CN1158901A

CN1158901A - Process of carburizing sponge iron

Info

Publication number: CN1158901A
Application number: CN96121704A
Authority: CN
Inventors: G·艾尔森赫梅尔; K-H·菲茨舍尔
Original assignee: Metallgesellschaft AG
Current assignee: GEA Group AG
Priority date: 1995-10-17
Filing date: 1996-10-17
Publication date: 1997-09-10
Also published as: ZA968730B; DE19538591C1

Abstract

Granular sponge iron, produced in a reduction zone at temperatures in the range of 800 to 1100 deg C in the presence of solid or gaseous reducing agents, is passed from the reduction zone to a holding vessel and brought into direct contact with gaseous or liquid hydrocarbons, with the sponge iron at a temperature of not less than 750 deg C. For example, sponge iron can be direct contact with hydrocarbon in backkick tube.

Description

Process of carburizing sponge iron

The present invention relates to make the method for granular carburizing sponge iron, described granular sponge iron is in the presence of solid or gaseous reducing agent, produces in temperature range is 800-1100 ℃ reduction zone.

In usually sponge iron was produced, as at revolving tubular furnace or also have and produce in the shaft furnace, the shortcoming of sponge iron was that its carbon content is very low.In revolving tubular furnace, be difficult for directly eliminating this shortcoming.United States Patent (USP) 4,734,128 have narrated how to establish cemented zone under the reduction zone of shaft furnace, so that introduce hydrocarbon polymer, especially Sweet natural gas.This has caused more more complicated operations of complex apparatus and reduction furnace.

The objective of the invention is to irrelevant with reduction furnace, the method that is easy to control is carried out carburizing sponge iron.According to the present invention, this purpose is finished like this: sponge iron is sent to from reaction zone is detained jar, make this sponge iron and gasiform therein, steam gasiform or liquid hydrocarbon polymer contact, wherein the temperature of sponge iron is at least 750 ℃.

For the thermal sponge iron of sponge iron being packed into wherein by in the delay jar of carburizing, then should jar continuously or termly therewith reduction furnace connect.This is detained jar, such as, also can be used to transmit and/or cooling sponge iron.This cooling can be as usually, such as carrying out indirectly by air or water.A kind of modification of the inventive method is to constitute like this, hydrocarbon polymer introduced in the return bend, wherein, such as, it is sprayed into.This return bend also can be used for the sponge iron of cooling heat.

Because carrying out the zone of carburizing can be fully or largely keep sealing to surrounding environment, so available quite few hydrocarbons is finished carburizing sponge iron with sufficiently high degree.In this respect importantly, at at least 750 ℃, be easy to make sponge iron directly to contact with hydrocarbon polymer and be more preferably under at least 800 ℃ the temperature, the velocity of diffusion of hydrocarbon polymer is also high simultaneously, thereby finishes hydrocarbon polymer more uniform distribution in sponge iron with the short residence time.The required carbon content of sponge iron is usually in the scope of 1-2% (weight).

According to one embodiment of the invention, the carburizing of sponge iron is at one, such as, in described in the DE-A-4406382, carry out in the return bend of establishing for cooling sponge iron.This known return bend water cooler comprises that several extend to the bypass pipe in exit, and whole entrance and exit internal communication of return bend therewith all.Under indirect refrigerative situation, bypass pipe increases the outside of return bend.Thermal sponge iron is regularly by these bypass pipes, when bypass pipe more or less contain many thermal sponge irons the time, it is useful that the hydrocarbon polymer that will be used for carburizing is introduced one or more bypass pipes.

Embodiment referring now to description of drawings present method.

Fig. 1 shows the simple embodiment of being detained jar with the longitudinal section.

Fig. 2 schematically shows the return bend water cooler.

Fig. 1 is the simplification figure as the tank 1 of the delay tank that makes thermal sponge iron 2 carburizings. This tank simultaneously can Be used as and transport container, yet this does not consider in the drawings. This tank comprises that filler 3 is used for the end of discharging Section's baffle plate 4. The hydrocarbon that is used for carburizing phoresys the batch of material of sponge iron 2 through pipeline 6. Should Sponge iron granularity scope is generally 0-20mm.

