RS107704A

RS107704A - Method for producing blister copper

Info

Publication number: RS107704A
Application number: YUP-1077/04A
Authority: RS
Inventors: Pekka Hanniala; IIkka Kojo
Original assignee: Outokumpu Oyj.,
Priority date: 2002-06-11
Filing date: 2003-06-02
Publication date: 2007-04-10
Also published as: WO2003104504A1; AR040256A1; EA200401402A1; CN1659293A; KR20050007600A; BR0311758A; FI20021114A0; CN100385024C; PL372533A1; EA007445B1; US20050199095A1; FI116069B; PE20040137A1; EP1511868A1; CA2488398A1; AU2003232264A1; JP2005536629A; MXPA04012084A; FI20021114L

Abstract

The invention relates to a method for producing blister copper, according to which method copper concentrate (5), flux (6) and oxygen-enriched air (7) are fed together into a suspension smelting furnace (1), such as a flash smelting furnace, so that there are created at least two molten phases, such as a white metal phase (11) and a slag phase (10); and that the white metal is oxidized after the suspension smelting furnace in at least one oxidizing reactor (12).

Description

POSTUPAK ZA PROIZVODNJU BLISTER BAKRA PROCEDURE FOR THE PRODUCTION OF BLISTER COPPER

Ovaj pronalazak odnosi se na postupak za dobijanje blister bakra definisan zahtevom 1. This invention relates to the process for obtaining blister copper defined by claim 1.

U postupku topljenja bakra u plamenoj peći osušen koncentrat bakra uvodi se u plamenu peć za topljenje zajedno sa vazduhom obogaćenim kiseonikom i silicijumskim peskom. Energija potrebna za postupak topljenja dobija se oksidacijom sumpora i železa. Toplotni bilans postupka podešava se obogaćivanjem vazduha kiseonikom, mada se ponekad koristi toplota dobijena sagorevanjem ulja ili prirodnog gasa kao izvora dodatne energije. Sumpor se oksidiše u sumpordioksid, a železo se oksidiše i prevodi u trosku kao železosilikat. Tečna faza razdvaja se od gasa u taložniku, pošto se troska i kamenac slegnu na dno peći, tako da je sloj kamenca najniži. U topljenju plamenom, kao i u drugim postupcima topljenja bakra, primarna funkcija troske je da u tečnoj fazi sakupi ono što se može izliti, kao što su svi oksidi i silikati železa i oksidni sastojci jalovine koji nastaju tokom procesa topljenja. Uobičajeno je da se troska hladi, usitnjava i flotira da bi se regenerisao bakar, ili se troska obrađuje postupkom redukcije u električnoj peći. U fazi kamenca, koji se obično dalje obrađuje konvertovanjem, dobija se 50-70 % bakra. U najšire primenjenom Feirce-Smith konvertovanju železo koje se sadrži u fazi kamenca oksiduje se uduvavanjem kiseonika u rastop i zajedno sa dodatim silicijumskim peskom obrazuje fajalitnu trosku koja na početku postupka konvertovanja pluta u reaktoru na površini belog metala bogatog bakrom. Beli metal sadrži 70-80 % bakra. Kada se kiseonik dalje uduvava u beli metal stvara se blister bakar koji sadrži oko 99 % bakra. Troska zadržava 5-10 % bakra koji se regeneriše flotacijom i uvođenjem koncentrata troske bogatog bakrom u plamenu peć za topljenje ili obradom troske u redukcionim uslovima, na primer, u električnoj peći. In the process of melting copper in a flame furnace, dried copper concentrate is introduced into the flame furnace for melting together with oxygen-enriched air and silicon sand. The energy required for the smelting process is obtained by the oxidation of sulfur and iron. The heat balance of the process is adjusted by enriching the air with oxygen, although sometimes the heat obtained by burning oil or natural gas is used as a source of additional energy. Sulfur is oxidized to sulfur dioxide, and iron is oxidized and converted into slag as ferrosilicate. The liquid phase separates from the gas in the precipitator, as the slag and scale settle to the bottom of the furnace, so that the scale layer is the lowest. In flame smelting, as in other copper smelting processes, the primary function of the slag is to collect in the liquid phase what can be poured out, such as any iron oxides and silicates and oxide constituents of the tailings produced during the smelting process. It is common for the slag to be cooled, pulverized and floated to recover the copper, or the slag is treated by a reduction process in an electric furnace. In the scale phase, which is usually further processed by converting, 50-70% of copper is obtained. In the most widely used Feirce-Smith conversion, the iron contained in the scale phase is oxidized by blowing oxygen into the melt and, together with the added silica sand, forms a fayalite slag that floats in the reactor on the surface of the copper-rich white metal at the beginning of the conversion process. White metal contains 70-80% copper. When oxygen is further blown into the white metal, blister copper is created, which contains about 99% copper. The slag retains 5-10% of copper, which is regenerated by flotation and introduction of a copper-rich slag concentrate into a blast furnace or by treating the slag under reducing conditions, for example, in an electric furnace.

