FI116069B - Procedure for making raw cups - Google Patents

Description

116069

METHOD FOR PREPARING COPPER COPPER

The invention relates to a process for the production of crude copper according to claim 1.

5

In copper flame smelting, the dried copper concentrate is fed to the flame flash furnace with oxygenated air and silica sand. The energy required for smelting is formed by oxidation of sulfur and iron. The process heat balance is controlled by oxygen enrichment of the process air, but sometimes oil or natural gas burners are also used as sources of additional energy. Sulfur oxidizes to sulfur dioxide and iron oxidizes and slags to iron silicate. The molten phases are separated from the gas in the lower furnace as slag and rock descend to the bottom of the furnace with the rock layer at the bottom. In flame smelting, as in other copper smelting processes, the primary function of the slag is to assemble the iron oxides formed in the smelting process and the silicate and oxide materials of the slate into a fluid, dischargable form. Generally, the slag is cooled, crushed and foamed to recover copper or treated in a reducing electric furnace process. In the rock phase, which is usually further processed by conversion, copper accumulates 50-70%. In the most commonly used Peirce-Smith conversion, iron in the rock phase '·' 20 oxidizes when blown oxygen to the melt and forms an • ·: 'silica sand slag that floats on top of the copper-rich white metal or white metal in the reactor. White metal contains 70 to 80 percent copper. When blowing oxygen further white, V: Blister copper, a copper with a copper content, is formed in the metal. 25 categories 99 percent. Slag still contains 5-10% copper, which is recovered by foaming and feeding back copper rich slag concentrate:.: To a flame retardant furnace or by treating the slag under reducing conditions; : for example in an electric oven.

*; ί; j 30 In principle, it is economically reasonable to produce directly blister copper, that is, »» • ·· crude copper from a sulphide concentrate in a single process step in a slurry reactor, subject to certain limitations. The major problem with this 2 116069 is that this process generates a large amount of slag, which is also rich in copper. In turn, the treatment of the slag to recover the copper contained therein causes additional process costs. When the copper content of the concentrate is high enough, typically at least 37% by weight, it is economically viable to produce blister copper in one process step. If the concentrate contains a small amount of iron or other slag-forming components, so that the slag is not formed as much, it is also profitable to process the concentrate with a lower copper content. Generating blister copper slag generally requires 10 two-step slag purification to recover the copper in a sufficiently high yield.

According to the prior art, when operating within a certain oxygen potential range, the so-called white metal is present in the smelting of copper, whereby the copper content of the corresponding slag phase is substantially lower compared with that of the blister copper being in equilibrium with the slag phase. Figure 1 (INSKO 261608 Vili, p. 9) shows a sulfur-oxygen potential diagram for the Cu-Fe-S-O-S1O2 system at 1300 ° C. The figure shows the concentration of the phases present in the copper smelting process under different conditions.

: * 20 It can be seen from the figure that when the white metal is present, the corresponding slag '·' "·] has a lower copper content than the slag in equilibrium with the blister copper.

/ t: .V .: PCT 00/09772 discloses a process for smelting copper concentrate:, ·. In the presence of 25 oxygen by continuous oxidation of concentrate or rock at a temperature of 1300 ° C or less. According to the process, the copper sulphide concentrate is smelted, V 'most of the iron is excreted into the slag and most of the sulfur is converted to: * sulfur dioxide. The product is white metal, stone or blister copper.

The object of the present invention is to eliminate the disadvantages of the prior art. A further object of the invention is to prevent the formation of high copper slag in the production of crude copper.

3, 116069

The invention is characterized in what is set forth in the characterizing part of claim 1. Other embodiments of the invention are characterized by what is stated in the other claims.

The process for the production of crude copper according to the invention has many advantages. According to the method, concentrate, slag former and oxygen-enriched air are fed together into a slurry melting furnace, such as a flame smelting furnace, to form at least two melt phases, a white metal phase and a slag phase, and wherein the white metal is oxidized after the slurry furnace. According to the method, the suspension melting furnace is preferably operated under conditions allowing the formation of white metal, wherein the oxygen potential in the furnace is in the range of 10'7 -10-6 and the partial pressure of sulfur dioxide is in the range of 0.2-1. White metal consists essentially of copper (70-80%) and sulfur. The white metal formed by melting does not contain substantially slagging components. When operating under the above conditions, the process preferably produces low copper slag which is suitable for direct processing to recover copper and does not require separate: · pre-reduction of the slag, for example in an electric furnace.

20 White metal is discharged from the furnace either continuously or in batches,. for oxidation to an oxidation reactor where the sulfur in the white metal is oxidized 7 using oxygen-enriched air to form sulfur dioxide and: 7 blister copper but little slag. According to a preferred embodiment of the invention, the oxidation reactor is arranged integral with the slurry melting furnace. Another preferred embodiment of the invention; According to an embodiment, the oxidation reactor is combined with a molten transfer. · With the aid of a closed melting trough in the slurry melting furnace.

When the oxidation reactor is closed, it is more advantageous to control the recovery of gases formed in the process. In one aspect of the invention ;;;;; According to 30 embodiments, the oxidation reactor is preferably a surface blowing reactor.

