BG64652B1 - Method for the production of blister copper in a suspension reactor - Google Patents

Abstract

The invention relates to a method for the production of blister copper by means of a pyrometallurgical technique in suspension reactor directly from its sulphide concentrate. By the method the concentrate of copper sulphide is fed to a suspension reactor in which also cooled and finely ground copper matte (intermediate product in the production of non-ferrous metals from ore), is fed in order to take up the liberated heat.

Description

Technical field

The invention relates to a process for the preparation of ferrous copper by pyrometallurgical means in a suspension reactor directly from its sulfide concentrate. The method is used in metallurgy.

BACKGROUND OF THE INVENTION

A method of producing crude copper or ferrous copper from a sulfide concentrate is carried out in several steps in which the concentrate is melted in a suspension reactor, such as an instant-melt furnace, air or oxygen-enriched air, resulting in rich in copper stone (50-75% Cu) and slag. This type of method is described, for example, in US 2506557. The copper-rich stone formed in an instant-melt furnace is converted, for example, into a Peirce-Smith converter or pulverized converter and then purified into an anode furnace.

A method is known for the production of black copper in a suspension reactor, which is closest in technical nature to the object of the present invention and is described in US 4030915. In this process, the black copper is obtained directly from a copper sulphide concentrate, fed into the reactor concentrate, flux and oxygen-saturated air.

With the known method, the production of raw copper is carried out in one step from a concentrate of copper sulfide and ore containing impurities such as lead, antimony, bismuth and arsenic. The suspension reactor is fed with finely divided copper concentrate, ore and oxygen or oxygen-enriched suspension air in the reactor operating zone. The feed is carried out at a high temperature in the lower part of the reactor zone so as to cause an effect against the melt below the reactor zone while the gases and circulating powders are directed away. The slag and the raw copper are separated from the melt by oxygen or oxygen-enriched air, which are fed into the reactor column in proportion to the copper concentrate and ore, which are oxidized in the reactor to such an extent that the melt containing only the raw copper and slag is brings out below, below the reactor zone.

The major problems encountered in the production of black copper include the slagging of copper to slag, the large amount of slag formed and the large amount of heat released during the combustion of the concentrate. The large amount of slag requires a large melting device in the surface area, which affects the funds invested in the process.

In addition to the amount of slag, another problem arising from the direct production of copper is the large amount of heat generated by the combustion of the sulfide concentrate, which is why the oxygen enrichment when burning a normal concentrate (with a copper content of 20-31% Cu) should be low, even below 50% oxygen, whereby the heating of nitrogen in the process air balances the heat savings. This results in a large amount of process gas, which requires a large volume of the furnace and, above all, large devices for treating this gas (boilers, electric precipitators, gas lines, factory acid flushing units, etc.). In order to design these devices associated with processing gas is smaller, it is necessary to obtain high oxygen enrichment in the suspension reactor (over 50% oxygen in process gas).

If the copper content of the concentrate is high enough, typically at least 37% Cu, such as in the Olympic Dam smelter thermal furnace used in Australia, where the copper content of the concentrate exceeds 50%, it is possible to produce black copper directly in one step , since the thermal value of the concentrate is generally lower, the higher the copper content of the concentrate. In fact, with a high copper content, the mineral sulphide ratio is low. When using the concentrate described above, a sufficiently high oxygen enrichment can be used and, as a result, the amount of process gas remains moderate.

A lower copper concentrate, if appropriate, is also suitable for direct production of black copper. For example, in the Glogow heat furnace used in Poland, black copper is obtained from concentrate at one stage, as the iron content is low and the resulting slag is not significantly high.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a method for the production of black copper in a slurry reactor providing a reduced relative amount of slag compared to the amount of black copper in its direct production, which is controlled by smaller process gas processing units with significantly increased overall capacity of the smelter, without the need to add additional concentrate.

