Voest-alpine Industrieanlagenbau Gmbh

Voest-alpine Industrieanlagenbau Gmbh & Co.

Brifer International Ltd.

Siegfried Zeller

Johannes Leopold Schenk

Leopold Werner Kepplinger

Roy Hubert Whipp, Jr

Konstantin Milionis

Johann Zirngast

Johann Reidetschlager

Johann Reidetschl&auml;ger

Felix Wallner

Hanspeter Ofner

Karl-Heinz Zimmerbauer

Karl Czermak

In a process for reducing iron-ore-containing particulate material in at least a two-stage process, reducing gas is conducted through at least two reaction zones consecutively arranged in series and formed by a moving particulate material and the particulate material passes through the reaction zones in reverse order to the reducing gas, with the particulate material being heated in the reaction zone arranged first for the particulate material and being reduced in the further reaction zone. In order to achieve a maximum preheating temperature without any formation of magnetite, the reducing gas added to the first reaction zone is conditioned such that no or hardly any reduction takes place, although for the particulate material a preheating temperature within the fringe range of starting a reduction is achieved, whereby either the degree of oxidation of the reducing gas is increased or the temperature of the reducing gas is decreased or both measures are carried out jointly and whereby, in the reactor zone arranged second for the iron ore, a temperature level of at least about 600&#xb0; C., preferably in the range of between 600 and 700&#xb0; C., in particular of between 620 and 660&#xb0; C., is adjusted and the iron-oxide-containing material is reduced to wuestite ().

Method for reducing a particulate material containing a metal, especially iron ore

In a process for the direct reduction of particulate iron-oxide-containing material by fluidization, a synthesis gas is introduced as a reducing gas into several fluidized bed zones consecutively arranged in series. The reducing gas is conducted from one fluidized bed zone to another fluidized bed zone in counterflow to a flow of particulate iron-oxide containing material through the fluidized bed zones. In order to reduce operating costs and, in particular, the energy demand, various process parameters are varied according to the temperature of the iron-oxide-containing material in the first fluidized bed zone being adjusted to be below 400&deg; C. (and, preferably, below 350&deg; C.), above 580&deg; C. (and preferably about 650&deg; C.), or to a temperature within the range of from 400&deg; C. to 580&deg; C. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is maintained to be below 400&deg; C., the temperature of the iron-oxide-containing material in the following fluidized bed zone is passed through the temperature range between 400&deg; C. and 580&deg; C. within a period of 10 minutes and, preferably, within 5 minutes. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is adjusted to a temperature above 580&deg; C., the temperature range of between 400&deg; C. and 580&deg; C. in the first fluidized bed zone is passed through within a maximum period of time of 10 minutes and, preferably, 5 minutes. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is adjusted to be within the range of from 400&deg; C. to 580&deg; C., the iron-oxide-containing material remains in the first fluidized bed zone within that temperature range for a maximum of 10 minutes and, preferably, 5 minutes, and the material is then passed on into the following fluidized bed zone immediately after having reached the desired temperature.

Plant for the direct reduction of particulate iron-oxide-containing material

A process for the direct reduction of particulate iron-oxide-containing material by fluidization. A synthesis gas is introduced as a reducing gas into several fluidized bed zones consecutively arranged in series for the reducing gas. The reducing gas is conducted from one fluidized bed zone to another fluidized bed zone in counterflow to the particulate iron-oxide containing material. In order to reduce operating costs and, in particular, the energy demand, the temperature of the iron-oxide-containing material is adjusted in the first fluidized bed zone to be either below 400&deg; C. (and, preferably, below 350&deg; C.), or above 580&deg; C. (and preferably about 650&deg; C.), or to a temperature ranging from 400&deg; C. to 580&deg; C. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is adjusted to be below 400&deg; C., the temperature range in the following fluidized bed zone between 400&deg; C. and 580&deg; C. is passed through within a period of 10 minutes and, preferably, within 5 minutes. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is adjusted to be above 580&deg; C., the temperature range in the first fluidized bed zone between 400&deg; C. and 580&deg; C. is passed through within a period of time of maximally 10 minutes and, preferably, 5 minutes. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is adjusted to be in the range of from 400&deg; C. to 580&deg; C., the iron-oxide-containing material remains within that temperature range for a maximum of 10 minutes and, preferably, 5 minutes, and the material is passed on into the following fluidized bed zone immediately after having reached the desired temperature.

Process and plant for the direct reduction of particulate iron-oxide-containing material

Process for producing sponge iron by direct reduction of

Process for reducing oxide-containing material and plant for carrying

In a process for the direct reduction of particulate iron-oxide-containing material by the fluidized bed method, reformed gas is mixed with top gas forming in the direct reduction of the iron-oxide-containing material and is fed to a fluidized-bed reduction zone as a reducing gas. To lower the energy demand and utilizing the potential of the reducing gas, both the top gas and the reformed gas are subjected to CO.sub.2 scrubbing and the reducing gas formed by mixing top gas with reformed gas is adjusted to an H.sub.2 content ranging between 45 and 75%, preferably between 50 and 65%, and to a CO content ranging between 10 and 20%.

Direct-reduction process for directly reducing particulate

Growing community of inventors

Leonding, Austria

Siegfried Zeller