JP4099080B2 - Converter operation method in metal melting and smelting. - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a converter operating method for producing a crude metal from a molten mat in a non-ferrous metal melting and smelting process.
[0002]
[Prior art]
In general, in the melting and smelting of non-ferrous metals (for example, copper, nickel, etc.), the dried concentrate is smelted in a flash furnace and separated into a molten mat (hereinafter referred to as a molten mat) and slag. By inserting the molten mat obtained in the furnace into the converter and injecting an oxygen-containing gas (for example, air, oxygen-enriched air, etc.) to cause an oxidation reaction (hereinafter referred to as oxygen-containing gas blowing) The quality of the molten mat is increased to produce a crude metal (eg, crude copper, crude nickel, etc.).
[0003]
The case of copper smelting is described below.
In performing the oxygen-containing gas blowing of the molten mat using the converter, the converter is first tilted and the molten mat is charged into the converter. Next, after the converter is upright, an oxygen-containing gas is blown from the tuyere. In this way, the impurity components in the molten mat are oxidized and separated to improve the quality of the molten mat.
[0004]
In other words, the copper content in the molten mat obtained in the flash smelting furnace is about 50 to 65% by mass, but the oxygen-containing gas blowing in the converter makes the impurity component in the molten mat slag as an oxide. And separate into SO ₂ gas to improve the quality of the molten matte. As a result, crude copper having a copper content of about 97 to 99% by mass is obtained.
Oxygen-containing gas blowing in converters is roughly divided into a period during which slag is produced (so-called copper making period), and a period during which molten white powder (ie, Cu ₂ S phase) is oxidized to form crude copper (so-called copper making stage). Is done.
[0005]
For example, there are cases in which the slagging period is divided into, for example, a first slagging period and a second slagging period. In both cases, FeS in the molten mat is oxidized and separated into slag by oxygen-containing gas blowing. This is the period during which the reaction to produce a Cu ₂ S phase called “kawa” proceeds.
The copper making period is a period during which a reaction for producing crude copper proceeds by removing white slag (ie, Cu ₂ S phase) by oxygen-containing gas blowing after removing the slag produced in the casting process. Immediately after starting the oxygen-containing gas blowing during the copper-making period, the oxidation reaction is not stable, and the flow rate of oxygen-containing gas blown into the white glue (that is, the blowing rate) varies.
[0006]
In order to increase the productivity of crude copper, when increasing the amount of molten mat charged to the converter and performing oxygen-containing gas blowing, the slag generated during the casting process is removed, and then the converter is used during the copper manufacturing process. The amount of white mold contained in the bath increases and the bath surface rises. For this reason, the hydrostatic pressure concerning a tuyere increases during ventilation. As a result, when the flow rate of oxygen-containing gas is increased during the period when the flow rate of oxygen-containing gas blown into the white river fluctuates (that is, immediately after the start of oxygen-containing gas blowing during the copper making stage), White buds blow up. White powder blown up from the converter's furnace mouth adheres to the converter's furnace mouth, the smoke hood, and the exhaust heat recovery device, and prevents the converter from rotating and reducing the amount of exhaust heat recovery. Interferes with the operation.
[0007]
Therefore, it is necessary to prevent the white puffing phenomenon that occurs for a while immediately after the start of the oxygen-containing gas blowing during the copper making stage. Therefore, the flow rate of the oxygen-containing gas in the oxygen-containing gas blowing is reduced to prevent the white puffing phenomenon, but since the progress of the oxidation reaction is suppressed, the problem that the productivity of crude copper is reduced There is.
[0008]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems. For example, in the case of copper smelting, the amount of molten mat charged in the converter is increased to increase the amount of white mold in the copper making stage, and the white mold by oxygen-containing gas blowing. An object of the present invention is to provide a converter operating method that can prevent the phenomenon of blown up and improve the productivity of crude copper.
[0009]
[Means for Solving the Problems]
The present invention relates to a converter operating method for producing a crude metal by containing a molten mat in a converter and performing oxygen-containing gas blowing to oxidize the molten mat in the converter by oxygen-containing gas blowing to and separated into the slag, the slag was removed and another part of the I or white is discharged from the converter, after performing a predetermined time an oxygen-containing gas blowing for I or remaining white converter furnace, and discharged a converter operation method of producing oxidized crude metal white leather by some white leather placed in re-charged into the converter performs an oxygen-containing gas blowing.
[0010]
In the above-described invention, as a first preferred embodiment, 5 to 40% by mass of white powder is discharged from the converter, and oxygen-containing gas blowing of the white powder in the converter is performed for 30 to 120 minutes. After that, it is preferable to charge the white powder discharged from the converter into the converter.
