JP2587814B2 - Method for treating concentrate from copper converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a copper converter entrained concentrate (hereinafter referred to as "Kamimi") obtained by solidifying a converter exhaust discharged from a copper converter and then performing a flotation treatment. Concentrate)), without melting the smelting furnace as it is, dissolving it in a separate furnace, removing impurities efficiently, and then repeating the copper content with less impurities to the existing copper smelting process. Things.

(Prior art)

In general, the copper content of the converter discharged from the copper converter is 3 ~.
Since it contains as much as 7% by weight, it cannot be discarded as it is, and valuable metals are recovered by various methods.

As a conventional method of treating the converter stake, the converter stake is repeatedly returned to a reverberation furnace for melting or an electric furnace. However, in this case, since a large amount of Fe ₃ O ₄ is contained in the converter, there is a disadvantage that the furnace bottom rises and the effective volume in the furnace tends to decrease. Also, a so-called slag cleaning using a reducing agent from a converter in a recently melted state using a reducing agent has been proposed, but a large-sized furnace is required in order to treat the entire amount of the converter from the converter as a solution. In the recovered copper content, As, Sb contained in the converter
Although impurities such as are concentrated, it is not preferable that these impurities are contained in a large amount in the subsequent electrolytic refining process, so that the recovered copper component is charged into an existing copper smelting process such as a converter. Separately, a process of purifying the recovered copper is required. However, since the recovered copper is generated at about 6% by weight with respect to the processing converter, this purification process also requires relatively large-scale equipment. Was needed.

In addition, the most widely used conventional method of treating the converter refuse is to once solidify the converter refuse, pulverize it, recover the concentrate with high copper content by flotation, and repeat it to the smelting furnace. The obtained enamel concentrate was then repeatedly treated in a smelting furnace for smelting sulfide concentrate, for example, a flash smelting furnace.

[Problems to be solved by the invention]

When the enamel concentrate obtained by the flotation process is repeated in the smelting furnace, most of the impurities such as As and Sb removed during the operation of the converter during the operation of the converter are entangled in the ore concentrating process. The disadvantage is that the impurities are repeatedly charged into the smelting furnace because they are distributed into the concentrate. In this smelting furnace, some of the impurities are removed during the smelting furnace production, but if the amount of impurities charged into the smelting furnace increases, the amount of impurities distributed in the production mat will inevitably increase. And the quality of impurities in the anode used for electrolytic refining eventually increases, which is not preferable.

For this reason, the total amount of impurities charged into the smelting furnace needs to be below a certain standard, but the amount of impurities brought into the smelting furnace by the enrichment concentrate is quite a fraction of the impurities charged into the smelting furnace. , And the processing capacity of copper concentrate with high impurity quality is limited.

As, S as impurities in flotation from converter
b forms mainly an alloy with metallic copper when viewed from the solidified converter, and because it forms an intermetallic compound with Ni, it is extremely difficult to remove these impurities in the beneficiation process. However, there is a problem that the concentration of impurities in the enamel concentrate is inevitable.

Although it contains 20 to 35 wt% of Fe during viewed concentrate from one, most of which forms a Fe ₃ O _4, the smelting furnace as for the Fe ₃ O ₄ is a flash smelting furnace When charged, this causes problems such as increased copper carry-out loss due to increased entanglement viscosity, rise in the hearth, and formation of a spatter layer at the interface between the entanglement and the mat, making it difficult to discharge the molten entanglement. In addition, S concentrate has low S grade, and the S / Cu weight ratio of ordinary copper concentrate is around 1, while the S / Cu ratio of gang concentrate is around 0.2. There is a problem in that the fuel properties of the ore burner are poor, the required amount of auxiliary fuel increases, and the melting capacity of the flash smelter decreases.

An object of the present invention is to provide a method for treating ash concentrate which has solved such disadvantages.

[Means for solving the problem]

In order to achieve this object, the present invention is to concentrate the copper concentrate obtained by beneficiating the converter from the copper converter, under a weak reducing or neutral atmosphere, at a temperature of 1200 to 1300 ° C and a Cu / S weight ratio of 4.3 or more. Dissolving while maintaining the entangled, matte and metal three phases,
The metal phase is separated and recovered, and after adding a sulfur source for forming a mat to the separated and recovered metal phase molten metal to generate a molten metal of the mat, the molten metal of the mat is depressurized in a vacuum purification device. By volatilizing and removing impurities such as As and Sb,
The molten metal of the mat is purified.

