Large quantities of bulk powder can be separated according to particle size and density by air classifiers. Classifiers disperse the powder and usually achieve size differentiation by drag and centrifugal forces acting on individual particles in the gas stream. A Donaldson ''acucut'' Classifier for the separation of B/sub 4/C powder is evaluated. Experimental tests were conducted to determine the particle cut sizes and powder yields obtained by variation of operating parameters. To assess the classifier's performance further results of the sharpness of the powder cuts were evaluated and compared with the vendor's prediction. 7 figures, 3 tables.

The report describes and highlights the more important factors associated with the termination of the Special Metallurgical (SM) Building at Mound Laboratory. As a result, a written record of the more important techniques and procedures is now available for reference by others involved in similar termination efforts. Included in this report is a description of the organizational units that were used in this effort along with a description of their responsibilities. A general description of the SM Building and a discussion of the more relevant procedures and equipment that were used are also presented. In addition, pertinent Health Physics information, such as personnel exposure, final wipe levels in the terminated facility, and assays of the structure, are provided. Based on the experience gained from this project, recommendations were made regarding the design of future radioactive material handling facilities so that when they are ultimately terminated the effort can be accomplished more efficiently.

Two high-pressure flow microreactors continue to function effectively for studies of the hydrodesulfurization of dibenzothiophene, methyl-substituted dibenzothiophene and also for studies of the hydrodenitrogenation of quinoline. The hydrodesulfurization of dibenzothiophene has been examined in a flow system in a totally reproducible fashion free from catalyst deactivation for extended periods. The reaction is first-order in dibenzothiophene, and all of the reaction products except H/sub 2/S are sulfur free. A program for determining the kinetics and reaction network of methyl-substituted dibenzothiophenes was started. For example, the rate for hydrodesulfurization of 4,6-dimethyldibenzothiophene is about one-fifth the rate for dibenzothiophene. The hydrocarbon reaction products except H/sub 2/S are sulfur free; therefore, the initial point of attack is concluded to be the C-S bond. The hydrodenitrogenation of quinoline was examined further by replacing white oil with hexadecane; this substitution permits the determination of the nitrogen-free reaction products by gas chromatography. These studies show that the C-N bond is broken after at least the heterocyclic ring and preferably both rings are hydrogenated. The hydrogenolysis reactions are rate limiting for the overall process of nitrogen removal. The hydrodenitrogenation of acridine is slower than that of quinoline. The reaction network shows that the molecule must be hydrogenated before …