JP3013437B2 - Copper purification method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for purifying copper for purifying crude copper into purified copper having a higher copper grade in a copper smelting process.

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

It melts and oxidizes copper concentrate supplied together with oxygen-enriched air, and contains Kawa M mainly composed of a mixture of copper sulfide and iron sulfide, gangue and solvent in copper concentrate, iron oxide, etc. Smelting furnace 1 for producing Karami S consisting of
Furnace 2 for separating Kawa M and Karami S generated in
And a copper making furnace 3 for further oxidizing the separated Kawa M to produce blister copper C, and purifying the blister copper C generated in the copper making furnace 3 to produce purified copper with higher copper quality. It is composed of furnaces 4,4. The smelting furnace 1 and the copper making furnace 3 are provided with lances 5 having a double-pipe structure so as to be able to move up and down by passing through the ceiling of these furnaces. Oxygen-enriched air, solvents, etc. are supplied into each furnace.
The separation furnace 2 is an electric furnace provided with the electrodes 6.

And, these smelting furnace 1, separation furnace 2, and copper making furnace 3
Are arranged in this order, and are connected by troughs 7A and 7B, which are flow paths of the molten metal, so that the molten metal flows down the troughs 7A and 7B by gravity.

The blister copper C continuously produced in the copper making furnace 3 is once held in a heat retaining furnace 8, then transferred to a ladle 9, transferred by a crane 10 and passed through a charging opening opening on the upper surface of the refining furnace 4. 4 and is usually subjected to an oxidation treatment and a reduction treatment to adjust the final copper quality.

However, in the copper smelting apparatus having such a configuration,
Since the refining process is a batch process, the generated blister copper C must be once held by the heat retaining furnace 8, and therefore, a ladle for transferring the blister copper from the heat retaining furnace 8 to the refining furnace 4 as well as the heat retaining furnace 8. It is necessary to supply equipment such as a crane 9 and a crane 10, and to supply energy for keeping the molten metal warm during this time. Therefore, as a result, the reduction of the construction cost and running cost of the smelting equipment and the downsizing of the smelting equipment are limited by these equipments.

Therefore, the heat retaining furnace 8 is abolished, and the plurality of refining furnaces 4 are connected to the copper making furnace 3 via a molten metal flow path, and molten copper is transferred from the copper making furnace 3 to the refining furnace 4 through the molten metal flow path. A system such as sending is conceivable.

[Problems to be Solved by the Invention] In such a refining furnace 4, batch processing is inevitably performed in order to adjust the molten metal in the furnace to a final target component. The above processing is performed after receiving the amount of. For example, 2 for one copper making furnace 3
In the case where the primary refining furnace 4 is connected and the molten copper is supplied alternately and the processing is performed, the total time of the receiving and refining processing becomes the cycle time, and the amount processed in one refining furnace 4 during this time Is set to be twice the production capacity of the copper furnace 3. Therefore, if the production amount from the copper furnace 3 fluctuates upward, if there is no flexibility in the throughput of the refining furnace 4, it is held in the copper furnace 3 as it is, or
The need for urgent storage in other holding facilities arises, and eventually, the above-described system without the heat retaining furnace 8 does not operate smoothly.

Means for Solving the Problems The present invention has been made to solve the above problems, and includes a step of receiving molten copper in a refining furnace, a step of oxidizing the molten copper in the refining furnace, and a step of refining. In a copper refining method comprising a step of reducing molten copper in a furnace and a step of discharging the molten copper after the reduction treatment from the refining furnace, the tuyere opening to the inner surface of the furnace body of the refining furnace is provided. The furnace body is tilted according to the depth of the molten copper that has been received, and the immersion depth of the tuyere is adjusted so that the tuyere opening position is below the surface of the molten copper. An oxidizing gas is blown from the tuyere to the surface of the molten copper substantially in parallel, so that the receiving step and the oxidizing step are performed at least in part.

When oxygen-enriched air is used as the oxidizing agent in the oxidation step, the oxygen enrichment rate is 25 to 35 vo.
l% is preferred.

