DE3333992A1 - Process for the recovery of metals from used hydroprocessing catalyst particles - Google Patents

Abstract

The metals to be recovered are composed of at least one metal of group VIII of the Periodic Table of the Elements and at least one metal of groups Vb or VIb of the Periodic Table of the Elements. The used catalyst particles are initially roasted at a temperature between 400 and 600 DEG C and then contacted with a first aqueous solution of ammonia and an ammonium salt with formation of a first enriched liquid. The once-leached used hydroprocessing catalysts are contacted with a second aqueous solution of sulphur dioxide with formation of a second enriched liquid. The metals from the second enriched liquid are precipitated using hydrogen sulphide and the precipitate is roasted with unroasted used hydroprocessing catalysts. The metals of groups Vb and VIb in the first enriched liquid are transferred into a first organic solution by liquid iron exchange. The first organic solution is stripped by an aqueous stripping solution and the metals are isolated by sequential precipitation. The metals of group VIII are isolated and purified by pure liquid ion exchange.

Description

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Process for the recovery of metals from used hydroprocessing ^ Catalyst particles '''·'

The invention relates to leaching and recovery methods of metals from spent hydroprocessing catalysts.

A modern development in crude oil processing is the quality improvement of metals and sulfur containing Raw materials, such as crude oils and residues, through hydroprocessing methods. One Such quality improvement is necessary to make the heavy starting material more valuable and lower convert boiling fractions and remove impurities, especially metals and sulfur, welcl 3 may pollute the atmosphere during incineration.

Crude oils contain various dissolved impurities, like nickel, vanadium, iron and sulfur. The lighter fractions are often under atmospheric pressure or distilled off under a partial vacuum, the metals remaining in a high-boiling fraction, uie is generally referred to as the residual fraction. Residual fractions generally contain at least 35 ppm metal impurities and often up to 100 ppm and in extreme cases more than 1000 ppm. These metals as well as any sulfur present are removed, leaving the starting material is improved by processing the starting material with a catalyst in the presence of hydrogen Such catalysts exist generally a solid support containing catalytic metals, either molybdenum or Tungsten with either nickel or cobalt. When using the catalyst, metals separate from the Ausgamys-

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material on its outer surface and the inner surface of its pores, which may cause the Pores become clogged and the activity of the catalyst is reduced to such an extent that that it no longer delivers the desired product quality. Such catalysts are called spent catalysts designates and contains catalytically ^ metals, _eine inorganic carrier matrix, metals that have been removed from the starting material, sulfur compounds as well a hydrocarbon-containing residue.

In recent times the available crude oils are becoming heavier so that the refineries are forced to produce larger quantities of hydroprocessing catalysts than previously required were used to remove metals and sulfur from the starting material. It is therefore possible that a shortage of valuable catalytic metals, especially cobalt, occurs. It was therefore tried to both the catalytic metals and the catalyst supports and obtain a reusable source of catalytic metals. Included Attempts have been made to extract the metals from the hydroprocessing catalysts, especially from hydrodesulphurisation and hydrodetallation catalysts.

A general method of leaching hydroprocessing catalysts is described in U.S. Patent 3,567,433. An aqueous ammonia and ammonium salt leach solution is contacted with the used catalyst particles. The conditions of the system, however, were not optimal, so that only a low level of metal recovery was achieved. !

Another leaching process is described in "Chemical Abstracts",

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^A 94: 178649x. Containing a spent catalyst containing aluminum, vanadium, nickel, cobalt and molybdenum, is with Amironiak and ammonium salts at line ^ temperature of more els 110 ⁰ C and under an oxygen

° partial pressure before. leached more than 1 kg / cm ² for monr than 1/2 h.

Other methods of recovering metals from spent demetallization and desulfurization catalysts are known. U.S. Pat. No. 4,216,113

. writes the chlorination of spent catalysts to convert the vanadium into vanadium tetrachloride as well as the nickel in nickel chloride when recovered by solvent extraction. The US PS 4,145,397 describes the recovery of metals from spent catalysts by roasting at high temperatures Temperatures and leaching with an alkaline solution.

