Voest Develops the Basic Oxygen Process for Steelmaking

Date Early 1952

The Austrian state-owned steel complex, Voest, perfected a new method for producing steel known as the basic oxygen, or L-D, process.

Also known as L-D process

Locale Austria

Key Figures

• Robert Durrer (1890-1978), Swiss scientist
• F. A. Loosley (1891-1966), Canadian head of research and development at Dofasco Steel
• Theodor Suess (1894-1956), Austrian works manager at Voest

Summary of Event

The modern industrial world is built on ferrous metal. Until 1857, ferrous metal meant cast iron and wrought iron, though a few specialty uses of steel, especially for cutlery and swords, had existed for centuries. In 1857, Henry Bessemer developed the first large-scale method of making steel, the Bessemer converter. By the 1880’s, modification of his concepts (particularly the development of a “basic” process that could handle ores high in phosphor) had made large-scale production of steel possible.

Bessemer’s invention depended on the use of ordinary air, infused into the molten metal, to burn off excess carbon. Bessemer himself had recognized that if it had been possible to use pure oxygen instead of air, oxidation of the carbon would be far more efficient and rapid. Pure oxygen was not available in Bessemer’s day, except at very high prices, so steel producers settled for what was readily available, ordinary air. In 1929, however, the Linde-Frakl process for separating the oxygen in air from the other elements was discovered, and for the first time inexpensive oxygen became available.

Nearly twenty years elapsed before the ready availability of pure oxygen was applied to refining the method of making steel. The first experiments were carried out in Switzerland by Robert Durrer. In 1949, he succeeded in making steel expeditiously in a laboratory setting through the use of a blast of pure oxygen. Switzerland, however, had no large-scale metallurgical industry, so the Swiss turned the idea over to the Austrians, who for centuries had exploited the large deposits of iron ore in a mountain in central Austria.

Theodor Suess, the works manager of the state-owned Austrian steel complex, Voest, instituted some pilot projects. The results were sufficiently favorable to induce Voest to authorize construction of production converters. In 1952, the first “heat” (as a batch of steel is called) was “blown in,” at the Voest works in Linz. The following year, another converter was put into production at the works in Donauwitz. These two initial locations led to the basic oxygen process sometimes being referred to as the L-D process.

The basic oxygen, or L-D, process makes use of a converter similar to the Bessemer converter. Unlike the Bessemer, however, the L-D converter blows pure oxygen into the molten metal from above through a water-cooled injector known as a lance. The oxygen burns off the excess carbon rapidly, and the molten metal can then be poured off into ingots, which can later be reheated and formed into the ultimately desired shape. The great advantage of the process is the speed with which a “heat” reaches the desirable metallurgical composition for steel, with a carbon content between 0.1 percent and 2 percent. The basic oxygen process requires about forty minutes. In contrast, the prevailing method of making steel, using an open-hearth furnace (which transferred the technique from the closed Bessemer converter to an open-burning furnace to which the necessary additives could be introduced by hand) requires eight to eleven hours for a “heat” or batch.

The L-D process was not without its drawbacks, however. It was adopted by the Austrians because, by carefully calibrating the timing and amount of oxygen introduced, they could turn their moderately phosphoric ore into steel without further intervention. The process required ore of a standardized metallurgical, or chemical, content, for which the lancing had been calculated. It produced a large amount of iron-oxide dust that polluted the surrounding atmosphere, and it required a lining in the converter of dolomitic brick. The specific chemical content of the brick contributed to the chemical mixture that produced the desired result.

The Austrians quickly realized that the process was an improvement. In May, 1952, the patent specifications for the new process were turned over to a new company, Brassert Oxygen Technik, or BOT, which filed patent applications around the world. BOT embarked on an aggressive marketing campaign, bringing potential customers to Austria to observe the process in action. Despite BOT’s efforts, the new process was slow to catch on, even though in 1953 BOT licensed a U.S. firm, Kaiser Engineers, to spread the process in the United States.

Many factors serve to explain the reluctance of steel producers around the world to adopt the new process. One of these was the large investment most major steel producers had in their open-hearth furnaces. Another was uncertainty about the pollution factor. Later, special pollution-control equipment would be developed to deal with this problem. A third concern was whether the necessary refractory liners for the new converters would be available. A fourth was the fact that the new process could handle a load that contained no more than 30 percent scrap, preferably less. In practice, therefore, it would only work where a blast furnacesmelting ore was already set up.

