Doctoral Dissertations

Abstract

“Results of physical modelling and kinetic (mass transfer) simulation of a counter-current reaction launder (CCRL) for metals refining are presented. Physical modelling was conducted in a 200 cm long (L) by 20 cm wide (W) channel, using tetrachlorethylene to model 'metal' and water to model 'slag'. A thermal tracer technique was used to measure the eddy thermal diffusivity ( αe) and the 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). Liquid 'metal' height (H1) was kept constant at 20 cm, while the liquid 'slag' height (Hu) was varied between 5 and 18 cm. Nitrogen was bottom injected at a rate per unit area of 7.5 cm/min, through up to 16 central bubblers placed along the length of the CCRL. Low extents of longitudinal mixing in the 'metal' of De/uL less than 0.1 were measured. Interphase mass transfer coefficients of the order of 0.004 cm/s were estimated from the measured interphase heat transfer coefficient (hov = 1.3 to 2.0 kW/mK). Interphase heat transport was found to be a strong function of the gas stirring energy input (∈), according to hov ∞∈ 0.63, provided H1/W and H1/Hu met, or exceeded unity.

Kinetic simulation was applied to prediction of the performance of a novel CCRL process for production of low carbon ferromanganese (LC FeMn). A dimensionless (NCCRL)s = (kAp/m)s of 1.8 in the slag was predicted to yield highly refined LC FeMn (0.70 % Si), at a 97 % silicon utilization efficiency, and with a 89 % recovery of manganese to the alloy. A transitory reaction, tanks-in-series kinetic model was used to investigate nitrogen absorption and desorption. Substitution of argon for nitrogen was predicted to reduce the liquid LC FeMn nitrogen content from 0.98 to 0.025 % N, but at an estimated additional operating cost of about $10 /t LC FeMn”--Abstract, page iv.

Advisor(s)

Robertson, D. G. C.

Committee Member(s)

Watson, John L.
Morris, Arthur E., 1935-
O'Keefe, T. J. (Thomas J.)
Medrow, Robert A.

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 G1125229 2927 is gratefully acknowledged.

Publisher

University of Missouri--Rolla

Publication Date

Fall 1994

Journal article titles appearing in thesis/dissertation

  • 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 (CCRL) Process
  • Modeling of a Counter-Current Reaction Launder (CCRL) Process for Metal Refining
  • Physical Modeling of Three-Phase Mixing in a Counter-Current Reaction Launder (CCRL) Process for Metal Refining

Pagination

xxii, 230 pages

Note about bibliography

Includes bibliographical references.

Rights

© 1994 Lloyd Robert Nelson, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Thesis Number

T 6908

Print OCLC #

34182477

Download
Off-campus S&T users

Share My Dissertation If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the button above.

Share

 
COinS