DE2501010A1 - HYDROMETALLURGICAL PROCESS FOR THE EXTRACTION OF COPPER - Google Patents

Description

Hydrometallurgical process for the extraction of copper

The present invention relates generally to an improved one hydrometallurgical process for the extraction of metallic Copper from copper-containing material. In particular, the improvement relates to the metal chloride treatment of copper sulfide ore concentrate entr at en.

US Pat. No. 3,785,944 describes a hydrometallurgical process for the treatment of copper sulfide ore concentrates, especially those containing ohalcopyrite. This procedure has four
basic levels: An oxidation level in which copper-containing material is mixed with an iron (III) chloride and copper (II)
-chloride-containing solution is oxidized, whereby a

609829/0702

· ■. '■ - "· - 2 - YY 1821

Containing iron (II) chloride "and additional amounts of copper (II) chloride Solution gives; edn'e reduction level in which the in Solution located copper-II-chlori-d from the "oxidation stage essentially using fresh copper sulfide ore is reduced to copper-I-chloride; a copper extraction stage, in which one - preferably electrolytically metallic copper - AuG the copper chloride solution wins; and a regeneration cleaning stage, in which the "ferric chloride" is by oxidation simultaneous extraction of excess iron and sulfate ions and other impurities regenerated.

DIE weitere- development- ^of: process-to-the present invention found / additional information as well as procedures and conditions that · the benefits that the ■ basic. Highly reinforce method offered by U.S. Patent 3 * 785,944. -

The present invention relates to a hydrometallurgical process for the production of copper metal with a reduction stage, in which copper-iron sulfide concentrates are placed in a copper-II -Aqueous chloride solution containing chloride; 'by one part of copper to be soluble in the materials and an essential Rope from copper (II) chloride to copper (I) chloride , reduce, where one. the total chloride ion concentration im Relationship to. Water content of the chloride solution at the desired value; and a precipitation of the copper-I-chloride in the Solution by adding a salty metal chloride compound • the one made from potassium chloride, magnesium chloride, my mixture of magnesium and potassium chloride, or a mixture of any of the.

- 3 - D 1821

Prevents preceding substances or substance mixtures with sodium chloride; with a copper recovery stage in which the metallic copper is obtained by reducing the copper chloride in the solution from the reduction stage and the copper chloride is regenerated; and an oxidation stage, which is combined with a regeneration and purification stage in order to avoid the formation of deposits in the system in which the raffinate from the copper recovery stage is reacted with oxygen, whereby
a ferric chloride-containing solution forms which at the same time oxidizes the unreacted material from the reduction ons stage in order to make substantially all of the remaining copper soluble in the material. This creates a solution that contains copper (II) and iron (II) chloride, whereby at the same time the reaction of the iron (II) chloride with oxygen and hydrolysis precipitates compounds that reduce the iron-sulfate ratio of jarosite ("jarosite") exhibit significant proportions in this way
remove iron and also sulphate ions and other impurities from the chloride solution; and with a return
the copper (II) chloride-containing chloride solution to 'Redukti onsstufe.

Other advantages of the present invention will become apparent from the following description, examples, and claims.

In the accompanying drawings, FIG. 1 is a simplified flow diagram of the method of the present invention, in FIG which the oxidation, regeneration and purification stages are combined;

B09829 / 0702

2191010

- 4 - ■ D 1821

Pig. 2 shows a stoichiometric molar balance in diagram form in order to basic chemistry of the process of pig. 1 to be explained in application to chalcopyrite;

Pig. 3 is a flow chart of an embodiment of the method

according to the present invention, in which the oxidation and the regeneration and purification stages are combined;

Pig. FIG. 4 shows a simplified flow chart of the method according to FIG present invention "in which the oxidation and regeneration purification stages are separate;

Pig. 5 is a table showing the effect of chloride ion concentration on the reduction of copper (II) to copper (I) chloride in the embodiment with separate oxidation and Shows regeneration cleaning stage;

Pig. 6 is a table which shows the effect of oxidation and ChIoridionenkonzentration to the reduction of Kupf he II to copper ^ -I chloride, in the embodiment with additional amm close preconceived regeneration purification stage;

Pig. 7 a diagram of the effect of the chloride ion concentrations tration on the reduction of copper (II) to copper (I) chloride in the reduction stage;

Pig. 8 is a diagram of data from a test facility with a comparison of the concentrations of sulfate ions in the in the combined oxidation and regeneration cleaning stage liquids leaking in or out of it, whereby. the process liquid once only sodium chloride and furthermore potassium chloride is added in addition to sodium chloride.

