Specialized metallurgical processes – compositions for use therei – Processes – Producing or treating free metal
Patent
1992-11-03
1996-02-06
Andrews, Melvyn
Specialized metallurgical processes, compositions for use therei
Processes
Producing or treating free metal
75501, 75502, C21B 1100
Patent
active
054893259
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for producing metals and metal alloys, in particular iron and iron alloys, from metal oxides and ores, such as iron ore, including partly prereduced ores and metal oxide-containing slags, in a smelt reduction vessel in which fine-grained solids, such as carbon, carbonaceous fuels, metal oxides, slag forming agents and/or mixtures thereof, and oxidizing gases, such as oxygen, air and oxygen-containing gases, are directed into the molten metal below and/or from above the bath surface, and to a smelt reduction vessel for advantageously carrying out this process.
In recent years a number of new processes have become known that relate to the production of iron and steel. These processes have in common that they replace blast furnace coke, which is relatively expensive, by all conventional qualities of coal and reduce iron ore either after a prereduction step or directly in an iron bath reactor.
Some of these new processes are made more economical by utilizing the afterburning of the reaction gases from the iron bath in the gas space of the iron bath reactor. Since only about one third of the calorific value of coal is available during its combustion to carbon monoxide in the iron bath, a maximum afterburning of the reaction gases CO and H.sub.2 from the iron bath in the gas space thereabove is advantageous for the thermal efficiency of the process. However, the afterburning of the reaction gases involves the disadvantage that the resulting waste gases cannot be used for prereduction. European patent application no 01 26 391 overcomes this disadvantage by a composite process comprising, an ore prereduction step, e.g., a shaft furnace, and a melt-down gasifier, wherein the reaction gases escaping from the molten iron are at least partly afterburned, the resulting heat is largely transmitted to the melt, the reaction gases are then reduced by reducing agents on their way to the prereduction vessel, and are simultaneously cooled to an optimal reduction temperature.
German patent nos 36 07 774 and 36 07 775 deal with processes for smelt reduction of iron ore and are characterized by advantageous features for afterburning the reaction gases in a smelt reduction vessel. For example, the patents describe the use of hot air with a temperature of 800.degree. C. to 1500.degree. C. and multi-step afterburning.
German patent no 39 03 705 describes a process and a corresponding apparatus that made it possible for the first time to control afterburning selectively. The afterburning gas jet is blown onto the bath surface with a swirl, and the degree of afterburning can be varied by changing the swirl value.
While the new processes mentioned above are carried out in a specially shaped smelt reduction vessel, for example a kind of drum type reactor, there are also known processes that can be operated in conventional steelmaking converters such as LD vessels (BOF) or OBM/KMS converters with bottom tuyeres. On the basis of this technology smelt reduction processes have become known, for example, from Kobe Steel and Kawasaki in Japan and British Steel, Klockner-Werke and Krupp in Europe.
German patent no 36 07 776 deals with a problem common to all smelt reduction processes, namely how to treat the liquid and solids, e.g. iron droplets, in the waste gas stream from the smelt reduction vessel without causing undesirable caking and deposits on the vessel openings and in the following ducts. The solution described in the patent is to keep the iron droplets entrained in the waste gas stream in the waste gas ducts at a temperature higher than the solidification temperature of the iron droplets and then to cool the waste gas to under 1000.degree. C. in a separate space.
The present invention is concerned with providing a process for producing metals and metal alloys, in particular iron and iron alloys, from metal oxides and ores, such as iron ore, including partly prereduced ores and metal oxide-containing slags, in a smelt reduction vessel, that makes it possible to separate from the waste gas
REFERENCES:
patent: 4798624 (1989-01-01), Brotzmann et al.
patent: 4915731 (1990-04-01), Cooper
patent: 4976776 (1990-12-01), Elvander et al.
patent: 5051127 (1991-09-01), Hardie et al.
Andrews Barry S.
Batterham Robin J.
Keogh John V.
Andrews Melvyn
CRA Services Ltd.
LandOfFree
Process for producing metals and metal alloys in a smelt reducti does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for producing metals and metal alloys in a smelt reducti, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing metals and metal alloys in a smelt reducti will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2173163