DE1907543B2 - PROCESS AND DEVICE FOR CONTINUOUS REFINING OF METALS - Google Patents

Description

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The invention relates to a method for the continuous measurement not only of raw metals but also of alloys Refining metals by means of a gene and stone to understand. The earth oven is preferred according to patent 1294 022. Refining processes according to the invention, however, for the

The main patent 1 294 022 relates to a stove-continuous refining of pig iron to steel

furnace for continuous, simultaneous melting 5.

and refining of ores or concentrates, which in the present invention essentially corresponds to a smelting zone, a refining first refining zone, which is approximately circular in shape, and a slag separation zone, the first smelting and charging zone. The melting levels of these three zones have the same level as the stove described in the main patent and are in the oven with one another. The second refining zone corresponds to that in connection. Nevertheless, the refining zones of the main patent are,
In the following text, the two expressions melting zone are formed circular, while refining and refining are equivalent to one another, the other two zones are elongated, e.g. B. used rectangular,
are trained. 15 During the first refining or fresh zone

While the main patent is designed to be roughly circular at the same time, the second As far as smelting and refining is concerned, the refining zone or fresh zone and the slagging zone are located The invention is based on the object of providing a veneer separation zone which is elongated and somewhat better continuous process in proposal to angular shape and shape. In the first round bring which alone the refining of metals 20 refining or fresh zone (in the following always which is referred to as the round fresh zone even in the molten state) is the slag are present. Here, a hearth furnace should come into use essentially in direct current with the metal, which has the same basic structure as that, while in the second refining or Hearth oven of the main patent has, in some fresh zones (in the following always as elongated fresh points however, if necessary, in adaptation to the zone designated) essentially in countercurrent to Refining process modified or improved metal flows. These three oven zones will be sert is. formed by three chambers, which are essentially

The method according to the invention is thereby present as separate units, but with one another

indicates that connect. The connection points lie

30 roughly in one plane.

a) The unrefined metal and oxygen-containing For the refining process, it is special Gases entered a first refining zone conveniently when the capacity of the round fresh zone at least as large, especially little-

b) the unrefined metal in the first tab is twice the capacity Finishing zone along an approximately circular 35 of the second or elongated fresh zone.

Train made to flow and partially raf- The molten, not yet refined metal

is finished, is preferably tangential to the walls of the

c) In the first refining zone, the metal is added to the round fresh zone, while the refining is carried out with kidneyed or refined metal formed during refining on that of the round Slag is brought to flow in cocurrent 40 fresh zone distant end of the elongated fresh, zone or near this end.

d) the partially refined metal from the first The hearth furnace can be roughly the shape and shape Have refining zone in a second refining zone of a T, L or U.

zone and at a flow into a The advantage of the round fresh zone, in which the measurement

Slag separation zone is prevented, 45 tall along with that formed during refining

e) Oxygen-containing gases are fed to the complete raffi slag in cocurrent, is available kidneys into the second refining zone, especially in an increase in the contact time between ben be, slag and metal, both along a relative

f) the residence time of the metal in the first raffi-large way flow and here with each other in nation zone at least as large, in particular 5 ° contact.

twice as large as in the second one. Another advantage of the round fresh zone is

Refining zone, in that it is a reservoir for the elongated fresh

g) the fully refined metal continuously forms zone, so that small and short-term Schwanaus the second refining zone changes in the composition of the raw metal is deducted, 55 or stone can be compensated so that

h) in the second refining zone, the slag is a uniform melt in the elongated fresh

guided in countercurrent to the metal and flows in via zone. To achieve that the melt

the first refining zone in the slag - lingers long enough in the round fresh zone is

separation zone is entered, - as already mentioned above - the version

i) a part of the capacity of the round fresh zone in the slag separation zone 60 is at least as high

metal separating out from the slag large, preferably at least twice as large as

re-entered into the first refining zone - the capacity of the elongated fresh zone,

and by increasing the contact time of the in the

k) the slag with a low metal content results in circulating raw materials in a continuous fresh zone

Of course, from the slag separation zone 65 there is a substantial improvement in the refining

is withdrawn to the outside. effect.