£ 09829/0702

D 1821

US Pat. No. 3,785,944 discloses the possibility of either combining the regeneration-cleaning stage and the oxidation stage or performing them separately. In combined operation, the oxidation stage reaction takes place in the presence of oxygen, which is a condition for the regeneration-purification stage. In this procedure, the reaction of chalcopyrite in contact with the raffinate liquid from the electrolysis stage in the presence of oxygen causes a continuous oxidation of the reaction liquid, i.e. the oxidation of copper-I to copper-II-chloride and iron-II to iron III- chloride depending on the amount of reactive chloride ion present in the reaction solution. To the extent that no sufficient. If the amount of reactive chloride ions is present in order to enable the conversion of all the iron into iron (III) chloride, iron (III) hydrate precipitates out. /

These processes can be explained by the following chemical reaction formulas: _

Reduction stage

2CuFeS ₂ + 3OuGl ₂ -> 4-GuOl +

+ 2S + GuIeS

for electrolysis

for combined oxidation, regeneration and cleaning

509829/0702

Electrolysis stage

D 1821

4-OuCl + FeCl,

2Cu +

product

for combined oxidation, regeneration and cleaning

Combination of oxidation, regeneration and cleaning

+ 2S + 2CuCl ₂ +

z. reduction

₀ + 2Fe (OH) _x + 4S

Residue

The availability of oxygen dictates the final solution reaction, as in the combined oxidation, regeneration and cleaning takes place, offers the advantage of the higher reactivity of iron (III) in addition to copper (II) chloride -chloride and its higher oxidizing power during the reaction, to ensure that the chalcopyrite as | far as possible is made soluble. In the simplified equation is the residue is represented as iron (III) hydroxide, but can be found in the preferably executed form of the invention are present as jarosite.

By controlling the inventory of reactive chloride ions in the process liquid the eventual iron

5 09 829/070 2

- 7 - D 1821

The concentration in the converted liquid can be reduced to almost zero for the benefit of electrolysis. Preferably will however, a minimal amount of iron is retained in the fully converted liquid in the form of iron (III) chloride to ensure that all of the converted copper is in solution present as copper (II) chloride. This provision for additional things reactive chloride ion in the process liquid can be represented by the above-mentioned Process equations adds the following reaction equations:

Ee duct i ons stuf et

2OuFeS ₂ + 3GuGl ₂ - ^ 4GuGl + FeGl ₂ + 2S + GuFeS ₂ 0.1GuFeS ₂ + 0.3FeGl ₃ -> 0.1GuGl + 0.4-FeGl ₂ + 0.2S 2 / ICuFeS ₂ + 3GuGl ₂ + 0 , 3FeGl ₅ -> 4.1GuGl + 1.4FeGl ₂ + 2.2S + GuFeS ₂

Electrolysis stage

4GuOl + FeGl ₅ 2Ou + 2OuCIo + FeCl ₀

0.1GuGl + 0.4FeGl ₀ - * 0.1Gu + 0.3FeGl ₀ + 0.1FeCl,

4.1GuGl + 1.4FeOl ₂ - ^ 2.1Gu + 2CuCl ₂ + 1.3FeCl ₂ + 0.1FeGl,

509829/0702

- 8 - D 1821

Combined oxidation and regeneration cleaning stage

OuIeS ₂ + 2S + 2CuOl ₂ + FeOl ₂ + 3> O ₂ + j> H ₂ O 3OuOl ₂ +

+ 4-S

0.2S + 0.1FeOl ₅ + 0,

0.1 FeOl, + 0.2 FeOl, + 0.1 Fe (OH) ^ + 0.2S

OuFeS ₂ + 2.2S + 2OuOl ₂ + 1.3FeOl ₂ + 0, IFeOl ₃ + 3.3

_2—

It should be noted that the provision for a minimum residual iron content in the converted process liquid of the combined oxidation, regeneration and purification stage - "for example as FeCl _7. - to ensure that the entire copper content of the solution is present as Eupfer-II chloride , on the electrolysis has a compensating effect: The copper dissolved by this residual iron (III) chloride from the process feed solids to the reduction stage causes the regeneration of stoichiometrically equivalent iron (III) chloride in the anolyte when it settles on the cathode of the electrolysis stage one third of the iron (III) chloride originally contained in the converted process liquid from the aforementioned combined oxidation, regeneration and purification stage.

In this way, a means can be identified by which the "com-

5 09829/0 70 2

- 9 - D 1821

combined "process offers the possibility of utilizing the leaching power of ferric chloride on the one hand, in order to achieve maximum solubilization of the chalcopyrite. ensure, and on the other hand a desired limitation the iron content in the electrolyte by controlling the available stock of reactive chlorine ion in the process liquid to reach.

The combined oxidation-regeneration-cleaning remains within the basic teaching of US _{Pat. No. 3 · 785 · 9 ^ 5} cLie teaches an oxidation stage in which the higher oxidizing power of iron (III) chloride is made available in addition to copper (II) chloride is in order to achieve a maximum dissolving power for Ghalkopyrite, and lets this work together with the reduction stage, in which the converted liquid from the oxidation stage with the process raw materials or solids (in stoichiometric excess) is brought into contact, whereby the Eupfer-II -chloride is essentially reduced to KJupfer-I-chloride in preparation for electrolysis. The teaching of the "combined" process contains the disclosure that the simultaneous oxidation-regeneration and purification reaction enables the iron content of the reacted liquid to be reduced almost to zero in a controlled manner. In this way, the iron content of the feed solution for the electrolysis can be limited essentially to the iron dissolved in the reduction stage, which has beneficial effects on the quality of the electrolytic copper produced.