An article in Engineering and Mining Journal, May 1978 Page 105, describe a plant for processing spent catalysts that do not contain cobalt, by first leaching with sodium hydroxide and then with ammonium carbonate.

Cobalt is a metal that is particularly difficult to remove from hydroprocessing catalysts using conventional aqueous leaching methods. Under optimum leaching conditions len I can Auslauglö- an aqueous' solution of ammonia and an ammonium salt hardly more than about 50% of the cobalt on the spent catalyst to be removed. It has been found that when spent catalysts are leached with a first aqueous solution of ammonia and an ammonium salt and then leached with a second aqueous solution, sulfur dioxide is dissolved in the

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^ is', the total cobalt recovery is over 90 ° s of the metal that was present in the spent catalyst used.

The invention relates to a method of recovery the metals from spent hydroprocessing catalyst particles, these metals being composed of at least one metal from Group VIII of the Periodic Table of the Elements and at least one metal from groups Vb and VIb of the Periodic Table of the Elements. The method consists of the following levels:

(a) Roasting the particles in an atmosphere "containing molecular oxygen at a temperature between 400 and 600 ⁰ C,

(b) leaching the particles with a first aqueous solution, which contains ammonia and an ammonium salt, at a temperature that is below atmospheric Boiling point of the first aqueous solution, with a first enriched liquid and once leached Particles accumulate,

(c) separating the once leached particles from the first enriched solution,

(d) leaching the once leached particles with a second aqueous solution that contains sulfur dioxide, with a second enriched liquid and twice there are leached particles,

(e) separating the second enriched liquid from the twice leached particles,

(f) precipitation of metal sulfides from the second enriched one Liquid by adding hydrogen sulfide,

(g) Roasting the precipitated metal sulfides with fresh spent catalyst in stage (a),

(h) converting the metals in the first enriched

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Liquid of the groups Vb and VIb in a ει: st α

organic solution through liquid ion exchange. (i) Stripping the mecallo from the first organic

Solution with an arstan aqueous stripping solution, δ (j) separation of the metals by successive röl-tande precipitation,

(k) selective conversion of metals from group VIII ..as Periodic Table of the Elements of the first enriched Liquid into at least one second organic solution by series liquid ion exchange and

(1) Stripping each of the second organic solutions to form aqueous solutions containing -.iinsojne metals.
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The invention is illustrated by the attached drawings explained. Show it:

Fig. 1 is a flow sheet showing details of the exit stages according to the present invention;

Fig. 2 is a flow sheet showing the entire Fliersenema according to the present invention;

3 shows a Raman spectrum of a new vanadium bicarbonate complex. !

The following are preferred embodiments of the invention explained.

Leaching

Metals that are loden on hydroprocessing catalysts are, in particular the combination of Mickel, cobalt, Molybdenum and vanadium can be consumed at the same time

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fcen hydroprocessing catalysts by using a aqueous leaching solution from ammonia and an Aniraoniurr.-salt removed. Used Hydroprocessiag catalysts can be regarded as high quality ore, ° that a certain metal composition ^ ufv / eisc. That Leaching is the method of choice for metal removal from this particular ore because the carriers are porous and the metals are individually known to be leachable. However, about the separation of the metals to simplify and enable maximum recovery of the inorganic carrier matrix "in an intact state," should the chosen leaching conditions not allow iron, an impurity frequently found in oil, to or inorganic carrier leached out.

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One of the more valuable metals in a spent catalyst is cobalt. Typically, less than 50 % of the cobalt is leached from the catalyst using an aqueous ammonia solution. It has been found that by contacting the catalyst, once leached with an ammonia leaching solution, with a second aqueous leaching solution in which sulfur dioxide (SO-) is dissolved, more than 90% of the total starting amount of cobalt contained in the unroasted spent catalyst is present to recover.

To simplify processing, it is preferable to 'to process a stream containing aqueous metals. An aqueous ammoniacal one is best suited Current. To the metals, which by the aqueous'30 -, - solution have been leached into "the ammoniacal solution To transfer, the metals are precipitated as sulfides. The metal sulfides recovered in this way become with non-roasted spent catalyst

'55 mix and roast again 'and roast with it again

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aqueous ammoniacal solution leached. The first enriched liquid, the metals-containing product of the first aqueous solution, therefore has an equilibrium value of cobalt, which is greater than in the case that the feed consists only of spent catalysts consists.