The flowing against and with each other

The term “metals” includes the two slag streams in accordance with the invention and their concluding one

3 4

Leakage into the slag separation zone is caused by minor reactions with the refractory

once through the design of the furnace itself, to the wall material; this slag film helps that

to reduce others by applying great heat at suitable angles, which of the hot

Nozzles support the oxygen-containing gas on the metal surface on the ceiling of the fresh chamber

Allow slag to impinge in such a way that the 5 is reflected.

Currents are forced in the desired direction devices, such as being placed at shallow angles. The oxygen from these nozzles supports designated nozzles or slag collectors, can also the burning of carbon monoxide or brought to the slag flow of the other two Avoid flammable gases from the bath from the fresh zone into the third fresh zone step. This way both the heat will be io or at least as small as possible, as well as the impulse of oxygen on the otherwise would be in this third fresh stage Transfer slag. a burn of iron oxides in the slag

If one carries out a freshness of molten raw material, make it noticeable.

iron according to the above procedure with a corresponding amount of foaming of the backward flowing

Plant 15 produced by the present invention slag is cheap, very strong foaming in the

through, so a little of the basic flux can through one or the other fresh zone, however

in the round fresh zone near the inlet opening for spraying or injecting (through lances or

the molten pig iron can be added. The other means) of suitably finely divided solids

larger proportion of the basic flux is used, e.g. B. lime, limestone or fluoride on the

but preferably closer to where the outlet opening surface of the slag is contained,

tion for the steel-containing end of the elongated The drawings serve for further explanation

Fresh zone added; the slag that is close to the invention. They show typical furnace arrangements

this end is formed by a wall or a gene in which the round fresh zone with 10, the longitudinal

Baffle causes it to flow against the metal. borrowed fresh zone with 11 and the slag separating

This results in an outflow of the slag with the 25 training zone denoted by 12.

Metal prevents. F i g. 1 shows the sectional view of a furnace according to

The round freshness zone serves primarily to initiate the present invention, in which the round freshness is uniformly desiliconized, and zone 10 at the apex of a right angle to initiate the removal of the carbon. is brought, which is formed by the elongated fresh zone 11 and titanium and other rapidly oxidizable elements 30 of the slag separation zone 12;
are removed in this zone. F i g. 2 shows the sectional view of a furnace in FIG

The larger proportion of the basic flux will cause the elongated fresh zone 11 and the slag, preferably at the end of the elongated fresh zone, separation zone 12 to be parallel to one another which the steel is tapped, added. Pushed there are attached that it is against two the resulting slag is highly basic and over 35 sides of the round fresh zone 10 in oxidized so that they may open up to more than 25% of these;

FeO and the remainder mainly contains CaO. This F i g. 3 shows the sectional view of a U-shaped

well oxidized slag reacts violently with the coal furnace in which the elongated fresh zone 11 and the

metal containing fuel and produced notably slag separation zone 12, the legs of the U

worth amounts of carbon monoxide and thereby 40 and in which the round fresh zone 10 in this U die

also a violent simmering of the bath. Form for the steel connection of the two legs;

preparation, this is a favorable phenomenon, because that F i g. 4 shows a cross section along the line

with proper mixing of the highly basic 4-4 from FIG. 2.