The problem is solved by a method of producing black copper in a suspension reactor, in which the black copper is obtained directly from a copper sulphide concentrate, the concentrate, flux and oxygenated air being fed into the reactor. According to the invention, cooled and finely ground copper stone is fed into the slurry reactor along with the concentrate, binding to the heat released from the concentrate and reducing the relative amount of slag formed. The air was fed to the suspension reactor, oxygenated at least 50% O ₂ .

In a preferred embodiment of the process according to the invention, the copper content of the concentrate fed to the suspension reactor is at least 31%.

Preferably, a method is used in which the slag from the black copper producing suspension reactor is treated in two steps.

The slag can be treated in one-stage or preferably two-stage scrubbing. The two-step cleaning method involves two electric furnaces or one electric furnace and an installation for concentrating the slag.

The slag from the black copper-producing slurry reactor is treated in an electric furnace and then the slag from the electric furnace is treated in a slag concentration plant.

If the slag is treated in a slag concentration plant, the slag concentrate can be fed back into the suspension reactor and the black copper goes for ordinary treatment in an anode furnace.

A method according to one embodiment of the present invention is preferred, in which the slag from the electric furnace is cooled slowly and processed in a slag concentration plant, from where the slag concentrate is transferred to the slurry reactor, the slag being a waste slag having a copper content of 0.3-0.5 % Si.

It is also proposed to carry out the method of treating slag from the copper-producing slurry reactor in two electric furnaces.

The copper stone fed into the slurry reactor is formed into a rock producing reactor, with the copper content of the concentrate fed to the rock producing reactor being 20-31% Cu.

The slag from the producing rock reactor is slowly cooled and treated in a slag concentration plant from where the resulting slag concentrate is transferred to the producing rock reactor, resulting in a waste slag with a copper content of 0.3-0.5% Cu.

There is also provided an embodiment of the method according to this aspect of the invention, in which the slag from the stone-producing reactor is slowly cooled and treated in a slag concentration plant from where the resulting slag concentrate is transferred to the black-copper slurry reactor, waste slag with a copper content of 0.3-0.5% Cu is obtained.

In yet another preferred embodiment of the method according to the present invention, the slag from the black copper slurry reactor is first treated in an electric furnace, the resulting slag is then cooled slowly and transferred to a slag concentration plant together with the slag from the producing stone. reactor in which they are jointly treated.

The process according to the invention is preferably implemented in such a way that the stone reactor is a slurry smelter.

Particularly preferred is a method according to the invention, in which the stone-producing slurry melting furnace is an instant melting furnace.

If there are two melting devices, at least one of which is a slurry melting furnace, the normal copper concentrates are treated in the stone-forming devices. The resulting stone is granulated and fed finely in the black copper smelter along with the concentrate, whereby the concentrate of the black copper furnace is richer in copper than normal (the copper content is over 31%).

The advantages of the present invention over the prior art are due to the fact that a new method for the production of black copper in a slurry is developed, in which the cooled and finely ground copper stone is fed into the slurry reactor together with the concentrate to bind with the heat released from this concentrate containing copper sulfide, thereby reducing the relative amount of slag. The copper stone is obtained in a separate device cooled, for example by granulation, and then finely ground. Reducing the relative amount of slag means that less slag is generated than the amount of copper produced by the conventional method.

By applying this method, it is possible to use high oxygen enrichment for the direct production of black copper, and the process can be controlled by smaller process gas processing units than the prior art devices for this process. purpose. In addition, the advantage is that the total capacity of the melting furnace can be significantly increased without the need to add an additional amount of concentrate to the total amount supplied to the slurry reactor.

The basic concept of the present method is that instead of the conventional method in which the additional heat is bound to the nitrogen in the gas, in this method the heat is bound to the cooled copper stone. Thus, by adding chilled copper stone to the concentrate, oxygen enrichment can be increased as the proportion of the stone increases with both the enriched and depleted copper concentrate. If the proportion of chilled and finely ground copper stone in the feed quantity is very large, the oxygen enrichment can increase significantly, then even in depleted concentrate and direct production of black copper becomes significantly economical.