509829/0702

- 10 - D 1821

In addition, the combined oxidation, regeneration and purification have the advantage that the jarosite iron hydrate and other compounds from the regeneration-purification reaction in the presence of the remaining undissolved solids precipitate, which tends to form deposits in the Process plant reduced and limited:

(a) The irregular surface of the solid particles, which in the aggregate is considerably larger than the smooth touched ones Areas of the plant components, offers preferred locations for the crystallization of the precipitated compounds;

(b) The presence of solids in the system leads to a If it is in effect, shower the deposits from the system walls be removed.

The summary of the oxidation and regeneration cleaning stages offers additional procedural advantages., by simplifying the process itself and reducing the requirements for the systems to be used.

U.S. Patent 3,785,944 demonstrates the extremely beneficial effect of maintaining a desired total concentration of chloride ions in the process liquid by increasing the inventory of reactive chloride ions in the process liquid by adding "a suitable salty metal chloride such as sodium chloride, potassium chloride, Magnesium chloride or mixtures thereof "increased. These useful '[_.'_ · ■ ..... ·

509829/0702

- 11 -. D 1821

Effects discussed in US Pat. No. 3 · 785 · W-Regarding. Sodium chloride can be summarized as follows:

1. The solubility of copper (I) chloride is increased.

2. The secondary reaction, which is a loss of supply from the solution in the reduction stage (stage A) "effected is slowed down; an additional reduction performance can thus be achieved.

3. The solubilization · of the copper in the oxidation stage reinforced. - ■.

4-. The oxidation of sulfur to sulfate ions is slowed down.

5. During treatment from reduction to metal extraction s level is the process solution against an atmospheric one Protected against reoxidation of the copper-I-chloride.

6. It will have a beneficial influence on the quality of the produced Electrolytic copper exercised.

It has been "already mentioned that in connection with the corn-" amalgamated Oxidation-regeneration-cleaning a significant reduction in the iron content and the total concentration of chloride ions of the process fluid. After the apprenticeship US Pat. No. 3,785. ° Λ4- is said to be the total chloride concentration by adding a suitable salty metal chloride such as sodium chloride, potassium chloride, magnesium chloride and their Mixtures "are kept at the desired value.

Experience gained in laboratory tests and the operation of test facilities with regard to separate oxidation and j

509829/0702

2SQ1Q1Q

- 12 - D 1821

Regeneration-purification and the iron content of the process liquid (see FIG. 2 of US-PS 3-785-W-) indicated that the desired total chloride ion concentration in the process liquid under these conditions by addition of salty metal chloride, i.e. sodium chloride alone, • reached near saturation point. This result was called Considered acceptable and in U.S. Patent No. 3 x 785 x 9 ^ as "preferred Embodiment "shown, since sodium chloride is usually the most economical of the salty ones Metal is tallchloride.

Further laboratory tests and experience on test facilities, in which the oxidation and the regeneration-purification stage according to the preferably executed process

. Rensweise, as they were represented by the chemical reactions already explained, summarized and simultaneously have shown that all of the desirable chloride ion concentration is not increased by the addition of the salty metal chloride, i.e. sodium chloride alone, can reach near saturation. However, the additional Chloride ion, which is required to compensate for the decrease in chloride ion with the lower concentration of iron related in the process fluid, achieve, by adding magnesium chloride or, preferably, the process liquid, instead of sodium chloride, as added salty metal chloride, which are already almost saturated with sodium chloride

. ' is to add potassium chloride to a concentration sufficient for the combination of these two salty metal chlorides in the

509829/0702

^<: 25Q101Q

- 13 - D 1821

Process liquid almost saturation results.

Preferably, potassium chloride is added to the process liquid in combination with sodium chloride as a salty metal chloride additive, based on the discovery that to the extent that the potassium (along with iron) is available in the process liquid, almost all of it Sulfate ion
as potassium ferrous gas in the regeneration-cleaning reaction
fails. This fact is of particular benefit in terms of preventing deposits in the system parts.

The chemistry of the process fluid in terms of chloride ion concentration in the. Optional operating modes is explained in FIGS. 5 and 6.

The tables give the chemistry of the reduction stage for separate Oxidation and regeneration purification stage (corresponding to the Fig. 2 in U.S. Patent No. 3,785,944) in comparison with the summarized Operating mode, which is the subject of further testing and development in the .present application.

The chemical structure for the reaction system is in moles per 1000 moles of water and also given in percent by weight.

The reaction time was in a stirred, reflux condenser equipped vessel at a constant temperature of

107 ° C kept constant for one hour.

509829/0702

2 5 0101Q

- 14 - D 1821

The data are for increasingly varying total amounts of chloride ions (Cl ") in the feed liquid to the reduction stage specified for each operating mode of the process:

1. Separate oxidation and regeneration cleaning stage

a. 175 moles of Cl "achieved by maintaining the sodium chloride concentration to 71 moles.

b. 155 moles of Cl ", resulting from a decrease in the sodium chloride concentration, to 5.1 moles for the purpose of effect ("for

effect "). .., '· ■

c. 140 mol Cl ", resulting from a reduction in the sodium chloride concentration to 36 moles for effect.

d. 125 moles of Cl "resulting from a decrease in sodium chloride concentration to 21 moles for effect.

