AU603105B2 - Method for concentrating oxidized copper ore - Google Patents

Description

r4 BCEMII1PHA5IoPrAI13Aw3IsL'.,,, All P CT Mmapiapontioc~ MEA'QZIYHAPOZII-IA313A5IBKA, OHIYBJII4KOBAHHASI B COOTBETCTBI1 C .1OTOBOPOM 0 HATEHTHOH1 KOOI-IEPAUII14 (PCT) Me)aaPoJJwa3 KJiaCCHujnKalmai (11) Homep mCetw2ylipoaiih0 ny6.TniKaiifi: WO 88/07591 (21) Ho'aep m M~tiapoit~fi 3ARBIH: PCT/SU87/00036 [MAKI-IMUTON, Zhakhan Makhmutovich, Dzhezkazgan TOITIAEB KiiprI436ft KyulKanideB1V4; (22) )Ja~a me)Ic.1yHapoAHuio 1ozanii: 4IKe3Ka3raji 472810, yn. 30 neT [Iofe1b], xt. 5, KB. 76 24 mapTa 1987 (24.03.87) (SU) [TOPAEV, Kirgizbai Kushkalievich, Dzhezkazgan )KYPIIHOB MypaT )KYpHHOB141; Kapara- Ha470040, ynr. Ba~aimcKa2, Lt. 3 1, KB. I11 (SU) [ZHU- (71) 3aRiBirreah: XH4MHKO-METAJIJIYPFM4'IECK~fI -RINOV, Murat Zhurinovich, Karaganda ),TO- HHCTIITYT UEHTPAJ~bHO-KA3AXCTAH- PEUJ MapK 3anmaHoBHtl; Kaparawna 470032, YR.

CKOT-O OT4LEJiEHHAI AKAZIEMIIM HAYK a~3ep)KiiicKoro,.a. 81, KB. 15 (SU) [UGORETS, Mark KA3AXCKOfl CCP [SU/SU]; KaparaHaa 470032, Zalmanovich, Karaganda CEM14HA Onbra YJI. aL3ep)lUHHcKoro, at. 63 (SU) [KHIMIKO-ME- 14BaHoB~a; KaparaHna 470032, YR. ai3epWIHHcxoro, TALLURGICHESKY INSTITUT TSENTRALNO- ai. 81, KB. 5 (SU) [SEMINA, Olga Ivanovna, Karaganda KAZAKJ-STANSKOGO OTDELENIA AKADEMII CAF14H.TbIKOBA 3o. bai4TYPClHoBHa; Ka- NAUK KAZAKHSKOI SSR, Karaganda paraHaa 470074, np. CTpoHTenef1, 2. 1, KB. 134 (SU) [SAGINDYKOVA, Zoya Baitursinovna, Karaganda (72) H3o6peT2Tejm: EAEIIIOB A6nvya.m; Kaparawa470074 YFOPEUJ BHTanmf1 MapKoBwil; KaparaHna YR. COBeTCKofi KoHCTHTYLIMM, 4, KB. 540 (SU) 470032, y.T. 43ep)viHcKoro,.a. 81, KB. 15 (SU) [UGO- [BAESHOV, Abduali, Karaganda BEKTYP- RETS, Vitaly Markovich, Karagandli (SU)J. I-JIArAHOB Hypanbi CynraHoBHwI; KaparaHna 470074, 3YHOB .Tleoi~wa AH4CIMOBI4L1; MOCKaa 115409, yJ1. COBeTCKofi KoHiCTHTYUMVI, 2. 4, KB, 179 (SU) y.T1. MOCK]3Opeqbe, a. 57, KB. 8 (SU) [GLAZUNOV, [BEKTURGANOV, Nuraly Sultanovich, Karaganda Leonid Anisimovich, Moscow KOJITYHOBA AB1IIIEB 4KaHTOpe i-lYpflaHoBldtl; Kapara- JTho6oBb HiiKoJIeBHB; Anmaiim 702400, TaUJKeHT- H21a 470060, YR. MHW4yp1H, a. 21/3, KB. 4 (SU) [ABI- MR~ YR. floKRloHcKoro, n. 6, KB. 14 (SU) [KOL- SHEV, Dzhantore Nurlanovich, Karaganda TUNOVA, L-jubov Nikolaevna, Almalyk rIH- Ceprefi BnamimiMl)OB IN; KaparaHzna JIELIKMIt BavcArimfi MimxafnoBii'; AJImanhI 702400 470074, YR. MyKBHO~a, z. 24, KB. 15 (SU) [BELYAEV, TaUIKeHTCMa. YR6.r. ymaraplHa, i. 11, KB. 23 (Su) Sergei Vadimirovich, Karaganda XAIIPOBA [PILETSKY, x. ,;Mikhailovich, Alma,'yk (SUMJ, rylbKa3Hpa KeH :eraMH~oBHa; KaparaHita 470076, YR. Kpb1J1oaa, at. 44, KB. 22 (SU) [KHAIROVA, Gui- (74) Areirr: zhazira Kenzhegazinovna, Karaganda (SU)I. CIIM CCCP; IvOCKBa 103735, yn. Kyfi6bluieBa, nt. 5/2 (SU) CBeTJIBHa flaBnIOBHa; Kaparaania 470055, 6ynbaap [THE USSR CHAMBER OF COMMERCE AND Mupa, a. 57/1, KB. 50 (SU) [SIM, Svetlana Pavlovna, INDUSTRY, Moscow Karaganda I4BHIIIEB KaHaT CaHcb136aernltl; KaparaHita 470040, 6ynbaap Miipa, a. 80, KB3. 40 (SU) (81) Yna3aniiibe rocyitapcTlla: AU, BR, DE, GB, JP [IBISHEV, Kanat Sansyzbaevich, Karaganda MAXMYTOB AKaxaH MaXMYroBH4l; llLKe3K3raH O1TV6JuucoBaHa 472810, 6ynbaap KoCMOHaBTOB, R. 25a, KB. 19 (SU) C oniteno~f 0 AmeyCdyHaP06H0Af noucKe (54) Title: METHOD FOR CONCENTRATING OXIDIZED COPPER ORE (54) Ha3salime H13o6pe'reHHR: CrIOCOE OBOFAIUEHI45 OK1HCJIEHHOII ME4IHOT4 PY~bI (57) Abstract A method for concentrating oxidized copper ore comprises preparation of the pulp, introduction of an ionized sulphide therein and flotation. Before flotation, the pulp and/or water solution of the ionized sulphide is subjected to electrolyses at a current density of 5-500 A/rn 2 Use may be made of sulphides containing from I to 9 sulphur atoms. Such sulphides are introduced into the pulp having a temperature of 30-1000C.

