DE2521690C3 - Process for the selective dissolution of non-ferrous metals contained in minerals and sulphidic concentrates - Google Patents

Description

4. The method according to any one of claims 1-3, considered, since the post-treatment of this characterized in that as a regeneration type of concentrates in the conventional Memittel Hydrochloric acid is used and the pH value 35 tallurgie almost insurmountable difficulties of the solution in the presence of ferrous chloride.

at most 1, in the absence of iron (II) - hydrometallurgical processes for selective

chloride does not exceed 3. solution of metals have already been given;

5. The method according to claim 4, characterized, for example, in DT-PS 6 80 519 (cf. records that the pH value over the throughput 30 Chem. Zentralblatt 1940/1, p. 2237, »Processing the hydrochloric acid used for regeneration from copper-nickel-stone ") describes a process, is trolled. in which the mineral with copper (II) chloride solution

6. The method according to claim 4 or 5, characterized by leaching; from a part of the marked after, that the air throughput to the lye present, the copper is precipitated, Generation is controlled in such a way that the redox 35 regenerates with chlorine while the rest of the caustic solution potential of the solution in the course of the process is that in the electrolysis of the main remains exactly constant. Nickel-containing solution is obtained.

7. The method according to any one of claims 1-3, in FR patent application 74-06765 (cf. DT-AS characterized in that as regeneration 25 08 890) is a method for selective dissolving medium iron (II) chloride as well a solution of non-ferrous substances contained in pyrite minerals is used, the pH of which is given as between 1 and 3 metals. Here, too, the lye is through and its temperature is above 90 ^° C. Injection of chlorine regenerates. The procedure represents

8. The method according to claim 7, characterized in that compared to the prior art one shows that the aqueous solution after the rule shows some progress, but shows a number of generation of a treatment to remove the 45 disadvantages, of which the circumstance particularly is subjected to precipitated Goethits. it should be mentioned that the procedure only

9. The method according to claim 7 or 8, characterized over iron is selective if this is in the form of pyrite characterized in that the regeneration of the aqueous is present. In addition, the use of Solution is carried out so that it contains at least gaseous, elemental chlorine in the application lg / 1 copper (l) ions and 2g / l iron (II) ions 50 and recovery contains great toxicity and corrosion. sion problems with it, too, is the use

10. The method according to any one of claims 1-9, extremely large amounts of chlorine from an ecological point of view characterized in that the leaching is problematic.

a temperature above 50 ^° C., preferably when using chlorine as the oxidizing agent

70-105 ⁰ C is made. 55 also leads to troublesome side reactions, since the

Solubility of chlorine in water leads to direct oxidation of the minerals or concentrates.

is sufficiently high, two such undesirable side reactions are approximately the following oxidation reactions 60 of the sulfur:

The invention relates to a method that it er S ⁰ + 3 Cl + 4 H O-> SO ₄ ² ~ + 8 H ⁺ + 6 Ch

bt, contained in minerals or sulphidic concentrations 224

th contained metals copper, lead, zinc as well as and

thus associated precious metals compared to g ₂ - α. 4 Cl + 4 HO-> SO ² ~ + 8 H ⁺ + 8 Ch

Bring en and sulfur selectively into solution. 65 224

The invention relates particularly to sulfidic The invention is accordingly the object to-

minerals, the non-ferrous metals as sulphides, sulpho- grunde.a method for the selective dissolution of non-imonides or sulfoarsenides in very finely crystalline ferrous metals to indicate the disadvantages mentioned

has and by the content of the output HnSsTn iron and silicon little affected ^3Γ ° ί lobe "the process at a large number * '' Earn and sulfidic concentrates Toggle '° hlr% Sn to. The method of the invention ^We n while in contrast to which the aforementioned FR-ί Ag not be associated with the use of gas production ^a Aer. It is accordingly the appropriate detailed procedures destinations a. for example, demanded ^"erd ™ · / * ^0, ™ maximum amount should jentaj gated on non-ferrous metals , at the same time a part of the sulfur and the pyrite are attacked. On the other hand, it can also be assumed, for example, that a lower dissolution yield is achieved with the non-ferrous metals, in order to compensate for the amounts of

^TO Anseanssprodukt contained non-ferrous metals processing conditions from the following ^lffl U .f nhne that pyrite and sulfur The only important case in detail emerges

aqueous

α = -SS: 55SS

materials and the objective of the respective vcu are consumed:
2 Cu _{+ +} 2 H _{+ +} V. O ^ 2 C- ₊

ShhÄÄ

Presence of Egg ^^

3 in the absence of iron (I) chloride. In Fa iner regeneration with iron chloride and Lu S t, the pH is advantageously between 1 and 3, the temperature above 9O ⁰ C.