2. Combined oxidation and regeneration cleaning stage.

a. 122 mol Cl ", resulting from a reduction in the iron chloride concentration from 32.5 mol FeCl ₂ to 4.0 mol FeCl-.

b. 140 moles of Cl ", resulting from an increase in the sodium chloride concentration from 71> 0 to 80.5 mol (very close to of saturation), and adding 8.5 moles of potassium chloride.

c. 155 mol Cl ", resulting from an increase in the sodium chloride concentration from 71» Ο to 80.5 mol (very close to the Saturation), and adding 23.5 mol of potassium chloride.

d. 175 mol Cl ", resulting from an increase in the sodium chloride _{concentration from 71?} 0 to 80.5 mol (very close to saturation), and the addition of 43.5 mol of potassium chloride.

S09829 / 0702

- 15 - D 1821

e. 175 moles of Cl ", achieved by adding magnesium chloride alone as the salty metal chloride at 62.0 moles per 1000 moles of water.

As can be seen, with the decrease in the total Cl ~ concentration under the conditions outlined above, the reduction from 100 % of the copper (II) ions in the feed liquid to copper (I) ions in the reacted liquid varied in the extremes of 97.3. .. 99.7 % at 175 moles Cl "Ms 75.0 ... 76.9% at 122 ... 125 moles Cl". Even "with the high reduction to copper I ions that was achieved, no copper loss from the solution as a result of the secondary reaction" was noticeable.

In summary, those in the tables show the Pig. 5 and 6 outlined selected numbers have the essential influence of the total chi oridio concentration on the reduction stage (step A), the reaction of the crude copper sulfide concentrates for the reduction of copper-II- to copper-I-chloride. Me the operation With the oxidation and regeneration purification stage kept separate, the total chloride concentration was adjusted by adjusting varied with sodium chloride ITaCl. For the summarized

Operation with a reduced iron concentration was, as already indicated, the compensating addition of the chloride ion by replacement of the NaCl is achieved by magnesium chloride, MgGIp, and alternatively by adding potassium chloride as required the desired total chloride ion concentration over the value achievable with NaGl alone due to its solubility to lift.

509829/0702

250101Q "

- 16 - D 1821

The information given in the tables of the J ¹ Ig. 5 and 6 are shown graphically in FIGS.

The progressive relationship between the total chloride ion (Cl ") concentration and the accompanying reduction of the copper- • -II- to copper-I-chloride in the converted liquid is shown for the range of the total chloride ion concentration, which is 122 ... 175 moles of Cl "per 1000 moles of HgO and alternatively as 16 ... 21 % Cl" is expressed.

As can be seen, with the combined oxidation and regeneration cleaning, the chloride system - with low. Iron content and fortified with sodium and potassium chloride - as shown in solid line in the diagram, a more favorable environment for the reduction of copper-II to copper-I than in the separate Oxidation and regeneration cleaning operation which is a high iron chloride system that uses sodium chloride alone is amplified (cf. the dashed curve in the diagram). This fact is another basis for the already expressed preference for the further addition of potassium chloride - in addition to the salty metal chloride - to the system.

The basic chemistry for the preferably carried out! Form of the process in which · the oxidation with the rain; rier cleaning stage is summarized is in application j Chalcopyrite represented by the stoichiometric molar balance of the figure.

509829/0 702

250101Q

- 17 - D 1821

The essential discovery "already" described, namely that almost all of the suIfation in the process liquid in the Regenerating-cleaning reaction as Kaiiumeisenjarοsit in that. The amount depends on how the potassium ion (together with iron) is available is supported by the operational data of pilot plants graphically illustrated in FIG. As can be seen the sulphate ion content falls in the liquid the oxidation in the presence of only sodium chloride as the salty metal chloride additive sharply to almost zero when one considers the process liquid Potassium chloride adds in the system.

The simplified basic procedure for treatment of copper-containing raw material, in which the oxidation and the Regeneration-cleaning stage are summarized, results from the diagram of Fig. 1; the basic chemistry is through the stoichiometric molar balance of FIG. 2 - in application to ohalcopyrite - explained. What a more complete description relates to the form preferably carried out, but this will now be given in detail with reference to FIG.

In the treatment of copper sulfide ore concentrates, which mainly contain chalcopyrite, the fresh ore concentrates are fed to _{the reduction stage 1, step: A, on line 2 (FIG. 3).} The terms "fresh" or "raw" used here denote copper-containing material that has not previously been reacted in the system with any reactants. Copper (II) chloride, sodium chloride and potassium chloride are used in the Reduktiönsstu-

509829/0 7 02

25Q101Q

- 18 - D 1821

fe 1, step-A, fed via line 3, fresh sodium chloride and addition of potassium chloride into line 3 via the Line 3A.

In the reduction stage 1, step A, the against the atmosphere is essentially complete, the copper (II) chloride becomes essentially reduced to copper-I-chloride in the solution, by reaction with the sulfide ore concentrates at almost the atmospheric boiling temperature, about 107 C · The partially converted Sulphide ore concentrates as well as a certain proportion of unreacted copper (II) chloride, the copper (I) chloride, Containing ferrous chloride, sodium chloride and potassium chloride Solution runs via line 4- to a separator, in which the solids are separated from the solution by gravity sedimentation.