 Hereinafter, the present invention will be described in detail.

The copper converter discharged from the copper converter for mat treatment produced by the ordinary smelting furnace is solidified and pulverized in accordance with a normal method, and the enrichment concentrate having high copper content and almost all of the copper content are separated by flotation. It is separated into tailings that do not contain much. At this time, the distribution of impurities depends on the grade in the converter and the conditions of the beneficiation.
40 to 90% by weight of Sb and 50 to 80% by weight of As in the converter are distributed in the gang concentrate. The tailings are discarded and the lees concentrate is melted in a melting furnace according to the method of the invention.

The type of the melting furnace is not particularly limited as long as the entangled concentrate can be melted in a weak reducing or neutral atmosphere, but an electric furnace is practically convenient. The melting temperature may be about 1200-1300 ° C. If the Cu / S weight ratio in tangled concentrate is 4.3 or more,
Just dissolve tangled concentrate alone, tangled, matte,
Three phases of metal can be obtained, but if the Cu / S weight ratio is less than 4.3, only two phases of mat can be obtained, so if metal copper such as copper scrap is added to obtain three phases good.

When three phases of mat and metal are formed in the smelting furnace, 90% or more of As and Sb in the leash concentrate are distributed to the metal phase. For such behavior of As and Sb in copper smelting, see, for example, Akira Yazawa “Distribution of various elem
ents between copper, matte and slag "Erzmetall 33 (1
980) has also been confirmed in laboratory scale equilibrium experiments as described on pages 377-382.

In the smelting furnace of the gang concentrate, an intermediate product with a high As and Sb grade such as a copper removal slime or a slag of a copper refining furnace may be charged and treated together with the gang concentrate.

The filth produced in this melting furnace may be rejected as it is, but if the copper quality is high, the process may be repeated from the converter to the beneficiation process. Since the produced mat has low quality of As, Sb, etc., it can be directly charged into a copper converter for mat treatment produced in a smelting furnace. However, since the produced metal phase is enriched in As, Sb, etc. as described above, it is charged into a copper converter through the purification step described below. Only small things are needed.

The copper-based metal phase produced and separated and recovered in the melting furnace is then charged into a vacuum furnace. Here, while maintaining the molten state, a sulfur source is added to the extent that a mat phase is formed. As a sulfur source, elemental sulfur may be blown by nitrogen gas, or iron sulfide may be added. It is preferable to add a sulfur source so that the S grade of the mat is 22% by weight or more. If the S grade is less than 22% by weight, the volatility of As and Sb is undesirably reduced. Next, the pressure inside the vacuum furnace is 0.6 mmH
g until the pressure drops below 0.6 mmHg.
This state is maintained in the molten mat for at least 5 minutes.
Volatile recovery of Zn, Pb, As, Sb, Bi, etc. While the amount of volatile components is large, the degree of vacuum does not increase so much depending on the scale of the apparatus and the suction capacity, and when the degree of vacuum is 0.6 mmHg or less, further volatilization can no longer be expected. It is good to continue for more than a minute. The temperature of the molten metal in the vacuum furnace may be maintained at a temperature equal to or higher than the melting temperature by using a low-frequency induction furnace or the like.

Pb, Zn, Sn, As, Sb, Bi, and the like volatilized in a vacuum furnace can be separated and recovered into respective metals by a wet treatment method or the like after being recovered by an appropriate dust collector.

The refined mat from which impurities have been removed by a vacuum furnace as much as possible is contained in the mash concentrate by repeatedly processing the mat produced in the melting furnace described above together with the ordinary copper converter for mat processing produced in the smelting furnace. Most of the copper can be put on the route of electrolytic refining.

Regarding which step of the converter of the mat treatment, the purified mat is to be repeated, when the elemental sulfur is used for the mat formation in the present invention, it is sufficient to charge the mat during the copper making stage, since iron is not particularly mixed. When iron sulfide is used as a sulfur source, the mat contains iron, so it is necessary to repeat the fermentation period.

In addition, as a method of purifying the metal phase produced from the melting furnace,
In addition to the method of the present invention, for example, a method of directly performing vacuum purification without sulphiding metallic copper, a method of adding a Na compound or a Ca compound to metallic copper to remove impurities by entangling, a method of sulphidizing metallic copper to form a mat Thereafter, there is a method of blowing an inert gas to volatilize and remove impurities. However, the removal rate of impurities, particularly Sb, is low by the vacuum purification method or the inert gas injection method of metallic copper. In addition, in the method of adding the Na and Ca compounds, a considerable amount of copper is contained in the entangled product, so that the loss of copper is increased, and As and Sb in the entangled are stable oxides. There is a drawback that it is difficult to recover from wastewater.