[Action] In the present invention, in parallel with the reception of molten copper to the refining furnace,
An oxidation treatment of copper is performed. Since the oxidation treatment is usually performed by blowing air or oxidized air as an oxidant into molten copper from a tuyere provided in the furnace body,
It is better to start oxidation after the depth of molten copper in the refining furnace exceeds a certain amount by acceptance.

Here, in the present invention, the oxidizing gas is blown into the molten copper from the tuyere while tilting the furnace body according to the molten copper depth such that the opening position of the tuyere is below the surface of the molten copper. The oxidizing gas blown from the tuyere is blown in the molten copper almost parallel to the surface of the molten copper, and reacts sufficiently with the molten copper,
A stable reaction is performed without excessively stirring the molten copper.
Thus, the oxidation treatment can be performed even when the amount of molten copper is small, and the oxidation treatment is always performed in a state where the reaction efficiency of the blown air is high.

At this time, by using oxygen-enriched air as the oxidizing agent, the heat balance of the reaction and the oxidation reaction efficiency are controlled according to the situation.

[Embodiment] Fig. 1 shows an embodiment of an apparatus for performing the method of the present invention.

The copper making furnace 3 and the refining furnace 4 are connected by a gutter 11 which is a molten metal flow path, and the blister copper C generated in the copper making furnace 3
It flows down to the purification furnace 4 through 11. Two refining furnaces 4 are provided, and these are arranged in parallel with each other. Gutter 11
Is divided into two flow paths through a branch point provided in the middle, and the main gutter 11A and a branch from the main gutter 11A
4 and 4, two branch gutters 11B and 11B. The vicinity of the connection point between the branch gutter 11B and the main gutter 11A is slightly shallow at the bottom, and a castable or massive refractory is dropped into this portion to form one branch gutter 11B.
A molten metal flow path switching device 12 for blocking the flow of the molten metal to B and causing the molten metal to flow to the other branch trough 11B. In addition, these gutters, including gutters 7A and 7B connecting other furnaces,
A lid and the like are installed at the upper part, and a heat retaining device such as a burner and equipment for adjusting the atmosphere are provided at necessary places, so that the molten metal flowing down the gutter is maintained in a relatively high sealed state. It has become.

As shown in FIGS. 2 to 4, the refining furnace 4 has a closed cylindrical furnace body 21 including end plates 21a at both ends and a body 21b, and is provided on the body 21b. The plurality of support rings 23 contacting the guide rings 22, 22 are supported so as to be rotatable around the axis with the axis horizontal.
A tilt gear 24 installed at one end of the tilt gear 21;
Is tilted by a driving device 25 connected to the motor. Further, one end plate 21a of the furnace body 21 has a furnace body 21a.
A burner 26 for maintaining the temperature of the molten metal in the furnace is installed toward the inside, and a tuyere 27, 27 for supplying air or oxygen-enriched air or a reducing agent into the furnace is purified in the body 21b. Tap holes 28 for casting cast copper into the anode are provided on opposite sides. Further, a charging port 29 for charging a lump such as anode dust into the furnace is provided substantially at the center of the upper side of the body 21b of the refining furnace 4. Also, the torso 21
As shown in FIG. 4, the upper side of the end opposite to the burner 26 of b opens in an oval shape along the circumferential direction from the vertex at the normal position of the furnace toward the tap hole 28 side. Flue exit 30
Are formed.

Cover the end of the exhaust duct so as to cover this flue port 30
An opening 31 is provided. As shown in FIG. 5, the opening is formed at an angle so as to cover the entire flue port 30 in the range of the tilting of the furnace body 21. A gutter 11B, which is a flow path of the molten metal in which the blister copper C flows, is inserted from a side surface of the cover 31, and its end 11C is positioned facing the above-mentioned flue port. The end gutter 11C has a water-cooled jacket structure like the cover 31.