amendmnents imade under Section 49 and is correct f or printing.

J. P. I DE C 1988

ASTRAAN

2 NOV 1988 PATENT OFFICE 4 13 W. 11 V III OTDELENTA AKADEMII NAUK KAZAKHSKOI SSER 6 g n ea Direotbi Position:. GRIFFITH HASSEL FRAZER, SYDNEY, AUSTRALIA (57) Pe4)epaR: Cnocod oboraigekHmn O~mcmmHo2 me~nHog PYAnU BIK~tiaeT nrIoTOBzeHne flyIbab, B~e~eim e B iiee 2OH1i32pyemoro CYAB 29 14 IOTau~m. rlepeAn ;omau.ej ny~mny o/mr-z LOAiiuk paCTBo~p 2aoHmuflyemoro cybimz noAepraK) 7ieRT.pohI23 11pM flAOTHOCTR Tom~ 5-500 Alm 1Ip.0 8T OM M Ory T OUT.6 .0CflO)I3o3aiu cyzAlu, o~epaige OT I AO 9 aTO- MOB cepu. 1 abiue CyA420gU BBOAST B rlynIbny imCiouji TemtiepeTypy 30-100 0

C.

HCKJIIOqMTJIL6HO XtU I 1JIEfI H0OPMAUIHH Koabi, mcI1OJb3yembie xI1 o6OMatieHMM c-rpaH-tmJeHOB PCT Ha T1HTYJIbHbIX J1MCTax 6powiop, B KOTopbIX HYGIcKYIOTCsi me)KMlHapoaJie 3aSIBX1H B C0OTBeTCTBW1i c PCT: AaCTPH51 ABCTPanH1l Eap6a;'ioc Benbrmlsi fionramwi Spa3~umsi U~eHTPanbHoaftpIKaHcvaRq Pecny6nHta Ko~ro KamePYll OenepaTHBHax Pecriy6nmia repmaHH IAAHH9 4'paHUIHS ra6oH Be. Ko6pHTaHHla BeHrpi l4TaJnwq AnflOHm Kope~cI~as Hapoj3Ho-jtemoicpaT1'ieC~aR PeCrhYfrlMa IKo~efimga Pecny6nHKa flHX~eHWT.-H LWpn JAaiKa Jhtoxcem6ypr M OHaxo Manaracxap manti MaapMTaHH51 HHiiepnaHnb1 HOPaeri CynaH WJBeUMa Cell ra.1i C013eTCKII COMo Toro CoeZHCHHb~e flTaTbr AmepHmm METHOD FOR BENEFICIATING OXIDIZED COPPER ORES Field of the Art The present invention relates to ferrous metallurgy, deals with a method for extracting copper into concentrate and, more particularly, with a method for beneficiating oxidized copper ores.

