Extreme energy method for impacting abrasive particles against a surface to be treated

A method of abrasive blasting a surface to be cleaned or treated comprising supplying an oxy-fuel mixture to an internal burner combustion chamber open at a downstream end to, in order, a restricting nozzle, a restricting nozzle throat, a supersonic expansion nozzle section, and an extended nozzle length forming an elongated duct by combusting said oxygen and fuel mixture within said combustion chamber, producing a flow of high-temperature products of combustion to supersonic velocity through said restricting nozzle throat and said supersonic expansion nozzle section, forming a jet stream and maintaining the supersonic flow through the elongated duct, introducing abrasive particles into the supersonic flow in the vicinity of said elongated duct to thereby accelerate the particles to extreme velocity, and maintaining the combustion pressure sufficiently high to limit the jet stream temperature passing through the elongated duct to a level which is insufficient to raise the temperature of the particle to the plastic point of the particles.