JP2006307293A - Method for collecting copper by floatation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collecting method for increasing a quantity of collected copper by floatation. <P>SOLUTION: This collecting method comprises the steps of: finishing a reaction of producing white matte in a slag-making period; reducing an amount of supplied oxygen, namely, inhibiting overblowing; subsequently discharging converter slag by tilting a copper converter; feeding the converter slag to a concentration facility; and subjecting the converter slag to a floatation in the concentration facility. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for recovering copper contained in a converter generated in a converter (hereinafter referred to as a copper converter) used when performing copper smelting.

In general, in copper smelting, as shown in FIG. 1, dry copper concentrate is smelted in a self-smelting furnace 1 and glue 6 (so-called mat, copper content 55 to 70% by mass) and entanglement 5 (so-called slag) In addition, the glue 6 is charged into the copper converter 2 and blown. In addition, in order to distinguish the leash 5 generated in the auto-smelting furnace 1 from the leash generated in the copper converter described later, it is referred to as the auto-melting furnace leash 5.
This melting furnace tang 5 is fed to the granulation facility and disposed of as a pulverized trash.

When the molten furnace 6 obtained in the self-melting furnace 1 is accommodated in the copper converter 2 and blown, air or oxygen is enriched from a plurality of tuyere (not shown) provided in the furnace body. Blow in an oxygen-containing gas such as air. In this way, impurities in the glue 6 are oxidized in the canning period and separated into SO ₂ gas, entanglement 7 and white glue. Further, in the copper making period, the white glue is purified to obtain crude copper 8 (copper content 98 to 98%). 99% by mass) is obtained. In addition, in order to distinguish the leash 7 generated in the copper converter 2 from the self-melting furnace leash 5 described above, it is referred to as the converter leash 7.

The crude copper 8 is further purified in the refining furnace 4 and then injected into a mold by a cast copper machine (not shown) to form an anode plate.
On the other hand, after the forging period is completed, the converter ring 7 is discharged from the furnace port 9 by tilting the copper converter 2 before starting the smelting of the copper making period. The converter rod 7 discharged from the copper converter 2 is subjected to flotation with the beneficiation equipment 3 and separated into copper concentrate and iron concentrate.

  The beneficiation facility 3 is a facility that separates copper concentrate and iron concentrate using liquid buoyancy (that is, performs flotation). A foaming agent and a collecting agent are added to a liquid for separating copper concentrate and iron concentrate (hereinafter referred to as a separation liquid), and bubbles are always floating in the separation liquid. If the separator 7 is put into the separated liquid, the copper sulfide ore particles adhere to the bubbles by the collector and float on the separated liquid surface. On the other hand, other particles settle to the bottom of the separation liquid. The particles floating on the surface of the separation liquid in this way are copper concentrates having a large copper content, and the particles settled on the bottom of the separation liquid are iron concentrates having a large iron content.

After the copper concentrate is dried, it is charged again into the self-melting furnace 1, so that the copper contained in the copper concentrate can be effectively recovered as a raw material for the anode plate.
However, because iron concentrate is sold outside and is mainly used as a raw material for cement, copper contained in iron concentrate cannot be recovered.
For example, Patent Document 1 discloses a technique that uses a separated liquid in which a collection agent is added in addition to a foaming agent. According to this technique, the particles of the converter tang 7 (particularly metal copper) easily adhere to the bubbles by the collector, and the amount of copper concentrate recovered increases. However, since the technique disclosed in Patent Document 1 does not suppress the metal copper contained in the ore, a significant increase in the recovered amount of copper (particularly metal copper) by flotation cannot be expected.
JP 52-65104 A

  An object of the present invention is to provide a recovery method that solves the above problems and significantly increases the amount of copper recovered by flotation.

The inventors have studied a smelting reaction in a copper converter and found that metal copper is produced by cooling from the converter discharged after the slagging period. In other words, the smelting reaction during the smelting period is expressed by the following equation (1). Here, Cu ₂ S · 2FeS is the cute and Cu ₂ S is the white. O ₂ is supplied by an oxygen-containing gas such as air or oxygen-enriched air.
Cu ₂ S · 2FeS + 3O ₂ → 2FeO + 2SO ₂ + Cu ₂ S (1)
When the smelting reaction during this smelting period is completed, the copper converter is tilted to discharge only the converter from the furnace port. At this time, the lower the viscosity from the converter, the easier it can be discharged from the furnace port. Therefore, after completion of the smelting reaction in the smelting period, oxygen-containing gas is supplied (hereinafter referred to as overblow) to burn oxygen and lower the temperature of the converter, thereby reducing the viscosity of the converter. It is common to make it.

