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Full-Text Articles in Science and Technology Studies
Alternative Al Production Methods: Part 2 - Thermodynamic Analyses Of Indirect Carbothermal Routes, M A. Dewan, M A. Rhamdhani, G A. Brooks, B J. Monaghan, L Prentice
Alternative Al Production Methods: Part 2 - Thermodynamic Analyses Of Indirect Carbothermal Routes, M A. Dewan, M A. Rhamdhani, G A. Brooks, B J. Monaghan, L Prentice
Brian Monaghan
It has been widely claimed that direct and indirect carbothermic reduction of alumina for the production of aluminium have the potential to consume less energy, generate fewer perfluorocarbons and have lower total greenhouse gas emissions compared to the Hall-He´ roult process. A review of alternative aluminium production techniques focusing on the indirect carbothermal reduction routes has been presented in the Part 1 paper. In this Part 2 paper, systematic thermodynamic analyses of indirect carbothermal reduction routes are presented. These include the analyses of the Stage 1 of the process where alumina is converted to intermediate aluminium compounds before they are …
Blast Furnace Hearth Refractory And Coke Ash Mineral Interactions, P B. Drain, M W. Chapman, R J. Nightingale, B J. Monaghan
Blast Furnace Hearth Refractory And Coke Ash Mineral Interactions, P B. Drain, M W. Chapman, R J. Nightingale, B J. Monaghan
Brian Monaghan
In the blast furnace hearth the calcium aluminate by-products of coke dissolution can react with the hearth refractories. Reactions between these coke ash minerals and the aluminosilicate and alumina-carbon hearth refractories may result in increased refractory wear reducing the blast furnace campaign life. Hence improved understanding of these interactions may have implications for the campaign life of the blast furnace hearth refractory materials. The interactions between the coke ash minerals and aluminosilicate hearth refractory have been assessed by heating samples of calcium aluminates (CA, CA2 & CA6) coupled with aluminosilicate refractory to temperatures representative of the blast furnace hearth (1450 …
Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan
Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan
Brian Monaghan
Thermodynamic analysis was carried out to interpret the results of corrosion testing of nickel ferrite samples in cryolite-based baths. The equilibrium between cryolite-based baths and nickel ferrite was considered. Isopleths between cryolite-based baths and nickel ferrite confirmed that for the temperature range of interest (1223-1273 K) there was limited solubility of nickel ferrite in the bath. To better understand the formation of the metal from nickel ferrite, the effect of reducing potentials on nickel ferrite and nickel ferrite-cryolite-based bath systems were considered. The formation of a metal phase was predicted at relatively high pO2. The metal phase was nickel-rich at …
Flow Of Molten Slag Through Coke Channels, Hazem Labib George, Brian Joseph Monaghan, Raymond James Longbottom, Sheng Jason Chew, Peter Richard Austin
Flow Of Molten Slag Through Coke Channels, Hazem Labib George, Brian Joseph Monaghan, Raymond James Longbottom, Sheng Jason Chew, Peter Richard Austin
Brian Monaghan
In the lower zone of the iron making blast furnace, liquid iron and slag descend counter-current to reducing gases through a packed bed of coke. The characteristics of the flow of these liquids and their holdup influence product quality and furnace operation. The present study aimed to establish the criteria for the passage of slag through the narrow pore necks that form between coke particles. The flow of slag through coke pore necks has been simulated using an experimental technique that assesses slag flow from a funnel entering a narrow channel of known diameter. Synthetic coke was mainly used to …
Alternative Al Production Methods: Part 1 - A Review Of Indirect Carbothermal Routes, M A. Rhamdhani, M A. Dewan, G A. Brooks, B J. Monaghan, L Prentice
Alternative Al Production Methods: Part 1 - A Review Of Indirect Carbothermal Routes, M A. Rhamdhani, M A. Dewan, G A. Brooks, B J. Monaghan, L Prentice
Brian Monaghan
The production of Al from its ores at present relies on the Bayer (alumina production) and the Hall- Heroult (Al production) process. The cost associated with alumina production and apparent disadvantages of the Hall-Heroult process have led to intensive research to find alternative routes for Al production. The direct carbothermal reduction process has been thoroughly investigated as an alternative technique. Another alternative includes the indirect carbothermal reduction route where alumina (or aluminous ores) is first reduced to intermediate Al compounds before reduced further to Al. The present study reviews and provides systematic thermodynamic analyses of alternative Al production routes. In …
The Dynamic Wetting Characteristics Of Ladle Slags On Spinel, Hamed Abdeyazdan, Neslihan Dogan, Muhammad Rhamdhani, Michael W. Chapman, Brian Monaghan
The Dynamic Wetting Characteristics Of Ladle Slags On Spinel, Hamed Abdeyazdan, Neslihan Dogan, Muhammad Rhamdhani, Michael W. Chapman, Brian Monaghan
Brian Monaghan
Inclusion removal by slag is primarily achieved by optimizing process conditions that promote slag contact with the inclusion. For efficient inclusion removal the inclusions must adhere to the slag phase. The strength of the attachment can be characterised by the wettability of the slag on the inclusions.