It should also be noted that this is in accordance with the invention Process for the regeneration of copper (I) chloride with a mixture of ferric chloride and What is the separation of the iron contained in the solution as an easily filterable hydroxide, which is generally 6o

known as "Goethite" is permitted. "" Change in accordance with the selective open! "Ungsver-

Only the oxidation must enisp'echend hither LÄ3Ä this ι ^ ^u _{^'ll evidenced by} main-

to Fe verm _{untef χ possible 1? t} . _Under

«^ * ^ * _Occurs just a very slow one

Stion desFe ^ a, where the Cu * + without equal-Ox is dat.on des I ^ e, _{+ changed}

ze.Uge B'Wung ^ _{k (ar protrj}

_Legal or legal procedures

that this nut JJ _u ^ _{d Vortdle der Se e} u _tI v, -

tied ^ Jjog _{H. Setting} or simple

totskon oil ^ e ^a J _{chsatzes when} using

Controls ^ ^ ^^ _{or air not achieved}

_{e according to the invention} ,

compared to sulfur and iron

5 ⁶

Set to conventional methods very wide applic- ^^ gSÜ SSSS is ^ S tbS availability and so for example the treatment ^^ "Jf ^ r presence of the solvent in

of iron-rich minerals and concentrates of dissolved, on the other _hand, sulfur in elemental copper, zinc and lead, which by different solution, wainrenuai u

iial flotation have been obtained and so far in the 5 state ^{we have obtained} ";.,. _hin7UWpU . _n

conventional metallurgy cannot be processed j £ ^^^^^^^

This broad applicability is already today in the hydrogen electrode

With regard to the increasing shortage, high nism not above 800 ^ mV.

percent ores of particular interest, since already to doxpotent.al a "'""* ™ _ ⁿ * ^{upMII) Chlond}

increasingly poorer deposits are being mined without corresponding copper chloride.

and raw material sources previously considered unsuitable Example 1

need to be developed. ... . _a . . ■ _T """,,"" _vrin Vimfwm

The technical progress, on the other hand, lies in the example of the leaching of ^ g

the avoidance of corrosion, toxicity and ₁₅ chloride on a ^ ^om ^ .jS ^^? ^l f ±.

ecological risks associated with the large-scale mineral. The zinc ^and .. " ^lead ™ _p ^e _n ^ ™ _nn ^eig " f

Application of elemental chlorine are bound up very badly for ^ «gja" ^^ ⁰ ; ^

as well as in the higher economically-handelsgee.gnete lead and zinc concentrates_ delivered with it

that would be made accessible by being cheap and freely accessible. The product has the following approximate

Air as an oxidizing agent also significantly increases the composition.

can be. _7o - 10 8 ° /

The invention is described ^below with reference to Aus Λ "~ 4 29 ° /

examples of management explained in more detail. Jl, ~ ' ₀ J °

A. Dissolution level ₂₅ S ⁰ = 15%. °

The mineral or starting concentrate is disintegrated. . ,

small and with stirring at a temperature above- The leaching is carried out in two stages

half room temperature in a section of a In the first stage the fresh mineral is _using

Introduced into the reactor, which leached a solution of copper (I) - a solution containing 40 g / 1 of copper (II) ions

and copperdD chloride. Contains 30 and 250 g / l sodium chloride. In the second

The leaching solution also contains a dissolving step, the residue from the first leaching with

medium for the copper chloride, e.g. B. Alkali Chloride, a fresh solution of the same composition

Alkaline earth chlorides, ammonium chloride and iron (II) - added. With each leaching, the corresponds to

chloride. In an industrial application, the introduced amount of the solution 1.1 Qs, based on

