Abstract: A process for the production of steel with increased ductility in which a sulfur-containing steel melt is deoxidized and, if desired, is supplied with alloying elements, the deoxidized melt is treated with calcium as part of a purification action simultaneously reducing the sulfur content and the reaction is carried out in a casting ladle having a lining free from siliceous oxides. The melt is covered with a synthetic slag free from siliceous oxides and the calcium-containing substance is introduced in fine-grain particulate form into the melt in a carrier gas at a level at least 2000 mm below the melt surface and at a rate which is less than the maximum rate at which the calcium-containing substance is capable of reacting with the melt.

Abstract: A process for making a steel melt for continuous casting in which the steel melt is formed in a smelting unit under an iron-oxide-containing slag which is held back while the steel melt is tapped and subjected to deoxidation with silicon or aluminum. The sulfur-containing deoxidized melt is then subjected to an aftertreatment with a calcium-containing substance, especially calcium-silicon or calcium carbide in a covered ladle with a silica-free lining after the steel melt is covered with a synthetic slag formed from pulverulent lime and 10 to 30% of a silica-free fluorite and/or alumina fluxing agent which does not release oxygen to the melt. The calcium-containing substance is introduced in an amount which is greater than that required for desulfurization and/or establishing the viscosity of the melt, at a depth of at least 2000 mm and about 300 mm above the bottom of the ladle in a neutral carrier gas (e.g. argon).

Abstract: A process for the production of steel with increased ductility in which a sulfur-containing steel melt is deoxidized and, if desired, is supplied with alloying elements, the deoxidized melt is treated with calcium as part of a purification action simultaneously reducing the sulfur content and the reaction is carried out in a casting ladle having a lining free from siliceous oxides. The melt is covered with a synthetic slag free from siliceous oxides and the calcium-containing substance is introduced in fine-grain particulate form into the melt in a carrier gas at a level at least 2000 mm below the melt surface and at a rate which is less than the maximum rate at which the calcium-containing substance is capable of reacting with the melt.

Abstract: A steel melt is confined and subjected to a partial vacuum. A particulate additive is entrained by a neutral nonreactive carrier gas and introduced into the melt below the surface thereof at a depth such that the additive is immediately vaporized and rises toward the surface of the melt in the form of bubbles which react with components of the melt. With particulate calcium as the additive an injection depth 1500 mm, a temperature of approximately 1500.degree.C, and a vacuum of 20 Torr allows the sulfur content of a steel melt readily to be reduced below 0.005% by weight.

Abstract: The direct reduction of iron ore, e.g., in a shaft furnace, uses a pair of reducing-gas generating reformers which are alternately heated and functionally interchanged to produce the reducing gas. Downstream of each of the reformers is an air-preheating heat exchanger and between both reformers and the direct-reduction furnace there is provided a buffer heat exchanger. The combination reduces the fluctuations of the reducing-gas temperature at the inlet to the direct-reduction furnace and is able to maintain a reducing-gas temperature close to the desirable maximum for effective reduction.