One of the earliest firms to show serious interest in the new technology was Dofasco, a Canadian steel producer. Between 1952 and 1954, Dofasco, pushed by its head of research and development, F. A. Loosley, built pilot operations to test the methodology. The results were sufficiently promising that in 1954 Dofasco built the first basic oxygen furnace outside Austria. Dofasco had recently built its own blast furnace, so it had ore available on site. It was able to devise ways of dealing with the pollution problem, and it found refractory liners that would work. It became the first North American producer of basic oxygen steel.

Having bought the licensing rights in 1953, Kaiser Engineers was looking for a U.S. steel producer adventuresome enough to invest in the new technology. It found that producer in McLouth Steel, a small steel plant in Detroit, Michigan. Kaiser Engineers supplied much of the technical advice that enabled McLouth to build the first U.S. basic oxygen steel facility, though McLouth also sent one of its engineers to Europe to observe the Austrian operations. McLouth, which had backing from General Motors, also made use of technical descriptions in the literature.

One factor that held back adoption of basic oxygen steelmaking was the question of specifications. Many major engineering projects came with precise specifications detailing the type of steel to be used and even the method of its manufacture. Until basic oxygen steel was recognized as an acceptable form by the engineering fraternity, so that job specifications included it as appropriate in specific applications, it could not find large-scale markets. It took a number of years for engineers to modify their specifications so that basic oxygen steel could be used.

The next major conversion to the new steelmaking process occurred in Japan. The Japanese had learned of the process early, while Japanese metallurgical engineers were touring Europe in 1951. Some of them stopped off at the Voest works to look at the pilot projects there, and they talked with the Swiss inventor, Robert Durrer. These engineers carried knowledge of the new technique back to Japan. In 1957 and 1958, Yawata Steel and Nippon Kokan, the largest and third-largest steel producers in Japan, decided to implement the basic oxygen process. An important contributor to this decision was the Ministry of International Trade and Industry, which brokered a licensing arrangement through Nippon Kokan, which in turn had signed a one-time payment arrangement with BOT. The licensing arrangement allowed other producers besides Nippon Kokan to use the technique in Japan.

The Japanese made two important technical improvements in the basic oxygen technology. They developed a multiholed lance for blowing in oxygen, thus dispersing it more effectively in the molten metal and prolonging the life of the refractory lining of the converter vessel. They also pioneered the OG process for recovering some of the gases produced in the converter. This procedure reduced the pollution generated by the basic oxygen converter.

The first large American steel producer to adopt the basic oxygen process was Jones and Laughlin, which decided to implement the new process for several reasons. It had some of the oldest equipment in the American steel industry, ripe for replacement. It also had experienced significant technical difficulties at its Aliquippa plant, difficulties it was unable to solve by modifying its open-hearth procedures. It therefore signed an agreement with Kaiser Engineers to build some of the new converters for Aliquippa. These converters were constructed on license from Kaiser Engineers by Pennsylvania Engineering, with the exception of the lances, which were imported from Voest in Austria. Subsequent lances, however, were built in the United States. Some of Jones and Laughlin’s production managers were sent to Dofasco for training, and technical advisers were brought to the Aliquippa plant both from Kaiser Engineers and from Austria.

Other European countries were somewhat slower to adopt the new process. A major cause for the delay was the necessary modification of the process to fit the high phosphoric ores available in Germany and France. Europeans also experimented with modifications of the basic oxygen technique by developing converters that revolved. These converters, known as Kaldo in Sweden and Rotor in Germany, proved in the end to have sufficient technical difficulties that they were abandoned in favor of the standard basic oxygen converter. The problems they had been designed to solve could be better dealt with through modifications of the lance and through adjustments in additives.

Significance

The basic oxygen process has significant advantages over older procedures. It does not require additional heat, whereas the open-hearth technique calls for the infusion of nine to twelve gallons of fuel oil to raise the temperature of the metal to the level necessary to burn off all the excess carbon. The investment cost of the converter is about half that of an open-hearth furnace. Fewer refractories are required, less than half those needed in an open-hearth furnace. Most important of all, however, a “heat” requires less than an hour, as compared with the eight or more hours needed for a “heat” in an open-hearth furnace.

There were some disadvantages to the basic oxygen process. Perhaps the most important was the limited amount of scrap that could be included in a “heat,” a maximum of 30 percent. Because the process required at least 70 percent new ore, it could be operated most effectively only in conjunction with a blast furnace. Counterbalancing this last factor was the rapid development of the electric arc furnace, which could operate with 100 percent scrap. A firm with its own blast furnace could, with both an oxygen converter and an electric arc furnace, handle the available raw material.

