CA2565643C

CA2565643C - Operation method of copper smelting

Info

Publication number: CA2565643C
Application number: CA 2565643
Authority: CA
Inventors: Toshihiro Kamegai; Susumu Akagi; Fumiaki Sato; Katsuya Toda
Original assignee: Nippon Mining and Metals Co Ltd
Current assignee: JX Nippon Mining and Metals Corp
Priority date: 2006-06-28
Filing date: 2006-10-26
Publication date: 2011-08-02
Anticipated expiration: 2026-10-26
Also published as: CN100485061C; KR20080001580A; CA2565643A1; KR100877090B1; CN101096725A

Abstract

In copper smelting, copper sulfide ore is smelted in a flash furnace, and a converter, and is refined in an anode furnace. The anode is electrolytically refined. Precious group metal (PGM), such as Pt and Pd are separated from the copper and concentrated in the sludge of the electrolytic process. Powder or granular material containing PGM is conventionally recycled in the copper smelting process such that the recycling material is charged into the flash furnace together with the copper ore and the flux. The recovery ratio is enhanced by means of blowing the recycling material into the converter or the anode furnace through a tuyere(s).

Description

OPERATION METHOD OF COPPER SMELTING
BACKGROUND OF INVENTION
1. Field of Invention The present invention relates to an operation method of copper smelting, more particularly to a method for treating precious metal in a converter or an anode furnace used in the copper smelting process.

2. Background Technique Various methods are implemented in the smelting process of copper sulfide ore. A representative process comprises smelting of copper-sulfide ore concentrates in a flash furnace or the like to produce matte, treating the matte in a converter to produce crude copper having approximately 98.5 mass % of copper content, refining the crude copper in an anode furnace to enhance the copper content up to 99.3 mass % to 99.5 mass %, casting the refined copper into anodes, and finally subjecting the anodes to electrolytic refining to produce electric copper having 99.99 mass % or more of purity.
During this process, precious metals such as gold, silver and platinum contained in the raw material are concentrated in the sludge yielded in the electrolytic refining.
Precious metal is used for ornamentals, lead frame of IC, catalyzer of automobile exhaust-gas, an exhaust-gas sensor, dental materials and the like.
The precious metal is recycled in two forms, that is, scraps or other miscellaneous industrial waste. The scrap of precious metal is usually subjected to the wet recovering process (c.f., JOURNAL OF THE MINING AND MATERIALS PROCESSING INSTITUTE OF
JAPAN) Vol. 113 (1997) No.12, Great Special Edition of Recycling, pages 1115 -1117).
It is known from Great Special Edition of Recycling, ditto, pages 1173 - 1174 that the industrial waste containing precious metal is calcined and sieved and is then returned to the copper smelting process.
The copper ore, flux components and recycling raw material in the powder form are blown into the shaft of a flash furnace together with oxygen and are then rapidly subjected to reactions to form matte and slag. The matte and slag are stored in a hearth and then separated into upper and lower layers under gravity difference.
The matte produced in the smelting furnace is treated in a converter to attain the following conversions. That is, the iron contained in the matte is oxidized and the resultant oxide is separated in the slag phase, and the sulfur bonded with the iron of the matte is separated in the gas phase. White matte is thus yielded in the slag-making process. In the subsequent copper-making process, the sulfur of the white matte is separated in the gas phase, and crude copper is yielded.
The crude copper yielded in the converter is subjected to the oxidizing and reducing steps in the anode furnace to remove excess sulfur and oxygen. The refined copper is cast into an anode having the appropriate shape for electrolytic refining.
The platinum group elements indicated herein are Pt, Pd, Rh, Ru, Ir and Os and are referred to as PGM hereinafter. The raw material in the powder form 1 mm or less of size containing PGM has heretofore been charged into the flash furnace together with the copper ore and flux. Since PGM contained in the raw material powder has affinity to Cu in the high-temperature melt, major portion of PGM is included into the anode, and is electrolytically separated from Cu into sludge. The sludge is then subjected to the known refining process to separately recover each element of PGM.
Japanese Unexamined Patent Publication (kokai) No. 57-32339 entitled Operation Method of Copper Smelting Converter proposes to charge the silicate ore or silica stone through tuyeres of a converter. However, this publication does not mention a step of blowing the recycling material through the tuyeres.
Japanese Unexamined Patent Publication (kokai) No. 57-192233 entitled Operation Method of Copper Smelting Converter limits the materials charged into the converter through the tuyeres to the ore or ore-concentrate in the form of powder, and the flue dust generated in the copper smelting. However, this publication does not mention a step of blowing the recycling material through the tuyeres.