U principu je ekonomski razumno da se blister bakar proizvodi direktno, odnosno da se direktno proizvodi blister bakar od sulfidnog koncentrata u jednoj fazi postupka u reaktoru za suspenziju, uz poštovanje određenih ograničenja. Ovde je najveći problem što se u pomenutom postupku stvara mnogo troske i što se velika količina bakra sakuplja u toj troski. Sa druge strane obrada troske radi regeneracije bakra sadržane u njoj stvara posebne troškove postupka. Kada je sadržaj bakra u koncentratu dovoljno visok, tipično najmanje 37mas.%, ekonomski je isplativo proizvoditi blister bakar u jednoj procesnoj fazi. Ako koncentrat sadrži samo male količine železa ili drugih komponenata koje obrazuju trosku, u kom slučaju količina stvorene troske nije velika, obrada koncentrata sa nižim sadržajem bakra je isplativa. U proizvodnji blister bakra generalno je potrebno dvofazno prečišćavanje troske koja se stvori da bi se obezbedio dovoljno visok prinos regenerisanog bakra. In principle, it is economically reasonable to produce blister copper directly, i.e. to produce blister copper directly from sulfide concentrate in one stage of the process in a suspension reactor, subject to certain limitations. The biggest problem here is that a lot of slag is created in the mentioned process and that a large amount of copper is collected in that slag. On the other hand, the processing of slag in order to regenerate the copper contained in it creates special costs of the procedure. When the copper content in the concentrate is high enough, typically at least 37% by mass, it is economically viable to produce blister copper in one process stage. If the concentrate contains only small amounts of iron or other slag-forming components, in which case the amount of slag generated is not large, processing the concentrate with a lower copper content is profitable. In the production of blister copper, a two-phase purification of the slag that is generated is generally required to ensure a sufficiently high yield of regenerated copper.

Prema stanju tehnike, kada se radi u datom području potencijala kiseonika, stvara se tokom topljenja bakra tzv. beli metal, i u tom slučaju sadržaj bakra u nagrađenoj fazi troske je suštinski manji nego u slučaju kada je blister bakar u ravnoteži sa fazom troske. Na Fig. 1 (INSKO 261608 VIII, strana 9) prikazan je dijagram potencijala sumpor-kiseonik za Cu-Fe-S-0-SiC>2 sistem na temperaturi od 1300°C. Na toj slici zapažaju se sadržaji raznih faza koje se javljaju u postupku topljenja bakra u različitim uslovima. Sa te slike se može videti da kada je prisutan beli metal, sadržaj bakra u troski je niži nego u troski gde je blister bakar u ravnoteži. According to the state of the art, when working in a given range of oxygen potential, the so-called white metal, and in that case the copper content in the prized slag phase is substantially lower than in the case where the blister copper is in equilibrium with the slag phase. In Fig. 1 (INSKO 261608 VIII, page 9) shows the sulfur-oxygen potential diagram for the Cu-Fe-S-0-SiC>2 system at a temperature of 1300°C. This picture shows the contents of various phases that occur in the copper smelting process under different conditions. It can be seen from that figure that when white metal is present, the copper content of the slag is lower than in the slag where blister copper is in equilibrium.