Behaviour Of New Zealand Ironsand During Iron Ore Sintering, Zhe Wang, Harold Rogers, David Pinson, Brian J. Monaghan, Sheng Chew, Paul Zulli, Sharon Nightingale, Guangqing Zhang
Behaviour Of New Zealand Ironsand During Iron Ore Sintering, Zhe Wang, Harold Rogers, David Pinson, Brian J. Monaghan, Sheng Chew, Paul Zulli, Sharon Nightingale, Guangqing Zhang
Brian Monaghan
Titanium-bearing burdens are commonly introduced into blast furnaces to protect the hearlh because the so-called "titanium bear" which is a precipitate of carbide, nitride and carbonitride of titanium may form in the blast furnace hearth if Ti02 is present in the feed [1 , 2J. New Zealand ironsand is a titanomagnetite, containing around 60 wt.% iron, 8 wt.% titanium and other substances such as silica, phosphorus and lime [3, 4]. Since it is competitive in price, introduction of the ironsand into the ferrous feed can reduce the production cost and potentially increase blast furnace campaign life. An appropriate method of …
Inclusion Reactivity: Morphology And Composition Changes Of Spinel (Mgal2o4) In Steel, Neslihan Dogan, Raymond Longbottom, Mark Henry Reid, Michael W. Chapman, Paton Wilson, Les Moore, Brian Monaghan
Inclusion Reactivity: Morphology And Composition Changes Of Spinel (Mgal2o4) In Steel, Neslihan Dogan, Raymond Longbottom, Mark Henry Reid, Michael W. Chapman, Paton Wilson, Les Moore, Brian Monaghan
Brian Monaghan
Due to an ever increasing demand for cleaner, high quality steels, there is an increasing push for steelmakers to lower the non-metallic inclusion contents of the steel they produce. Understanding inclusion reactivity in steel is key in producing high quality steels at high production rates. Our current knowledge in controlling and predicting inclusion development during liquid steel processing is limited. In this study, spinel (MgAI204) inclusions of close to stoichiometric MgO.AI2O3 and known size distribution where added to the liquid steel bath prior to assessing their reactivity. The pO2 of the gas phase was controlled to 10-13 atm throughout the …
Interfacial Assessment Of Cao-Al2o3-Sio2-Mgo Slags On Mgal2o4 Spinel, Hamed Abdeyazdan, Neslihan Dogan, M Akbar Rhamdhani, Michael Chapman, Brian J. Monaghan
Interfacial Assessment Of Cao-Al2o3-Sio2-Mgo Slags On Mgal2o4 Spinel, Hamed Abdeyazdan, Neslihan Dogan, M Akbar Rhamdhani, Michael Chapman, Brian J. Monaghan
Brian Monaghan
Steel cleanness is an important and growing research area driven by the demands to produce high quality steel. Lowering the inclusion content in steel is an important criterion for clean steel. It is therefore important to better understand the interaction between inclusions and slag to improve the removability of inclusions from liquid steel. For efficient inclusion removal the inclusions must attach/bond with the slag phase. The strength of the attachment can be characterised by the wettability of the slag on the inclusions. In this study, the dynamic wetting of ladle slags of the CaO-Al2O3-SiO2- MgO system on a solid spinel …
Strength And Bonding In Reduced Ironsand-Coal Compacts, R J. Longbottom, B J. Monaghan, S A. Nightingale, J G. Mathieson
Strength And Bonding In Reduced Ironsand-Coal Compacts, R J. Longbottom, B J. Monaghan, S A. Nightingale, J G. Mathieson
Brian Monaghan