DISCLOSURE OF INVENTION
1. Problem to be Solved by the Invention The present inventors investigated in detail the behavior of the recycling material containing PGM charged into a flash furnace and discovered the following facts. When the raw material in the powder or granular form containing a large amount of PGM is charged into a flash furnace, approximately 10 % of the respective elements of PGM is transferred into slag. As is described hereinabove, the raw materials charged into a flash furnace are brought into reactions and are then separated into matte containing copper and slag containing most of the impurities.
The matte and slag are separated into the lower and upper layers, respectively, due to the gravity difference. Most of the copper and precious metal transferred into the slag are not recovered but are lost.
Presumably, PGM is transferred into the slag, because the ultra fine particles among PGM, such as the ground powder of the ornamentals and dental alloy, has such slow settling velocity in the slag in the flash furnace that the PGM
is not brought into contact with the underlying matte. The slag containing PGM is tapped from the flash furnace. In addition, since PGM has a very high melting point, its melting time is prolonged.
The present inventors conceived then an idea that the recovering ratio of PGM can be enhanced by means of blowing the recycling material through a tuyere(s) of the converter or the anode furnace into the molten white matte or molten crude copper, thereby causing direct reaction of the PGM with the white matte crude copper.
It is, therefore, an object of the present invention to improve the operation object of the operation method of copper smelting, in which recycling material containing one or more elements of PGM, namely, Pt, Pd, Rh, Ru, Ir and Os, are treated in the flash furnace, in such a manner that the lost PGM is recovered to enhance the recovering ratio of PGM.
2. Means for Solving Problem In accordance with the objects of the present invention, the recycling material containing one or more elements of PGM is not charged into the flash furnace but is charged into the converter or anode furnace by the following methods.
(1) An operation method of copper smelting, characterized in that the recycling material in powder or granular form containing one or more elements of PGM
is blown through a tuyere or tuyeres of a converter or an anode furnace and is brought into direct contact with the white matte or crude copper, thereby concentrating PGM
in the crude copper.
(2) An operation method of copper smelting according to (1), wherein the recycling material, which contains one or more elements of PGM, has 3mm or less of particle size and is dried to 10 mass % or less of moisture.
(3) An operation method of copper smelting according to (1) or (2), wherein the recycling material, which contains one or more elements of PGM, is blown through one or more selected tuyeres of the converter or the anode furnace.