According to the method according to the invention, the initial amount of lead and zinc is of course 35, with Qs

a cheap chloride is selected for reasons of cost, the amount specified is that for the corresponding

for example sodium chloride, which is stoichiometric required in a concentration of chemical reactions.

tration of 100-250 g / l is used; depending on which is borrowed. After completion of the conversions, the

starting material to be treated and the respective residue and washed in 410 ml of warm water

However, other chlorides 40 can also be reslurried for process objectives. After analyzing the

to be chosen. the different solutions obtained are the

In this part of the leaching reactor, the solution yields c

metals contained in the mineral or starting concentrate.

Non-ferrous metals in the corresponding metal in the table below

table

composition
(% or g / l) Zn Pb Ag CD Fe Starting mineral 10.8% 4.29% 44g /% 0.03% 9.7% Solution after 1st leaching 8.65 g / l 7.6 g / l 4.86 mg / 1 26 mg / 1 2.9 mg / 1 Yield of dissolution
after 1st leaching 45% 92% 62% 50% 0.02% Solution after 2nd leaching 8.95 g / l 0.87 g / l 2.2 mg / 1 25 mg / 1 22 mg / 1 Washing solution 1.73 g / l 61 mg / 1 3.2 mg / 1 End residue 0.84% 0.18% 6 g / t 30 g / t 12%

Overall yield 94% 97% 89% 92% 0.04%

The results show that the uptake is only an extremely small percentage Solution yields of the non-ferrous metals all over iron in the solution, from which the selectivity of the er-90% in the case of lead, even 97% of the method according to the invention clearly emerged be achieved. In contrast, goes.

B. Regeneration of copperdD chloride can be carried out with salt atmospheric pressure, what how

acid and air already mentioned, a significant advantage of the

represents inventive method.

In this first way of carrying out the regeneration, the following is the composition of the anration, the leaching solution caught by the actual leaching 5 and the solution originating from the dissolution stage are introduced into another part of the reactor, which is equal to a given amount of non-ferrous metals, where air is set with stirring Volume explained in more detail,
introduced under atmospheric pressure and hydrochloric acid to increase the solubility of the formed. The copper (H) chloride is "in situ" copper (II) chloride, the solution should primarily be regenerated and then, in turn, can preferably contain a chloride for the purpose, e.g. B. iron (II) leaching can be used. chloride, alkali and alkaline earth metal chlorides and

Carrying out the two process stages of ammonium chloride. In the case of using

Leaching or regeneration can either be sodium chloride's concentration

in two compartments of the same reactor or in 100-250 g / l.

a single reactor. 15 The initial concentration of copper (II) -

As already mentioned, the different chlorides only have to be determined by the speed

driving parameters determined depending on the nature of the reaction to be required. The inventive

Treating mineral or sulfidic concentrate method according to the advantage that

as well as solutions chosen by the respective procedural objectives can be used in which the ratio

will. In the following, therefore, the determination 20 of the weight of the copper becomes the total weight of the

the physico-chemical conditions in the valuable metals in the treated product is small,

lye reactor explained, d. H. the pH of the solution, which is possible due to the fact that the

and their redox potential as well as the selection of the copper (I) chloride according to its formation

Composition and volume of the initial hydrochloric acid and air is oxidized. It is on the other hand

borrowed leaching solution. 25 it is clear that the oxidation process takes place via the intermediate

During the regeneration stage, the products of the pair copper (I) chloride / copper (II) chlorine

Oxidation reactions that the theoretically required one sets in very slowly when the initial one

borrowed or stoichiometric amount Qs of hydrochloric acid solution contains no copper. The copper used

depends on the mineral treated. The practical concentration is preferably above 5 g / l.