Refining slag is guaranteed with the steel, The corresponding reference numerals have in the

from which it removes sulfur and phosphorus. 45 different figures have the same meaning. In

When considering low carbon steels F i g. 1 with 3 is the direction of flow of the metal through content, such as. B. wants to produce troubled steel, solid lines shown, the direction of flow of it is advantageous to use suitable means to infiltrate slag by dash-dotted lines,
Large quantities of slag into the area at the end of the steel containing the furnace shown in FIGS. 1, 2 and 3 with very low all a round fresh zone 10 in which the slag according to the carbon content is to be avoided. This is achieved and the metal flows halfway in the same direction, preferably through very flat grooves, and an elongated second fresh zone 11, in the nozzles or through a slag gate. Through the slag halfway opposite to the media, the fresh chamber is divided into three tall flows, as well as a slag separation zone 12. Fresh zones, the round zone in which the 55 In these figures, zones 11 and 12 are always slag flows in the same direction as the metal, connected to zone 10. The relative arrangement of the fresh zone in which the slag flows against one another and towards the zones 11 and 12 in a directed manner, and a final fresh zone zone 10 are essentially, for the sake of example, with little or no slag flow. These do not choose or place any limitations on the process third refining zone accepts the low 60 metal in accordance with the present invention. The per- carbon content on from the sulfur and phos- phosal choice of furnace construction is made by the phor already removed by refining. Here, special factors of the individual systems occur determined, no large slag formation, because only the such. B. through the available space, carbon must be removed, which leaves the tape in the operating order, transport options in the form of carbon monoxide bubbles. Nevertheless, 65 and the specific fresh processes that are usually to be carried out with the formation of a thin film of slag. In Fig. 1 are e.g. B. ser third fresh zone by the reaction of iron the zones 11 and 12 at right angles to each other oxide and basic flux and also arranged. The open arrangements shown in FIG. 1

5 6

1 and 2 have the advantage that the verzone 12 (shown in FIG. 4) has a gradient

different parts of the furnace are easily serviced and carried out, which is continuously separated from the slag

Repair are accessible, whereas the through kendamm 27 down to the confluence of the

F i g. 3 a small basic expansion zone 12 extends into the fresh zone 10 of the oven,

which is particularly suitable for systems with 5 There the floor level is also roughly

of limited size. at the same height as the metal surface 31 in the fresh

The molten metal that goes to a refining zone 10. This creates the metal that comes out of the

is to be subjected, slag 31 α is separated tangentially into the furnace in the zone 12, causes

Entered through a channel 13, the fresh food along the bottom 30 in the round fresh zone 10

material is withdrawn through the tap opening 14 to flow back io the furnace. A flow of metal

However, you can also open other than those shown from the fresh zones 10 and 11 in the slag

As a result, the feed to the size separation zone 12 to be freshened is halfway reduced.

use terials. prevents.

Oxygen jets or jets of an oxygen The slag shaft 28 has a much larger one

containing gas are in the slowly flowing depth and a much larger total volume than the

Blown molten metal. This is done relatively flat and sloping part of zone 12. He

in the fresh zones 10 and 11 by a large number of this allows the dwell time of the slow against the

of lances, e.g. B. 34, 15, 16, 17 and 18. The lance slag tapping hole 29 flows slag

34 is preferably grown approximately tangentially on the kungsvoll. As a result, the slag has

Fresh zone 10 attached. The lances can provide a 20 greater opportunity for gravitational separation

appropriate inclination can be given so that they match that of fine metal beads from the slag. That I

Concomitant or counter-flowing slag flow into the slowly accumulating at the bottom of the shaft 28

Flowing towards the slag separation zone 12, metal can be tapped at suitable intervals

permit. As an alternative to inclining the whole country to be (which rarely has to be done) and with

zen, it is sufficient to return the end pieces of the gas-carrying drilling 25 of a pouring ladle to the main freshening zone 10.

to be arranged on the lances at such angles. But it can also be above

nen that the slag flow are pumped into the desired Rieh dam 27, so that it is due to the

direction is steered. Gravitation flows back into the fresh zone 10.