Moreover, as a second preferred embodiment, 20-30% by mass of white powder is discharged from the converter, and oxygen-containing gas blowing of the white powder in the converter is performed for 30-120 minutes, and then from the converter. It is preferable to charge the discharged white glue into the converter.
[0011]
As a third preferred embodiment, the crude metal is preferably crude copper or crude nickel.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a layout diagram schematically showing an example of a copper smelting apparatus to which the present invention is applied.
The oxygen-containing gas blowing performed in the converter 1 improves the quality of the molten mat obtained in a flash smelting furnace (not shown). That is, a molten mat having a copper content of about 50 to 65% by mass obtained in a flash furnace is charged into the converter 1 from the furnace port 3, and oxygen-containing gas (for example, air, oxygen-enriched air, etc.) is added to the feather. Blowing through the mouth 2 and blowing oxygen-containing gas to produce crude copper having a copper content of about 97 to 99% by mass.
[0013]
This oxygen-containing gas blowing is roughly divided into a period during which slag is produced (so-called “making period”) and a period during which the quality of the molten white glue in the latter period is raised (so-called copper making period).
In performing the oxygen-containing gas blowing during the formation period, the converter 1 is tilted and the molten mat in the ladle 7 is charged into the converter 1 from the furnace port 3 using an overhead crane (not shown). Further, the converter 1 is erected and oxygen-containing gas is blown from the tuyere 2. The seizure period may be divided into a plurality of seizure periods (for example, the first and second periods, or the first, second and third periods). However, in each case, the oxygen in the oxygen-containing gas blown from the tuyere 2 oxidizes FeS in the molten mat to separate the Fe content into the slag, the S content into the SO ₂ gas, In other words, the reaction for producing the Cu ₂ S phase proceeds. When the oxygen-containing gas blowing in the cutting period (for example, the first cutting period and the second cutting period) is completed, the converter 1 is tilted to remove the slag from the furnace port 3 to the slag ladle.
[0014]
After removing the slag in the final period (for example, the second period or the third period), another white glue ladle is prepared before the converter 1.
Next, the converter 1 is tilted to discharge white glue from the furnace port 3 and temporarily stored in the ladle 7. If the amount of white glue discharged at this time is less than 20% by mass of the amount of white glue contained in the converter 1 after the removal of slag, the white glue is blown by oxygen-containing gas blowing during the copper-making stage described later. Blows up from the furnace port 3. On the other hand, if the amount exceeds 30% by mass, the amount of white mold in the furnace is small and the reaction time is shortened, so that white mold may blow up when the discharged white mold is recharged in the furnace. Therefore, after removing the slag generated in the final cutting period, the amount of white mold discharged from the converter 1 is 20-30 with respect to the amount of white mold accommodated in the converter 1 after removing the slag. Within the range of mass% is preferable. In addition, white glue may be discharged after the end of the first building period, or may be discharged after the end of the second building period, and may be selected according to the operation status.
[0015]
Next, in order to perform oxygen-containing gas blowing during the copper making stage, the converter 1 is erected, and oxygen-containing gas is blown from the tuyere 2 into the white glue remaining in the converter 1. At this time, since the bath surface of the white glue remaining in the converter 1 is lowered, in a period in which the flow rate of the oxygen-containing gas blown into the white glue fluctuates (that is, immediately after the start of air blowing during the copper making stage), Even if the flow rate of the oxygen-containing gas increases, it is possible to prevent white glue from blowing up from the furnace port 3 of the converter 1. Moreover, since the amount of white powder in the converter 1 is reduced, the hydrostatic pressure due to the white powder applied to the tuyere 2 is also reduced, and the load of a blower (not shown) for feeding oxygen-containing gas to the tuyere 2 is reduced. It can be reduced and power consumption can be reduced.
[0016]
Thus, after oxygen-containing gas blowing during the copper making stage was performed for 30 to 120 minutes, the converter 1 was tilted back to the home position, the air blowing was stopped, and then the molten white glue stored in the ladle 7 was again returned to the furnace. The converter 1 is charged from the mouth 3. This white glue may be from the same converter 1 that has been discharged, or may be charged from another converter 1 that has been discharged. If the required time from the start of the oxygen-containing gas blowing during the copper making period to the re-charging of the white glue stored in the ladle 7 is less than 30 minutes, the flow rate of the oxygen-containing gas in the oxygen-containing gas blowing is stable. Therefore, white glue blows up from the furnace port 3 when the flow rate of the oxygen-containing gas increases. On the other hand, after 120 minutes, since the white mold in the furnace is near the end point of the reaction, unreacted Cu ₂ S in the white mold charged again from the ladle 7 is intensively oxidized. There is a case where it blows up from the furnace port 3. Therefore, it is preferable that the time required from the start of the oxygen-containing gas blowing during the copper making period until the white glue stored in the ladle 7 is charged again is within a range of 30 to 120 minutes.
