Accession Number : AD0699645

Title :   STUDY OF INTERNAL REACTION DURING THERMAL OXIDATION OF CARBON-GRAPHITE MATERIALS,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Shein,L. N. ; Chalykh,E. F. ; Rozeman,I. M.

Report Date : 25 SEP 1969

Pagination or Media Count : 25

Abstract : The kinetics of thermal oxidative pretreating of pressed work pieces containing coke, natural graphite and coal pitch were experimentally studied and theoretically analyzed to define the effects of adsorption and diffusion involving the porous body and the pitch binder coating the pore surfaces. The material used in experimental measurements comprised 65 percent pyrolytic petroleum coke, 5 percent natural graphite, and 30 percent Magnitogorsk coal pitch. The transition of the pitch binder into a solid material and the migration of the reaction zone from the surface in the center of the sample were determined from the yield of volatile materials by a published technique at 200 and 240 C. The effective diffusion coefficient was derived by correlating the yield of volatile products, the amount of consumed oxygen, and the change of gas yield with time. The amount of oxygen penetrating the material and its concentration gradient were derived. The porosity was measured and mathematical models were derived defining the effective diffusion coefficient as a function of porosity and pore structure. The effect of temperature on diffusion was considered. The nonisothermal condition of the process was experimentally determined and discussed and it was shown that the migration of reaction zones is the main factor limiting the usability of the process. (Author)

Descriptors :   (*PITCH(MATERIAL), *OXIDATION), (*BINDERS, PITCH(MATERIAL)), (*CARBON, PELLETS), DIFFUSION, GRAPHITE, POROUS MATERIALS, COAL, USSR

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE