DE1161034B - Pyrometallurgical refining process for copper - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 22 b

German class: 40 a -15/14

Number: 1 161 034

File number: N 22069 VI a / 40 a

Filing date: September 8, 1962

Opening day: January 9, 1964

The invention relates to a pyrometallurgical refining process for copper.

The invention is based on the object of an improved process for the refining of To create copper, which is carried out in an economical manner with a high reaction capacity can be.

Another purpose of the invention is to provide a novel process for refining Copper, which fully achieves the best possible results in heating, oxidation and reduction can only be achieved by the supply of fuel that is mixed with air, which oxygen contains in various proportions (hereinafter referred to as "air").

Another purpose of the invention is to create a novel process in which copper is produced suitable setting of the respective ratio of fuel to "air" for each heating stage, Oxidation and reduction can be refined without the aid of any other additional fuel can.

Other purposes, features and advantages of the invention will appear from the description.

The conventional pyrometallurgical process for refining copper includes the steps of refining from raw copper to anode copper followed by electrolytic refining to copper cathodes and subsequent melting and casting into wire bars. Similar procedures are also being widespread performed in the treatment and refining of copper waste.

These conventional methods generally involve melting the copper charge, heating it in a flame furnace or any other suitable furnace, and removing contaminants in the charge by air oxidation, and finally reducing the Cu ₂ O.

The oxidation is effected by means of air blown on the surface of the molten metal or into the molten metal, and causing Pb, Zn, S, As, Sb, Ni, Co, Mn, Bi and Fe contained in the molten metal to dissolve deposit from the molten copper. The volatile impurities are carried away in the exhaust gas, while the impurities remaining in the slag floating on the surface of the molten copper are removed from the furnace. The molten copper remaining in the furnace is completely or almost completely saturated _{with Cu 2 O.} Refining the

Pyrometallurgical refining process
for copper

Applicant:

Nippon Mining Co. Ltd., Tokyo

Representative:

Dipl.-Ing. Dipl.-Chem. Dr. phil. Dr. techn.

J. Reitstötter

and Dr.-Ing. W. Bunte, patent attorneys,

Munich 15, Haydnstr. 5

Named as inventor:
Toshio Ito, Hitachi (Japan)

Claimed priority:

Japan September 27, 1961 (No. 34 862)

Copper is then completed by reducing the molten copper with a reducing agent to remove oxygen. The copper refined in this way is then cast in casting molds in the desired shape. The reduction treatment given above is what is known as poling, for which green wood is considered the most suitable reducing agent. Since the suitability of the mentioned green wood depends on its water content, its size and its shape, the accessibility and the cost of the same form an economic problem. Since fuels are generally burned on the surface of the molten mass, in all of the previously known refining processes, a considerable amount of heat is lost and wasted in the course of the oxidation and poling treatments. In addition, during the reduction of the large amount of Cu ₂ O formed in the course of oxidation, the reaction between green wood and Cu ₂ O is carried out only on the surface of the melt, and as a result of evaporation of moisture from the green wood as time goes on, there is a tendency that the stirring effect will decrease in the course of this reaction. Accordingly, the reduction treatment requires a long period of time. In view of the increasing shortage of suitable green wood, the above-mentioned conventional methods have the difficulty of economically maintaining the heat

309 778/275

performance as well as the response performance. is the case with conventional known methods.

In the invention there is an improved refining In addition, the process is according to the invention

method indicated by which the above because of its simple and cheap mode of operation

Deficiencies and disadvantages are completely overcome. superior to any conventional method.

The characteristic feature of the invention is 5 Furthermore, the iin method according to the

in that the best results in each stage of the invention fuel used by one or

Heating, oxidation and reduction are achieved using a mixture of two or more types of fuel

can be formed simply by forming combustibles mixed with "air". A different one can also be used

substance is supplied. Type of fuel for each stage of oxidation, reduction

In the case of the fuel used in accordance with the invention, heating and heating can be used or instead

it can be liquid fuel, for example, in some cases the oxygen content in the

Heavy oil or light oil, or powdered carbon "air" with the type of fuel used

Substance-containing materials including solid fuel can be changed.

materials, for example coal, coke, charcoal, saw-As in the method according to the invention all types

flour and the like. 15 of fuels for which the oxygen ratio

In general, these are fuels that one has been appropriately adjusted. always in the bathroom of the

Having a wide range of options, being blown on molten copper easily and cheaply, is that

available on the market. They are more economical than the thermal performance is considerably improved. So is as a result

normally used green wood. the improved heat utilization in the previous

Of the above-mentioned fuels, the 20 lying processes do not require supplementary heating of fuels present in powdered form in the maneuverable, while in the conventional processes the desired ratio is mixed with "air" and additional or supplementary heating fuel is required by means of a combined mixing and supply. Furthermore, in the oxidation stage of the device, for. B. a speed controllable method according to the invention due to the small feed device with injector, blown under the surface 25 oxygen partial pressure in the combustion gas Verder molten mass. Accordingly, liquid fuels are effectively up to one in purity from the range of the desired degrees separated by oxidation called fuels in atomized form by injection and disposal, without any excessive directions such as an injection feeder in the growth of oxygen in the molten one Add copper to the molten mass. It can also be blown through in the reduction stage. close contact of the Cu ₂ O in the molten copper

The refining takes place in two stages, namely with the reducing material the reaction is rapid the oxidation and the reduction of the molten material are brought about, as violent agitation of copper. In the oxidation stage, this entire stage takes place through the end. In this case use of the lower tendency of copper 35 to oxidize, the reaction rate is reduced by the against other impurities a selective course of the chemical reaction conducive to regulated Oxidation at optimal temperature causes, while temperature accelerates, being this temperature In the reduction stage, a deoxidation with opti- mally occurring within the melt Temperature is maintained by close contact with a burning fuel. Reducing agent with the oxygen in the melted 40 On the other hand, there is a further advantage that the zenen copper is carried out; It should be noted that molten copper is replaced by unburned carbon also in the subsequent casting process a substance-containing material, which on its surface optimal temperature is required. swims, is protected from reoxidation.

After further research and numerous types of copper materials on which the procedure

Experiments in which the special features of FIG. 45 according to the invention are applicable are e.g. B.

Refining processes described above into consideration of black copper or electrolytic copper and / or

drawn, it has been found that by scrap copper and the like, in particular, the process

suitable regulation of the respective mixing ratio - extremely efficient in the production of anodes -

nisses of fuel to "air" in every stage of copper, when molten copper from one

Heating, oxidation and reduction provide better results.

nits can be achieved. That should be the features of the invention listed above

Oxygen ratio, namely the ratio of the fact, can be seen from the following examples in which

actually supplied amount of oxygen (b) to that is further described for the invention; the examples

the combustion of theoretically necessary oxygen serve for illustration, but the invention is not

quantity (α), ie b / a ■ 100 (%), in each case within the 55 restricted to this.

Range from about 80 to 130% during heating,. .

within the range of about 100 to 200% Example 1

melted during the oxidation and within the range of approximately 20 metric tons (t)

from about 20 to 100% during the reduction of a copper (containing 0.02% S and 0.6% O)

be put to the respective purposes in more effective 60 a converter were in a cylindrical 40 t

Way to achieve. Anode furnace introduced; on the surface of the

In summary, according to the molten mass, floating slag became

Invention, the desired refining advantageous and deducted, then powdered coal in one

Can be done economically by adding amount of 0.8 kg / min into the molten copper

only the above-mentioned oxygen ratio inside was blown and the oxygen ratio was at

half of the range from 20 to 200% is set, 150% is kept.

without the aid of an additional or after 30 minutes of blowing a sample of the

supplementary fuel such as heavy oil, such as molten copper, for the purpose of analysis

taken out. Since the S content was less than 0.01%, the coal feed rate became readjusted to 1.4 kg / min and the oxygen ratio to 90 to 100%, and under these conditions Powdered coal was blown into the molten copper for 1 hour.

The injection was then interrupted in order to allow a further supply of molten copper the converter. About 20 tons of molten copper (0.02% S and 0.6% O containing) introduced into the anode furnace. After drawing the slag, it became powdery for 20 minutes Coal under the conditions where the coal feed rate is 0.8 kg / min and the Oxygen ratio was 150%, blown into the molten copper.

Subsequently, the coal feed rate was set to 2.8 kg / min and the oxygen ratio to 32 bis 35% changed, and under these conditions, blowing was continued for 2.5 hours. A share molten copper was taken out and analyzed. Because the result of the analysis is satisfactory the blowing was stopped and the refined copper was poured into molds.

The powdered charcoal used was of the following nature:

Washed coal style

powdered coal grain size - 150 mesh

analysis

Calorific value 7910 kcal / kg

volatile constituents 36.5%

solid carbon 56.0%

Ashes 5.9%

Moisture 1.6%

Sulfur 0.4%

Analyzes of the original feed and the finished product were as follows:

feed
Finished product

CuC / o)

98.73
99.40

PbOVo)

0.13
0.12

0.019
0.007

O ( ¹ Vo)

0.60
0.10

rest
rest

100 100

Example 2

40

45

In a similar manner to Example 1, black copper was refined with powdered charcoal.

After the first supply of molten copper from the converter, the feed in the first stage for 25 minutes under blowing conditions at which the charcoal feed rate 0.8 kg / min and the oxygen ratio was 140%, and 35 minutes in the next stage long under blowing conditions in which the charcoal feed rate is 1.5 kg / min and the Oxygen ratio was 30 to 32%, treated. After the second feed of molten Copper from the converter was first fed to the batch for 45 minutes under conditions where the Charcoal feed rate was 0.8 kg / min and the oxygen ratio was 140%, and in the next stage for 35 minutes under blowing conditions where the charcoal feed rate was used 1.5 kg / min and the oxygen ratio was 30 to 32%. After the third feed of molten copper from the converter was first taking the batch for 45 minutes Conditions in which the coal feed rate is 0.8 kg / min and the oxygen ratio Was 140%, and in the next stage for 2 hours under conditions where the charcoal feed rate 2.0 kg / min and the oxygen ratio was 30 to 32%.

The charcoal used was as follows:

Type of charcoal whitish charcoal

Grain size - 150 mesh

analysis

Calorific value 6920 kcal / kg

volatile components 2.6%

solid carbon 84.7%

Ash 2.0%

Humidity 10.7%

Sulfur 0.08%

Analyzes of the original charge and the finished refined product were as follows:

feed
Finished product

98.85
99.38

Pb (»/")

0.18
0.14

0.018
0.004

O (V

0.54
0.10

rest
rest

Example 3

In a manner similar to Example 1, black copper was blown from a converter a mixture of powdered charcoal and finely powdered charcoal into the molten copper refined. After the first supply of molten copper from the converter, the batch was in the first stage for 30 minutes under blowing conditions in which the fuel feed rate the mixture of powdered charcoal and finely divided charcoal (mixing ratio 50:50 Parts by weight) was 0.8 kg / min and the oxygen ratio was 140%, and in the next stage For 40 minutes under conditions where the fuel feed rate is 1.5 kg / min and the oxygen ratio was 30%. After the second feed of molten Copper from the converter was first fed to the batch for 45 minutes under conditions where the The fuel supply rate was 0.8 kg / min and the oxygen ratio was 140%, and then For 2.5 hours under conditions where the fuel feed rate is 2.5 kg / min and the oxygen ratio was 30 to 32%.

The fuels used were the same as in Example 1 and 2, respectively.

On the other hand, the analyzes of the original batch and the finished product were as follows:

feed
Finished product

Cu (V ₀ )

98.89
99.35

Pb (Vo)

0.16
0.15

S (Vo)

0.020
0.008

O (Vo)

0.61
0.10

rest
rest

Example 4

53 t of electrolytic copper were put into a 55 t flame furnace imported and melted by burning heavy oil. It was drawn and then slag powdered charcoal is blown into the molten copper under conditions where the The fuel feed rate was 2.5 kg / min and the oxygen ratio was 30 to 33%. To After 1.5 hours of blowing, a portion of the melt was taken out and analyzed. Since that The result was satisfactory, the blowing was stopped and the finished product in the usual way Way to shed wire bars.

