Effect of particle size and particle size distribution on the burning rate of barium chromate-boron pyrotechnic delay compositions
Date of Award
Master of Science in Chemical Engineering - (M.S.)
Chemical Engineering and Chemistry
Carl W. Carlson
The burning rate of barium chromate-boron delay compositions is shown to be related to the 10 percent particle size point on the particle size distribution curve (particle size vs. percent greater than size) for either of the components. The burning rate is also shown to be inversely proportional to the 10 percent point of the barium chromate; and to follow a hyperbolic type relationship with the 10 percent of the boron, decreasing asymptotically as the 10 percent point increases. No correlations were found between the burning rate of the compositions and the average particle diameter, the mean particle diameter, or the 50 percent point for either component.
The average particle diameter (APD) as determined with the Fisher Sub-Sieve Sizer, is presently specified as the measure of the particle size of the components of barium chromate-boron delay compositions. As the validity of the APD is subject to question, other methods of particle size analysis were considered. The Mine Safety Appliances (MSA) Particle Size Analyzer was thus selected for the determination of the particle size distribution of barium chromate and boron.
The APD was found to be closely related to the product of the uniformity index of the sample and either the NSA 50 percent point of the ESA dm (mean particle diameter.) For barium chromate the APD's were approximately equal to the modified ESA values. A low degree of inequality between the NSA and APD values existed for the boron samples.
Freeman, Donald J., "Effect of particle size and particle size distribution on the burning rate of barium chromate-boron pyrotechnic delay compositions" (1965). Theses. 2150.