Prior Art With respect to their mineralogical composition the copper ores fall into the following categories: sulphide ores, oxidized ores, and mixed (sulphide- -oxidized) ores. Copper can be successfully extracted from sulphide ores by conventional methods of foam floatation. However, employment of foam floatation for beneficiating oxidized and mixed ores fails, as a rule, to provide satisfactory results. This should be attributed to the presence in said ores of hard-to- -floatate minerals such as chrysocoll cuprite, brochantite, etc. However, depletion of copper ore reserves imparts an overgrowing importance to the oxidized ores. It is with a view to improving the beneficiation of said ores that a number of combination processes has been developed which comprise metallurgical and floatation methods.

US Patent No. 4200455, IPC C22B 15/10, publ.

29.04.84 teaches roasting of oxidized copper ore in a reducing atmosphere at 500 1000 0 C with additions of hydrochloric acid and hydrogen sulphide followed by leaching sulphur out of the roasted ore with an ammonia-carbonate solution. This method involves considerable energy expenditures required for heating Ithe entire bulk of the ore to the above-mentioned I temperature. The method is accompanied by discharges IN O 2 of dust and toxic gaseous products of roasting, which calls for solving the problems of dust catching and purification of exit gases. Furthermore, the use of such toxic materials as ammonia and hydrogen sulphide creates a need for special safety measures which makes the process still more expensive.

In another known method disclosed in US Patent No. 2989394, NPC 75-2, publ. 20.06.1961 oxidized copper ore is mixed with iron sulphides (pyrite or pyrrhotine) and chlorides of alkali or alkaline-earth metals. This mixture is roasted at a temperature of 500 80000 in a neutral or reducing medium in the presence of steam. The copper sulphides formed during roasting are separated from the barren rock by floatation. This method accounts for 82% of copper extracted into concentrate. Like the previously-described method, this method is power-intensive and, in addition, its realization involves the formation of toxic gaseous products of roasting and dust.

It also known that copper can be extracted from oxidized copper ores by leaching them with solutions of alkalies or acids. Thus, US Patent No. 3985855, IPC C01G 3/00 publ. 12.11.1976 suggests a 25% solution of sodium hydroxide to be used as a leaching agent. The process is conducted at 60-100oC in the presence of a silicate material taken in the amount of 50 100% of the mass of the initial ore. Then the copper-bearing solution is separated from the solid phase by filtration. This method is characterized by a high consumption of reagents, employment of toxic and costly causting soda and by operations involving additional complications wuch as separation of solid and liquid phases and regeneration of the alkali solution.

C 35 Widely known in the art is a method for benefi- Sciating oxidized copper ores, comprising leaching 3 the copper out of them with sulphuric acid, introduction of iron chips into the pulp, and floatating the precipitated metallic copper. There are also other known methods for beneficiation of oxidized ores, using acids for the purpose. According to US Patent No. 4008072, IPC C22B 15/08, publ. 15.02.1977, the pulp, resulting after leaching copper from the oxidized ore with sulphuric acie is treated with ionized sulphides, mostly hydrogen sulphide. Then the pulp is floatated as an ordinary sulphide ore.

However, the use of acid leaching is not always expedient. Thus, processing ores with a high content of carbonates of alkali earth metals brings about a considerable increase in the amount of used acid due to its interaction with said carbonates. Other difficulties are also experienced. A high corrosiveness of acids poses a problem of protecting equipment against their attach; besides, dump waste products, such as floatation tails and acid-containing sewage present environment-pollution hazard.

The above-cited methods for beneficiating oxidized copper ores lack in effectiveness. Some of them are fraught with substantial energy expenditures and pollute environment with noxious materials, while others involve the use of alkalies and acids dangeous to the attending personnel and bring about additional difficulties connected with decontamination of dump waste products and regeneration of solvents.

Disclosure of the Invention The object of the present invention is to provide such a method for beneficiating oxidized copper ores, wnich would ensure maximum possible extraction of copper into concentrate, simplify the process and diminish the environment pollution hazard.

R 35 This object is achieved by providing a method uI 4 for beneficiating oxidized copper ores, comprising the preparation of a pulp, injecting ionized sulphide into it, floatating the sulpide-treated pulp and producing a copper concentrate in which, according to the invention, before floatation, the prepared pulp or an aqueous solution of ionized sulphide is subjected to electrolysis at a current density of to 500 A/m 2 The method proposed herein provides for extracting copper into concentrate from oxidized hard-to- -beneficiate ores at a high extraction degree, reaching 97%. In addition, the invention ensures a considerable reduction of deleleterious effluents discharged into the environment. Furthermore, the invention simplifies the technology of the process for beneficiating copper ores.