In addition, as a method for purifying a metal phase, the applicant has filed Japanese Patent Application No. 60-98.
After applying vacuum treatment in the metal phase to remove volatile Zn and Pb etc. as filed in Application No. 722, vulcanizing the molten copper to form a mat, then purifying in vacuum to remove As, Sb etc. Can also.

〔Example〕

Example 1 2.5 g of coke was added to 250 g of the enamel concentrate described in Table 1 and the mixture was placed in an alumina crucible, covered with an alumina cover, and placed in a siliconite furnace in which N ₂ was flowing at 1 / min. After heating and holding at 1300 ° C. for 4 hours, the crucible was taken out, cooled and solidified, and the sample was observed, weighed, and subjected to chemical analysis. The sample in the crucible was entangled and separated into three phases of mat and metal, and the separability was good. Table 1 shows the yield and the analytical value (% by weight).

As is clear from the above table, most of As and Sb are concentrated in the metal phase.

Example 2 182 K of entangling concentrate same as that used in Example 1 in a single-phase electric furnace having a brick inner diameter of 600 mm, a depth of 880 mm, and a transformer capacity of 200 KVA.
g was dissolved over 88 minutes without additives. Power consumption is 104KW
H. The results are shown in Table 2.

Example 3 This example describes an example in which copper obtained by dissolving enamel concentrate according to the present invention is converted to a matte phase, and impurities are volatilized and removed in a vacuum purifier.

The recovered copper of Cu84.1, As1.40, Sb1.51, Fe3.4, and S0.26 is maintained at 1200 ° C by weight or by adding elemental sulfur to the content of S at 22.4% by weight. , And 11.2% by weight were charged into a Tamman tube having an inner diameter of 33 mm and a height of 150 mm, and the inside of the furnace was replaced with a neutral gas in a high-frequency vacuum melting furnace, and then heated to a predetermined temperature in about 30 minutes. After increasing the degree of vacuum with a vacuum pump and sucking volatiles, bring the degree of vacuum to 0.04 to 0.6 mmHg, then 5
Maintained ~ 15. Table 3 shows the quality of the purified mat and the like after removing the impurities.

From the results in the above table, Test No. 1 was obtained by performing vacuum purification in the metal state without vulcanization, and almost no As and Sb were removed. Test Nos. 2 to 4 were conducted in accordance with the method of the present invention. Among them, No. 2 was vulcanized to S22.4%, brought to a vacuum of 0.6 mmHg at 1230 ° C., and held for 5 minutes. It was also found that the volatility of Sb was good. Test No. 3 is a test
No. 2 and others were brought to a vacuum of 0.2 mmHg under the same conditions and maintained for 15 minutes, and in Test No. 4, the temperature was 1150 ° C., but the volatility was good in each case. In test No. 5, vacuum purification was performed without sufficient vulcanization for forming the mat phase, and both the metal phase and the mat phase remained, and Sb was hardly volatilized, but As was large. The part volatilized.

From these results, it is effective to volatilize impurities by volatilizing the metallic copper recovered by dissolving the entangled concentrate to the extent that S is added to form a complete matte phase.

(Effect)

As described above in detail, according to the method of the present invention, it is possible to remove impurities such as As and Sb from copper in the entangled concentrate with relatively small-scale equipment and recover the recovered copper. Since it can be repeated in the furnace process, the allowable capacity of impurity treatment in the smelting furnace is increased, and the problem caused by Fe ₃ O ₄ for processing entangled concentrate in the smelting furnace is solved, and smelting It becomes possible to increase the raw material concentrate processing capacity in the furnace and to reduce the amount of auxiliary fuel.

Claims (1)

(57) [Claims] 1. A concentrate obtained from a copper converter obtained by beneficiating a concentrate from a copper converter is subjected to a weak reducing or neutral atmosphere at 1200 to 13%.
At 00 ° C., dissolving while maintaining the Cu / S weight ratio at 4.3 or higher,
Entangling, obtaining three phases of mat and metal, separating and recovering the metal phase, and adding a sulfur source for forming a mat to the separated and recovered melt of the metal phase to generate a molten metal of the mat; And purifying the molten metal of the mat by depressurizing the molten metal of the mat in a vacuum purifier to volatilize and remove impurities, thereby purifying the molten metal of the mat.