Degree Type

Dissertation

Date of Award

1989

Degree Name

Doctor of Philosophy

Department

Chemical and Biological Engineering

First Advisor

Lawrence E. Burkhart

Abstract

Submicron spherical particles of the yttria precursor Y(OH)CO[subscript]3·H[subscript]2O were continuously precipitated in three types of reactors: (1) mixed-suspension mixed-product removal (MSMPR), (2) semi-batch, and (3) packed bed. The homogeneous precipitation occurred as a result of the thermal decomposition of urea in an aqueous yttrium nitrate solution;A wide variety of particle size distributions were produced from these reactors. Mathematical models, which assumed that particle growth was by a diffusion mechanism, successfully allowed the size and shape of the particle size distributions to be predicted and controlled. It was shown that the concentration of the rate-limiting diffusing species could be calculated from a simple analysis of the particle size distribution from the MSMPR reactor. From such an analysis, it appeared that carbonate was the rate-limiting diffusant.

DOI

https://doi.org/10.31274/rtd-180813-12548

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Harold Ray Jouett, II

Language

en

Proquest ID

AAI9014913

File Format

application/pdf

File Size

186 pages

Share

COinS