A little of the basic flux can be in the slag deposit area 12 as well

Round fresh zone 10 can be entered (the arrangement 30 is suitable for adding additives to the slag

tion of such a supply of such material (possibly via the passage 33). When freshening up

rialien is not critical, and therefore it is in that of pig iron these additives can be given,

Drawing also not shown), the bulk of this to the deposition of the iron from the slag too

Flux is, however, preferably improved by the lance (e.g. by adding ferrosili-

17 or through additional pipes in the neighboring 35 cium, calcium carbide, coal, coke or other

injected shaft of this nozzle. reducing substances), or the slag for

In the in F i g. 1 and 3, other uses after tapping men of the invention are to make heat-resistant islands 19 suitable (e.g. silica, soda, etc., along the walls of the refining zone 11 at suitable to convert the slag into glass).
Locations attached (generally in an outlet 40 A gas outlet 32 is in a suitable location about two-thirds to three-quarters of the embodiment shown in Fig. 4 over the entire length of the elongate zone 11). It is convenient to have slag shaft 28 attached,
In this constriction between such islands a jets of oxygen or an oxygen-containing gas or several nozzles 23, 24 at shallow angles are arranged by the lances 25 and 34, which produce oxygen-containing gas on the liquid 45 by at least a portion Blow the des into the furnace surface in such a way that a slag flow gasses in a noticeable percentage of coal present in the final or third fresh zone 22 to burn off monoxide which can be avoided from boiling. The islands 19 can rise through the bath. The lances 24 also support metal tubes or blocks (in the drawings not showing the circulation of liquids in the round) to be liquid cooled. Their shape is with 5 ° fresh zone 10. The lances 25, the smooth surfaces 21, also help. Slag from the round fresh zone 10 into the

The heat-resistant islands 19 can either convey slag separation zone 12,

as part of the refractory lining of the furnace.

be asked. They can also be made from heat-resistant, for example

end materials, such as B. Dolomite blocks - 55 Molten pig iron was placed in a furnace from

build, which is lowered into the furnace or on other to the one in F i g. 1 with one fill rate

Manner introduced through suitable openings of 4 t / hour. The pig iron had the following

will. gende composition:

In the slag separation zone 12, a

Slag dam 27 (shown in Fig. 4) built at 60 ° C, 3.75%

and a slag shaft 28, which is between Si 1.15%

the slag dam 27 and the outlet port 29 Mn ·. 0.8%

for the slag is arranged. The slag P 0.09 per cent

dam 27 can through metal tubes or blocks 35 S 0.06%

be liquid-cooled. 65 Fe rest

In the slag separation zone 12 there is

less turbulence than in the other furnace

zones. The bottom 30 of the slag-separating lime (1.6 mm particle diameter), the fine

ground fluoride was added. This flux was added via lance 17 at a rate of 54 kg of lime and 2.2 kg of fluoride per ton of steel produced. A violently foaming slag was produced in the elongated fresh zone. This slag, with an initially almost infinite ratio of CaO to SiO ₂ , flowed freely backwards in the direction of the round fresh zone 10 and through it. With a final basicity ratio (CaO: SiO ₂ ) of 2.2 to 27, it was tapped into a graining groove (not shown).

During the first two hours of operation, the oxygen injection rate was chosen so that one High carbon steel (0.9 to 1.0% C) was produced. The other elements were here represented with the following percentages:

Si,

Mn 0.30%

P 0.008%

S 0.008%

Fe rest

25th

So over 90% of the phosphorus and over 85% of the sulfur were removed when lime was added, which was lower than in steel preparation with conventional feed. The effectiveness of the Oxygen was high as only 1300 cubic feet of oxygen was used on the net ton of steel produced.

In the remaining hours of the experiment, the same pig iron was used to make a steel with to produce low carbon content, which had the following composition:

C 0.15%

Si 0.02%

Mn 0.03%

P 0.004%

S 0.006%

Fe rest

40

45

In this case over 95% of the phosphorus and 90% of the sulfur were removed.