In this investigation, the strength and bonding within reduced ironsand-coal compacts were studied, with the aim of better understanding the binding mechanisms in the reduced compacts and, based on this understanding, to improve their strength. Ironsand ore and sub-bituminous coal were mixed and pressed into compacts, which were reduced by heating in a thermogravimetric furnace to temperatures between 1273 and 1573 K under argon. The progress of the reaction was monitored by measuring the weight loss with time. The reduced compacts were found to have low strength in compression testing. The main form of bonding between the reduced ironsand particles …
The Effect Of Slag Basicity On Spinal Inclusion Wettability, Hamed Abdeyazdan, Brian J. Monaghan, Neslihan Dogan, M Akbar Rhamdhani
The Effect Of Slag Basicity On Spinal Inclusion Wettability, Hamed Abdeyazdan, Brian J. Monaghan, Neslihan Dogan, M Akbar Rhamdhani
Brian Monaghan
Steel cleanness is an important and growing research area driven by the demands to produce high quality steel. Inclusion content in steel is an important criterion to assess clean steel. MgO.Ah03 spinel inclusions cause problems in steel processing and are generally deleterious to steel products due to their high melting point and high hardness. Jnclusions are generally r· moved by rea ting with slag. This is primarily achieved by optimizing lhe PI' 'ess omliLions to promote contact and reaction between the inclusion and S,l,lg '. or efticient rem val from the steel the inclusions must attach to and dissolve in …
Thermodynamic Assessment Of Aluminium Production Through Carbosulphidation Route, Nazmul Huda, Muhammad A. Rhamdhani, M A. Dewan, Geoffrey A. Brooks, B J. Monaghan, L Prentice
Thermodynamic Assessment Of Aluminium Production Through Carbosulphidation Route, Nazmul Huda, Muhammad A. Rhamdhani, M A. Dewan, Geoffrey A. Brooks, B J. Monaghan, L Prentice
Brian Monaghan
Indirect carbothermal reduction of alumina for the production of aluminium has been claimed to be better compared to the existing Hall-Heroult process in-terms of energy usage, generation of perfluorocarbons and overall greenhouse gas emission. In the process, alumina is reduced to an intermediate compound which is then further reduced to Al. It has been shown from the previous thermodynamic study by the authors that high conversion of alumina can be obtained if it is reduced to Al-chloride, Al-nitride or Al-sulphide. This paper deals with detailed systematic thermodynamic analysis of the process through carbosulphidation route, where alumina is first reduced to …
Aluminium Production Route Through Carbosulfidation Of Alumina Utilising H2s, Nazmul Huda, M Akbar Rhamdhani, G A. Brooks, B J. Monaghan, L Prentice
Aluminium Production Route Through Carbosulfidation Of Alumina Utilising H2s, Nazmul Huda, M Akbar Rhamdhani, G A. Brooks, B J. Monaghan, L Prentice
Brian Monaghan
Indirect carbothermal reduction of alumina for the production of aluminum utilizes different reducing agents to convert alumina into intermediate aluminum compounds. In the present study, the carbosulfidation route for aluminum production utilizing H2S(g) as the reductant and sulfur source has been investigated, in particular the formation of AhS3 in the first step of the process. The results of the thermodynamic analysis predicted that conversion of Ah03(S) to AhS3(l) significantly increases above 1400°C at 1 atmosphere pressure. Experimental investigations were carried out at temperatures of 1100 to 1500°C using dilute H2S(g) gas in argon. The reaction products were analyzed using scanning …