Electrolysis can be use for treating the initial pulp either before or after injecting the ionizing sulphide into it, or for treating an aqueous solution of sulphide, or both the pulp and the aqueous solution of ionized sulphide, each separately.

It is good practice to carry out the electrolysis at a current density of 5 to 500 A/m 2 and a respective voltage of 0.5 to 50 V.

It is desirable that the ionized sulpide be constituted by sodium sulphide, calcium sulphide, magnesium sulphide or ammonium sulphide of the following formulas: Na 2 Sn, CaSn, MgS n (MH4) 2 Sn where n 1 to 9.

The use of sulphides containing a prescribed number of sulphur atoms, namely 1 to 9, ensures a more complete extraction of copper into concentrate.

An increase in copper extraction in this case amount to 2 to It is recommendable that the pulp be heated to 100 0 C before introducing ionized sulphide into it. This practice'will bring about a further 3 to increase in copper extra'ction.

Said and other advantages of the present inven- 'tion will become apparent from a detailed description of the method that follows.

Oxidized ore is crushed then further divided in water to a degree sufficient-for effective separation of mineral copper from barren rock, namely to a degree at which 50 to 100 of ore passes through a sieve of 0.74 mm mesh. The resulting pulp is mixed with limited quantities of electrolytes. Said electrolytes may be constituted by aqueous solutions of salts, alkalies or acids. Preference-should be given to substances minimizing the problem of environment pollution, namely, lime, sodium sulphate, potassium sulphate, sodium carb'onate. Then the pulp is delivered to an electrolytic cell of a conventional design in the form of a vessel accommodating electrodes, i.e.

an anode and a cathode, and a pulp mixing device.

The electrodes may be of steel, graphite and similar materials. The shape of the electrodes may also vary from plate type, rod type, to grid and cylindrical electrodes. The process of electrolysis is conducted by stirring the pulp for 20 to 200 min at a current density of 5 to 500 A/m 2 and a voltage of 0.5 o 50 V.

Through contact with the electrodes, the particles of copper mineral suspended due to stirring of the pulp undergo transformations. For example, after contact of these minerals with the cathode, the surface of said minerals becomes covered with metallic copper. Concurrently, the reduced metallic copper is oxidized on the anode, yielding copper oxide.

Inasmuch as these particles are solid and do not dissolve during electrolysis, they do not settle on the electrodes. Thus, the hard-to-floatate copper-bearing x r: 1 I- 6 minerals are transformed into metallic copper and copper oxide which can be comparatively easily separated by the'foam floatation method. The process of electrolysis can be conducted either to complete decomposition of copper mineral or to partial transformation since subsequent floatation can be ensured only by partial coating of the particles of said minerals with a layer of metallic copper or copper oxide. On completion of the electrolysis ionized sulphide is introduced into the pulp in such a Squantity as to ensure that the ratio of the mass of sulphur incoming with it in relation to the oxidized copper ore would be 0.005 to 1:1, i.e. .one mass part of oxidized copper in the ore should correspond to h 15 0.005 to 1 mass parts of sulphur.

It is practicable that the ionized sulphide should be constituted by sulphides of sodium, calcium, magnesium or ammonium of the following formulas: Na 2 n CaS n MgS n

(NH

4 2

S'

wherein n 1 to 9, due to their accessibility, simplicity of production and handling. Most prererable are sodium sulphides, of which sodium pentasulphide Na 2

S

5 is the best. The interaction of said sulphide with the copper oxide contained in the surface layer of the copper mineral particles yields copper sulphi.

des with concurrent liberation of elementary sulphur which likewise is-found on the surface of said particles. Now the pulp is floatated with the use of ordinary reagents, viz., butyl xanthate as collector and a mixture of monohydric and dinydroxy alcohols of tyrane and dioxane series as a frothing agent.

These operations improve the floatation properties of copper minerals, giving a 5 to 10%o increase in the extraction of copper into concentrate.

SL .i35 The current density of 5 to 500 A/m used during

IT,,.

I

7 electrolysis is selected because the current density below 5 A/m 2 is insufficient for the required transformation of the surface of copper mineral particles, 2 whereas the current density above 500 A/m fails to increase the extraction of copper into concentrate but causes an additional consumption of electric energy.

As stated above, electrolysis takes from 20 to 200 min. This time is selected because the period of electrolysis shorter than 20 min will be insufficient for successful extraction of copper by subsequent floatation, while its period exceeding 200 min fails to ensure additional extraction of copper but only extends the process, which is undesirable.