The spent catalyst which is obtained from the catalytic reaction vessel ^v is heavily contaminated with carbon- ^ gen deposits, referred to as "coke", and sulfur. These contaminants can be easily removed by burning in an atmosphere containing molecular oxygen, such as air, but it has been found that the amount of metals leached from the catalyst particles, particularly nickel, is reduced when the Catalyst is roasted at too high a temperature. . Preferred conditions for the reaction with oxygen are a temperature of less than 600 ^° C., preferably between 400 and 500 ^° C. The temperature can be controlled by diluting the oxygen with nitrogen or by other known methods. The catalyst treated in this way is free of substantial amounts of carbonaceous residue and the metals contained therein can be easily removed by a first aqueous leach solution. The first aqueous leach solution is a solution of ammonia and an ammonium salt. Such a solution is alkaline and preferable in terms of solubilizing vanadium and molybdenum and contains free ammonia, an effective complexing agent for nickel and cobalt. Ammonia and ammonium carbonate solutions are particularly well suited since they allow reagent to be cycled out by distillation of the enriched liquid and reabsorption in fresh or recycled aqueous solution. Is ammonium sulfate

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another preferred ammonium salt for practicing the invention. Nickel and cobalt are free from Cations and form amine complexes, and molybdenum and vanadium are in the form of anionic oxide ions and form ammonium salts.

The catalyst support of the spent catalyst particles often consists of aluminum oxide. Mixtures of aluminum oxide as well as other refractory inorganic Oxides, for example silicon dioxide, boron oxide, magnesium oxide and titanium oxide, as well as carriers that are natural Occurring clays containing aluminum oxide, for example kaolin or halloysite, can according to the Process according to the invention are leached.

It should be noted that the catalyst is typically in the form of uniformly shaped particles, elongated extrudates or spherical particles. Other shapes can be according to the invention Procedure to be processed. The catalyst can be crushed or otherwise processed to its To change shape before applying the invention.

In a buffered system, such as an ammonia and ammonium salt leach system, two factors must go into one optimal extraction can be set, namely the concentration of the ■ leaching species and the pH of the leaching solutions. The solution must contain sufficient ammonia to remove the nickel and cobalt complex present to bind, and sufficient. '! close to ammonium ions, to control the pH. The pH should not be lower than 9.5, otherwise the degree of recovery suffers from molybdenum and vanadium, and should not be higher than 11, otherwise the degree of recovery of nickel and Cobalt is deteriorated. A concentration of ammo

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nia (NH ^ (aq) ₍ hereinafter referred to as ammonia, plus NH ₄ (aq), hereinafter referred to as ammonium, of no more than 6 molar, the ammonia concentration approximately corresponding to the ammonium ion concentration, meets these requirements. The solution preferably has an at least six times the molar ratio of ammonia compared to the amount of cobalt ions plus nickel ions calculated from the spent catalyst particles, the molar concentration of the ammonium salt

! Ö should not exceed a value of approximately 2 molar, otherwise a vanadium complex will precipitate. A particularly preferred leaching system is such a system which the ammonia concentration is initially substantially equal to the ammonium ion concentration, where both species are present in approximately 2 molar concentrations.

The leach time has been found to be important for maximum cobalt recovery. To increase cobalt recovery, the catalyst particles should not be in contact with the deposit solution for a period of time greater than 15 minutes. The temperature . the leaching is also important. In general, as the temperature rises, any other species will go. into the solution, but a practical upper limit is the boiling point of the solution at atmospheric pressure, above which a pressure vessel is required. In practice, a temperature between approximately 85 and 95 ° C has been found to be optimal. After 15 min at about · 85 ⁰ C, the leach solution typically contains more than 85% of molybdenum, about 75% to 80% of nickel, 75 to 85% of vanadium and at least 45% of the cobalt (these percentages refer to the Weight of the amount of metal in the solution compared to the amount of metal on the spent catalyst

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before leaching). Less than 0.1 % of the alumina and less than 5% of the iron is extracted.