According to another embodiment, the oxidation reactor is an injection reactor, whereby white 4116069 metal in solid form can also be melted preferably by injecting it with the oxidant gas. As an oxidation reactor, for example, an Ausmelt, Isasmelt or Mitsubishi type reactor is preferably used.

The slag is discharged separately from the slurry melting furnace and treated in accordance with an embodiment of the invention in an electric furnace to recover its copper content. According to another embodiment of the invention, the slag is subjected to flotation after the slag melting furnace to recover the copper content of the slag. Advantageously, the process of the invention does not produce any slag with a high copper content and thus avoids unnecessary copper recycling and the consequent copper losses.

The invention will now be described in detail with reference to the accompanying drawings.

Figure 1 Sulfur-oxygen potential diagram for Cu-Fe-S-0-SiO 2 system

at 1300 ° C

t; ·. Fig. 2a Process diagram of a process according to the invention ♦

Figure 2b Process diagram of a process according to another embodiment of the invention 20 *

Figure 2a illustrates a method according to the invention. Thus, concentrate 5, slag former 6 and oxygen-enriched air 7 are fed together into the flame smelting furnace 1, thereby forming two melt phases 25, white metal phase 11 and slag phase 10 at its lower part 4. In addition to white metal and slag, a small amount of blister copper is generated, which is also fed to the oxidation reactor 12. The process gases generated in the flame smelting furnace 1 are fed through a furnace riser 2 to a waste heat boiler 8 The white metal 11 is discharged from furnace 1 either continuously or batchwise into the oxidation reactor 12, where the sulfur in the white metal is oxidized using oxygen-enriched air 16, whereby sulfur dioxide and blister copper 5 but not slag are formed. According to an embodiment of the invention shown in Fig. 2a, the oxidation reactor 12 is arranged in fixed connection with the flame smelting furnace. In the second embodiment of the invention shown in Fig. 2b, the oxidation reactor 12 is connected via a melt trough 13 directly to a flame smelting furnace. The slag 10 formed in the flame smelting furnace 1 is led to a slag treatment 14, 10, alternatively either to an electric furnace or to a flotation to recover the copper content of the slag. According to one embodiment of the invention, the oxidation reactor is preferably a surface blowing or injection reactor, whereby white metal in solid form can also be melted preferably by injecting it with the oxidant gas. The oxidation reactor is preferably an Ausmelt, Isasmelt or Mitsubishi reactor, for example.

The invention will now be illustrated by way of example.

:: · EXAMPLE

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Using the process of the invention, a copper concentrate having a concentration of 20 to 30% Cu, 28% Fe, 30% S, 6% S1O2 is melted in a flame smelting furnace at 163 tph · (tph = tons / hour) along with silica sand fed at 21 tph.

; During thawing, the furnace is blown with 63493 Nm3 / h and oxygen: 25 21956 Nm3 / h with an oxygen enrichment of 41% and an oxygen factor of 171 Nm3 O2 per tonne of total feed.

As a result of the oxidation reactions, the melting furnace produces molten white metal: 62004 kg / h (content 79% Cu, 0.5% Fe) and slag 109702 kg / h (content 4%: 30 Cu, 44% Fe). In addition, a small amount of dust is generated and recycled back to the flame smelting furnace.

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The slag is treated in a slag concentrate to produce a slag concentrate of 8844 kg / h (46% Cu, 25% Fe) and which slag concentrate is fed back to the flame smelting furnace together with the concentrate.

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The resulting white metal is treated in an oxidation reactor fed with 4328 Nm3 / h of technical oxygen and 18979 Nm3 / h of air. Blister copper 49274 kg / h (98% Cu, 0.04% Fe) and a small amount of slag (1 ton / h, 50% Cu, 27% Fe) are produced. The slag is granulated and fed back into 10 flame smelting furnaces.

In the example above, a total of 4,575 kg of Cu, which corresponds to about 9% of the total copper content of the concentrate, is recycled in the slag concentrate and in the slag of the oxidation reactor. If the blister 15 of the concentrate were directly melted, the amount of slag would be about 130 t / h, which would contain up to 50% of the total copper content of the concentrate.

It will be apparent to one skilled in the art that various embodiments of the invention are not limited to the examples above, but may vary within the scope of the appended claims.

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Claims (8)

A method of making shrimp cups, according to which the method of copper (5), slag-forming (6) and oxygen-enriched air (7) is fed together in a flame melting furnace (1), two phases of melting; such as white metal (11) and slag (10) are formed, characterized in that white metal is oxidized after the flame melting furnace in at least one oxidation reactor (12). Process according to claim 1, characterized in that the oxidation reactor 10 (12) is arranged stationary in connection with the flame melting furnace (1). Method according to claim 1, characterized in that the oxidation rectifier (12) is coupled with a melting channel (13) to the flame melting furnace (1). 15 Process according to claims 1-3, characterized in that the oxidation reactor (12) is a surface blowing reactor. Process according to claims 1-3, characterized in that the oxidation reactor (12) is an injection reactor. 20 Method according to claim 5, characterized in that solid white metal is injected into the oxidation reactor · [(12). Method according to claim 1, characterized in that the slag (10). . 25 is treated after the flame melting furnace (1) in an electric furnace to collect its copper furnace. Method according to claim 1, characterized in that the slag (10); treated after the flame melting furnace (1) in flotation to collect its / 30 copper furnace.