The number of sulphur atoms contained in ionized sulphides may very from 1 to 9. As is known, one atom of sulphur is the minimum possible number for the given gioup of ionized sulphides. The upper limit is selected because the ionized sulphides with more than 9 atoms of sulphur are poorly soluble in water, the resulting solutions become quickly oxidized, which fact renders their handling difficult and reduces the effect of their utilization.

The amount of sulphur introduced into the pulp with the ionized sulphide in the form of sulphide ions in relation to the oxidized copper ore is 0.005 to 1:1.

Its amount less than 0.005 mass parts will be insufficient for achieving the required change in the state of the surface of copper minerals. An increase in the amount of "introduced sulphur over 1 mass part fails to ensure any additional extraction of copper and results only in excesively high expenditures of the reagent.

Other embodiments of the method are also possible.

Thus, in one of them the pulp subjected to electrolysis already contains one of the above-mentioned sulphides, Q1''' 8 which is used in an amount sufficient for introducing into the pulp 0.005 tp 1 mass part of sulphur per mass part of the oxidized copper ore. After the electrolysis conducted for 20 to 200 min at a current 2.

density of 5 to 500 A/m 2 the pulp. is turned over for floatation.

Subjecting'-the pulp to electrolysis after introducing ionized sulphide into it'increases the degree of copper sulphidizing- thereby raising its extraction into concentrate by 2 to A characteristic-feature of a further embodiment of the proposed method lies in that electrolysis is used only for the aqueous solution of the ionized sulphide. This solution is electrolyzed for 1 to min at a current density of 5 to 500 A/m Then'the solution of sulphide is ad;-d to the-pulp in such an amount that the mass of sulphur delivered with said pulp in relation to the oxidized copper of the ore is 0.005 to 1:1. Then the pulp is fed to the floatation machine and floatated. Electrolysis'of the aqueous sulphide solution raises the chemical activity and stability of the latter, i.e. the ability to retain its properties for a sufficiently long time. This increases the degree of copper extraction by 3 to This embodiment of the invention is the simplest and most economical one since it calls for minimum expenditures ef electric energy so that it can be successfully used for beneficiating lean oxidized copper ores.

It is recommendable that the solution of ionized sulphide be introduced into the pulp prihesated to to 1000C. This gives another 3 to 11% gain in the extraction of copper into concentrate.

A current density below 5 A/m 2 is insufficient for activating the solution of ionized sulphide.

Increasing the current denty above 500 A/m reduces Increasing the current dens ty above 500 A/m reduces 9 the reactivity of this solution due to predominance of secondary reactions. Extraction of copper into concentric diminished correspondingly.

If the electrolysis of the ionized sulphide solution takes less than 1 min, it fails to provide the degree of its electrochemical activation required for satisfactory results during subsequent floatation; conversely, if electrolysis lasts in excess of 20 min, this does not conduce to additional extraction of copper but only causes an unduly lengthening of the process.

Introduction of the ionized sulphide into the pulp heated to less than 30 0 C does not bring about any substantial increase in copper extraction. Heating the pulp above 1000C also fails to give any further increase of copper extraction but only involves additional technical difficulties.

Still another embodiment of the method consists in that the pulp and the aqueous solution of said sulphide are subjected separately to electrolysis conducted at a current density of 5 to 100 A/m The duration of pulp electrolysis in 20 to 200 min while electrolysis of the aqueous sulphide solution is 1 to 20 min. Then the pulp is combined with the sulphide solution and directed to floatation. Realization of the given embo'diment of the method is characterized by the fullest extraction of copper from ore, reaching 92 to 97%.

The Best Embodiment of the Invention The starting oxidized copper ore is crushed and divided in the presence of water to a point when it contains 70% of particles with a grain size under 0.74 mm. The pulp prepared in this manner is mixed with line in an amount providing for pH of 11. Then S 35 the pulp is electrolyed for 30 min at a current rV" 0>' L ~ll..i 2 density of 50 A/m On completion of electrolysis the pulp is heated to 600C and mixed with a solution of sidium pentasulphide Na 2

S

5 which has been electrochemically activated, i.e. subjected to electrolysis, in the amount ensuring a 0.15 mass ratio of sulphur to the oxidized copper of the initial ore. This solution of sodium pentasulphide is activated by electrolysis for 15 min at a current density of 2 200 A/m After mixing the pulp with said sulphide, the pulp is subjected to floatation.

The collector used in the process of floatation is constituted by butyl xanthate and the frothing agent, by a mixture of monohydric and dihydric alcohols of tyrane and dioxane series. Extraction of copper into concentrate is 96.8%.

