JPH04183831A - Refining of copper - Google Patents

Abstract

PURPOSE:To improve treating capacity of the refining furnace by overlapping a stage receiving molten metal into a refining furnace and a part of the stage consisting of oxidation treatment of molten copper in the refining furnace. CONSTITUTION:The molten black copper is manufactured continuously by continuous copper refining facilities consisting of a smelting furnace, separation furnace and refining furnace and received in a refining furnace. In the case of using 2 sets of refining furnaces, while black copper is received into one of the refining furnace, the other furnace executing oxidation, reduction and casting of black copper and related work of received black copper from the previous batch. In this case, on the last batch of receiving stage, oxidation of black copper received in parallel are executed. Receiving and oxidation are proceeded in parallel and refining time for black copper is shortened by overlapped time to improve the production capacity of the refining furnace themselves.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a copper refining method for refining blister copper into refined copper of higher copper grade in a copper smelting process.

[Prior Art] Conventionally, as an apparatus for smelting copper, a multi-furnace smelting apparatus as shown in FIG. 11, for example, is known.

This melts and oxidizes copper concentrate supplied with oxygen-enriched air, and produces Kawa M, which is mainly composed of a mixture of copper sulfide and iron sulfide, as well as gangue and solvent in the copper concentrate, and oxidized copper concentrate. A smelting furnace 1 that produces a sinter S made of iron or the like; a separation furnace 2 that separates the sinter M and the sinter S produced in the smelting furnace I;
A copper making furnace 3 that further oxidizes the separated steel M to produce blister copper C; and a refining furnace 4 that refines the blister copper C produced in this steel making furnace 3 to produce refined copper with higher copper quality. It is composed of 4. In the smelting furnace 1 and the copper making furnace 3, lances 5... having a double pipe structure are installed through the ceilings of these furnaces so as to be able to rise and fall freely, and the lances 5...
Copper concentrate, oxygen-enriched air, solvent, etc. are supplied to each furnace through the furnace. Separation furnace 2 is an electric furnace equipped with electrodes 6.

The smelting furnace 11, the separation furnace 2, and the copper making furnace 3 have height differences in this order, and are connected by gutter 7A, 7B, which is a flow path for the molten metal, and the molten metal flows through the gutter 7A. , 7B flowing down by gravity.

The blister copper C continuously produced in the steelmaking furnace 3 is first held in a heat-retaining furnace 8, then transferred to a ladle 9, and then transferred by a crane 10 through a charging port that opens on two sides of the refining furnace 4. The copper is poured into the refining furnace 4, and is usually subjected to oxidation treatment and reduction treatment to adjust the final copper grade.

However, in a copper smelting apparatus having such a configuration, since the refining process is a batch process, the generated blister copper C must be temporarily held in the heat retention furnace 8.
In addition to the heat retention furnace 8, equipment such as a dropper 9 and a crane IO for transferring the blister copper from the heat retention furnace 8 to the refining furnace 4, and the supply of energy to keep the molten metal warm during this time are required. As a result, these facilities limit the reduction in construction costs and running costs of smelting facilities, and the ability to make smelting facilities more compact.

Therefore, the heat retention furnace 8 is abolished, and a plurality of refining furnaces 4 are connected to the steel making furnace 3 via molten metal flow paths, and molten copper is sent from the steel making furnace 3 to the refining furnace 4 via the molten metal flow paths. A system can be considered.

[Problem to be solved by the invention] By the way, in such a refining furnace 4, in order to adjust the molten metal in the furnace to the final target composition, batch processing is inevitably performed, and a predetermined process according to the capacity of the refining fP4 is performed. After accepting the amount of , perform the above processing. For example, when two refining furnaces 4 are connected to one steelmaking furnace 3 and molten copper is alternately supplied and processed, the total time for receiving and refining processing is the cycle time, and within this time The production capacity of the steelmaking furnace 3 is set to be twice the amount processed by one refining furnace 4. Therefore, if the production volume from the copper-making furnace 3 fluctuates double, and there is no flexibility in the throughput of the refining furnace 4, it should be kept in the steel-making furnace 3 as it is, or transferred to other holding equipment. The need for emergency storage arose, and in the end, the insulating furnace 8 was eliminated.''The system described in item 1 would no longer operate smoothly.