Another advantage of the method of the present invention is that the relative amount of slag generated in the slurry reactor decreases as the proportion of the feed stone increases, while the losses of copper in the slag also decrease the amount of copper circulating through the slag. decreases.

Deposits of silicate iron ores or calcium ferrite in the black copper furnace may be used depending on the composition of the concentrate.

If both the production of stone and black copper are carried out in the same melting furnace so that the treatment of the slag can be carried out together, then it is appropriate that the two reactors use the same type of slag.

If the slag concentration is part of the technological slag, the slag is considered to be of silicate ore. The stone supplied to the black copper furnace may be a stone obtained in any kind from the known melting furnaces.

It is also advantageous that the slag from the stone kiln is treated in the prior art, for example in a slag concentrating plant, and the slag from the black copper furnace is first treated in an electric furnace, from where it goes to the concentrating plant. slag.

This results in a decrease in the relative amount of slag and an increase in copper yield without the addition of additional concentrate.

Description of the attached figures

Figure 1 shows a schematic diagram of an embodiment of the invention using a slurry smelter and an electric furnace;

Figure 2 is another embodiment of the invention using two slurry melters, a slag concentration plant and an electric furnace.

Examples of carrying out the invention

According to Figure 1, a copper sulphide concentrate is fed with flux and copper stone into a slurry smelter, which in this case is an instant melt furnace (FSF). The simplified scheme shows that oxygen is supplied to the furnace, but rather it is oxygen-enriched. As noted above, the advantage is that oxygen enrichment is above 50%. The black copper formed in the instant-melt furnace is transferred to an anode furnace and therein is purified in the usual manner and deposited in the anodes.

The slag from the instant melting furnace is treated in an electric furnace (EF), which slag can be silicate iron ore or calcium ferrite. The black copper produced in the electric furnace goes directly to the anode furnace and the small amount of slag obtained in the anode furnace goes to the electric furnace.

Figure 2 shows a diagram according to a second embodiment of the present invention, wherein there are two melting devices, one is a black copper furnace and the other is a copper stone furnace that feeds into a black copper furnace. In order to form a copper stone, the copper sulfide concentrate and silicate containing flux, such as sand, are fed, according to the prior art, to the reactor well of the initial melt reactor, oxygenated or saturated. oxygen gas. In this case, the initial melting reactor is an instant melting furnace, but could be another rock formation reactor. The concentrate fed to this stone kiln is preferably a depleted or normal concentrate having a copper content of about 20-31% Cu. The copper stone is formed at the bottom of the lower section of the furnace with instant melting, and on it is obtained a fayalite slag, which contains some copper.

The copper concentrate, which is a sulfide concentrate, is fed to the black copper (FSF) suspension reactor, but its copper content is preferably higher (20% Cu content over 31%) than the concentrate supplied to the smelter an initial melting furnace that produces the stone. Thus, the sulfur and iron content of the concentrate fed to the copper furnace is lower than the poorer 25 concentrate, and thus the melt value of the concentrate is also lower than the concentrate fed to the stone-producing furnace for the initial melting. The copper stone formed in the stone-producing furnace for initial melting is granulated, milled, and fed together with the copper concentrate, silicate-containing flux and oxygen or oxygen-enriched air into the black copper reactor, which is preferably instant melting furnace. 35

Obviously, not all the amount needs to be obtained from the stone-producing furnace for initial melting, since some stone can be obtained elsewhere.

Black copper is obtained in a black 40-furnace, ready to be fed into an anode furnace, where the raw copper is fed in the molten state. The copper to be purified in the anode furnace is deposited in copper anodes.

The slag formed in the production furnace for the initial melting furnace is cooled slowly and in a milled state. The slag is concentrated (thickened) by flotation in a slag concentration plant, and the resulting slag concentrate is returned to the same producing 50 smelter for initial melting. Because the copper content of the concentrate obtained is often quite high, it can also be transferred to the black copper furnace. The loss of slag concentrate is waste slag with a Cu content of about 0.30-0.50%, preferably 0.30-0.35%.