The amount used depends on the diameter chosen. The choice of the initial concentration of copper

management, but is approximately between 1 and also depends on the corresponding procedural

1.05 Qs. aim, whereby the concentration range is advantageous

The pH of the solution must be below 1. 10-50 g / l.

if the solution contains iron (II), the volume of the solution used is the result

and on the other hand be below 3 if the solution is not 35 due to physico-chemical factors. The in

Contains iron (II). The pH may be turbidity obtained by Vcr reactor should not more than about

Change in the throughput of a 30Volum-% solids in the reactor, whereby under

guided air and / or hydrochloric acid in a simple manner taking into account the type of mineral treated

be regulated. or concentrate the ratio of the volume of the

The redox potential of the solution must, as already determined in the solution, for the weight of the valuable metals

mentioned, lie between 400 and 800 mV. The exact one is. In the case of treating a mineral with only

Choosing the potential within this range will contain low levels of copper, lead and zinc

depends within wide limits of the Ar _t of this ratio to bchan- erhöhl; in the case of a concentrate

from the sulfidic product. When working at, on the other hand, the ratio is considerably lower,

a potential in the vicinity of 400 mV a 45 .....

great selectivity for the dissolution of the Nichtiscn- »c 1 s ρ 1 c ι ι

metullc compared to sulfur and iron. The example concerns the attack by hydrochloric acid and

This first type of pH adjustment is in particular air on zinc blende in the presence of copper (li) -

of interest when the sulphides of the considered chloride; the Ausluugcrcuktor as well as the oxidation

Non-ferrous metals compared to copper (U) chloride very 50 reactors are separated by a decoder,

are reactive. It is accordingly to achieve a The device is initially with 3.26 1 Auslaugc-

high yield of dissolution and a high solution filled, with 1.6 I on the Ausluugereiiktor

Selectivity then not required, with a high and 11 on the oxidation reactor and the

Potential to work. On the other hand, when the product is left in the decanter. The solution owns

is of lower reactivity, the following composition can nevertheless be 55:

a potential close to 40OmV set _Cu » ₊ _, 15 _B / | ( _tl i _s CuCU)

if the main objective of the procedure is the NuCl = 120 a / l
Is selectivity and not yield. In most

Filling the potential will close to a value. The solution of the Ausluugcraktors will boil

increased from 700 mV to a high yield to βο heated, d. H. to a temperature of 103 "C while

achieve, even if this results in a little more iron and the solution in the oxidation reactor to 80 "C

Sulfur are dissolved, heated, then, at the time of 0.100 g

The potential is preferably determined by changing the aperture with the following composition

of the throughput of the Zn introduced into the reactor = 54 7! /

Air held at a constant value, 65 _s . ^ '^ \\ y

The retraction temperature must be above 50 ⁰ C and * '"

cheating preferably 70-105 ⁰ C. introduced into the Ausltuigercaktor.

The processing steps for the leaching can be carried out at the rate of flow from the oxidation reactor

coming solution that enters the leaching reactor is 1.5 l / h, while the throughput of the Return of separated material from the decanter to the leaching reactor is 0.5 l / h. The throughput of the oxygen introduced into the oxidation reactor is 160 l / h. In the oxidation reactor 6 N hydrochloric acid is also introduced, the throughput of which is determined by the pH. The The process lasts 16 h, during which the development of the content of Cu + ions as well as the potential is followed in the leaching and oxidation reactor. After 16 hours, 260 ml of hydrochloric acid solution are added and recovered 37.0 g of leach residue containing 2.7% zinc. The zinc yield of the process is 98.1% accordingly.

Example 3

The example concerns the leaching of blende with hydrochloric acid and air in the presence of copper (II) chloride, the leaching and the oxidation reaction being carried out in the same reactor.

The experiment is carried out in a cylindrical reactor with a stirrer, the bottom of which consists of a porous plate consists of a glass frit. At time 0 the reactor is filled with 1 l of the leaching solution and 30 g aperture loaded. The materials used have the following compositions:

Leaching solution:
cover

Cu ²¹ = 15 g / l (as CuCU)
NaCl = 120 g / l
Zn = 54.8%
S = 31.4%.

The temperature in the reactor is maintained at 90 "C", while the pH value by the automatic addition of about 6 N hydrochloric acid at a constant value was kept at 1.5.

After 5 h and 35 min, 52 ml of hydrochloric acid are added and 17 g of residue with a content of 36% won. The dissolution yield of the zinc is correspondingly 62.7%.

Example 4

The procedure is as in the previous example, a Blci-Kupfcr concentrate being used as the treated product, which comes from a Blci-Ontkupfertingswerk and contains about 44.5% copper, 37.1% lead and 16.5% sulfur.