(4) An operation method of copper smelting according to any one of (1) through (3), wherein the recycling material, which contains one or more elements of PGM, is blown into the converter during the copper-making stage.
According to an aspect of the invention there is provided an operation method of copper smelting comprising producing a matte and treating the matte in a converter to produce crude copper, wherein the method comprises blowing a recycling material containing a platinum-group metal which is Pt, Pd, Rh, Ru, Ir, Os, or any combination thereof, hereinafter referred to as PGM, in powder or granular form, into the converter, wherein the PGM has a particle size of 3mm or 3a less and is blown through a tuyere or tuyeres of the converter during the copper production stage, thereby concentrating PGM in the crude copper.
According to another aspect of the invention there is provided an operation method of copper smelting comprising producing a matte, treating the matte in a converter to produce crude copper and refining the crude copper in an anode furnace for producing copper to be subjected to electrolytic refining, wherein a recycling material containing a platinum-group metal which is Pt, Pd, Rh, Ru, Ir, Os, or any combination thereof, hereinafter referred to as PGM, is brought into contact, in powder or granular form, with the crude copper, wherein the PGM
has a particle size of 3mm or less and is blown into the anode furnace through a tuyere or tuyeres of the anode furnace, thereby concentrating PGM in the crude copper.
DESCRIPTION OF PREFERRED EMBODIMENTS
The recycling material treated by the method of the present invention contains one or more elements of PGM, i.e., Pt, Pd, Rh, Ru, Ir and Os. The content of each element is usually from a few ppm to a few mass%, specifically, lppm to 5 mass%. More specifically, the Pt content is from 50 g/t (50 ppm) to 1000g/t (0.1%) and the Pd content is from 100 g/t (100 ppm) to 5000 g/t (0.5%).
The recycling material may have any composition provided that it can be smelted in a converter or an anode furnace, and its PGM can be separated from the major portion of the recycling material. Since the recycling material originates from almost all of industries, it is difficult to specify the components of the recycling material.
An example of the balance of PGM is usually from 0 to 95 mass % of metal, such as Fe, Cu, Al and the like, from 0 to 95 mass % of their oxides, from 0 to 95 mass %
of sulfides of Fe and Cu, S102, A1203, as well as from 0 to 95 mass % of calcined C of the plastics, which derive from the industrial waste.
The properties of the recycling material should be such that it does not clog the blowing tubes. The recycling material should therefore be preliminarily dried to 10 mass % or less of moisture and any coarse grains or pieces of the recycling material should be preliminarily refined to 3 mm or less. Drying is carried out by means of for example a steam drier at a temperature of from 100 to 150CC. A sieve is used to adjust the size of the recycling material to eliminate foreign matters mixed in the recycling material.
In an embodiment of blowing the recycling material into a PS converter, the recycling material is blown preferably not during the slag forming stage, in which the slag and the white matte are co-present in the furnace, but during the copper-making stage, in which the white matte and crude copper are co-present, so as to avoid the transferring of PGM into the slag and hence the PGM loss. Blowing of the recycling material during the copper-making stage is preferable because of the following specific reasons. Since the slag-making stage is for approximately 1 hour and is relatively short, while the copper-making stage is for approximately 3 hours and is relatively long, the melting time of PGM can be kept for a long period of time by means of blowing the recycling material during the copper-making stage. In addition, the recycling material, which is blown during the slag-making stage and may not be molten, is transferred into the slag and is lost, while the recycling material, which is blown during the copper-making stage but is not yet molten, is transferred into the mush. In the next converter operation, the-mush is vigorously reacted with the matte, which is supplied from a smelting furnace, e.g., a flash furnace and is again transferred into the matte.
A furnace for treating the recycling material is a smelting furnace of matte, such as a PS converter, or a subsequent refining furnace, e.g., anode furnace.
The anode furnace is used in a case where the amount of the recycling material small, and further the amount of the impurities, which exert detrimental influence upon the subsequent electrolytic refining process, is at a low level The anode furnace is less preferable than the converter for treating the recycling material, because the anode furnace belong to the final stage for preparing the anode, and the impurities added from the recycling material to the anode material should later be removed, which is disadvantageous.