The once leached catalyst particles are then contacted removed from the first-enriched liquid and a second aqueous solution of sulfur dioxide / either by direct bubbling SO _n in the leaching tank or by separate preparation of an aqueous solution of SO ₂ and inserting this previously prepared solution in the leach tank is established. The temperature of this solution should be between 65 and 100 ^° C. and preferably between 80 and 100 ^° C. Since it is preferable to leach out as much metal as possible with as little solution as possible, it is preferable that the second solution be as saturated as possible in SO ~.

The twice leached catalyst is then removed from the second enriched liquid and the metals dissolved therein are precipitated by adding hydrogen sulfide to the solution. The typical precipitated metals have been found to be about 5% nickel, about 2% molybdenum and vanadium, and about 35% cobalt, the percentages being based on the amount present on the unroasted catalyst. The precipitated metal sulfides are removed from the second enriched liquid and mixed with unroasted spent catalyst. The mixture is roasted and leached with ammonia. The temperature of the second enriched liquid should be lowered ^{to a value between 10 and 30 0} C before the precipitation with H _{9 S.} A concentration of approximately 0.1 molar H ₉ S in the second enriched liquid causes rapid precipitation of the metals sought.

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The alumina support of the catalyst tends to leach into the second aqueous solution. Typical Amounts can be up to 10% of the total alumina. Because iron does not come from hydrogen sulfide is precipitated, the invention allows easy separation of the valuable catalytic metals from the less valuable contaminant metals.

Extraction of molybdenum and vanadium

The first enriched liquid of the ammoniacal leach is extracted sequentially with various liquid ion exchange reagents. The meta11ions searched for can be divided into two categories. Metals fall into the first category. Group VIII, especially cobalt and nickel, which are present as cations in the enriched liquid. In the second category all metals of groups V and V, in particular molybdenum, tungsten and vanadium, which are present in the enriched liquid as oxyanions. In carrying out the invention in practice \ will the oxyanions extracted first. The metals of groups V and VI are converted into a first organic solution by a first liquid ion exchange. The extraction can be carried out directly using an enriched liquid from an ammonia and ammonium salt solution. This solution typically has a pH of about 10 to 10.5. The preferred organic extractant is a quaternary ammonium compound of the general formula RR ¹ ^ Cl, where R is methyl and R ^{1 is} a group between Cg and C ^ ₂ . Such organic extractants are available from the Henkel Corporation under the product

/ ■ Rv

Aliquat ^ 336 and Sherex Chemical Co.

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marketed under the trademark Adogen® 464 and are available from Aldrich Chemical as methyltricaprylammonium chloride in impure form.

The quaternary ammonium compounds are in organic Solution, preferably in a hydrocarbon solution, for example kerosene, before, such Solution with a paraffinic alcohol such as decanol, can be conditioned. Contacting the aqueous phase with the anion exchange reagent causes one Extraction of both molybdenum and vanadium. The reaction can generally be expressed as follows:

Ma ^Y ~ + y_ RAR Ma + A ^X ~,

^X

where χ and y are small integers in typical Way, between 0 and 10, and M is any group V or VI metal oxyanion, while R is any organic substituent, which is the quaternary amine makes it sufficiently hydrophobic. It was fixed

(S)
indicates that when Aliquat 336 is the anion exchange reagent, the extraction tends to be limited by molybdenum in equilibrium ζμ. In practice it has been found that the use of multi-stage extraction units results in an easier extraction of molybdenum than single-stage extractions.

Stripping and recovery of vanadium and molybdenum

The metals are then from the organic phase in the aqueous phase by means of an aqueous solution of Bicarbonate or carbonate or stripped of other anions. A preferred stripping solution is a saturated

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te aqueous solution of ammonium bicarbonate, and has a pH of about 8 and a temperature of about 0 to 3O ⁰ C. It has been found that the stripping appears to be limited by the vanadium. If one knows that vanadium is present, then a bicarbonate stripping solution is particularly suitable for stripping vanadium from the organic phase.