[Means for Solving the Problems] The present invention has been made to solve the problems set forth in item 1. In a copper refining method that consists of a step of oxidizing molten copper, a step of reducing the molten copper in a refining furnace, and a step of discharging the molten copper from the refining furnace after the reduction treatment, the receiving step and the oxidation treatment are The steps are performed at least partially overlapping each other.

The invention of claim 2 is the invention of claim 1, in which the furnace body of the refining furnace is provided with a tuyere that opens on the inner surface, and the furnace body is tilted according to the depth of the received molten copper to open the tuyere. Oxidizing gas is blown into the tuyere while adjusting the immersion depth.

Further, the invention according to claim 3 uses oxygen-enriched air as the oxidizing agent in the above-mentioned oxidation step. The oxygen enrichment rate is preferably 25 to 35 vol%.

[Operation] In the invention of the first claim, the oxidation treatment of the copper is performed in parallel with the reception of the molten copper into the refining furnace. Oxidation treatment is usually performed by blowing air or oxidized enriched air as an oxidizing agent into the molten copper through tuyeres installed in the furnace body, so the depth of the molten copper in the refining furnace is kept constant by receiving it. It is better to start oxidation after exceeding the amount.

In the invention of the second claim, the oxidizing gas is blown into the molten copper from the tuyere while tilting the furnace body according to the depth of the molten copper so that the opening position of the tuyere is below the surface of the molten copper. . The oxidizing gas blown through the tuyere is blown into the molten copper almost parallel to the surface of the molten copper, reacts sufficiently with the molten copper, and
To perform a stable reaction without excessively stirring molten copper.

As a result, oxidation treatment can be performed even when the amount of molten copper is small, and the oxidation treatment can be performed in a state where the reaction efficiency of the blown air is always high.

In the third aspect of the invention, by using oxygen-enriched air as an oxidizing agent, the heat balance of the reaction and the oxidation reaction efficiency are controlled depending on the situation.

[Embodiment] FIG. 1 shows an embodiment of an apparatus for carrying out the method of the present invention, and the same parts as in FIG. 11 are denoted by the same reference numerals, and a description thereof will be omitted.

The steelmaking furnace 3 and the refining furnace 4 are connected by a gutter II, which is a molten metal flow path, and the blister copper C produced in the steelmaking furnace 3 flows down into the refining furnace 4 through the gutter 11.

Two refining furnaces 4 are provided, and these are arranged in parallel to each other. The gutter 11 branches into two channels through a branch point provided in the middle, a main gutter 11A, and two branch gutter 11B, 11B branched from this and each connected to the refining furnace 4°4. It consists of The bottom near the connection point between the branch gutter 11B and the main gutter 11A is slightly shallow, and by dropping castable or lump-like refractories into this part, the flow of molten metal to the one branch gutter 11B is blocked. It constitutes a switching device 12 for a molten metal flow path that causes the molten metal to flow down to the other branch gutter 11B. These gutters, including gutters 7A and 7B that connect other furnaces, have lids installed on top, and are equipped with heat retention devices such as burners and equipment for atmosphere adjustment where necessary. This allows the molten metal flowing down the gutter to be maintained in a relatively highly sealed state.

As shown in FIGS. 2 to 4, the refining furnace 4 has a closed cylindrical furnace body 21 consisting of end plates 21a at both ends and a body 21b. A plurality of support wheels 2 in contact with the guide rings 22 and 22
3... is supported rotatably around the axis with its axis horizontal, and is tilted by a tilting gear 24 installed on one end side of the furnace body 21 and a drive device 25 connected to this tilting gear 24. It has become so. In addition, this furnace body 2
A burner 26 is installed on one end plate 21a of the furnace body 21 to maintain the temperature of the molten metal in the furnace, and the body 21b is equipped with a burner 26 for supplying air or oxygen-enriched air or a reducing agent into the furnace. Tuyeres 27, 27 for pouring the refined copper into the anode are installed on opposite sides. Furthermore, a charging port 29 for charging lumps such as anode waste into the furnace is provided at the upper center of the body 21b of the refining furnace 4. As shown in FIG. 4, on the upper side of the end opposite to the burner 26, there is a smoke opening extending in an oval shape along the circumferential direction from the apex at the normal position of the furnace toward the tap outlet 28 side. A road entrance 30 is formed.