5 A number of the tuyeres, through which the recycling material is blown, is dependent upon the amount of the recycling material, and may be only one or all of the tuyeres. Diameter of the tuyeres is usually from 42.9 to 50.8 mm. Appropriate amount of the recycling material blown per operation may be approximately 0.5 to 5 tons.
BRIEF DESCRIPTION OF DRAWING
Figure 1 illustrates a plant for blowing the recycling material containing one or more elements of PGM into a converter according to an embodiment of the present invention.
EXAMPLES
Example 1 A test for treating the recycling material 10 ton in total was carried out for days using a converter operated for the commercial production of copper. One ton of the recycling material was blown into the converter during its each operation.
Figure 1 shown a plant used for the test.
The data in average of the test for 4 days are described in the following.
The recycling material contained 299 g/t of Pt and 1644 g/t of Pd. The other components of the recycling material were 19 % of Si, 14 % of Al, 11 % of Ba, 9 % of Fe, 5 % of Ca, 4 % of S, 4 % of Ni, 3 % of Cu, 3 % of Zn in terms of the metallic elements.
The recycling material was sieved to 3 mm or less and dried at 135`C using a steam drier to 2 mass % or less moisture and occasionally to 10 mass % of moisture and then stored in the blowing tank 1. High-pressure air generated in the compressor 2 was conveyed through the drain-separator 3 and the drier 4 at a rate of 7.8Nm3/min and was used as carrier gas of the recycling material at a rate of from 5 to 50 kg/minute. The obtained solid - air mixture was blown through a tuyere 6 into the melt 7, which was formed in the copper-making stage and the white matte and the crude copper were co-present. Clogging of the blowing pipe 11 did not occur. In addition, the steam explosion did not occur in the converter 10 during the blowing of the solid-air mixture mentioned above.
The balance of Pt and Pd is shown in Table 1, with the proviso that the blown amount of Pt and Pd amounts to 100%, respectively..
Table 1 Crude Converter Converter Copper of Dust Slag Converter Transfer Ratio of Pt (%) 98.6 1.1 0.3 Transfer Ratio of Pd (%) 98.1 0.5 1.4 The crude copper was totally tapped into the ladle and then poured in an anode furnace. The converter slag remained partly in the converter, and then the next converter operation was started so that converter slag was again formed. The total of the remaining slag and the slag again formed were tapped in the next operation. The converter slag in Table 1 indicates this total slag.
As shown in Table 1, 98.6 % of Pt and 98.1 % of Pd of the recycling material was transferred to the crude copper formed in the converter. This ratio indicates more efficient recovery of Pt and Pd than that by means of charging the recycling material into the preceding flash furnace. Note that the transfer ratio into the slag is approximately 10% in the case of charging into the flash furnace. The Cu grade of the resultant crude copper was as usual.

Example 2 The same recycling material as in Example 1 in amount of 5 ton was blown into an anode furnace operated for the commercial production of copper. The balance of Pt and Pd is shown in Table 2. The Cu grade of the resultant refined copper was as usual.

Table 2 Refined Anode Furnace Copper Dust Transfer Ratio of Pt (%) 99.6 0.4 Transfer Ratio of Pd (%) 99.7 0.3 INDUSTRIAL APPLICABILITY
When the recycling material containing PGM is treated in the copper smelting process, the recycling material is charged into a converter or an anode furnace. In this case, the recycling material is not brought into direct contact with the slag.
The slag loss of PGM can, therefore, be avoided, and recovery ratio of PGM amounting to 98% or more is attained.

Claims

1. An operation method of copper smelting comprising producing a matte and treating the matte in a converter to produce crude copper, wherein the method comprises blowing a recycling material containing a platinum-group metal which is Pt, Pd, Rh, Ru, Ir, Os, or any combination thereof, hereinafter referred to as PGM, in powder or granular form, into the converter, wherein the PGM has a particle size of 3mm or less and is blown through a tuyere or tuyeres of the converter during the copper production stage, thereby concentrating PGM in the crude copper.

2. An operation method of copper smelting comprising producing a matte, treating the matte in a converter to produce crude copper and refining the crude copper in an anode furnace for producing copper to be subjected to electrolytic refining, wherein a recycling material containing a platinum-group metal which is Pt, Pd, Rh, Ru, Ir, Os, or any combination thereof, hereinafter referred to as PGM, is brought into contact, in powder or granular form, with the crude copper, wherein the PGM has a particle size of 3mm or less and is blown into the anode furnace through a tuyere or tuyeres of the anode furnace, thereby concentrating PGM in the crude copper.

3. An operation method of copper smelting according to claim 1 or 2, wherein the recycling material is dried to 2 mass% or less of moisture.