Iz objavljene prijave PCT 00/09772 poznat je postupak za topljenje koncentrata bakra u prisustvu kiseonika kontinuiranom oksidacijom koncentrata ili kamenca na temperaturi od 1300°C ili nižoj. Prema tom postupku sulfidni koncentrat bakra se topi, najveći deo prisutnog železa uklanja se kao troska, a najveći deo sumpora prevodi se u sumpordioksid. Dobijeni proizvod je beli metal, kamenac ili blister bakar. From the published application PCT 00/09772 a procedure for melting copper concentrate in the presence of oxygen by continuous oxidation of the concentrate or scale at a temperature of 1300°C or lower is known. According to this process, the copper sulphide concentrate is melted, most of the iron present is removed as slag, and most of the sulfur is converted into sulfur dioxide. The resulting product is white metal, scale or blister copper.

Predmet ovog pronalaska jeste da eliminiše neke od nedostataka stanja tehnike. Drugi predmet ovog pronalaska je da spreči formiranje troske sa visokim sadržajem bakra tokom proizvodnje blister bakra. The object of this invention is to eliminate some of the disadvantages of the prior art. Another object of the present invention is to prevent the formation of slag with a high copper content during the production of blister copper.

Ovaj pronalazak okarakterisan je sadržajem zahteva 1. Druga ostvarenja ovog pronalaska okarakterisana su sadržajem ostalih zahteva. This invention is characterized by the content of claim 1. Other embodiments of this invention are characterized by the content of other claims.

Postupak prema ovom pronalsku za proizvodnju blister bakra ima nekoliko prednosti. Prema ovom postupku, koncentrat, topitelj i vazduh obogaćen kiseonikom zajedno se uvode u peć za topljenje suspenzije, kao što je plamena peć, tako da se obrazuju najmanje dve tečne faze, faza belog metala i faza troske, a beli metal se oksidiše posle peći za toplenje suspenzije najmanje u jednom reaktoru za oksidaciju. Prema ovom postupku operacije u peći za topljenje suspenzije pogodno se izvode u uslovima koji obezbeđuju obrazovanje belog metala, što znači daje potencijal kiseonika u peći u opsegu 10"<7->10"<6>i daje parcijalni pritisak sumpordioksida u opsegu 0,2-1. Beli metal se suštinski sastoji od bakra (70-80 %) i sumpora. Beli metal obrazovan tokom topljenja u suštini ne sadrži komponente troske. Kada se radi u gore opisanim uslovima, prednost je što se nagrađuje troska sa malim sadržajem bakra koja je pogodna za direktnu obradu radi regeneracije bakra, i što nije potrebna odvojena primarna redukcija troske, na primer u električnoj peći. The process according to this invention for the production of blister copper has several advantages. According to this process, concentrate, solvent and oxygen-enriched air are introduced together into a slurry melting furnace, such as a flame furnace, so that at least two liquid phases, a white metal phase and a slag phase, are formed, and the white metal is oxidized after the slurry heating furnace in at least one oxidation reactor. According to this procedure, operations in the furnace for melting the slurry are conveniently carried out under conditions that ensure the formation of white metal, which means that the oxygen potential in the furnace is in the range of 10"<7->10"<6> and gives a partial pressure of sulfur dioxide in the range of 0.2-1. The white metal essentially consists of copper (70-80%) and sulphur. The white metal formed during smelting is essentially free of slag components. When operating under the conditions described above, the advantage is that a slag with a low copper content is rewarded which is suitable for direct processing for copper regeneration, and that separate primary reduction of the slag, for example in an electric furnace, is not required.