A cover 31 at the end of the exhaust duct is open and provided to cover the flue port 30. As shown in FIG. 5, this is opened at an angle that covers the entire flue opening 30 within the tilting range of the furnace body 21. A gutter 11B, which is a molten metal flow path through which the blister copper C flows down, is inserted from the side surface of the cover 31, and its end portion 11C is positioned facing above the flue opening. This end gutter 11G has a cover 31
It also has a water-cooled jacket structure.

In the smelting equipment configured as described above, molten blister copper C is continuously produced by continuous copper making equipment consisting of a smelting furnace 1, a separation furnace 2, and a copper making furnace 3, and flows down from the steel making furnace 3 through a gutter +1A. Then, by the switching device 12 of the branch gutter 11, the gutter 11B, 1
1B and is received into the refining furnace 4 through the flue opening 30 from the end 11C.

Normal reception is carried out with the furnace body 21 standing upright as shown in FIG. Tilt it so that the opening 27.27 is below the molten metal surface. In this state, the tuyere 27.27 is placed inside the furnace body 21.
First, air or oxygen-enriched air is supplied to oxidize the blister copper C for a predetermined period of time to bring the sulfur concentration in the steel closer to the target value.

Further, a reducing agent mainly composed of a mixture of hydrocarbons and air is supplied to perform a reduction treatment, and bring the oxygen concentration in the steel close to a predetermined value. In addition, the flue gas generated at this time is from the flue port 3.
0, is collected into the exhaust duct via the cover 31 and processed. Further, the karami S is discharged from the charging port 29.

In this way, when the blister copper C in the furnace is refined and becomes refined steel with higher copper quality, the drive device 25 is operated again to move the furnace body 21.
Tilt further to bring it into the tilted state shown in Figure 8,
Molten copper is discharged from the tap 28 and poured into an anode mold through an intermediate ladle, cast into an anode plate, and transferred to an electrolytic treatment process.

Two refining furnaces 4 are provided, and the blister copper C produced in the steelmaking furnace 3 is transferred to one of these two refining furnaces 4. It is forced to flow down selectively.

While one refining furnace 4 is receiving blister copper C, the other refining furnace 4 is oxidizing, reducing, refining, and casting the received blister copper C as an anode in parallel.

Hereinafter, a refining method in which blister copper is received (injected, oxidized, reduced, and cast) using two refining furnaces 4 will be described with reference to FIGS. 9 and 10.

FIG. 9 shows the case of the conventional method when the processing capacity of the refining furnace and the processing capacity of the steelmaking furnace are equal.

While one refining furnace (1) is receiving blister copper C, the other refining furnace (2) is performing oxidation, reduction, and casting of the blister copper C received in the previous process, as well as associated operations. . In this example, it takes 2 hours to oxidize the blister copper C, 2 hours to reduce it, and 4 hours to cast the blister copper C.
30 minutes of tuyere cleaning between oxidation and reduction, 1 hour of casting preparation between reduction and casting, and 30 minutes of casting cleanup between casting and acceptance of the next process. It is done as a work. That is, it takes 10 hours to refine the received blister copper, cast it as an anode, and make it ready to accept the next blister copper, which is equal to the time of reception. Therefore, in the refining furnace 4, after casting and clearing, there is almost no waiting time between the next receiving steps.

The example of FIG.
In parallel with the charging, the blister copper C received in the furnace is oxidized. In other words, in this example, it takes 85 hours to receive the steel from the steelmaking furnace to the refining furnace, but the process from oxidation to the casting piece takes 10 hours.
The time is saved by duplicating the receiving and oxidation steps.

This receiving oxidation is performed after the furnace body 21 is changed from the position shown in FIG. 6 to the position shown in FIG. 7 by the drive device 25.
This process continues even after the receiving fJ of blister copper C in the refining furnace (+) is completed.

