Acoustic mixing system for creating propellant mixture

A method of creating a propellant mixture, the method comprising:

• forming an explosive composition mixture, the explosive composition mixture comprising an explosive material, and one or more additives,
• placing the explosive composition mixture into a mixing vessel assembly, the mixing vessel assembly comprising an upper dish and a lower dish, the upper and lower dishes
• collectively forming a closed mixing zone having a maximum vertical height;
• operating an acoustic mixing system at an operating frequency such that the acoustic mixing system causes a vertical displacement of the mixing vessel, the acoustic mixing system having a resonant frequency, the resonant frequency being constant when the acoustic mixing system is at rest and varying when the acoustic mixing system is in operation;
• wherein the acoustic mixing system is operated in a manner such that the operating frequency is substantially similar to the resonant frequency and a ratio of the maximum vertical height of the closed mixing zone to the vertical displacement of the mixing vessel assembly is 2.0 or less, and
• wherein the acoustic mixing system is operated in a manner such that the operating frequency is greater than 20 Hz and less than 100 Hz.