Beli metal izliva se iz peći bilo kontinualno bilo u šaržama, da bi bio oksidisan u reaktoru za oksidaciju, gde se sumpor sadržan u belom metalu oksidiše vazduhom obogaćenim kiseonikom, tako da se formiraju sumpor dioksid i blister bakar, gotovo bez troske. Prema pogodnom ostvarenju ovog pronalaska, reaktor za oksidaciju je postavljen na stacionaran način u vezi sa peći za topljenje suspenzije. Prema drugom pogodnom ostvarenju ovog pronalaska reaktor za oksidaciju povezan je sa peći za topljenje suspenzije pomoću zatvorenog ispušnog kanala za rastop koji omogućava transfer rastopa. Kada je reaktor za oksidaciju zatvoreni reaktor, sakupljanje i regeneracija gasova stvorenih u postupku pogodnije se kontrolišu. Prema pogodnom ostvarenju ovog pronalaska reaktor za oksidaciju je poželjno reaktor sa uduvavanjem na površinu. Prema drugom pogodnom ostvarenju, reaktor za oksidaciju je injekcioni reaktor, pomoću koga se pogodno može topiti i beli metal u čvrstom stanju injektiranjem u rastvor zajedno sa oksidacionim gasom. Pogodan reaktor za oksidaciju za primenu je na primer reaktor tipa Ausmelt, Isasmelt ili Mitsubishi. The white metal is poured from the furnace either continuously or in batches, to be oxidized in the oxidation reactor, where the sulfur contained in the white metal is oxidized by oxygen-enriched air, so that sulfur dioxide and blister copper are formed, almost without slag. According to a preferred embodiment of the present invention, the oxidation reactor is mounted in a stationary manner in connection with the slurry melting furnace. According to another suitable embodiment of the present invention, the oxidation reactor is connected to the furnace for melting the slurry by means of a closed outlet channel for the melt which enables the transfer of the melt. When the oxidation reactor is a closed reactor, the collection and regeneration of the gases generated in the process are more conveniently controlled. According to a suitable embodiment of the present invention, the oxidation reactor is preferably a surface blown reactor. According to another suitable embodiment, the oxidation reactor is an injection reactor, by means of which white metal can conveniently be melted in a solid state by injecting it into the solution together with the oxidizing gas. A suitable oxidation reactor for use is for example an Ausmelt, Isasmelt or Mitsubishi type reactor.

Troska se odvojeno izliva iz peći za topljenje suspenzije i prema pogodnom ostvarenju ovog pronalaska obrađuje se u električnoj peći radi regeneracije bakra sadržanog u njoj. Prema drugom pogodnom ostvarenju ovog pronalaska, troska se posle peći za topljenje suspenzije obrađuje flotacijom radi regeneracije sadržaja bakra. Kada se primenjuje postupak prema ovom pronalasku prednost je što se ne obrazuje troska sa visokim sadržajem bakra i što se izbegavaju nepotrebna recirkulacija bakra i rezultujući gubitci na bakru. The slag is poured separately from the slurry smelting furnace and, according to a suitable embodiment of the present invention, is processed in an electric furnace to regenerate the copper contained therein. According to another suitable embodiment of the present invention, the slag is treated by flotation after the slurry smelting furnace in order to regenerate the copper content. When the process of the present invention is applied, the advantage is that no slag with a high copper content is formed and unnecessary recirculation of copper and the resulting copper losses are avoided.

Pronalazak je u nastavku detaljno opisan uz poziv na nacrt. The invention is described in detail below with reference to the drawings.

Fig. 1 prikazuje dijgram potencijala sumpor-kiseonik sistema Cu-Fe-S-0-Si02na temperaturi od 1300°C. Fig. 1 shows the sulfur-oxygen potential diagram of the Cu-Fe-S-0-Si02 system at a temperature of 1300°C.

Fig. 2a prikazuje procesnu šemu postupka prema ovom pronalasku. Fig. 2a shows a process flow diagram of the method according to the present invention.