The overall process sees the leaching of consumed Catalysts with an aqueous solution of ammonia and an ammonium salt before, then it is preferable that the stripping solution is a saturated solution of ammonium bicarbonate. In this way no new Ions, introduced into the streams allowing easy recycling of the streams to earlier stages of the process. Ammonium is preferred as ammonium metavanadate is a preferred product of this process.

If vanadium is present, it can be recovered from the aqueous solution by adjusting its pH to about 7 by adding concentrated HCl. Chloride ions have proven to be important for the kinetics of vanadium metavanadate precipitation (cf. Zhurnal Prikladnoi Khimii, 43, pages 949-954, 1970). Excess ammonium chloride is added to the aqueous solution and any undissolved ammonium chloride is removed by filtration to give a saturated ammonium chloride solution. The solution is heated to 75 to 8O ⁰ C for 20 min, then slowly cooled to about 30 min ⁰ C for a period of about 30th The solution is cooled further to approximately 0 ^° C. for 3 h. Crystals are collected by filtration while the solution is in the cold state and washed with cold H2O.

The "obtained aqueous Losu.kj can either molybdenum or Tungsten or no metals at all. The molybdenum or tungsten can du.-ch lowering the volume of the Solution until the metals begin to separate out can be obtained. The precipitation can be achieved by adding a.

suitable ions to form a less soluble salt, for example calcium hydroxide can be added to precipitate the less soluble calcium molybdate.
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Extraction and recovery of cobalt and nickel

The metals of group VIII, which are still in the first enriched solution, are each selectively converted into an organic solution by serial liquid ion exchange convicted. Any organic solution thus formed is then stripped, whereby an aqueous solution containing the 20th Group VIII metal is obtained. The most prevalent metals in the group hydrodesulphurisation or hydrodesulphurisation catalysts, which are present in the enriched liquid, are. Nickel and cobalt.

Nickel is extracted with an organic nickel extractant. Preferred organic extractants are oximes. The hydroxyoxime component corresponds to the general formula

OH MOH
· '—C - r-n'

R ''

wherein R, R 'and R "are selected from a variety of organic hydrocarbon radicals such as aliphatic solid and

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Alkylaryl radicals, can consist: R "can also be hydrogen. Preferably, R and R ^{1 are} unsaturated hydrocarbons or branched alkyl groups which contain about I 6 to about 20 carbon atoms. R and R ¹ are preferably the same. represents hydrogen or unsaturated hydrocarbon or branched alkyl groups containing about 6 to 20 carbon atoms.

Suitable oximes are described, for example, in US Pat

3,224,873, 3,592,775, 3,455,680, 3,428,499, 3,276,863, and 3,197,274. A particularly suitable extrusion agent consists of 2-hydroxy-4-nonylbenzophenoxy: u, which is a primary extraction agent in a preparation which also contains a CK -hydroxyoxime and of

ig) by Henkel Corporation under the trademark LIJC ^ 64N. Also of note are 8-diethyl-7-hydroxy-5-dodecanone oxime, which is the primary extractant in a formulation sold by Henkel Corporation under the trademark LIIC 63, and 2-hydroxy-4-dodecylbenzophenoxime, which is the primary extractant is in a preparation that also contains a ^ '- hydroxyoxime and from the Henkel Ο

will.

kel Corporation under the trademark LIX 64

The preferred extractant consists of LIX ^ 64N. This agent contains about 46 to 50% β-hydroxybenzophenoxime and about 1 to 2% of an aliphatic »Λ-Hydroxyoxime in a hydrocarbon diluent like kerosene. This extractant causes an almost quantitative extraction of nickel and ensures a very high degree of separation with respect to Nickel (II) versus cobalt (III).

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Nickel is stripped from the extractant by any suitable stripping solution such as sulfuric acid.

Cobalt is then extracted when performing the serial extraction. The cobalt in the enriched liquid is in the trivalent oxidation state and must be reduced to the divalent oxidation state before it can be easily extracted by conventional cobalt extractants. Cobalt (III) is conveniently reduced to cobalt (II) by contacting the cobalt (III) solution with cobalt metal. A form of cobalt metal for this reduction is ^v cobalt meal.