The present invention is commercially advantageous over other known methods.

1. It solves effectively the problem of beneficating oxidized copper ores, while from the viewpoint of its technical and economic characteristics it surpasses other methods of a similar application.

2. An important advantage of the present method is a higher degree of copper extraction from oxidized ores whose processing by the known methods fails to ensure satisfactory results.

3. The proposed method as a whole simplifies the process of benefication by obviating the operation of leaching which usually brings about additional complications such as separation of solid and liquid phases, protection of equipment against the attack of acids, regeneration of the leaching agent, etc- 4. The present invention contributes to environment protection. Its realization is not accompanied by evolution of toxic gases, while the dump wastes Z products (floatation tails, sewage) do not call for

D:

~-lii I 11 additional special decontamination.

The present method lends itsels easily to industrial application, because its realization does not call for sophisticated and cumberson equipment.

The process of electrolysis can be successfully carried out in floating machine chambers equipped with electrodes.

6. The method of the invention can be used to advantage for processing intermediate and dump waste products of copper manufacture containing oxidized compounds of copper, dusts, slags, ash, etc.

For a better understanding of the invention it will now be made more apparent by way of examples of realization of the method for beneficiating oxidized copper ores.

Example 1 A starting oxidized copper ore contained 1.34% of copper including 1.07% of copper contained in such oxidized minerals as chrysocoll, brochantite, malachite. Said ore is crushed, and divided in water to the point when it contains 70% of particles of a grain size under 0.74 mm. The pulp prepared in this manner is mixed with lime and the pH of the medium is brought to 11. Then the pulp is loaded into an electrolytic 25 cell and subjected to electrolysis for 120 min at a 2 current density of 150 A/m Then the temperature of the pulp is brought to 30 0 C and an aqueous solution of sodium sulphide Na 2 S is added to said pulp in such an amount that the mass of sulphur entering with this solution in the form of sulphide ion would be 0.05 per mass part of oxidized copper in the ore. The pulp treated in this manner is turned over for floatation in which the collector is constituted by butyl xanthate and the frothing agent, by mixture of monohydric and 35 dihydric alcohols of tyrane and dioxane series.

NT a :~V I 17 S- 12 Extraction of copper into concentrate equallied 86.2%.

Example 2 The initial oxidized ore contained 1.08% copper, of which 1.03% accounted for oxidized minerals, mostly chrysocoll. The ore is crushed and divided in water to a 0.74 mm grain size of 70% of its particles. The prepared pulp is mixed with sulphide Na 2

S

9 in an amount ensuring the 0.8 mass ratio of sulphur to the exidized copper in the ore. Then the pulp was subjected to electrolysis for 20 min at a current density of 500 A/m 2 On completion of the electrolysis the pulp was floated by the semer reagents as specified in Example 1. Extraction of copper into concentrate was 91.3%.

1 5Example 3 The initial oxidized copper ore containing 1.19% of copper (including 0.95% of oxidized compounds) is crushed and divided to the same degree of dispersity as that stated in the foregoing examples. The obtained pulp is heated to 1000C and sodium sulphide Na 2

S

5 is added to it in an amount' corresponding to the mass ratio of sulphur to oxidized copper in the ore equalling 0.15. Said sulphide is added to the pulp in the form of its aqueous solution which is preliminarily electrolyzed for 15 min at a current density of 200 2 A/m Then the pulp is floatated with the above-stated reagents. Extraction of copper into condentrate is 90.8%.

Exampl e 4 The source' ore and the conditions of its dispersation are the same as in Example 1. In the given example the pulp and sulphide Na 2

S

5 electrolyzed separately. Thus, the pulp is electrolyzed for 30 min at a current density of 5 A/m after feeding lime into it and after bringing the pH of the medium to 11. The S- 13 aqueous solution of sodium pentasulphide is electrolyz- 2 ed for 10 min at a current density of 150 A/m This solution of 'sodium pentasulphide is introduced in the pulp heated t.6 600C in an amount sufficient for the 0.15 mass ratio of the incoming sulphur to the oxidized copper of the ore. Then the pulp is floatated.

Extraction of copper into a concentrate reaches 94.5%.

Example The starting ore containes 0.42% of copper including 0.34% of copper in the oxidized minerals (mostly chrysocoll The process is conducte'd as described in Example 3. The data of the present example prove the possibility of successful beneficiation of lean oxidized ores and give grounds for conclusion about the expedi-ency of utilizing the present method for exploitation of the deposits of above-mentioned ores.

Industrial Applicability The present invention may find application in the beneficiation of oxidized copper ores in the mining industry for the extraction of copper.

