Patent ID: 6132536
Filing Date: 2000-10-17
Classification: B01F,C06B,Y10T

Abstract:
A method for preparing a solid propellant mixture of aggregated oxidant and fuel particles in a binder, comprising the steps of:(a) admixing solid particles in a solution of the binder in a mixing container equipped with a variable-speed impeller and a countersolvent supply system, wherein the solid particles have a size smaller than a desired particle size of the aggregated particles;(b) adding a first countersolvent portion to the admixture of step (a) while maintaining agitation; wherein the first countersolvent portion is less than or about equal to an amount needed for coacervation without effecting coacervation;(c) while agitating with the impeller, metering a second countersolvent portion from the countersolvent supply system into the mixture of step (b) to exceed the countersolvent-solvent ratio required for coacervation to precipitate the binder and form aggregated particles, wherein a countersolvent metering rate and impeller speed are matched to obtain the desired particle size distribution of the aggregated particles;(d) admixing excess countersolvent into the mixture from step (c) while maintaining agitation with the impeller;(e) maintaining agitation of the mixture from step (d) for a period of time to allow the binder in the aggregated particles to harden;(f) optionally rinsing the hardened aggregated particles from step (e) with additional countersolvent.