The advantages of the basic oxygen process overrode the disadvantages. Some other new technologies combined to produce this effect. The most important of these was continuous casting. Because of the short time required for a “heat,” it was possible, if a plant had two or three converters, to synchronize output with the fill needs of a continuous caster, thus largely canceling out some of the economic drawbacks of the batch process. Continuous production, always more economical, was now possible in the basic steel industry, particularly after development of computer-controlled rolling mills.

These new technologies forced major changes in the world’s steel industry. Labor requirements for the basic oxygen converter were about half those for the open-hearth furnace. The high speed of the new technology required far less manual labor but much more technical expertise. Labor requirements were significantly reduced, producing major social dislocations in steel-producing regions. This effect was magnified by the fact that demand for steel dropped sharply in the 1970’s, further reducing the need for steelworkers, even as excess capacity, that is, too many plants producing more steel than the market demanded, was reached at the global level, exacerbating problems for the steel industry and putting immense pressure on all but the most productive firms.

The U.S. steel industry was slower than either the Japanese or the European to convert to the basic oxygen technique. The U.S. industry generally operated with larger quantities, and it took a number of years before the basic oxygen technique was adapted to converters with an output equivalent to that of the open-hearth furnace. By the time that had happened, world steel demand had begun to drop. U.S. companies were less profitable, failing to generate internally the capital needed for the major investment involved in abandoning open-hearth furnaces for oxygen converters. Although union contracts enabled companies to change work assignments when new technologies were introduced, there was stiff resistance to reducing employment of steelworkers, most of whom had lived all their lives in one-industry towns. Finally, engineers at the steel firms were wedded to the old methods and reluctant to change, as were the large bureaucracies of the big U.S. steel firms.

The basic oxygen technology in steel was part of a spate of new technical developments that revolutionized industrial production, drastically reducing the role of manual labor and dramatically increasing the need for highly skilled individuals with technical expertise. Because capital costs were significantly lower than for alternative processes, it allowed a number of developing countries to enter a heavy industry and compete successfully with the old industrial giants. It thus changed the face of the steel industry.

Bibliography

Bain, Trevor. Banking the Furnace: Restructuring of the Steel Industry in Eight Countries. Kalamazoo, Mich.: W. E. Upjohn Institute for Employment Research, 1992. Although the main focus of this work is on the mechanisms used to cushion job loss, it contains numerous tables showing the effects of restructuring on labor requirements.

D’Costa, Anthony P. The Global Restructuring of the Steel Industry: Innovations, Institutions, and Industrial Change. New York: Routledge, 1999. Overview of the twentieth century evolution of the steel industry, including technical innovations such as the oxygen process and their effects upon the global steel trade. Bibliographic references and index.

Gold, Bela, Gerhard Rosegger, and Myles G. Boylan, Jr. Evaluating Technological Innovations: Methods, Expectations, and Findings. Lexington, Mass.: Lexington Books, 1980. Three chapters by Rosegger compare the basic oxygen technique with the open-hearth furnace. Using interviews with officials of five firms, Rosegger confirms the cost advantage of the basic oxygen furnace.

Hoerr, John P. And the Wolf Finally Came: The Decline of the American Steel Industry. Pittsburgh: University of Pittsburgh Press, 1988. A voluminous, impressionistic study of the management techniques of the American steel industry.

Hogan, William T. World Steel in the 1980’s: A Case of Survival. Lexington, Mass.: Lexington Books, 1983. A broad survey of developments in the steel industry in the late 1970’s and early 1980’s. Organized geographically, the study compares the industry of each country by technology. Hogan predicts that future expansion will occur largely in developing nations.

International Labor Organization. “Productivity Improvement and Its Effects on the Level of Employment and Working Conditions in the Iron and Steel Industry.” Geneva: Author, 1986. This pamphlet provides an excellent analysis of the state of the international steel industry in the mid-1980’s, showing where other countries have outstripped the United States.

Lynn, Leonard H. How Japan Innovates: A Comparison with the United States in the Case of Oxygen Steelmaking. Boulder, Colo.: Westview Press, 1982. An indispensable book for information on the diffusion of the basic oxygen process. Should be used in conjunction with Hoerr’s book, as the latter details hindrances in management, which Lynn glosses over.