Fig. 2 shows for the revolution pipe 8 that cools off continuously thermal sponge iron, the temperature scope of thermal sponge iron Be generally 800-1100 ℃, it is from unshowned reducing zone here, such as revolving tubular furnace, And through passage 9 be sent to the revolution pipe entrance position 10. In a kind of unshowned mode here, will The revolution pipe is supported on 2

runners

11 and 12, and this pipe comprises several bypass pipes 13,1 4 and 15. When implementing, as in described in the DE-A-4406382, these The number of pipe is in 8-30 or more scope. For indirectly cooling off this sponge iron, from making cooling water Cooling water is sprayed at the outside of bypass pipe through the retaining device 17 of nozzle 18 or the discharge of overflow weir.

The hydrocarbon that is used for carburizing, such as light oil or natural gas from unshowned container through fixing pipe Line 19 then by a box 20 that floating seal is housed, is sent to the annular pipe through pipeline 21 22, enter

pipe

13,14 and 15 through discharging pipeline 23 therefrom then. Pipe 21,2 2 and 23 manage 8 with revolution communicates, and pipeline 21 extends to box 20 through the shell of revolution pipe 8 Near.

Hydrocarbon is injected into

pipe

13,14 and 15 inside through discharging pipeline 23. Work as revolution Pipe 8 is when its longitudinal axis rotation, and sponge iron always is not present in all bypass pipes. On the contrary, pipe 1 3 is empty when being in upper position. Because it is inappropriate that hydrocarbon is sprayed into the sky pipe, so Valve 24 is set discharging pipeline 23 so that on demand open and close discharging pipeline 23. The control of valve 24 System is reached by controller 25 and finishes from its signal line 26 that stretches out. So just guaranteed only at

bypass pipe

14 and 15 be in than lower position and when all or mostly sponge iron being housed just with hydrocarbon chemical combination Thing sprays in these pipes. Sponge iron in revolution in-pipe and rolling regularly arrives with the revolution pipe inner The pipe 13 that communicates, 14 and 15, when these pipes upwards turn to during turning round the pipe rotation then, Sponge iron flows back to again the inside of revolution pipe.

, emit as managing 8 through unshowned skewed slot from revolution 29 through cooling and the sponge iron of carburizing. Usually, the sponge iron temperature is lower than 100 ℃ now, and carbon content is 0.8-2.5% (weight Amount). This sponge iron further can be processed into steel now.

Embodiment

In the revolution tube furnace of 4.8 meters of diameters, long 80m, by adding carbon reduction, the amount when adding rhombspar and taking off gastral cavity sulphur with 20.8t/ is produced sponge iron.Reduction temperature is about 1040 ℃.When temperature is 1010 ℃, sponge iron is added to basically in as shown in Figure 2 the return bend water cooler.The diameter of this water cooler is 3.6m, and long is 50m.This water cooler setting is about 16 bypass pipes into 3m.Pipeline 23 in being arranged at this return bend inlet zone at return bend when half is equipped with sponge iron at least, is introduced heated oil in this return bend by 17.5 liters of sponge iron per ton.By this technology, with sponge iron from initial carbon content 0.15% (weight) carburizing to 1.4% (weight).When temperature is 90 ℃, the sponge iron of carburizing is emitted from the gyrotron water cooler.

Claims

1. method that makes granular carburizing sponge iron, this sponge iron is in the presence of solid or gaseous reducing agent, produce in the reduction zone under 800-1100 ℃ temperature range, it is characterized in that: sponge iron autoreduction district is sent to is detained jar, and make sponge iron in being detained jar with gasiform, the hydrocarbon polymer that steams gasiform or liquid state directly contacts, and wherein the temperature of sponge iron is at least 750 ℃.

2. the method for claim 1 is characterized in that, sponge iron cools off indirectly with air in being detained jar.

3. the method for claim 1 is characterized in that, the sponge iron water cools off indirectly in being detained jar.

4. each method of claim 1-3 is characterized in that, moves when sponge iron is contacted with hydrocarbon polymer to be detained jar.

5. the method for claim 4 is characterized in that, sponge iron is contacted with hydrocarbon polymer.

6. the method for claim 5 is characterized in that, is detained the return bend water cooler that jar is designed to be included as many bypass pipes that sponge iron to be cooled passes through, and wherein hydrocarbon polymer is introduced among at least one of this pipe.

7. the method for claim 6 is characterized in that, hydrocarbon polymer is regularly alternately introduced in 2 bypass pipes at least.