The cobalt (II) is then πι it an extractant, which is a metal chelating ß-diketone extractant contains, extracted. A preferred extractant is the ß-diketone of the formal

wherein η is 1 to 4, m is 0, 1 or 2 and R is a Denotes an alkyl group having 1 to 25 carbon atoms. The compounds and their preparation are described in U.S. Pat 4,152,396 and are marketed by Henkel Chemical under the trademark LIX 51.

Other organic cobalt (II) extractants are the oximes, dioximes and diketones, as described above as nickel extractants have been described. Will be the same extractant · for both cobalt and for

If G5 uses nickel, the "selectivity" can be achieved by the

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-21-1. The oxidation state of the cobalt can be set.

Suitably, the metal chelating β-diketone extractant is dissolved in kerosene with about 10 to 15% of a conditioning agent. Advantageously, the conditioning agent consists of an alcohol containing about 10 carbon atoms, with decanol being preferred. A preferred hydrocarbon is kerosene. An example of a preferred hydrocarbon is Kermac ^ 470B, marketed by Kerr-McGee. The ratio of metal chelating ß-diketone to the alcohol to the hydrocarbon to be used depends on various aspects, for example the speed and completeness of the phase separations and the concentration of cobalt in the liquid to be extracted. If Decanol and Kermac ⁴ * 470B are selected as alcohol and hydrocarbon, respectively, then the optimal decanol concentration is approximately 15 percent by volume, with a concentration between approximately 10 and 20 percent by volume being appropriate.

The maximum loading capacity of cobalt (II) on the 5 percent by volume ß-diketone extraction solution is approximately 2.6 g per liter. Beyond this value, precipitation begins in the organic phase. An organic solution containing about 5% by volume of the β-diketone extractant is typically sufficient to remove all of the cobalt from an ammoniacal leach solution of the spent catalysts. It is therefore preferable if the organic extractant solution for the spent catalysts contains approximately 5 percent by volume ß-diketone and approximately 15 percent by volume decanol and approximately 75 to 85 percent by volume Kermac ⁰ 47 0B. Suitably the extraction step is carried out at a temperature between about room temperature

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and about 40 ⁰ C and carried out in one or in two stages of a countercurrent extraction. The loading of a ß-diketone extraction solution with cobalt (II) is strongly pH-dependent. Cobalt (II) loading begins in weakly acidic solutions, with the maximum loading occurring between a pH of 7.5 and 9.5. Adjusting the pH by evaporating the ammonia from the aqueous leach liquor prior to the extraction of nickel therefore facilitates cobalt (II) extraction. If necessary, the pH at this point can be further adjusted by adding sulfuric acid or ammonium hydroxide, depending on whether the pH needs to be adjusted up or down. It has been found that extractions in solutions with less than 50 g / l ammonia concentration are beneficial.

The organic phase, which contains cobalt, can be stripped by various alternative methods. One The traditional stripping method that is widely used is the stripping of the cobalt with sulfuric acid for recovery of cobalt sulfate in the aqueous phase. Another suitable stripping method is the use of an ammonia and ammonium salt solution for stripping cobalt from the organic phase. Another method is adding of other metal ions, for example copper (II) or nickel (II), in order to remove the cobalt from the organic extractant and to convert it into an aqueous solution .

The aqueous solutions of the Group VIII metals that are produced in accordance with the invention can be further used to produce pure metal or a salt which can be used directly for Formation of a new catalyst can be used, processed. Nickel or cobalt can be electrical or be reduced directly by hydrogen gas. the

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Aqueous solutions of nickel or cobalt can be used directly as a metal source for the impregnation of new catalysts be used.

The drawings are explained in more detail below.