[0017]
Thereafter, the converter 1 is erected and oxygen-containing gas blowing is continued to produce crude copper.
In the present invention, even if the amount of the molten mat accommodated in the converter 1 is increased, the furnace port 3 of the converter 1 is in a period in which the flow rate of the oxygen-containing gas immediately after the start of the oxygen-containing gas blowing in the copper-making period fluctuates. Therefore, it is possible to operate the converter 1 without any trouble. Therefore, since it is not necessary to reduce the flow rate of the oxygen-containing gas in the oxygen-containing gas blowing, the productivity of crude copper is improved. Moreover, since the amount of white powder in the converter 1 is reduced immediately after the start of the copper making period, it is possible to reduce the load on the blower that supplies the oxygen-containing gas to the tuyere 2 and to reduce power consumption.
[0018]
【Example】
In the dry smelting of copper, using the equipment shown in Fig. 1 (PS converter, diameter 3960mm, length 13000mm), oxygen-containing gas blowing was performed on a molten matte of 63 mass% Cu grade to produce crude copper. . That is, the molten mat obtained in the flash furnace was 170 tons in the first casting period, 50 tons in the second casting period, and was charged into the converter 1 to perform oxygen-containing gas blowing in the casting period. After removing the generated slag, 45 tons of white glue was discharged to the ladle 7. At this time, the amount of white powder stored in the ladle 7 corresponds to 24% by mass of the amount of white powder stored in the converter 1 after removing the slag.
[0019]
Next, oxygen-containing gas blowing in the copper making stage was performed for 90 minutes on the white mold remaining in the converter 1. After that, white glue stored in the ladle 7 was charged again into the converter 1 by an overhead crane (not shown), and oxygen-containing gas blowing during the copper-making period was continued to produce crude copper. At this time, the average blowing rate was 44100 Nm ³ / hr. This is an invention example.
[0020]
On the other hand, as a comparative example, the molten mat obtained in the flash smelting furnace was charged into the converter 1 in the same manner as in the inventive examples, and oxygen-containing gas blowing during the smelting period was performed. After removing the produced slag, oxygen-containing gas blowing was performed during the copper making stage to produce crude copper. At this time, the average air flow rate was 42800 Nm ³ / hr.
Therefore, in the present invention, it was confirmed that even if the amount of the molten mat charged in the converter 1 is increased and the oxygen-containing gas blowing is performed, the phenomenon of white powder blowing up can be prevented without reducing the blowing rate. Moreover, when the converter 1 is operated by applying the present invention, the amount of blown air increases, so the time required for blowing the oxygen-containing gas during the copper making period is shortened and the productivity is improved.
[0021]
【The invention's effect】
In the present invention, even if the amount of molten mat charged in the converter is increased and oxygen-containing gas blowing is performed, it is possible to prevent white powder from blowing up without reducing the blown amount. improves. Moreover, since the amount of white powder in the converter is decreasing immediately after the start of the copper making period, it is possible to reduce the load on the blower that supplies the oxygen-containing gas to the tuyere and to reduce power consumption.
[Brief description of the drawings]
FIG. 1 is a layout diagram schematically showing an example of an apparatus to which the present invention is applied.
[Explanation of symbols]
1 Converter 2 Tuyere 3 Furnace 4 Tilting device 5 Waste heat boiler 6 Movable hood 7 Ladle

Claims (4)

In a converter operating method for producing a crude metal by containing a molten mat in a converter and performing oxygen-containing gas blowing, white oxygen and slag are obtained by oxidizing the molten mat in the converter by the oxygen-containing gas blowing. And removing the slag, discharging a part of the white river from the converter, and performing the oxygen-containing gas blowing on the white river remaining in the converter, converter operation method characterized by the production of oxidized crude metal the white leather by some white leather that has been discharged again charged into the converter performing the oxygen-containing gas blowing .   5 to 40% by mass of the white river was discharged from the converter, and the oxygen-containing gas blowing of the white river in the converter was performed for 30 to 120 minutes, and then discharged from the converter. The converter operation method according to claim 1, wherein the white glue is charged into the converter.   20-30% by mass of the white river was discharged from the converter, and the oxygen-containing gas blowing of the white river in the converter was performed for 30-120 minutes, and then discharged from the converter. The converter operation method according to claim 1, wherein the white glue is charged into the converter.   The converter operation method according to claim 1, wherein the crude metal is crude copper or crude nickel.

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