Specialized metallurgical processes – compositions for use therei – Processes – Electrothermic processes
Patent
1981-10-22
1983-07-12
Rosenberg, P. D.
Specialized metallurgical processes, compositions for use therei
Processes
Electrothermic processes
75 51, 75 53, 75 59, 75 60, C21C 534, C21C 536
Patent
active
043928862
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method of recovering CO-rich exhaust gas in refining of metal in a furnace for refining metal, and more particularly relates to a novel method for refining iron in order to generate a large amount of CO by means of a converter provided with an exhaust gas-recovering apparatus, wherein granular limestone (CaCO.sub.3) is blown into molten iron to decompose thermally the limestone and to generate CO.sub.2, and the generated CO.sub.2 is reacted with carbon contained in the molten iron.
BACKGROUND ART
An apparatus for recovering exhaust gas is installed in a large number of converters at present to recover exhaust gas generated from the converter during blowing. Recovered exhaust gas in converter contains a large amount of CO, and therefore the recovered exhaust gas is an important energy source in view of the recent high cost of petroluem. In order to increase the energy level in the exhaust gas to be recovered, the following various methods have hitherto been carried out.
1. The ratio of charge for recovering OG gas is increased.
2. The amount of air sucked into the duct is decreased in order to recover CO, which is generated from converter, without combustion as possible.
3. The time from the beginning of blowing to the beginning of recovering of exhaust gas, and the time from the completion of recovering of exhaust gas to the completion of blowing are made as short as possible. That is, the time for recoving exhaust gas during blowing is made long as possible. For this purpose, for example, analysis of components of exhaust gas is carried out in a shorter period of time.
However, the amount of CO gas generated from converter is limited, and further exhaust gas must be kept to a composition outside of the explosion composition in view of the safety operation. Accordingly, when these conditions are taken into consideration, the above described methods are still insufficient.
There have been proposed ideas, wherein a conventional converter-exhaust gas recovering apparatus is used not only for collecting generated gas, but also for converting the energy system and recovering the converted energy system. As one of these ideas, a method has been proposed, wherein coke or coal as a carbon source is charged into a converter and reacted with O.sub.2 therein so as to be converted into CO gas, and the resulting CO gas is recovered. However, in this method, a large amount of oxygen source must be additionally added in order to convert C into CO, and further the cost of coke or coal must be taken into consideration, and therefore a high merit can not be expected.
While, in the conventional technic, limestone has been used for a long time as a solvent in a converter. Particularly, in an LD converter, limestone has been used as an inexpensive substitute for quicklime, and further as a cooling agent. However, when limestone is charged into a converter from its top, substantially all the limestone is decomposed to form CaO and CO.sub.2 gas through the reaction represented by the following formula (1), and it is impossible to increase the recovered amount of CO-rich exchaust gas. according the formula (1) by roasting limestone, and CO.sub.2 generated as a by-product in the reaction is discarded at present.
DISCLOSURE OF THE INVENTION
The present invention proposes an inexpensive and simple method of generating and recovering a large amount of exhaust gas having a high CO concentration by adding limestone to a furnace for refining metal, and intends to overcome the drawbacks of conventional technics by this method.
That is, the feature of the present invention lies in a method of generating a large amount of CO in refining of metal, wherein granular limestone is blown, together with a carrier gas, into a molten iron kept in a metal-refining vessel through a tuyere located beneath the bath surface at the time when the molten iron has a residual carbon concentration of at least 0.3%. In order to generate particularly large amount of CO, it is necessary that the maximum d
REFERENCES:
patent: 3771998 (1973-11-01), Knuppel
patent: 3988421 (1976-10-01), Rinaldi
Bada Hajime
Kodaka Mikio
Morishita Hitoshi
Sudo Fumio
Kawasaki Steel Corporation
Rosenberg P. D.
LandOfFree
Method of recovering CO-rich exhaust gas in refining of metal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of recovering CO-rich exhaust gas in refining of metal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of recovering CO-rich exhaust gas in refining of metal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-197092