Development of viscosity models for multiphase slag system

Kondratiev, Alex. (2004). Development of viscosity models for multiphase slag system PhD Thesis, School of Engineering, The University of Queensland.

       
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Author Kondratiev, Alex.
Thesis Title Development of viscosity models for multiphase slag system
School, Centre or Institute School of Engineering
Institution The University of Queensland
Publication date 2004
Thesis type PhD Thesis
Supervisor Dr. Evgueni Jak
Prof Peter C. Hayes
Total pages 414
Collection year 2004
Language eng
Subjects L
640205 Other non-ferrous ores (e.g. copper, zinc)
291301 Process Metallurgy
Formatted abstract

Slags are molten oxides and are present in a number of the high temperature industrial processes, for example, smelting processes used to produce metals and coal gasification processes used to produce electricity. These complex liquid oxide phases play a key role in removing unwanted elements from the several hundred million tonnes of metal produced annually as well as in removing massive amounts of coal ashes during the gasification processes. Given the scale of the industry even small improvements to operating practice result in significant economic gains. 

 

Despite the relative maturity of the metallurgical and coal industries, problems of accurately predicting the physical and chemical properties of complex slags still remain. Understanding and controlling the behaviour of the slag phase is crucial to improving the technical and economic efficiencies of these operations. Viscosity is one of the most important properties of the slags. 

 

The aim of this project is to develop a general model of the viscosities of complex molten and multi-phase slag systems based on the fundamental chemical and structural properties of the melts. These fundamental properties will be derived from chemical thermodynamic models, which have recently been developed in collaboration by the research teams of The University of Queensland and The University of Montreal. The fundamental properties derived from the thermodynamic model will then be related to the viscosity of the homogeneous liquid slag. In addition, use of new thermodynamic models in conjunction with the FactSage computer database, will enable the viscosities of multi-phase systems of importance to industrial operations to be predicted. The viscosity modelling has the potential for widespread industrial applications. 

 

Summary of the work undertaken by PhD candidate: 

·        •   critical and broad review of scientific literature on the theory of   
   liquid viscosity, experimental results and models of the silicate 
   structure, experimental results and models of the viscosity of fully
   liquid as well as partly crystallised silicate melts (chapters 
   1-6);
•    modified Urbain viscosity model for fully liquid slags in the Alz03-
   CaO-'FeO'-SiOz system at metallic iron saturation  
   (chapter7);
•   heterogeneous viscosity model (Roscoe's equation with newly 
   optimised coefficients in conjunction with thennodynamic
   computer package FactSage©) for partly crystallised slags in the 
   Ah03-CaO-'FeO'-Si02 system at metallic iron saturation (chapter
   8);
•    application of the Vladimirov/Jak polymeric model to the
   description of the slag structure in the Al2)3- 
   CaO-‘FeO”-SiO2 system at metallic iron saturation and estimation
   of the average size of the structural units of viscous flow in this
   system (chapter 9);
•    quasi-chemical viscosity model for fully liquid slags in the
   Ah03-CaO-'FeO'-Si02 system at metallic iron saturation (chapter
   10);
•    development of the high temperature viscosity apparatus (chapter
   11); 

applications of the modified Urbain viscosity model to various industrial processes (coal blending, slag deposit flow) (chapter 12). 

Keyword Slag

Document type: Thesis
Collection: UQ Theses (RHD) - UQ staff and students only
 
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Created: Fri, 24 Aug 2007, 18:28:58 EST