The steel market has been characterized by an increasing demand for higher value added products (such as thinner gauge strip, galvanized and organically coated steels). On the supply side there has been strong growth in electric arc steelmaking, with larger capacity mini mills competing directly with conventional plants for certain flat products. Regional scrap shortages and higher quality requirements are contributing to the development of new processes supplying alternative EAF charges (Direct Reduced Iron, Hot Briquetted Iron, smelting reduction and iron carbide). In addition environmental considerations are having a growing impact on steelmaking technologies (Fig. 1).

Fig. 1: Alternative iron and steelmaking routes [1]

Direct reduction processes have been developed using either natural gas or coal to reduce iron ore in the form of lump, pellets or fines to an iron rich charge material for electric arc furnaces. Two processes predominate: Midrex and Hyl, both of which use lump ore or pellets and gas as a reductant. Together these account for over 90% of world DRI output.

Iron carbide is a new charge material made from iron ore fines, using natural gas. Commercial scale production has only recently started. There are a number of other processes currently under development to use iron ore fines. Gas based processes include Circored and Finmet and coal based processes include Circofer and Fastmet.

Smelting reduction is an alternative approach to iron making which uses coal to reduce iron ore in the forms of lump ore, pellets or fines to molten iron. There is only one commercial process currently operating which is Corex, based on either lump ore or pellets developed by Voest Alpine. There are a number of fines based smelting reduction processes currently under development. These include:

The changing face of the industry offers numerous opportunities for adapting and improving existing processes, as well as developing new technologies. The number of available process routes and alternative plant configurations will continue to grow.

At the primary metals stage there are opportunities such as improved scrap quality control, use of mini blast furnaces for ironmaking, commercial development of new smelting reduction processes, and adoption of improved direct reduction technologies. The developments in electric arc steelmaking have been in DC arc furnaces, continuous charging, charge preheating and post combustion. In the near future, smelting reduction processes are likely to account for a markedly increased share of new ironmaking capacity. Very few conventional blast furnace BOF plants are likely to be built.

The optimum process route for a given project depends on the planned capacity, target product range, and proposed location for the new plant. Process selection will also depend on whether it is a completely new plant, or a revamped plant at an existing site. The engineering companies will increasingly be called upon to provide support to their customers during business planning and negotiations with their key business partners, for instance to secure long-term contracts with steel customers, or power suppliers.

Engineering companies will also have to develop closer relationships with investors and customers and provide them with support in negotiating long term contracts. At the business level, engineering companies will need to become more involved in joint ventures and partnerships in the countries where they operate. Such joint ventures and partnerships with other companies will be required both to comply with local market conditions and to help customers secure project finance. Finally in their enhanced role of general consultant to the industry, engineering companies will need to carry out systematic technology watching and acquire skills to assist customers in selecting the optimum process for their projects. A tentative forecast of the technologies likely to be used in the main producing regions is provided by Table 1.

Table 1: Process routes: tentative regional guidelines [1]

Faced with an increasing demand for their services, engineering companies will also be under pressure to enhance the range of skills and services offered. This will require new modes of operation, as well as major cultural and organizational changes within process plant suppliers. Firms will work closely in a consultancy capacity with customers, raw materials and utilities suppliers to develop optimum technological solutions.

Authors note: The key points in this article are abstracted from the book The Steel Industry in the New Millennium in the section "The Engineering Business in the Early Decades of the Next Century".

[1] R. Ranieri and J. Aylen (ed.): The Steel Industry in the New Millennium. The Engineering Business in the Early Decades of the Next Century.