed molding material produced by processing molding material from molds that have not been used for casting and/or cores and/or parts thereof,
• a third processed molding material produced by processing molds used for casting outside the molding material cycle and/or cores and/or parts thereof,
• and optionally smectite-containing clay,
• wherein, in the molding material produced, the total proportion of material from molds and cores formed from a molding material bound by a binder other than smectite-containing clay is less than 10% by weight.