QI

ZNT

Claims (9)

1. A method for beneficiating oxidized copper ores, comprising preparing a pulp, adding ionized sulphide thereto, and floating the pulp, characterized in that prior to floatation the pulp is subjected to electrolysis at a current density of 5 to 500 A/m 2 the pulp particles being in contact with the electrode.

2. A method as claimed in claim 1 wherein prior to adding the ionized sulphide to the pulp, an aqueous solution of the sulphide is treated by electrolysis.

3. A method as claimed in claim 1 or claim 2 wherein the S.. Spulp is subjected to electrolysis for 20 to 200 minutes at a pulp temperature of 30 to 100°C. :15

4. A method as claimed in any one of claims 1-3, wherein the sulphides employed contain from 1 to 9 atoms of sulphur.

5. A method as claimed in any one of the preceding claims wherein the solution of sulphide is introduced into the pulp when the pulp has a temperature of 30-100"C.

6. A method for beneficiating oxidised copper ores substantially as herein described with reference to any one of the Examples and The Best Embodiment of The Invention. S.. DATED this 16th day of August 1990 KHIMIKO-METALLURGICHESKY INSTITUT i TSENTRALNO-KAZAKHSTANSKOGO OTDELENIA AKADEMII NAUK KAZAKHSKOI SSR S-14- 8117S/MS E u NT. .1' PG.~li 15 METHOD FOR BENEFICIATING OXIDIZED COPPER ORES ABSTRACT A methbd for beneficiating oxidized copper ores comprises preparation of a pulp, introduction of ionized sulphide thereinto, and floatation. Before the floatation the pulp and/or aqueous solution of ionized sulphide is subjected to electrolyses at a 2 current density of 5 to 500 A/m 2 The sulphides employed may contain from 1 to 9 atoms of sulphur. These sulphides are introduced into the pulp heated having a temperature of 30 100 0 C. INTERNATIONAL SEARCH REPORT International Application No PCT/SU 87/00036 I. CLASSIFICATION OF SUBJECT MATTER (it several classification symbols apply, Indicate all) 6 According to International Patent Classification (IPC) or to both National Classification and IPC 4 TI t, C 4 C 22 B 15/00 II, FIELDS SEARCHED Minimum Documentation Searched

7 Classification System Classification Symbols Int.Cl. 4 C 22 B 15/00 Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included In the Fields Searched III. DOCUMENTS CONSIDERED TO BE RELEVANT Category Citation of Document, 1" with Indication, where appropriate, of the relevant passages 12 Relevant to Claim No.13 A D.S. Sobolev et al.: "Praktika obogaschenia 1,2,3 rud tsvetnylch i redkikh metallov", vol. II, Obogaschenie mednylch rud, 1960, Gosudarstvennoe nauchno-teknicheskoe Sizdatelstvo literatury po gornomu delu (Moscow), see pages 102-103 A Obogaschenie rud tsvetnykh metallov, sbornik 1,2 nauchnykh trudov No. 5, 1972, Srednaziatsky nauchno-issledovatelsky dnstitut tsvetnoi metallurgii (Tashkent), see pages 57, 39 A V.A. Chanturin et al.: "Elektro-khimicheskie 1 metody intensifikatsii protsessa flotatsii", 1983 Nauka, (Moscow), see page 11, lines 12- Special categories of cited documents: 10 later document published after the International filing date document denfning the general state o the art which is not or pioriity date ad not in conflict with the application but considered to be of particular relevance cited to underand the principle or theory underlying the Iconsidered to be of particular nvention arlir document but published on or after the international document of particular relevance; the claimed invention Scannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or involve an inventive step which I cited to establlsh the publcation date of another document of particular relevance; the claimed invention citation or other special reason (as specified) cannot be considered to Involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled document published prior to the international filing date but in the art, later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 24 November 1987 (24.11.87) 18 December 1987 (18.12.87) International Searching Authority Signature of Authorized Officer ISA/SU Form PCT/ISA/210 (second sheet) (January 1965) -u ~IVT O~ MeMAYHEaPOAHaS aIsta PC~T/SU 8?/OUC3 1. KflACCHC:)HKALAHSI OfilbEITA M306PEYEHHSI (ecAH flpHmaHRIOTCR HOCKDA1,H0{ KnaccH",pxaLHOHbX HHAeRcOB, YOW).0for B C0011 01CTill c kemayiaPOHOA KnaccHqJHKaL~meA H3O6peTeHHA1 (MH1) vIIH KaK