However, when overblowing is performed, magnetite is generated only from the converter, and the magnetite reacts with some of the white glue that is discharged at the same time as the converter, as shown in the following equation (2). Metal copper is produced. Here, Fe ₃ O ₄ is magnetite.
Fe ₃ O ₄ +1/2 Cu ₂ S → Cu + 3FeO + 1 / 2SO ₂ (2)
If the amount of oxygen supplied by overblowing after the smelting reaction in the smelting period is reduced, magnetite can be reduced and the production of metal copper can be suppressed. Accordingly, since the amount of metal copper is reduced, the amount of copper recovered can be significantly increased without using a collection agent capable of recovering metal copper when performing flotation from the converter.

The present invention has been made based on such knowledge.
That is, the present invention is a method for recovering copper contained in a converter tangled by a copper smelting process using a copper converter, and suppresses overblow after completion of the reaction to produce white glue during the slagging period. , Reducing the oxygen supply, then tilting the copper converter to discharge it from the converter, feeding the converter to the beneficiation facility, and performing flotation at the beneficiation facility, so that it is included in the converter This is a recovery method for recovering copper.

In addition, the copper collect | recovered by a flotation means the copper contained in the copper concentrate isolate | separated from the converter. That is, since the copper concentrate is dried and charged again into the self-melting furnace, the copper contained in the copper concentrate is effectively used as a raw material for the anode plate.
In the copper recovery method of the present invention, it is preferable that the time required for overblowing is within 5 minutes.

Furthermore, when using a collection agent in the flotation from the converter, it is preferable to use dodecyl mercaptan and 2-mercaptobenzothiazole as the collection agent. The mixing ratio of the amount of dodecyl mercaptan used M ₁ (kg) and the amount of 2-mercaptobenzothiazole used M ₂ (kg) is converted to the value of M ₁ / (M ₁ + M ₂ ). Therefore, it is preferable to satisfy the range of 0.25 to 0.75.

  According to the present invention, the amount of copper recovered can be remarkably increased by applying flotation to the converter generated when smelting copper using a copper converter.

The copper recovery method of the present invention will be described with reference to FIG.
An oxygen-containing gas is blown into the copper converter 2 containing the glue 6 through a tuyere (not shown). After the smelting reaction shown in the formula (1) is completed in the copper converter 2, the overblow is further performed to raise the temperature of the converter 7, thereby reducing the viscosity of the converter 7. . However, when overblowing is performed, it is necessary to reduce the supply amount of oxygen in order to suppress the production of metal copper according to equation (2) by reducing the production amount of magnetite.

The amount of oxygen supplied by overblowing varies depending on the oxygen concentration in the oxygen-containing gas and the time required for overblowing. Therefore, it is possible to reduce the supply amount of overblow oxygen by the following method (a) or (b).
(a) Reduce the oxygen concentration in the oxygen-containing gas and blow to reach the target temperature when the smelting reaction ends.
(b) The oxygen concentration in the oxygen-containing gas is set to be the same as the conventional one, while the time required for overblowing is shortened.

In the operation of the copper converter 2, it is difficult to change the oxygen concentration of the oxygen-containing gas during the operation. If the above method (a) is carried out, an oxygen-containing gas having a low oxygen concentration must be used during the steelmaking and coppermaking periods. As a result, the blowing time in the copper converter 2 is extended, leading to a decrease in productivity.
Therefore, it is preferable to employ the above method (b). Conventionally, overblow for about 20 minutes has been performed. However, if the heat insulation in the copper converter 2 is maintained, the converter tang 7 can be removed from the furnace port 9 even if the overblow is shortened to within 5 minutes. Can be discharged. If the heat retaining property in the copper converter 2 can be maintained at a high level, the converter 7 can be discharged even if the overblow time is zero (that is, overblow is not performed).

However, when the oxygen concentration of the oxygen-containing gas can be easily changed during the operation of the copper converter 2, the amount of oxygen supplied by overblowing may be reduced by the method (a).
By suppressing the generation of magnetite in the converter 7 in this way, it is possible to suppress the production of metal copper due to the reaction of formula (2). By sending the waste from the converter 7 to the beneficiation facility, flotation is performed at the beneficiation facility, and the copper concentrate is recovered, so that the amount of copper recovered can be significantly increased only by using conventional collectors. . That is, the copper content of the copper concentrate increases by suppressing the production of metal copper.

  In addition, when flotation is performed, if a new collection agent is added to the collection agent conventionally used in the separation liquid, the amount of copper concentrate recovered increases, so the amount of copper recovered further increases. It is possible. When a collector is used, a conventionally known collector (for example, xanthates, dithiophosphates, dithiocarbamates, mercaptans, disantogens, etc.) may be used. However, in order to increase the recovery amount of metal copper in flotation, it is preferable to use dodecyl mercaptan and 2-mercaptobenzothiazole together.