The cupric chloride, cupric chloride, ferrous chloride, sodium chloride and potassium chloride-containing solution from the separation device 5 is then via the line 6 to the reduction stage 7, step B, in which one also enters cement copper via line 8. The cement copper is used to at almost the atmospheric boiling temperature, about 107 ° C, almost that to reduce all remaining copper (II) chloride to copper (I) chloride At the same time, the cement copper is in the form of copper -I-chloride made soluble.

The solution from reduction stage 7 »step B, the copper-I-chloride, iron-I-chloride, sodium chloride and potassium chloride ¹

509829/0702

250101Q

. -. - 19 - D 1821

contains, goes off via line 9 and enters a suitable filter 12 - for example a sand filter - to remove suspended Taking off solids.

If there is a calcium sulphate sal in the process liquid accumulates, the salary can be reduced to an acceptable value, if, in order to remove it from the system, one takes a Kristg.1-lization step provides. The filtered electrolyte solution then runs on line 13 into the electrolyte cells 14 The copper-I-chloride is electrolytically decomposed in cells, whereby metallic copper settles on the cathodes and copper-II- -chloride regenerated at the anodes. At 15 the metallic Copper and possibly silver deposited with it removed from the electrolytic cells 14- ·.

The ferrous chloride, sodium chloride and potassium chloride as well solution containing regenerated copper (II) chloride from the electrolyte cells then goes on the line 16 to the oxidation and regeneration purification stage 19, which via the line 17 also the Solids - including the partially converted ore concentrates from the separating device 5 are fed. With one to about 14O ° G maintained reaction temperature and a pressure of et-,

2 '

wa 60 psig (4.22 kg / cm gauge) is introduced via line 18 air or oxygen into stage 19 where the iron -II-chloride oxidized to iron III-chloride, whereby the copper-II- -chloride acts as a catalyst in the solution. React at the same time iron (III) chloride and copper (II) chloride with the Solids and dissolve the copper from these essentially completely

509829/0702

250IQIQ

- 20 - D 1821

constantly out. These are also included in the procedural solution. dissolved excess iron as well as those present in the system Sulfate ions and other impurities in the form of basic iron oxide and potassium jarosite.

This combined stage is preferably carried out at an elevated temperature in order to reduce the time required for the oxidation and regeneration-cleaning reactions. It is believed that at a temperature above the melting point of sulfur but below the temperature at which the viscosity of sulfur increases abruptly, ie, within the range of about 115 to about 159 ° O, the superheated aqueous solution will remove the molten sulfur displaces the mineral surfaces and prevents them from being covered ("blinding"), which means that three minerals can come into contact with the oxidizing solution. The temperature range is preferably employed is about 14-0 ⁰ G to about 150 ° C. In laboratory tests, which were carried out in accordance with the procedure outlined above at 14-0 ⁰ G and 60 psig (4, 22 kg / cm overpressure) with oxygen at 60 min Copper from the copper sulfide ore concentrates, which consisted essentially of ghalcopyrite and have a typical particle size range.

. After cooling to below the atmospheric boiling temperature, in order to prevent uncontrolled flashing to prevent at what temperature the elementary

! Sulfur is in the solid J form, the resulting [ slurry containing the sulfur, insoluble residues, ■ potassium ■

509829/0702

I ■ til

25Q1Q1Q

- 21 - D 1821

jarosite precipitate, cupric chloride, ferric chloride, sodium chloride and containing potassium chloride, fed into the separator 21 through the line 20. Disconnect in this device the insoluble residue, sulfur and the potassium jarosite precipitate of the copper-II-chloride, Ferrous chloride, sodium chloride and potassium chloride containing solution. This solution is then returned to reduction stage 1, step A, through line 3. The solids are from the gate direction 21 in the line 22 placed in a wash filter 23 where essentially all of the rest Process fluid is displaced. the filtered solids (sulfur, insoluble residue and potassium jarqsite precipitate) are removed at 24 and the recovered liquid of the solution in line 3 through line 25 times added again. The solids can be according to conventional Process further treated to remove elemental sulfur, the potassium jarosite precipitate and any insoluble precious metals to remove.

It has been found that when carrying out the combined Stage at the atmospheric boiling temperature. average response time can be set to 10 or 12 hours must in order to achieve the desired 99% dissolution of copper from chalcopyrite concentrates of conventional particle size ranges. From an operational point of view, the mechanical advantage of atmospheric pressure can be at the expense realize a longer response time.

509829/07 02

250101Q

-22- D 1821

By checking the chloride level in the process liquid the final iron concentration in the converted liquid can be reduced to almost zero in order to achieve this the iron content in the process liquid as low as possible and thus the quality of the in the electrolysis stage generated copper. Preferably, however, a small amount of iron will be left in the reacted liquid (as ferric chloride) to ensure! that the whole converted copper is present in the solution as copper (II) chloride.