The slag formed in the black copper reactor filled by the instant melting furnace (FSF) is preferably transferred to the molten electric furnace (EF), for example through channels. In the electric furnace, the slag is reduced by coke and the black copper produced in the electric furnace is passed directly into the anode furnace. The slag from the electric furnace is cooled slowly, as is the slag from the slurry melting furnace producing the stone and is taken to the slag concentrator for co-treatment with the slag from the slurry melting furnace for initial melting.

Example 1.

Black copper was obtained in an instant melting slurry melting furnace as shown in Figure 1.

The feed to the instant melting furnace was 83.7 t / h, in the composition as follows: concentrate 36.1 t / h, slag concentrate 2.2 t / h, flux 4.4 t / h, stone 35.4 t / h and throat powder 5.6 t / h.

The concentrate composition is:

Si% 43.00

Fe% 14.00

S% 26.00

SiO ₂ % 5.00

The flux content of SiO ₂ supplied to the furnace is 90%.

The analysis of the copper stone is as follows: Si% 70.00

Fe% 7.96

S% 2134

The amount of oxygen supplied to the furnace is 13 400 Nm ³ / h and the amount of air is 4140 Nm ³ / h, the degree of oxygen enrichment is 74.6%.

35.6 t / h of black copper was obtained in an instant melting furnace and its copper content was 99.41%.

The amount of fayalite slag is 29.2 t / h and its composition is as follows:

20%

Fe 28.7%

S 0.1%

SiO ₂ 21%

The amount of gas leaving the furnace is 29 100 Nm ³ / h, the temperature is 1320 ° C and its analysis is

SO ₂ 42.3% and

O ₂ 2.1%

The gas is directed to a boiler that utilizes the treated gases, from which the resulting throat dust is returned to the furnace with instant melting.

The slag from the instant melting furnace and the anode furnace is treated together in an electric furnace, with the slag quantity of the instant melting furnace being 701 t / h, its content being 20% and the slag volume from the anode furnace being 4.5 t / h. Its vessel content is 60%. The coke delivered is 30 t / h. The amount of copper produced in the electric furnace is 121 t / h and its content is 99.35%.

The black copper from the electric furnace is fed to the anode furnace for purification with the black copper from the instant melting furnace. The amount of slag is 557 t / h and its content is 4%. Because its copper content is so high, the slag is transferred for further treatment to a slag concentration plant. As a result of the flotation concentration, the slag concentrate has a Cu content of 38.4% and the waste slag has a Cu content of 0.38%.

Example 2.

This example describes the solution shown in Figure 2.

The quantities of inlet and outlet material were calculated per 1000 kg of concentrate fed into the initial melting furnace. The original melting furnace in this case is an instant melting furnace.

1000 kg of concentrate was fed into the initial melting furnace in a composition as follows:

E 31%

Fe 25%

S 31%

The amount of flux, such as sand fed into the furnace, is 88 kg, the slag concentrate is 70 kg, and the circulating sludge is 22 kg. Thus, the total supply to the furnace is 1180 kg, since dust circulation is not taken into account here. 172 Nm ^{3 of} air and 157 Nm ^{3 of} oxygen were fed into the reaction shaft of the furnace for initial melting, so that the oxygen enrichment was 57%.

The amount of stone obtained in the initial melting furnace is 464 kg and its composition is:

Si 70.0%

Fe 7.0%

S 21.2% and temperature 1280 ° C.

The quantity of slag is 568 kg and its composition is:

Si 2.6% Fe 42% S 0.7% SiO ₂ 27% and

temperature 1320 ° C.

The stone formed in the initial melt furnace is granulated, milled, and the milled stone is fed into a slurry melt furnace for black copper to bind to the heat generated in the furnace. To form black copper, a concentrate of the following composition is fed into the furnace:

S 38%

Fe 29%

S 26% at 214 kg.