Because of the favorable influence of refining with slag flowing in the opposite direction, the iron losses were here in the slag hardly larger than 0.6% of the steel produced, in the production of steel with With a high carbon content, these losses were less than 0.5%. The heat generation was so great that an addition of 12 to 15% coolant in the form of cold crushed scrap can be added could. Evidence suggests that this freshening process is being carried out on a commercial basis Magnitude of scrap consumption can be over 35% and in this way is greater than in conventional steelmaking using oxygen.

Patent claims:

1. Process for the continuous refining of metals by means of a hearth furnace according to the patent 1294022, characterized in, that

a) the unrefined metal and oxygenated gases in a first refining zone be entered,

b) the unrefined metal in the first refining zone along a roughly circular one Train is made to flow and partially refined,

c) in the first refining zone, the metal together with those formed during refining Slag is made to flow in direct current,

d) the partially refined metal from the first refining zone to a second refining zone entered and prevented from flowing into a slag separation zone,

e) oxygen-containing gases for complete refining in the second refining zone be entered,

f) the residence time of the metal in the first refining zone is at least as long, in particular twice as large as in the second refining zone,

g) the fully refined metal continuously from the second refining zone is withdrawn to the outside,

h) in the second refining zone, the slag is deposited in countercurrent to the metal. and fed into the slag separation zone via the first refining zone will,

i) a part of that which separates out of the slag in the slag separation zone Metal is re-entered into the first refining zone and

k) the low metal slag continuously from the slag separation zone is withdrawn to the outside.

2. The method according to claim 1, characterized in that the unrefined metal and the oxygen-containing gases approximately tangentially and in the direction of flow in the circular path the first refining zone.

3. The method according to claim 1 or 2, characterized in that in the second Refining zone, slag flowing in countercurrent to the metal roughly tangential and in Direction of flow of the metal flowing along an approximately circular path into the first refining zone is entered.

4. The method according to one or more of the preceding claims, characterized in, that the fully refined metal from the second refining zone at one end the same is withdrawn, which is opposite the other end of the same, where the partially refined metal is fed from the first refining zone.

5. The method according to one or more of the preceding claims, characterized in, that the slag is withdrawn from the slag separation zone at one end thereof which is opposite the other end of the same where the slag from the first refining zone is fed.

6. The method according to one or more of the preceding claims, characterized in

109531/242

net that the metal from the second refining zone passed through a restriction into a third refining zone, further refined therein and is then continuously withdrawn to the outside.

7. The method according to claim 6, characterized in that that the slag flows from the second to the third refining zone is prevented.

8. The method according to one or more of the preceding claims, characterized in, that the slag is introduced into a slag basin of the slag separation zone, herein on deposited and separated from metal and then peeled off to the outside.

9. hearth furnace for performing the method according to claim 1 to 8, characterized in that that the capacity of the first refining zone (10), which is circular is at least as large as the capacity of the second refining zone (U), which is elongated.

10. hearth furnace according to claim 9, characterized in that the capacity of the the first refining zone (10) is at least twice the capacity of the second Refining zone (11).

11. hearth furnace according to claim 9 or 10, characterized in that the bottom of the slag separation zone (12), which is elongated, in the area of the connection between the slag separation zone (12) and the first Refining zone (10) is approximately level with the molten metal in the first refining zone (10).

12. Hearth furnace according to one or more of the preceding claims 9 to 11, characterized in that that the bottom of the slag separation zone (12) rises in the direction of the slag tap (29) upwards.

13. Hearth furnace according to one or more of the preceding claims 9 to 12, characterized in that the slag basin is arranged between the higher end of the bottom of the slag separation zone (12) and the slag tap (29).

14. Hearth furnace according to one or more of the preceding claims 9 to 13, characterized in that that the second refining zone (11) and the slag separation zone (12) are arranged approximately at right angles to one another.

15. hearth furnace "according to one or more of the preceding claims 9 to 14, characterized in that that the second refining zone (11) and the slag separation zone (12) on the same side or on opposite sides of the first refining zone (10) approximately are arranged parallel to each other.

1 sheet of drawings