At time 0 the reactor is charged with 11 leaching solution containing 30 g / l of kipfcr (] [) ions in the form of CuCl ₁ and 220 g / l of sodium chloride. 80 g of the lead-copper (I) concentrate are also introduced into the reactor and the temperature is ^{kept at 85 °} C. for 5 hours, the pH being kept at 2.0 by adding about 12 N hydrochloric acid. The flow rate of the air introduced into the reactor is about 200 l / h.

Determinations made in the course of the leaching allow the effectiveness of the oxidation of the copper (I) ions by hydrochloric acid and air to be established. The process is ended after 4 hours, after which the solution is filtered; the leaching residue is washed with an acidified saline solution of a concentrate tone of 270 g / l in order to remove the not completely dissolved lead chloride.

Finally, 12 g of residue are obtained,

which contains 0.35% copper and 0.38% lead. The process yield is accordingly:

99.9% for copper and
99.8% for lead.

Example 5

The example concerns the leaching of a massive pyrite with hydrochloric acid and air, the leaching

ίο made in a single reactor section will.

The experiment is carried out in a cylindrical reactor with stirring, the bottom of which consists of a porous plate consists of a glass frit. At time 0 1 1 of the leaching solution and 270 g become more massive Pyrite introduced into the reactor. The leaching solution contains 15 g / l copper (i;) ions in the form of copper (II) chloride and 120 g / l sodium chloride. The massive pyrite used has the following composition:

Zn = 4.25%

S = about 45%

Fe = about 40% (pyrite).

Because of its fine crystallinity, the product ^ 5 is difficult to concentrate by flotation.

The temperature in the reactor is kept at 9O ⁰ C, while the pH is maintained by automatic addition of about 6 N-hydrochloric acid to 2.0. Air is introduced through the porous plate at a rate of 160 l / h.

The process is carried out for 5 hours 10 minutes, 46.8 ml of hydrochloric acid being added during this time will.

When the leaching is complete, 288 g

moist residue obtained. After washing

with water the residue contains 0.55% zinc. the

leaching yield based on zinc is

with this method, this corresponds to 86.1%.

Examples

The example concerns the leaching of a complex concentrate from the flotation of a mineral with hydrochloric acid and air, the reactions of leaching and oxidation with stirring in the same cylindrical reactor can be made with a porous bottom plate.

At time 0 it becomes 11 of the leach solution and 50 g Concentrate introduced into the reactor. The leach solution contains 15 g / l copper (II) ions in the form of Copper (II) chloride and 120 g / l sodium chloride, the concentrate has the following composition:

Zn = 21.7% Pb- 9.08% "Fe = 12.2%.

The temperature in the reactor is kept at 9O ⁰ C. Air is introduced into the liquid through the porous base plate at a rate of 160 / h.

βο In the course of the leaching, the potential development or the copper (I) ion content of the solution is monitored. The presence of a significant one The amount of copper (I) ions indicates insufficient oxidation, which increases the air flow.

«5 sentence is required.

The process is ended after 1 hour. At this point, 62 ml of about 6 N hydrochloric acid are added, Then 40 g of moist residue are obtained,

which, after washing with water, has the following composition:

0.96% lead
0.85% zinc.

The process yields are accordingly:

for lead: 91.6%
for zinc: 96.9%.

The results show that the excellent yields achieved in a very short time which is a further advantage of the method according to the invention from an economic point of view.

C. Regeneration of the copper (II) chloride with
Ferrous chloride and air

The already mentioned regeneration of copper (II) chloride with iron (II) chloride and air under atmospheric pressure has the further advantage that a total leaching process is available stands, which is completely selective towards iron, since the iron, which is in the form of unaffected Pyrite could not be selectively removed, in the form of goethite after a transition stage of solution of iron (U) chloride is removed.

Depending on the type of products treated, the regeneration stage of the copper (II) chloride can go through Oxidation of the iron together with the regeneration method described above or others Place to be used.