Although one embodiment of the present invention with reference to the treatment of copper sulfide ore concentrates has been described, which consist essentially of chalcopyrite, it has also been found that a mixture of such sulfide ore concentrates and non-sulfidic material such as natural copper and copper oxides, carbonates and silicates are also effectively treated in accordance with the present invention Since essentially all copper ores contain chalcopyrite and most other copper-bearing materials contain chalcopyrite Ores are more easily soluble, the process j according to the present invention has the important advantage that leaches virtually any commercial copper concentrate or mixture of copper concentrates.

In a further embodiment of the present invention, as explained in the flow chart of FIG the use of potassium chloride alone or with sodium chloride

509829/0702

250101Q

- 23 - D 1821

proved to be advantageous in the process in which the steps of regeneration-purification and oxidation are separated be performed. The addition of potassium chloride makes potassium ions available in the process liquid, leaving practically all of the sulfate ion as potassium jarosite in the regeneration purification stage can fall out of the process liquid. This point is important for preventing buildup in the plants.

When converting copper (II) chloride from the oxidation stage with fresh chalcopyrite in the reduction stage it has been found that the achievable degree of reduction is achieved by a secondary reaction can be limited, which leads to a loss of copper from the solution. On the basis of the information currently available, it is assumed that that a stable form of copper sulfide precipitates. It has further pointed out that the reaction is temperature sensitive and that by limiting the temperature to atmospheric Boiling point - about 107 ° G - the copper (II) chloride reduction, which is possible with minimal or no loss of copper from the solution, with an average reaction time of four hours can reach. Limiting the temperatures of the reduction reaction can reduce the reaction rate to a certain extent. limit that practical control of the reaction becomes possible.

i A further reduction of the copper (II) chloride from the first | - Step of the reduction stage can be carried out with suitable -Reductions-ί • agents such as sulfur dioxide, sodium sulfite, metallic iron i

50 9829/0702

250101Q

- 24 - ■ D 1821

and metallic copper containing material. To the extent that scrap copper or cement copper is economical is available, its use would obviously be advantageous, as this copper becomes electrolytic copper in the electrolysis stage is refined. In fact, the entire reduction of copper (II) to copper (I) chloride can be carried out with one of these reducing agents carry out.

In the second step of the reduction stage (also referred to as step B ¹ ), the temperature at which the reaction is advantageously carried out varies with the reduction agent used. If, for example, cement-copper or metallic iron is used, the reaction temperature is close to atmospheric Boiling point (about 107 ° C) found to be satisfactory.

In both the oxidation and regeneration purification stage as The reactions are also preferred to the reduction stage Perform without contact with the atmosphere to avoid steam losses to avoid - the same in the reduction stage to avoid oxidation of copper-I- to copper-II-chloride.

It has been found to be advantageous to adjust the temperature of the electrolysis. As the temperature increases, the electrical conductivity of the electrolyte and also the solubility the dissolved salts too; both effects are beneficial. However, the vapor pressure of the hydrochloric acid in the then also rises Electrolyte, which is a disadvantage. Laboratory experiments and operational experience with test systems have shown that a temperature

509829/070 2

^<: .. ί 250101Q

'- 25 - D 1821

a temperature of about 55 G is preferably used, from about 30 ⁰ G "is raturbereich to about 60 ⁰ C for electrolysis acceptable.

It has also been found to be the preferred practice that to clarify pregnant solution before introducing it into the electrolytic cells. This is done to remove small particles that Remain in the solution and the quality of the cathode-.der metallic copper produced by electrolytic cells can adversely affect. The clearing is done by somebody suitable device - e.g. a sand filter.

The electrolysis of the pregnant (food) solution, the copper-I-chloride and contains ferrous chloride, causes a transition of copper ions to the cathode, where they represent metallic copper, and a simultaneous transition of chloride ions to Anode, where they are released in the presence of the anolyte solution and then copper-I-chloride present in it to copper-II-chloride oxidize. With separate oxidation and regeneration cleaning operations the process is preferably controlled so that the electrodeposited copper is no more than about half of the copper I proportion of that fed into the electrolysis pregnant solution.

However, as already stated, with the combined oxidation and Eegenerier-Cleaningbetrieb desired that a small proportion of ferric chloride with the copper (II) chloride is introduced from the oxidation stage into the heduction stage.

509829/0702

250101Q

- 26 - "'D 1821

In this! "All should be undressed in the electrolytic cell The amount of copper is half the copper I content of pregnant women Liquid around the one made soluble by the iron-III-chloride Exceed the amount in the reduction stage. Also, in the anode compartment of the cell, an amount of iron (III) chloride turns into iron (HI). -chloride oxidized, the stoichiometric to the electrolyzed Copper is equivalent and equal to one third of the amount reduced to ferrous chloride in the reduction stage.

The membranes employed in the "electrolytic cells" should desirably be substantially inert to the solution his and a maximum resistance to the hydraulic Solution flow and minimal electrical resistance '. Available materials that meet these conditions, are Teflon, polypropylene, polyethylene "and polyacrylic material, all with suitable - including felted, woven, needled, gas-expanded ("gas expanded") - texture and treated so as to have the desired limited permeability to the solution flow and a minimum electrical Resistance. Other suitable materials are, for example, the membranes used in the electrical desalination of water made of, for example, chlorosulfonated polyethylene films.