Fig. 2b prikazuje procesnu šemu postupka prema drugom pogodnom ostvarenju ovog pronalaska. Fig. 2a ilustruju postupak prema ovom pronalasku. Prema tom postupku koncentrat 5, topitelj 6 i vazduh 7 obogaćen kiseonikom zajedno se uvode u plamenu peć 1 za topljenje, tako da se u donjem delu 4 peći 1 stvaraju dve tečne faze, faza 11 belog metala i faza 10 troske. Faza 11 belog metala oksidiše se posle plamene peći u reaktoru 12 za oksidaciju pri čemu se nagrađuje blister bakar 15. Pored belog metala i troske u plamenoj peći za topljenje stvara se mala količina blister bakra koji se takođe prevodi u reaktor 12 za oksidaciju. Procesni gasovi stvoreni u plamenoj peći 1 odvode se uzlaznim kanalom 2 u bojler 8 za zagrevanje otpadnom toplotom odakle se stvorena prašina 9 recirkuliše nazad u plamenu peć za topljenje, a gasovi 17 odvode na dalju obradu. Beli metal 11 izliva se iz peći 1 kontinualno ili u šaržama u reaktor 12 za oksidaciju u kome se sumpor sadržan u belom metalu oksidiše vazduhom 16 obogaćenim kiseonikom, tako da se stvaraju sumpordioksid i blister bakar 15, ali ne i troska. Prema pogodnom ostvarenju ovog pronalaska prikazanom na Fig. 2a, reaktor 12 za oksidaciju postavlja se u vezu sa plamenom peći na stacionaran način. Prema drugom ostvarenju ovog pronalaska prikazanog na Fig. 2b reaktor 12 za oksidaciju povezan je direktno za plamenu peć preko ispušnog kanala 13. Troska 10 nagrađena u plamenoj peći 1 za topljenje sprovodi se na obradu 14 troske, bilo u električnu peć bilo u flotaciju da bi se iz troske regenerisao sadržani bakar. Prema pogodnom ostvarenju ovog pronalaska pogodan reaktor za oksidaciju je onaj sa duvanjem na površinu ili injekcioni reaktor u kom slučaju se i beli metal može topiti njegovim injektiranjem u rastop zajedno sa gasom za oksidaciju. Pogodno je da reaktor za oksidaciju bude tipa Ausmelt, Isasmelt ili Mitsubishi. Fig. 2b shows a process flow diagram of the procedure according to another preferred embodiment of the present invention. Fig. 2a illustrate the process of the present invention. According to this procedure, the concentrate 5, the solvent 6 and the oxygen-enriched air 7 are introduced together into the flame furnace 1 for melting, so that two liquid phases are created in the lower part 4 of the furnace 1, phase 11 of white metal and phase 10 of slag. White metal stage 11 is oxidized after the flame furnace in the oxidation reactor 12, awarding blister copper 15. In addition to the white metal and slag in the flame melting furnace, a small amount of blister copper is created, which is also transferred to the oxidation reactor 12. The process gases created in the flame furnace 1 are led through the ascending channel 2 to the boiler 8 for heating with waste heat, from where the created dust 9 is recirculated back to the flame furnace for melting, and the gases 17 are taken away for further processing. The white metal 11 is poured from the furnace 1 continuously or in batches into the oxidation reactor 12 in which the sulfur contained in the white metal is oxidized by oxygen-enriched air 16, so that sulfur dioxide and blister copper 15, but not slag, are formed. According to a preferred embodiment of the present invention shown in FIG. 2a, the oxidation reactor 12 is placed in connection with the furnace flame in a stationary manner. According to another embodiment of this invention shown in Fig. 2b the oxidation reactor 12 is connected directly to the flame furnace via the exhaust channel 13. The slag 10 awarded in the flame furnace 1 for smelting is sent to the slag treatment 14, either to an electric furnace or to flotation to regenerate the contained copper from the slag. According to a suitable embodiment of the present invention, a suitable reactor for oxidation is one with surface blowing or an injection reactor, in which case the white metal can also be melted by injecting it into the melt together with the oxidation gas. It is suitable for the oxidation reactor to be of the Ausmelt, Isasmelt or Mitsubishi type.

Pronalazak je ilustrovan sledećim primerom. The invention is illustrated by the following example.

Primer Example

Primenjujući postupak prema ovom pronalasku, koncentrat bakra sa 30% Cu, 28% Fe, 30% S, 6% Si02topi se u plamenoj peći za topljenje brzinom od 163tph (tph=tona/sat) zajedno sa silicijumskim peskom koji se uvodi u peć brzinom od 21 tph. Using the process of the present invention, copper concentrate with 30% Cu, 28% Fe, 30% S, 6% SiO2 is melted in a flame melting furnace at a rate of 163tph (tph=ton/hour) together with silica sand fed into the furnace at a rate of 21 tph.

Tokom procesa topljenja u plamenu peć uduvava se vazduh sa protokom od 63,493 NmVh i kiseonik u protoku od 21956Nm<3>/h tako daje obogaćenje kiseonikom 41% a koeficijent kiseonikaje 171Nm<3>02računato po unetoj toni. During the melting process, air is blown into the flame furnace with a flow rate of 63,493 NmVh and oxygen at a flow rate of 21956Nm<3>/h, so the oxygen enrichment is 41% and the oxygen coefficient is 171Nm<3>02 calculated per ton entered.

Kao rezultat reakcija oksidacije u plamenoj peći za topljenje stvara se beli metal u količini od 62,004 Kg/h (sadrži 79% Cu, 0.5% Fe) i troska u količini od 109,702 Kg/h (sadrži 4% Cu, 44% Fe). Pored toga stvara se mala količina prašine koja se recirkuliše u peć za topljenje. As a result of oxidation reactions in the flame melting furnace, white metal is created in the amount of 62,004 Kg/h (contains 79% Cu, 0.5% Fe) and slag in the amount of 109,702 Kg/h (contains 4% Cu, 44% Fe). In addition, a small amount of dust is generated which is recirculated into the melting furnace.