The powdered charcoal used was similar to that used in Example 2. Analyzes of the obtained wire bar were as follows:

99.97

FeOVo) Ο ' ⁰⁰⁰⁶

NiOVo) Ο ' ⁰⁰⁰³

Pb (%) 0.0008

S (%) Ο ' ⁰⁰¹¹

Sb (%) 0.0002

AsOYo) Ο ' ⁰⁰⁰²

SnOYo) Ο ' ⁰⁰⁰¹

O (%) 0.025

Other rest

Total (%) 100

Example 5

541 electrolytic coppers were placed in a 55-ton furnace imported and melted by burning heavy oil; Slag was drawn. Then became Sawdust is blown into the molten mass under conditions in which the fuel feed rate about 5 kg / min and the oxygen ratio was 27 to 30%. After 80 minutes of blowing it became part of the melt taken out and analyzed. Since the result was satisfactory, the blowing was stopped and the finished product is cast into wire bars in the usual way.

The composition of the sawdust used was as follows:

analysis

Calorific value 4510 kcal / kg

Humidity 30.1%

Ash 0.7%

volatile constituents 56.2%

solid carbon 43.1%

Elemental analysis

SnOY ₀ ) 0.0001

O (%) 0.024

Other rest

Total (%) 100

Example 6

581 black copper were put into a 60 t anode furnace (Containing 0.027% S and 0.38% O) introduced in a molten state. After pulling the slag that floated on the surface of the molten copper then became light oil into the molten one The mass is blown in under conditions in which the oil feed rate is 1 l / min and the oxygen ratio was 140%. After minutes of blowing, a sample of the molten copper taken for analysis; since the sulfur content was below 0.01%, the Fuel switched to sawdust, and blowing was carried out for 1 hour under conditions in which the sawdust supply rate was kg / min and the oxygen ratio was 30%. Then the treatment was stopped as the desired result was achieved and the refined one Copper poured into molds.

The nature of the light oil used was as follows:

Calorific value 11500 kcal / kg

specific weight 0.82

Sulfur 0.20%

The analyzes of the original batch and the finished product were as follows:

35 CuCZo) PbCZo) S ( ⁰ Zo) f ~ \ fO ^r \
\ J ^ 7 y ) Other total
CZo) feed
40 product 98.80
99.34 0.15
0.14 0.018
0.005 0.68
0.10 rest
rest 100
100

45

55

0.05

H (%) 6.27

O (%) 43.39

N (%) 0.01

C (%) 49.54

The analysis of the obtained wire bar was as follows:

Cu (%) 99.97

Fe (%) 0.0005

NiOY ₀ ) 0.0003

Pb (%) 0.0008

S (%) 0.0010

Sb (%) 0.0002

As (%) 0.0002

Claims (7)

Patent claims: 1. Pyrometallurgical refining process for copper, characterized in that liquid or solid carbonaceous fuel is blown into the copper bath by means of air, the oxygen content of the air used depending on the requirements of the individual process stages refining, such as heating, oxidation and reduction, is stopped. 2. The method according to claim 1, characterized in that the ratio of the actually supplied Amount of oxygen to the amount of oxygen theoretically necessary for combustion in the heating stage within the range of about 80 to 130%, in the oxidation stage within the range of about 100 to 200% and in the reduction stage within of the range from about 20 to 100%. 3. The method according to claim 1 or 2, characterized in that the starting material is black copper, Electrolytic copper, scrap copper and the like is used. 4. The method according to any one of claims 1 to 3, characterized in that a mixture of at least two of the types of copper mentioned in claim 3 are used. 9 10 5. The method according to any one of claims 1 to 4, substance in one or more stages of heating, characterized in that an oxidation and reduction is changed as the fuel.
Mixture of liquid fuel and solid 7. The method according to any one of claims 1 to 6, carbonaceous material is used. characterized in that the oxygen content 6. The method according to any one of claims 1 to 5, 5 in the "air" supplied with the fuel characterized in that the type of burning fuel is adapted. 309 778/275 12.63 © Bundesdruckerei Berlin