When dodecyl mercaptan and 2-mercaptobenzothiazole are used in combination, if the mixing ratio calculated by the following formula (3) is less than 0.25 or more than 0.75, the ability as a cooperative effect is suppressed. Recovery is difficult. Therefore, the mixing ratio preferably satisfies the range of 0.25 to 0.75.
Mixing ratio = M ₁ / (M ₁ + M ₂ ) (3)
M ₁ : Use amount of dodecyl mercaptan (kg)
M ₂ : Amount of 2-mercaptobenzothiazole used (kg)
The converter tang 7 is finely pulverized (so-called grinding) and then subjected to flotation. Flotation is
(A) Qualifying: The process of performing the first flotation
(B) Coarse selection: the process of performing secondary flotation
(C) Cleaning: A screening method comprising three stages of processes for performing third-stage flotation, and each process uses the buoyancy of the separation liquid. Dodecyl mercaptan and 2-mercaptobenzothialol can be used as a collector in any of the steps (A) to (C).

  However, when dodecyl mercaptan and 2-mercaptobenzothiazole are used in combination as a collecting agent to be added to the separation liquid, it is preferably used in a cleaning process in which the ratio of metal copper is high.

Copper smelting was performed using a series of facilities shown in FIG. That is, the dried copper concentrate is smelted in the auto-smelting furnace 1 and separated into the glue 6 and the auto-smelting furnace 5, and the glue 6 is charged into the copper converter 2 and blown, and the white copper is used to make the crude copper. 8 was produced.
When the molten furnace 6 obtained in the self-melting furnace 1 is accommodated in the copper converter 2 and blown, oxygen-enriched air is supplied from a plurality of tuyere (not shown) provided in the furnace body. Infused. In this way, impurities in the glue 6 were oxidized during the preparation period, and separated into SO ₂ gas, converter scrap 7 and white glue. The operator inserts the iron sample rod into the copper converter 2 while performing the squirting process, and then pulls out the iron sample rod and the color and appearance of the converter rod 7 attached to the iron sample rod. Was visually inspected to determine the end of the reaction of white glue formation (ie, the reaction of formula (1)) during the period of making.

After completion of the reaction during the preparation period, overblow was further performed for 5 minutes. Note that the oxygen-enriched air used for overblowing and the supply conditions thereof are the same as in blowing during the preparation period.
Next, the copper converter 2 was tilted before starting the smelting of the copper making stage, and the converter scissors 7 were discharged from the furnace port 9. The converter 7 was fed to the beneficiation equipment 3 for flotation and separated into iron concentrate and copper concentrate.

In the flotation cleaning process, dodecyl mercaptan and 2-mercaptobenzothiazole were added as collection agents. The mixing ratio (that is, the value calculated by equation (3)) was 0.50.
The above is an invention example.
On the other hand, as a comparative example, overblow was performed for 20 minutes. Further, dodecyl mercaptan was used as the collection agent. Other procedures were the same as in the inventive examples, and copper smelting was performed.

  When the copper content of the iron concentrate obtained by the copper smelting of the inventive example and the comparative example was investigated, it was 0.5% by mass in the inventive example and 1% by mass in the comparative example. This data shows that the amount of recovered copper is increased by applying the present invention to the floatation of the converter rod 7.

It is a flowchart which shows the process of the auto smelting furnace of copper smelting, a copper converter, and a beneficiation equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Self-melting furnace 2 Copper converter 3 Beneficiation equipment 4 Refinement furnace 5 Seen from self-melting furnace 6 Kawa 7 Seen from converter 8 Crude copper 9 Furnace

Claims (4)

  In the method of recovering copper contained in the converter tangled by the copper smelting using the copper converter, after the white-ring formation reaction is completed during the slagging period, the overblow is suppressed and the oxygen supply amount , Then tilting the copper converter to discharge the waste from the converter, supplying the waste from the converter to a beneficiation facility, and performing floating flotation at the beneficiation facility, thereby being included in the converter A method for recovering copper, comprising recovering copper.   The copper recovery method according to claim 1, wherein the time required for the overblow is 5 minutes or less.   The method for recovering copper according to claim 1 or 2, wherein dodecyl mercaptan and 2-mercaptobenzothiazole are used as a collecting agent used in the flotation. The mixing ratio of the amount M ₂ (kg) of the 2-mercaptobenzothiazole amount M ₁ and (kg) of the dodecyl mercaptan, in terms of the value of the _{M 1 / (M 1 + M} 2), 0.25~0.75 The copper recovery method according to claim 3, wherein the copper content satisfies the following range.

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