In the smelting apparatus having the above configuration, the smelting furnace 1
Molten blister copper C is continuously produced by a continuous copper making facility consisting of a separation furnace 2 and a copper making furnace 3 and flows down a gutter 11A from the copper making furnace 3; Refining furnace 4 from end 11C and flue port 30
Accepted to.

Normal reception is performed in the state shown in FIG. 6 with the furnace body 21 standing upright. After the reception of the blister copper C is completed, the furnace body 21 is tilted by the driving device 25, and the blades are moved as shown in FIG. The mouths 27, 27 are tilted so that they are below the surface of the molten metal.
In this state, first, air or oxygen-enriched air is supplied from the tuyere 27, 27 into the furnace body 21 to oxidize the crude copper C for a predetermined time, thereby bringing the sulfur concentration in the copper closer to the target value. Further, a reducing agent containing a mixture of hydrocarbon and air as a main component is supplied to perform a reducing treatment, so that the oxygen concentration in the copper approaches a predetermined value. The flue gas generated at this time is covered by the flue
Collected in the exhaust duct via 31 and processed. Also,
Karami S is discharged from the charging port 29.

In this way, the crude copper C in the furnace is refined to become refined copper having a higher copper quality. Then, the driving device 25 is operated again to further tilt the furnace body 21 to a tilting state as shown in FIG. Molten copper is poured from the tap hole 28, poured into an anode mold via an intermediate ladle, cast on an anode plate (anode), and transferred to an electrolytic treatment step.

The two purification furnaces 4 are provided, and the blister copper C generated in the copper making furnace 3 is supplied to the two purification furnaces 4 and 4 by a switching device 12 provided in a branch gutter 11 which is a molten metal flow path. It is allowed to flow down to one of them. While the blister copper C is being received in one of the refining furnaces 4, the other refining furnace 4 performs the work of oxidizing and reducing the received blister copper C for purification and casting as an anode in parallel.

Hereinafter, a refining method in the case where blister copper is received, oxidized, reduced, and cast by two refining furnaces 4 will be described with reference to FIG. 9 and FIG.

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

While one of the refining furnaces (1) is receiving blister copper C, the other refining furnace (2) performs oxidation, reduction, casting of the blister copper C received in the previous process and accompanying operations. . In this example, the blister copper C is oxidized for 2 hours,
It takes 2 hours for reduction and 4 hours for casting, 30 minutes tuyere cleaning between oxidation and reduction of blister copper C, 1 hour casting preparation between reduction and casting, and casting From the time the next process is accepted, the casting is cleared for 30 minutes as ancillary work. That is, it takes 10 hours for the accepted blister copper to be refined, cast as an anode, and ready to accept the next blister copper, which is equal to the time of acceptance. Thus, in the refining furnace 4, after casting and clearing, there is little waiting time between subsequent receiving steps.

The example of FIG. 10 shows the method of the present invention in the case where the capacity of the copper making furnace is larger than the processing capacity of the refining furnace. Then, the blister copper C received in the furnace is oxidized. In other words, in this example, the receiving from the copper making furnace to the refining furnace is performed in 8.5 hours, while the work from oxidation to clearing of the casting takes 10 hours. Saves time.

This receiving oxidation is performed by changing the furnace body 21 from the position shown in FIG. 6 to the position shown in FIG. 7 by the driving device 25 and then tilting the furnace body 21 in accordance with the depth of the received blister copper C, thereby forming the tuyere 27. , 27
While adjusting the immersion depth of the tuyeres 27, 27 so that the opening position of is below the molten metal surface (surface of molten copper) of blister copper C, the tuyeres 27, 27 are almost parallel to the molten copper surface from bladder C This is performed by blowing an oxidizing gas into the device. The oxidation of the blister copper C is continued even after the reception of the blister copper C in the refining furnace (1) is completed.

In this way, the receiving and oxidizing are performed in parallel, and the refining time of the blister copper is shortened by the overlap time, so that the processing capacity of the refining furnace itself is improved and the production of the pre-process is performed. When the smelting capacity is improved, the production speed of the entire equipment can be increased correspondingly.

