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Sydney, Australia

Grunbaum R.,ABB | Creutzer B.,ABB | Van Der Rest M.,OneSteel
Steel Times International | Year: 2010

OneSteel, Laverton North, Victoria, Australia, has commissioned a static var compensator (SVC) in its melt shop supplied by ABB, providing voltage support to the electric arc furnace (EAF). SVC replaces ASEA Tycap SVC, installed in 1980, and the melt shop comprises an EAF rated at 77MVA and a ladle furnace rated at 11MVA. With the SVC in operation, the power on time has dropped significantly, improving meltshop productivity from 39 minutes in stage 1 to 35 minutes in stage 5. The SVC since its operation, has resulted in a reduction in flicker caused by EAF action by a factor greater than 2 and is significantly below the required value of 0.8. The SVC can be controlled from the SVC control room where there is an operator workstation (OWS) based on a personal computer. The SVC is found to offer productivity improvement of the metallurgical process, as well as cost reductions.

Alam M.,Swinburne University of Technology | Irons G.,McMaster University | Brooks G.,Swinburne University of Technology | Fontana A.,OneSteel | Naser J.,Swinburne University of Technology
ISIJ International | Year: 2011

In Electric Arc Furnace (EAF) steelmaking, liquid metal splashes on the furnace wall due to the impingement of high speed oxygen jet on molten metal surface. The splashed metal droplets cause wear of furnace wall and loss of production. Optimization of the operating condition (lance angle, lance height and flow rate) may reduce splashing and increase productivity. In the present study, the effect of different operating conditions on the wall splashing rate was investigated. Air was injected on water surface in a small-scale thin slice model at different lance angles, lance heights and flow rates. Splashed liquid in the forward direction was collected and measured in each case. The forward splashing rate was found to increase with the increase of lance angle from the vertical and flow rate. The critical depth of penetration as well as the impact velocity for the onset of splashing was found to decreases with the increase of lance angle from the vertical. The effect of lance angle on the dimensionless Blowing number (NB), which is a measure of droplet generation rate, was quantified. A new approach has been proposed for modelling the gas jet impinging phenomenon inside the real furnace using room temperature water model. © 2011 ISIJ.

Zaharia M.,OneSteel | Yunos N.F.,University Malaysia Perlis | Sahajwalla V.,University of Technology, Sydney
From Materials to Structures: Advancement Through Innovation - Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 2012 | Year: 2013

The steel industry consumes a large amount of energy GHG emissions[1]. Rubber tires and agricultural wastes have the potential to be used in industries seeking alternative fuel and sustainable raw materials sources. Previous studies focused on recycling these materials as fuel resources, i.e. rubber in cement industry[2],[3] and agricultural materials for power production[4]. The present paper focuses on investigations of carbon/slag reactions, namely slag foaming using rubber and palm shell wastes as sustainable carbon sources through quantitative estimation of the slag volume. An improved volume ratio for the rubber blend compared to coke was seen. Foaming was also improved when palm shell char was used as carbon material. Industrial implementations at OneSteel showed reductions in electrical energy and carbon consumption. These results indicate that partial replacement of coke with rubber and palm shell is efficient due to improved interactions with EAF slag. © 2013 Taylor & Francis Group.

Kongkarat S.,University of New South Wales | Khanna R.,University of New South Wales | Koshy P.,University of New South Wales | O'Kane P.,OneSteel | Sahajwalla V.,University of New South Wales
ISIJ International | Year: 2012

Interactions between blends of metallurgical coke and polymers with EAF slag (30.5% FeO) at 1550°C have been investigated using a sessile drop arrangement to determine the influence the polymer and its chemical composition on carbon/slag interactions. Two polymers, namely polyethylene terephthalate (PET) and polyurethane (PU), were used in this study. The CO emissions during carbon/slag interactions for PET/Coke and PU/Coke blends were lower as compared to corresponding emissions from metallurgical coke. An improvement in slag foaming, as determined by the dynamic changes in the volume of the slag droplet, was observed when PET/Coke and PU/Coke blends were used compared to the coke alone. Relatively greater number of gas bubbles was found to be entrapped in the slag droplet along with reduced iron droplets. Higher level of H 2O formation was also seen in the case of PET/Coke and PU/Coke blends as a result of FeO reduction by H 2. These results indicate that volatiles (H 2 and CH 4) released from the polymer/coke blends can influence the interactions between carbon and slag (in addition to reduction reactions by solid carbon). This study shows that a variety of waste polymers can be utilised as a carbon resource in EAF steelmaking processes. © 2012 ISIJ.

Jones R.,OneSteel | Bannear M.,Technology and Development | Martin R.,Aglomsa CV
IRON ORE 2011, Proceedings | Year: 2011

OneSteel Whyalla's grate-kiln-cooler pelletising plant was commissioned in 1968 processing haematite feed from the local South Middleback Ranges mining area. The existence of a magnetite resource beneath the haematite ore at Iron Duke had been known for some time. In 2004, a decision was made to covert the primary iron source for the Whyalla steelworks from haematite to magnetite - known as project magnet. The intent of the project was to convert the feed to the steelworks from haematite to magnetite and to free up the remaining haematite resource for export. The pelletising plant was cut over to a magnetite feed in 2007. The thermochemical differences of magnetite compared to haematite are threefold: 1. the introduction of an exothermic reaction during conversion of magnetite to haematite, 2. the absence of bound water which existed within the haematite, and 3. lower gangue content requiring lower fl uxing levels and therefore lower calcination energy demand. The combination of these differences results in a signifi cantly different induration requirement for magnetite as compared to haematite. The change therefore required extensive research and test work to design modifi cations to the furnace and to ensure appropriate risk mitigation for the Whyalla steelworks. Preliminary pot-grate test work was performed to defi ne the pellet chemistry and confi rm the suitability of the magnetite to produce pellets suitable for the OneSteel blast furnace. A heating curve was developed by use of computer-based heat and mass balance modelling. Extensive pilot scale grate-kiln-cooler test work was then performed to confi rm the heating curve and to verify and fi ne-tune the pellet properties. Computation fl uid dynamics was used to design the physical changes to the furnace required to achieve the proposed heating curve. Following installation of an additional preheat zone, including a wall and dilution air fans, into the preheating furnace, and installation of an additional wall into the cooler, the modifi ed furnace was commissioning in December 2007. The plant performed as expected during commissioning with the actual heating curve matching the proposed curve and the produced pellets within blast furnace specifi cations.

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