Doctoral Dissertations

Abstract

"The mathematical modeling of the kinetics of metal/slag/gas reactions which occur in pyrometallurgical processes is very important in providing an insight into the coupled reactions that take place between the large number of components present among the reaction phases. A generic computer code was developed (in Pascal, called SMAK), based on the coupled reaction model proposed by Robertson et al. A new approach to kinetic modeling using free energy minimization to calculate the equilibrium condition at each interface, is also described. Unit operations, representing the different phases and interfaces in this approach, were connected together using the METSIM software. The kinetic model was applied to several metallurgical processes such as counter-current refining of low-carbon ferromanganese, zinc slag fuming (SMAK) and simultaneous de-S/de-P of pig iron (METSIM).

Physical modeling of a counter-current reaction launder (CCRL) for metals refining was performed to study the fluid flow and dispersion characteristics of the CCRL. This work was conducted in a 200 cm long (L) by 20 cm wide (W) channel, using tetrachloroethylene to model 'metal' and water to model to 'slag'. A thermal tracer technique was used to measure the eddy thermal diffusivity (αe) and interphase heat transfer coefficient (hov). The heat and mass transfer analogy was then applied to determine the extent of longitudinal mixing (De/uL) and to estimate the rate of interphase mass transport (kov). Nitrogen was bottom injected at a rate per unit area of 12.5 cm/min, through up to 14 central bubblers placed along the length of the CCRL. The results indicate that even under conditions of significant bottom gas injection, it should be possible to maintain acceptably low longitudinal mixing (De < 20 cm2/s and De/uL < 0.1) in the CCRL. Interphase mass-transfer coefficients of the order of 0.02 cm/s and higher, are predicted from the measured interphase heat transfer coefficients using the mass and heat transfer analogy. Adequate performance is likely to be possible for an industrial CCRL, based on extrapolation of these results to full-scale conditions"--Abstract, page v.

Advisor(s)

Robertson, D. G. C.

Committee Member(s)

Watson, John L.
Morris, Arthur E., 1935-
Peaslee, Kent D., 1956-2013
Reed, X. B., Jr.

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Metallurgical Engineering

Comments

Support of this research by the Department of the Interior’s Mineral Institute Program administered by the U.S. Bureau of Mines through the Generic Mineral Technology Center for Pyrometallurgy under Grant number USDI G1135229 2927 is gratefully acknowledged.

Publisher

University of Missouri--Rolla

Publication Date

Fall 1996

Journal article titles appearing in thesis/dissertation

  • Kinetic simulation of the zinc fuming of lead blast furnace slags in center-fed, hollow graphite electrode, DC plasma-arc furnaces
  • Thermodynamic and kinetic simulation of a novel counter-current reaction launder process for the production of refined low carbon ferromanganese
  • Kinetic simulation of the control of the nitrogen content of low carbon ferromanganese in a novel counter-current reaction launder process
  • Mathematical modeling of the kinetics of reactions between multiple phases: applied to the De-S and De-P of molten pig iron
  • The effect of high gas flowrates on the performance of a counter-current reaction launder (CCRL) process for metal refining

Pagination

xix, 127 pages

Note about bibliography

Includes bibliographic references.

Rights

© 1996 Krishnaswamy Narayana Swamy, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Thesis Number

T 7194

Print OCLC #

36904229

Electronic OCLC #

1089931723

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