The relative solution levels in the catholyte and anolyte compartments of the electrolytic cells are made by overflow-like arrangements controlled so that there is a hydraulic gradient from the catholyte to the anolyte compartment and thus a counterflow of the anolyte solution through the membranes into the catholyte compartments

509829/0702

250101Q

- 27 - D 1821 ■

is avoided. The anolyte solution contains copper (II) chloride .. Dignity let this solution flow back into the catholyte compartment, it would peel copper from the cathode and the electrical Effectiveness of the device "affect.

The practice of the present invention is not restricted to the use of "specific parts of the plant. The steps and methods Step e, which are described here ", can be carried out in batches or continuously and in conventional devices - e.g. reactors, and vessels opened by conventional means or can be completed against the atmosphere. Furthermore, each stage or step, which is described here can also be carried out in one or more reactors or containers. Further lies the use of available in compartments, divided or ■ segmented system units within the scope of the present invention .

509829/0702

Claims (16)

- 28 - D 1821 patent claims 1. Hydrometallurgical process for the production of metallic Copper with a reduction stage in which copper-iron -Sulfide ore concentrates containing materials in an aqueous Chloride solution are introduced, the copper (II) chloride contains in order to make the copper partially soluble in the materials and a substantial part of the copper -II-chloride to copper-I-chloride, and a copper recovery stage in which metallic copper is produced Reduction of the copper-I-chloride in the solution from the reduction stage obtained and copper (II) chloride is regenerated, characterized in that the total chloride ion concentration keeps the chloride solution at a desired value relative to the water content in order to prevent the precipitation of Keeping copper-I-chloride in the solution as low as possible by adding a salty metal chloride compound, those made of potassium chloride, magnesium chloride, a mixture of magnesium chloride and potassium chloride or a Mixing one of the preceding additives with sodium chloride is selected through an oxidation state, which is combined with a regeneration cleaning stage, to reduce deposits in the process plant and in which the solution from the copper recovery stage with oxygen converts to a solution that contains ferric chloride, which at the same time oxidizes the unreacted materials from the reduction step to essentially the to make all remaining copper soluble in the materials and so form a solution, the copper (II) chloride 509829/07 02 - 29 - D 1821 and ferric chloride contains, while at the same time by Reaction of ferrous chloride with oxygen and hydrolysis caused precipitation of compounds including those with the iron-sulphate ratio of jarosite to thereby to remove a substantial part of the iron as well as sulphate ions and other impurities from the chloride solution, and that the chloride solution containing copper (II) chloride returns to the reduction stage. 2. 'The method according to claim 1, characterized in that the total chloride ion concentration is kept at a value the degree of reduction from copper (II) to copper (I) chloride increased in the reduction stage with minimal copper loss from solution. . 3- The method according to claim 2, characterized in that one the chloride ion concentration close to that determined by the solubility the salty metal chlorides in the process solution allowed maximum. 4-. Process according to claim 3, characterized in that one with the addition of salty metal chloride, potassium chloride is also added. 5. The method according to claim 4, characterized in that one the salty metal chloride additive adds potassium chloride in the amount required to achieve the desired Removing as much as all of the sulphate ion by meth- 50 9829/070 2 - 30 - D 1821 dersclilag from the solution. 6 »" Method according to claim 4-, characterized in that one Sodium chloride is chosen as the salty metal chloride with which potassium chloride is added. 7 · Method according to one of the preceding claims, characterized characterized in that the residual iron concentration in the reacted liquid of the combined oxidation and limited the regeneration purification step by controlling the level of reactive chloride ion in the process liquid. 8. The method according to any one of claims 1 to 6, characterized in that that the extraction of iron from the chloride solution in the combined oxidation and regeneration -Cleaning level limited so that sufficient iron remains, to ensure that all of the copper chloride in the finally converted liquid as copper -Il chloride is present. 9- The method according to claim 8, characterized in that the copper by electrolysis in the copper extraction stage. wins and the amount obtained is equivalent to the copper dissolved in the process liquid, the copper-I-chloride oxidizing in the anolyte to copper-II-chloride and furthermore iron-II-chloride in an amount in the anolyte to iron- III -chloride is oxidized, which accounts for a third of the remainder of the iron III- 503829 / Q702 - 31 - D 1821 Chloride is equivalent to that in the final "converted I liquid of the combined oxidation and regeneration cleaning stage is present. 