PROCESS FOR PRODUCING MINERAL WOOL

The present invention relates to a process for producing insulating products based on mineral fibers, in particular on mineral wool, comprisingproviding a first binder composition containing(a) from 50% to 85% by weight of water, preferably from 70 to 82% of water(b) from 10% to 45% by weight, preferably 15 to 35% by weight of a saccharide component containing sucrose,(c) from 3% to 15% by weight, preferably from 5 to 12% by weight of one or more ammonium salts or primary amine salts of an acid,preparing a second binder composition comprising the dilution of the first aqueous binder composition with water to a solids content of between 3 and 7% by weight,applying the second binder composition to mineral fibers,forming an assembly of mineral fibers coated with the second binder composition, andheating the assembly of coated mineral fibers so as to form an assembly of mineral fibers bound by an insoluble binder,said process being characterized in that the first aqueous binder composition has a pH of less than 5.5, in that the ammonium salt or primary amine salt is a salt of strong acid or a salt of an acid having a pKa of less than or equal to 2.2, and in that the first and second binder compositions are devoid of salts of weak acids having at least a pKa of between 2.5 and 6.9.