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9 Haiero*I CcWJ1Ka Ha Ao,{ymeHT' 1 C Ylia3aHHem, rAoe HeOdxOAy'uO, 4aCTeii, OTHOCHTCR K nyHKTY Omi THOCaLi4HXCS K nP9Ame~y floHcl~afz copmynu~ $2" A Tl.C.Co6ojieB 1m gpyIMie ttllpaXT4~{a o~ora1TeHH 112,3 L4BeTHbDa p x meTajijiOB ,TOM fl,06oraige- H14e mer~lLix _19l60,Po CynA,,pCTBeHHoe Hayufl- -TeXHii4Lecxoe I43TaTejibCTBO I e aT~b lo Fop- HOMY -,e-Iy 'OCKBa CMOT-,04 C IU A 06or2TILeH4e pyA l TBeTHlTDC meTa3l7izoB, C60_0I1= Ha- YIEl-br TpyT7oB'o 19.72, CpeAHea34a-.ciw~ Hay~q- 112 -o14iego Ba ebcKr~i4 Pi 1TmoelTHV HIHCTIITyT L BeTHOTI meTa.71yp'mm (Tam-FeHT),,CMoT-pI c.57 9 A B. iY 1K gpyle "3.ieKTpoxt4MItle crne mve- TOrbi I4HTeHcoitKaLi4Hm npoi~ecca tJZOTaqi1iz'I 9 8 3 Hayx-a (MlocKLa), cMo'Tpl4 0.11, CTpoxni 12-30' *OC06biS KaTeropHH CCbiO'4Hi AOKymeHTOBt AO~ymeHT, oflpe~enso.HA o6uAHAi ypoBeHb *rex- T' ftee nO3AHHA AOtKYMGHT, OflY6rHOeaHHbl~ HHXH, KOTObl He HmeeT HaM6o116e 6AN9KaOrO nocJie gAaTbl MemfyHaPOA1CF1 nolaqH mmH OTHoweHHR K rlP8AmeTy nom4CKa. AaTbi npmopHiTeTa H He nopoHaLaHA sa~AKy, NO0 npseAeHHbI An floHHmaHms nP41HLAHna HAH TOO- ,Ea 6onee paHHHA nareHTHblA AOKYM9HT, Ho on6,H PH*, ma K0TOPbIX OcHoBbiaaeTCH H3O6P6TeHHe. KosaHblk Ha AraTy m8?K~yHaPoAHoA4 nOAaqH Hmn ,X AOKymeHT, HMeWOLLH HaH6o~lee 6AM3KOe oTmowe- nocs ,iee, HHe Kc fPOAMOTy floHc~a; Sa~qBAHH0e M3O6POTeHlie AO~meH, n~geralLLAA CM~eiw ps4na_ HO O0AaAaBT HOBH3HO,1 W H3o6p97aTeAbCK~m HHe(s) ma romOHTOT, mH KOTOPblA npmHOAHTCP PSRm C L16AWbO YCraHo8neHHR9 AaTbI nY6nHKaLAHH Apyro- AOKYMeHT, Hmenow'4A mam~onee 161113KOe OTHOWe- ro CCblnO4Horo AO~ymeHTa, a TaKMG( 8 Apyr~x HHO K nP'3AMey flOHCm(a; AOKY&~eHT a CO'4eTaHM 4ennIX (KaK YKA~amo). C 0flHWM iuwi HeCKOjnbtHMH noAo6HiMH AOKYMOH. TawH nopoLHT m300peaTebcKm1 YPO~eHb Sal;e- A0KykeHT, OTHOcRWIHACR K YCTHOMY paCKPITHMo, nemmoro H3O6pe9HHS, Taxoe COL4eTamH9l AOA24{Ho npH~oHeHHmo, BbICTaBK8 H T. A. 6blTb O'498HAIHO AJ1.9 Ami. a, 0f5J1Aaiou.ero nl3Ha- AOKYMeHT, ony6nlHKoRaHHbIr4AO A aTbi MeWAV11-- HHW4 8 AatQA o6JnaCTH TOXHIIKM. PDAHok flO~aq, HiJ' -tiac.re flaTbl ;ionpa w &AOyde4, r L~ac'nela M'~ro p~v~o'ro'r. me naTeHTHWOo COeAC:Tea. IV. YAOCTOBEPEI*1E OTH TA ALaia AeG1CTHT6enbHoro 3aeepweHHR meh(A1ymapo~Horc ALaTa OTflpa8R{H HacTO.Ru~ero OTL~eTa 0 MeM4AYH&Pa flOHCKa MOM flOHCKO O 24 iojq6-,oj 10987 (24.11.87) 1 18 AeIxadps 1987 (18.2.87) MeAYiaPOAHbi; floHKoBbi14 opraH *nc ynlonHoM04eHHoro PmUA cI'opma PCT/ISA/210 (a7oPOii AHCT) (SHmapb 1985r.