The flux, which is again sand, is fed in an amount of 44 kg. Thus, the total power supply is 710 kg, taking into account the losses caused by grinding. 50 Nm ^{3 of} air and 111 Nm ^{3 of} oxygen are fed into the copper furnace, so that the oxygen enrichment is 72%.

The amount of crude copper formed in the slurry melting furnace, which in this case is an instant melting furnace, is 362 kg and its content is:

S 98.8%

S 0.6% at 1280 ° C.

The amount of slag formed in the instant melting furnace is 239 kg and its composition is:

Si 20% Fe 312% S 0.1% SiO ₂ 21% p

temperature 1300 ° C.

The slag from the black copper furnace is directed to the electric furnace in the same way as the slag from the anode furnace, with the slag content being only 3 kg and its content being 60%. Add 10 kg of coke. In an electric furnace, 44 kg of black copper with a content of 96% is formed. The amount of slag in the electric furnace is 188 kg and its composition is as follows:

Si 4% Fe 273% S 4.8% SiO ₂ 17.6%

The slag coming from the initial melting furnace and the electric furnace is cooled slowly and sent for treatment to a concentrating installation. After the flotation concentration, the contents of the slag concentrate are:

S 29.3%

Fe 27.3%

S 4.8%

SiO ₂ 17.6% 5

The analysis of the waste slag is as follows: Cu 0.3%

Fe 43%

SiO ₂ 27.9%.

Claims (13)

Claims 1. A method of producing black copper in a slurry reactor, wherein the black copper is obtained directly from a copper sulphide concentrate by supplying the concentrate, flux and oxygenated air, characterized in that it is cooled and finely ground copper stone is fed into the slurry reactor along with the concentrate, binding to the heat released from the concentrate and reducing the relative amount of slag formed, whereby the air is fed to the slurry reactor by oxygen enrichment by at least 50% O ₂ . Method according to claim 1, characterized in that the copper content of the concentrate fed to the suspension reactor is at least 31%. Method according to claim 1, characterized in that the suspension reactor is an instant melting furnace. A method according to claim 1, characterized in that the slag from the black copper producing suspension reactor is treated in two stages. 5. The method according to claim 4, characterized in that the slag from the black copper producing slurry reactor is treated in one electric furnace and the slag from the electric furnace is treated in a slag concentration plant. Method according to claim 5, characterized in that the slag from the electric furnace is cooled slowly and processed in a slag concentration plant, from which the slurry concentrate is transferred to the slurry reactor, the slag being a waste slag having a copper content of 0.3-0.5% Si. Method according to claim 4, characterized in that the slag from the black copper producing suspension reactor is treated in two electric furnaces. A method according to claim 1, characterized in that the copper stone fed into the slurry reactor is formed into a production stone reactor, wherein the copper content of the concentrate fed to the production stone reactor is 20-31% Si. A method according to claim 8, characterized in that the slag from the producing stone reactor is slowly cooled and treated in a slag concentration plant, from which the resulting slag concentrate is transferred to the production stone reactor, thereby producing a waste slag with copper content of 0.3-0.5% Cu. A method according to claim 8, characterized in that the slag from the producing rock reactor is slowly cooled and treated in a slag concentration plant, from which the resulting slag concentrate is transferred to the black copper producing slurry reactor, thereby producing a waste slag with copper content of 0.3-0.5% Cu. A method according to any one of claims 1 to 8, characterized in that the slurry from the black copper producing slurry reactor is first treated in an electric furnace, and the slag obtained therefrom is slowly cooled and transferred to a slag concentration plant, together with the slag from the stone-producing reactor, which are jointly treated. 12. The method of claim 8, wherein the stone-producing reactor is a slurry smelter. The method of claim 10, wherein the stone-producing slurry melting furnace is an instant-melting furnace.