We all know that building competitive advantage in steel business requires continuous improvement in steelmaking practices. Electric Arc Furnace (EAF) is undoubtedly the heart of a minimill and a more efficient EAF is a strong base for a company’s competitiveness.  The recently concluded Second 2007 SEAISI Travelling Seminar focussed on improving energy efficiency in EAF steelmaking.  Strategies and practices to embrace elements of energy saving were presented by four invited speakers: Mr Eric Anderson (WorleyParsons GCT, USA), Dr Kritsada Prapakorn (National Metal and Materials Technology Center, Thailand), Mr Andres G Villa (HYL Technologies, SA de CV - Techint, Mexico), and Mr David T F Wu (Tung Ho Steel, Taiwan).  More than 165 participants in four cities, Hanoi, Bangkok, Manila and Cilegon enthusiastically listened to the lectures and many of them asked for some clarifications and advice from the speakers. 

  Mr Anderson gave a lecture on how by providing process analytical tool to the operator and engineers, a steel company can continuously improve the EAF operation and maximise earnings. The lecture also described the use of the Smart-Gas system, developed by WorleyParsons GCT, as a simple tool for tracking EAF energy efficiency and providing real-time feedback to steel-making operations.  The Smart-Gas system is low maintenance, consists of low-cost instrumentation, and provides continuous, real-time information on the energy efficiency of the EAF.  Monitoring of the energy inputs and losses continuously using Smart-Gas allows EAF operators and engineers to identify periods of the operation where the energy transfer efficiency to the steel is low.  During these periods the energy input to the EAF is underutilized and inefficiently used.

Mr Villa from HYL Technologies introduced the use of high-carbon DRI as a low-cost and high-quality raw material for EAF steelmaking.  The purity of DRI can reduce the residuals levels of steel scrap charges to the furnace, allowing the production of higher grades of steel. By increasing the level of carbon in DRI from typically 1.0 - 1.2 % up to ranges of 3 - 4% or more in the form of iron carbide, the value of DRI becomes even greater since it provides a source of chemical energy to the electric furnace and reduce electric energy consumption. This advantage can be further increased by supplying the DRI hot to the meltshop via direct pneumatic transport from the DR reactor, thus providing additional temperature as well as carbon for reducing the furnace power time.  These two factors can greatly increase productivity in the meltshop while reducing energy costs for steelmaking. 

The first ever travelling speaker from a regular member country, Dr Prapakorn of Thailand proposed a slag foaming detector to pursue the optimum EAF operation.   It is known that the benefit of slag foaming technique can significantly increase the energy efficiency in the EAF and also lower the refractory and electrode consumption and shorten the melting time. Unfortunately, maintaining a predictable and consistent foamy slag for every heat has eluded many steelmakers for a long time. To obtain and control optimum slag foaming in the furnace and maintain a suitable slag foaming practice, the slag foaming detector was developed and applied to improve slag foaming condition for electrical energy saving.

Mr Wu from Tung Ho Steel of Taiwan generously shared most of the company’s tricks of the trade in order to save energy in steelmaking process.  The lecture gave an overview on the practical strategies for saving and improving energy efficiency in DC arc furnace operation in the company for the past ten years. The strategies and practices are implemented and have been increasing productivity, decreasing costs, lowering electricity consumption, and controlling pollution. The measures incorporate first-rate scrap pre-treatment processes, efficient chemical energy use, good electricity regulation and excellent routine operation skills.

In conclusion, the lectures provided many strategies to improve efficiency in EAF steelmaking.  The participants have learnt that in the drive to succeed, improvements in efficiency must be made continuously. The region’s steelmakers must implement better practices to produce visible results in terms of lower production costs and higher productivity levels to become more competitive.