文档介绍：Advances in Environmental Research 4Ž. 2000 45᎐58
The partitioning of radionuclides during coal
combustion
Wayne S. Seames, Jost . WendtU
Department of Chemical and En¨ironmental Engineering, Uni¨ersity of Arizona, Tucson, AZ 85721, USA
Accepted 8 February 2000
Abstract
An important issue is the environmental impact of radionuclide-containing waste products from bustion.
Radionuclides vaporize in the hot portions of the bustor and then return to the solid phase in cooler
downstream zones. Understanding the mechanisms by which radionuclides transform from the vapor to the solid
phase is an important step for predicting and mitigating the effect of these radionuclides upon the environment. This
paper describes studies of bustion phase radionuclide transformations using a pilot-bustor.
Particulates were collected at two locations and analyzed using neutron activation. Comparing the distribution of
radionuclides at the two locations has suggested mechanisms for the partitioning of cesium, thorium, cobalt, and
cerium. bustion of Pittsburgh or Illinois ࠻6 coals, some radionuclides are vaporized in bustion
zone then partition back to the solid phase onto the surface or within pores of supermicron-size particles in the
bustion zone. Cesium and cobalt are reactive with aluminum᎐poundsŽ. . kaolinite in the
supermicron particle matrix. During bustion of an Ohio 5r6r7 blend coal, a portion of the radionuclides
vaporize well into the bustion zone then partition back to the solid phase onto the surface of submicron-size
particles in the bustion zone. However, a greater portion of the radionuclides appear to remain non-volati-
lized in supermicron particle fragments passing through bustor. Cesium, thorium, and cobalt are reactive
with pounds in the submicron particles. ᮊ 2000 Elsevier Science Ltd. All rights reserved.
Keywords: bustion; Radionuclides; Partitioning
1. Introduction centration of the radionuclides in the coal and the
partitioning