In this way, receiving and oxidation are carried out in parallel, and the overlapping time for refining c'J1 blister copper is shortened, which improves the throughput of the refining furnace itself.
- is achieved and the smelting capacity of the previous process improves, it becomes possible to correspondingly increase the production speed of the entire facility.

The timetables shown in Figures 9 to 1O are examples of the operating cycles of refining furnaces, and may be changed as appropriate depending on changes in the number and capacity of refining furnaces, refining capacity, processing time of each process, etc. should be selected.

Furthermore, the overlapping time between receiving blister copper and oxidation treatment in the case of Figure 1O should be appropriately set after considering the blister production rate, the oxidation treatment capacity of the refining furnace, etc.

[Effect of the invention] The invention of the first claim includes a step of receiving molten copper into a refining furnace, a step of oxidizing the molten copper in the refining furnace, a step of reducing the molten copper in the refining furnace, and a step of receiving the molten copper into a refining furnace. In a copper refining method consisting of a step of discharging molten copper that has undergone reduction treatment from a refining furnace, the receiving step and oxidation treatment step are performed at least partially overlapping each other, so that the overlapping time is Since the processing time of the refining furnace can be ended quickly, the processing capacity of the refining furnace can be improved as a result. In addition, since equipment with a predetermined processing capacity can more flexibly respond to fluctuations in the previous process, stable operation of the entire equipment can be achieved even in systems where the copper-making furnace is directly connected to the refining furnace without the need for a heat-retaining furnace. This will contribute to the promotion of

The invention of claim 2 provides a refining furnace with a tuyere that opens on the inner surface, and tilts the furnace body according to the depth of the molten copper put into the refining furnace to adjust the immersion depth of one blade. Since the oxidizing gas is blown into the tuyeres while being adjusted, the oxidizing gas can be blown into the molten copper in a direction where it fully reacts with the molten copper. Even when the amount of copper is small, oxidation treatment can be performed in a state where the reaction efficiency of the air constantly blown is high.

In the invention of claim 3, by using oxygen-enriched air as an oxidizing agent, the heat balance of the reaction and the oxidation reaction efficiency are controlled depending on the situation, and the reaction proceeds more efficiently, thereby increasing production efficiency. It is possible to direct the

[Brief explanation of drawings]

FIG. 1 is a plan view showing an overview of continuous copper manufacturing equipment suitable for carrying out the method of the present invention, FIGS. 2 to 5 are diagrams showing refining furnaces used in such steel manufacturing equipment, and FIGS. Figure 8 shows the reception, oxidation, and oxidation of blister copper in such a refining furnace.
A sectional view showing the tilting state during reduction and anode casting, FIG. 9 is a timetable showing an example of operation in such a refining furnace, FIG. 10 is a timetable showing the method of the present invention, and FIG. 11 1 is a sectional view showing an example of a conventional copper smelting apparatus. ■... Smelting furnace, 2... Separation furnace, 3... Steel making furnace, 4... Refining furnace, 5... Lance, 6... Electrode, 7A, 7B... Gutter, 8...・・Heating furnace, 9・・Dollar, IO・・Crane, 11・・Branch gutter, 11A, IIB・・Gutter, 11C・・Discharge port, 12・・・
- Switching device, 21... Furnace body, 21a... End plate, 21b... Body, 22... Guide ring, 23 - Support wheel, 24... Tilting gear, 25... Drive device, 26... ...Burner, 27...
Tuyere, 28...Tue spout, 29...Charging port, 30...Flue opening, 31...Cover, M...Kawa, S...Karami, C...Blunt copper.

Claims (3)

[Claims] (1) A process of receiving molten copper into a refining furnace, a process of oxidizing the molten copper in the refining furnace, a process of reducing the molten copper in the refining furnace, and transferring the molten copper after the reduction process to the refining furnace. A copper refining method comprising a step of discharging copper, characterized in that the receiving step and the oxidation treatment step are performed at least partially overlappingly. (2) The furnace body of the above-mentioned refining furnace is provided with a tuyere that opens on its inner surface, and the tuyere The method for refining copper according to claim 1, characterized in that a more oxidizing gas is blown into the copper. (3) The method for refining copper according to claim 1 or 2, characterized in that the oxidation treatment is carried out by blowing oxygen-enriched air into the molten copper.