10. Hydrometallurgical process for the production of metallic Copper from copper sulphide ore concentrates, which contain a significant proportion of chalcopyrite, with a reduction stage, in which the ore concentrates in an aqueous, copper-II-chloride containing solution can be added to make some of the copper soluble in the materials and to reduce essentially all of the copper (II) chloride, and with a copper extraction stage in which one metallic copper by electrolysers of copper-I-chloride in the solution from the ßedukti ons stage in electrolytic cells for the production of metallic copper in the cathode compartment and to regenerate the copper (II) chloride in the Anode compartment wins, characterized in that the total chloride ion concentration in the chloride solution relative to its water content by adding a salty metal chloride compound from that of potassium chloride, magnesium chloride, a mixture of magnesium chloride and potassium chloride as well as a mixture of one of the preceding additives i with sodium chloride existing group in an amount, which is close to the maximum permitted by the solubility of the salty metal chlorides in the chloride solution, through an oxidation stage, which is followed by a regeneration-cleaning stage is summarized to deposits in the system parts to prevent in which the solution from the coupling 509829/0702 - 32 - D 1821 fermentation stage with oxygen to form an iron (III) chloride containing solution is implemented, which at the same time the unreacted ore concentrates from the Eeduktionsstufe oxidized to solubilize essentially all of the remaining copper in the concentrates while creating a copper • -Il chloride and a minimal amount of ferric chloride containing solution forms, with simultaneous precipitation by hydrolysis of compounds including those, which have the iron sulfate ratios of jarosite, thereby eliminating both excess iron and excess To remove sulphate ion and other impurities from the chloride solution, and that the copper (II) chloride and the minimal iron (III) chloride content are contained Recirculates chloride solution to the reduction stage. 11. The method according to claim 10, characterized in that the copper generated at the cathodes in the electrolysis stage is kept essentially equivalent to the copper that is dissolved in the chloride solution and therefore υοώ. the oxidation of copper (II) chloride to copper (II) chloride in the anolyte and also of the oxidation of iron (II) chloride to iron (III) chloride in the anolyte in an amount that is one third of the remaining iron (III) chloride in the final converted liquid is equivalent to the combined oxidation and regeneration lowering stage. 509829/0702 - 33 - D 1821 12. Hydrometallurgical process for the production of copper, characterized in that one 1. "at around 107 ° G materials that are mainly fresh Chalcopyrite concentrates contain, with a limited amount of ferric chloride containing copper -Il chloride solution converts to such an essential part of copper (II) chloride to copper (I) chloride and iron-II-chloride, whereby the copper -Il chloride solution contains a sufficient amount of sodium chloride and contains potassium chloride to keep the total chloride concentration near the maximum relative to water, that of the solubility of the sodium and potassium chloride is allowed in the procedural solution; 2. in electrolytic cells the copper-I-chloride in the Solution from step 1 is electrolyzed to produce metallic copper in the cathode compartment and the copper-II - to regenerate chloride in the anode compartment; 3. at a temperature between about 107 ° C and about 159 ° G and a pressure between atmospheric and about 60 psig (4.22 kg / cm gauge) the ferric chloride in the used electrolyte with oxygen in the presence of regenerated copper (II) chloride to convert iron -IH-chloride and copper-II-chloride to regenerate the simultaneously oxidizing the unreacted ore concentrates from the step to essentially all of the remaining Copper in the ore concentrates soluble to ma - 50 98 29/07 02 - 34 - D 1821 chen, and thereby a copper (II) chloride and a limited Proportion of solution containing ferric chloride to train, namely "with simultaneous precipitation of ■ · excess iron as potassium jarοsite by hydrolysis, about excess iron and excess sulfate ion 'as well as other impurities from the copper (II) chloride solution to remove; and that one 4. which make a limited amount of ferric chloride the step 3 containing copper (II) chloride solution for Step 1 leads back. 13- hydrometallurgical process for the production of metalli- ' Shem copper with an oxidation stage in which materials containing copper-iron-sulfide ore concentrates are contained in an iron chloride and solution containing copper (II) chloride are oxidized until the copper content of the materials is in the form has been made substantially soluble by copper (II) chloride, with a reduction stage separate from the oxidation stage, in the at least a substantial part of the. Cuprous chloride in the solution from the oxidation stage is reduced to copper-I-chloride, and with an electrolysis stage e, in which metallic copper is obtained from the reduction stage by electrolysis of the copper (II) chloride solution and the copper (II) chloride are regenerated, and a regeneration-cleaning stage separate from the reduction and electrolysis stages, in which the iron-I-chloride in the solution from the electrolysis stage in the presence of the regenerating * 509829/0 7 02 - 35 - D 1821 ten Eupfer-II-chloride is reacted with oxygen in order to the iron (IXI) chloride required in the oxidation stage to regenerate, characterized in that the copper-II -chloride solution sufficient sodium chloride and potassium chloride contains, in order to keep the total chloride concentration relative to water close to that determined by the solubility of the sodium and des Potassium chloride 'in the process solution allowed maximum hold, and that one goes through the generation cleaning stage Hydrolysis compounds including potassium jarosite precipitate, so does the iron concentration in the process solution as well to keep the level of sulphate ions under control and remove other contaminants from the solution. . 14. The method according to claim 13, characterized in that the total chloride ion concentration is kept at a value the extent of the reduction of copper (II) chloride to copper (I) chloride in the reduction stage with minimal copper loss increased from the solution. 15. The method according to claim I3 or 14, characterized in that that the desired extraction of excess sulfate ions by precipitation by controlling the amount of potassium chloride carried out, which is added to the process solution .. 16. The method according to claim 13 »characterized in that one the desired extraction of excess iron through failure by controlling the stock of available reactive capable Ghloridionen performs in the process solution. Ci / Za ". · J 509829/0702