To carry this out, part of the solution used for leaching is introduced into the second section of the reactor, which accordingly contains copper (I) chloride and ice (II) chloride if the leaching was not completely selective. In this other section, the iron is oxidized to goethite, after a liquid-fcst separation has been carried out to remove the unaffected residue and the elemental sulfur from the leaching process.

In this part of the leaching process, in which the copper (I) chloride is oxidized to copper (II) chloride and the ice (II) chloride to goethite FcO (OH), the corresponding process conditions, in particular the pH value, must be strictly observed .

It is particularly not possible to oxidize under Atniosphürendruck iron (II) to goethite, if not at the same time, the acidity formed in these reactions is continuously neutralized. According to the invention, the neutralization can be carried out very easily due to the special conditions. To use up the acidity formed, it is sufficient to introduce excess air into the reaction medium, which results in a hydrolysis reaction of the iron and a regeneration of the copper (II) chloride. The reaction is very easy at atmospheric pressure when the pH is between 1 and 3.

From this point of view, it is advantageous if the emerging from the reactor and to be returned to the actual leaching intended solution at least 1 g / l copper (I) ions and 2 g / l iron (H) ions contains to adjust a pH value above 1 and below 3.

Numerous ίο carried out by the Applicant showed that the reaction temperature must be above 9O ⁰ C, so that the obtained goethite slurry having good filtration properties.

It is of course sufficient if only a part of the total is used at this stage Volume is treated accordingly in the leaching. The exact amount depends on the selectivity leaching against iron as well as the requirements resulting from the separation and purification stages

ao nissen related to the leaching take place.

Example 7

The example concerns the precipitation of goethite starting from a mixture of copper (l) chloride and ferrous chloride, which serves as a solvent for copper (I) chloride.

The solution is representative of a solution obtained by leaching a sulfidic concentrate with Copper (II) chloride is available.

A solution with the following composition is poured into a reactor with a porous bottom plate brought in:

Cu ¹ = 33.0 g / l (as CuCl)
Fe ^ ----- 162 g / l (as FeCl ₂ ).

The temperature is maintained at 95 C 2 ⁰ -J--, wherein compressed air is introduced with a through salt of 160 l / h.

When the process is complete, the solution is filtered off and the insoluble material is dried. In this way 34 g of iron oxide hydrate with the following composition are obtained:

Cu :. 2.65%
Fe - 46.6%.

From the results it can be seen that a part of iron in a solution containing copper (H) chloride dissolved in ice (i!) chloride, selectively as ice

so oxide hydrate can be separated.

The concentration of the solution in copper (I) ions is on the other hand measured at Deginn as well as at the end of the test. The concentration changes from 33 g / l to 8.0 g / l, from which it can be seen that eir

ss significant part of the copper (II) ioncn during dci Separation of the iron was regenerated.

Claims (3)

- Contain 2 form, which is why a concentration is extremely difficult and in many cases impossible even through total flotation. Such mines 1. Process for selective dissolution in mines will be, apart from the sulfuric acid minerals and sulphidic concentrates contained 5 production, as good as not degraded, although they are Non-ferrous metals by leaching considerable reserves of non-ferrous metal waste hold with an aqueous copper (II) chloride. dissolving and regenerating this solution, d a- The invention further relates to the treatment characterized in that the copper is made of complex ore concentrates, which at the same time (II) chloride solution in situ with air under atmos- pheric galena or galena, cover or zinc cover and spherical pressure and hydrochloric acid and / or iron (II) chalcopyrite as well as significant amounts of pyrite chloride is regenerated as a regeneration agent. hold, which according to conventional procedures for 2. The method according to claim 1, characterized in that copper, lead and zinc are not processed draws that the aqueous copper (II) chloride can be. solution also a solvent for the copper (l) - 15 Carrying out a differential flotation Containing chloride, such as alkali and alkaline earth metal, is impossible in numerous cases, or the FIo- chlorides, ammonium chloride and ferrous chloride. tation requires a complicated and costly 3. The method according to any one of claims 1 or 2, complex mineralogical treatment sequence. In characterized in that the aqueous copper- this case can have a global concentration of the (II) chloride solution a non-ferrous metal that is often drawn into the eye by flotation on the hydrogen electrode Redox potential of 400-800 mV can be considered and good recovery yields shows. . to lead. However, this possibility was not common