Method for extracting ammonium perchlorate from a solid composite propellant

A method for recovering ammonium perchlorate contained in a solid composite propellant, said method comprising the steps of:

• i) contacting, with a first aqueous solution, the solid composite propellant in the form of pieces;
• ii) subjecting said pieces of solid composite propellant present in said first aqueous solution to fragmentation so as to obtain fragments of solid composite propellant the largest dimension of which does not exceed 10 mm;
• iii) adding, to the mixture obtained in step ii), a second aqueous solution in which the amount of water is such that the W/P mass ratio is between 2.5 and 6.8 with W representing the sum of the mass of water in the first aqueous solution and the mass of water in the second aqueous solution and P representing the mass of solid composite propellant present in the form of pieces and stirring the whole whereby an aqueous suspension is obtained;
• iv) keeping said stirring for a time sufficient for the ammonium perchlorate to solubilise in the continuous phase of said suspension, said solubilisation being monitored by measuring the ionic conductivity of said aqueous suspension;
• v) separating the dispersed phase and the continuous phase of said aqueous suspension once the ionic conductivity reaches a stabilized value of less than 60 mS/cm;
• steps (i) to (iv) of said method being carried out at a temperature, identical or different, of less than or equal to 50° C.