The time tables shown in FIGS. 9 to 10 are examples of the operation cycle of the refining furnace, and may be appropriately changed according to changes in the number and capacity of the refining furnace, the refining capacity, and the processing time of each process. Things should be selected.

In addition, the overlap time between the reception of blister copper and the oxidation treatment in the case of FIG. 10 should be appropriately set after considering the production speed of blister copper and the oxidation treatment capacity of the refining furnace.

[Effects of the Invention] As described above, the present invention provides a process of receiving molten copper in a refining furnace, a process of oxidizing molten copper in a refining furnace, and a process of reducing molten copper in a refining furnace. In the method for purifying copper, comprising the step of discharging the molten copper having undergone the reduction treatment from the refining furnace, the furnace body of the refining furnace is provided with a tuyere opening on the inner surface thereof, according to the depth of the received molten copper. The furnace body is tilted to adjust the immersion depth of the tuyere so that the tuyere opening position is below the molten copper surface. By injecting the gas, the receiving step and the oxidizing step are performed so as to overlap at least a part thereof, so that the processing time of the refining furnace can be completed earlier by the overlapping time. As a result, the processing capacity of the refining furnace can be improved. You. And, because the equipment with a predetermined processing capacity can respond more flexibly to the fluctuations of the previous process, even in a system where the copper making furnace is directly connected to the refining furnace without the heat insulation furnace, the stable operation of the whole equipment can be achieved. It contributes to the promotion of

The oxidizing gas can be blown into the molten copper in such a direction as to sufficiently react with the molten copper, so that when the amount of molten copper is small, the reaction efficiency of the blown air is always high. Can be used for oxidation treatment.

At this time, by using oxygen-enriched air as the oxidizing agent, the heat balance of the reaction and the oxidation reaction efficiency are controlled according to the situation, and the reaction proceeds more efficiently, thereby improving the production efficiency. be able to.

[Brief description of the drawings]

FIG. 1 is a plan view showing an outline of a continuous copper making facility suitable for carrying out the method of the present invention, FIGS. 2 to 5 are views showing a refining furnace used in such a copper making facility, and FIG. FIG. 8 to FIG. 8 show the receiving and oxidizing of blister copper in such a refining furnace.
FIG. 9 is a cross-sectional view showing a tilting state in reduction and casting of an anode, FIG. 9 is a time table showing an example of operation in such a refining furnace, FIG. 10 is a time table showing a method of the present invention, FIG. FIG. 1 is a sectional view showing an example of a conventional copper smelting apparatus. DESCRIPTION OF SYMBOLS 1 ... Smelting furnace, 2 ... Separation furnace, 3 ... Copper making furnace, 4 ... Refining furnace, 5 ... Lance, 6 ... Electrode, 7A, 7B ... Gutter, 8 ... Heat insulation furnace, 9 ... ladle, 10 ... crane, 11 ... branch gutter, 11A, 11B ... gutter, 11C ... discharge port, 12 ... switching device, 21 ... furnace body, 21a ... mirror plate, 21b ... body , 22 ... guide ring, 23 ... support wheel, 24 ... tilting gear, 25 ... drive unit, 26 ... burner, 27 ... tuyere, 28 ... taphole, 29 ... inlet, 30 ... flue port, 31 ... cover, M ... Kawa, S ... Karami, C ... blister copper.

Claims (1)

(57) [Claims] 1. A step of receiving molten copper in a refining furnace, a step of oxidizing molten copper in a refining furnace, a step of reducing molten copper in a refining furnace, and a step of removing the molten copper having been subjected to the reduction processing. In the method for purifying copper comprising a step of discharging from a refining furnace, the furnace body of the refining furnace is provided with a tuyere opening on an inner surface thereof, and the furnace body is tilted according to a depth of the received molten copper,
By adjusting the immersion depth of the tuyere so that the opening position of the tuyere is below the surface of the molten copper, and blowing the oxidizing gas into the molten copper from the tuyere almost parallel to the surface of the molten copper, A method for purifying copper, wherein the step and the oxidation treatment step are performed at least in part.