Troska se obrađuje u pogonu za obogaćivanje troske tako daje količina stvorene troske 8,844 Kg/h (sadrži 46% Cu, 25% Fe) i ta troska se ponovo uvodi u plamenu peć za topljenje zajedno sa koncentratom. Nagrađeni beli metal obrađuje se u reaktoru za oksidaciju u koji se uvodi tehnički kiseonik sa protokom od 4,328 Nm<3>/h i vazduh pri 18,979 Nm<3>/h. Tako se stvara blister bakar u količini od 49,274Kg/h (sadrži 98% Cu, 0.04% Fe), i mala količina troske (lt/h, sadrži 50% Cu, 27% Fe). Troska se granuliše i vraća u plamenu peć za topljenje. The slag is processed in the slag beneficiation plant so that the amount of slag generated is 8,844 Kg/h (containing 46% Cu, 25% Fe) and this slag is reintroduced into the flame furnace for smelting together with the concentrate. The award-winning white metal is processed in an oxidation reactor where technical oxygen is introduced at a flow rate of 4,328 Nm<3>/h and air at 18,979 Nm<3>/h. This creates blister copper in the amount of 49,274Kg/h (contains 98% Cu, 0.04% Fe), and a small amount of slag (lt/h, contains 50% Cu, 27% Fe). The slag is granulated and returned to the furnace for melting.

U gornjem primeru, ukupna količina bakra koji se recirkuliše nazad u plamenu peć za topljenje u koncentratu troske i u troski iz reaktora za oksidaciju je 4,575Kg Cu, što odgovara oko 9% od ukupne količine bakra sadržane u koncentratu. Daje koncentrat topljen direktno u blister, količina troske bila bi oko 130t/h i sadržavala bi čak više od 50% ukupne količine bakra sadržane u koncentratu. In the above example, the total amount of copper recirculated back to the blast furnace in the slag concentrate and in the slag from the oxidation reactor is 4,575Kg Cu, which corresponds to about 9% of the total amount of copper contained in the concentrate. It gives a concentrate melted directly into the blister, the amount of slag would be around 130t/h and it would contain even more than 50% of the total amount of copper contained in the concentrate.

Za stručnjake iz ove oblasti očigledno je da su moguća razna ostvarenja pronalaska koja nisu ograničena na gornji primer ali koja mogu da variraju unutar patentnih zahteva koji slede. It is obvious to those skilled in the art that various embodiments of the invention are possible which are not limited to the above example but which may vary within the patent claims that follow.

Claims

1. A process for the production of blister copper in which a copper concentrate 5, a melter 6 and an oxygen-enriched air 7 are introduced together into a flame smelting furnace 1 creating at least two liquid phases, such as white metal 11 and slag 10 and where the white metal is oxidized after the flame smelting furnace in at least one oxidation reactor 12, characterized in that the oxygen potential is in the range 10"<7->10"<6>a partial pressure of sulfur dioxide in the flame furnace (1) for melting in the range of 0.2-1, and that the reactor (12) for oxidation is placed in connection with the flame of the furnace (1) for melting.

2. The method according to claim 1, characterized in that the oxidation reactor (12) is set to be installed so that it is connected to the flame of the melting furnace (1) in a stationary manner.

3. The method according to claim 1, characterized in that the reactor (12) for oxidation is connected to the flame of the furnace (1) for melting by means of an exhaust channel (13) for melting.

4. The method according to claims 1-3, characterized in that the reactor (12) for oxidation is a reactor with surface blowing.

5. The method according to claims 1-3, characterized in that the oxidation reactor (12) is an injection reactor.

6. The method according to claim 5, characterized in that a solid white metal is also injected into the reactor (12) for oxidation.

7. The method according to claim 1, indicated by the fact that the slag (10) after the furnace (1) for melting the suspension is processed in an electric furnace in order to regenerate the copper contained in it.

8. The method according to claim, characterized in that the slag (10) after the furnace (1) for melting the suspension is processed by flotation in order to regenerate the copper contained in it.