Fig. 1 shows in detail the leaching stages according to the present invention. Spent catalyst is roasted at 400 to 600 ⁰ C. The roasted catalyst is then mixed with an aqueous solution that is so

probably contains ammonia and an ammonium salt. The "temperature of this leaching" will be held at about 90 ° C. The first enriched liquid is in the manner shown in FIG further processed. The once worn out Ka

talysator is contacted with a saturated solution of sulfur dioxide 65-100 ⁰ C and preferably between 80 and 100 ⁰ C. The second enriched liquid is from the two-mil. removed catalytic converters that are discarded. The second enriched liquid is then contacted with the hydrogen, precipitating the metals from solution. The precipitated metals consist primarily of cobalt and molybdenum. The precipitated

Sulphides are again added to the roasting stage and roasted again and then again with the ammoniacal one Solution drained. In this way, essentially all of the cobalt is recovered, furthermore an ammoniacal current, which for the

Further processing can be used.

Fig. 2 shows the entire flow diagram according to the present invention Invention. Metals are made from used Kat ;; - analyzers, which are known to be cobalt,

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Containing nickel, molybdenum and vanadium.

The catalyst is first roasted and leached in the manner described. The first enriched Fluid then becomes a quaternary. Amine extracted, two first streams can be obtained, namely an organic stream containing molybdenum and vanadium, and an aqueous one Electricity containing cobalt and nickel. The first organic stream is mixed with an aqueous solution stripped of ammonium bicarbonate. Chlorwas

Hydrogen acid is added to the aqueous stripping solution and ammonium metavanadate precipitated. The volume of the solution is then reduced and ammonium molybdate failed.

Excess ammonia is removed from the first aqueous stream by heating the solution. The remaining first-enriched liquid is the Einwix ^- kung exposed to air, in order to ensure that the cobalt is in the trivalent oxidation state. It is then extracted with L1-% 4N, the nickel being removed and two second streams being obtained, namely an aqueous stream containing cobalt and any impurities and an organic stream containing nickel. The second organic solution is then stripped with sulfuric acid to give an acidic nickel-containing sulfate solution. The cobalt in the second aqueous stream is reduced over cobalt meal and extracted with LIX 51, two third streams being obtained, namely an aqueous and an organic stream.

The third aqueous stream again becomes the leach stage supplied, which is enriched in ammonia, which is removed from the q: ammonia distillation stage. The third

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- The ^1st organic stream is stripped with a solution of ammonia under ammonium carbonate.

Using the flow sheet shown in Figure 1, a process is provided which is fully compatible with ammoniacal leaching. Therefore, the enriched liquor from the leach should be in an aqueous ammoniacal solution.
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Examples ^v

The following examples illustrate the various examples according to the invention Stages.

example 1

This example shows the ammoniacal leaching stage ■ according to the present invention.

A spent hydrodesulfurization catalyst that Contains 1.45% by weight cobalt and 6.75% by weight molybdenum, is obtained from a pilot plant. The catalyst particles contain metals in addition to the catalytic 1.62% by weight nickel and 6.24% by weight vanadium and 9.86% by weight hydrocarbon-like deposits and 12.3 wt% sulfur.

The catalyst particles are in a bed with a: mm depth of about 19 for 3 hours and then roasted h at 438 ° C for 3 h at 310 ⁰ C. The temperature never exceeds 450 ⁰ C. Upon completion of the roasting hab.in the particles 10.2 parts by weight S lost its original weight. This weight loss is due to the

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dation and the subsequent loss of. carbon and returning sulfur to the atmosphere.

A leach solution is prepared by dissolving 179 g (NH.) “CO- in 1 liter of an aqueous 2M solution of NH ₄ OH. 98 g of catalyst particles that have been roasted in the manner described above, are placed in a 5 1 flask is heated to 85 ⁰ C. Aliquots are taken every 5 minutes and analyzed by ICP (inductively coupled plasma) to determine the metal content.

Table I shows the results. 15th

Table I. [Nij L HO ί {VI;? E | '· ■ e \ 73
73
35 rf 6
86
H 6 74 zo
76 5 ^ 7 i. · , Time (min) ■ j
10 % of the extracted metals [CoI 47
47
44

The concentrations of nickel, molybdenum and vanadium in the leach liquor increase with the passage of time, but the concentration of cobalt decreases after approximately 10 minutes. The leach time can be varied to increase the amount of metal sought. Since phosphorus can affect the processing of the leach liquor and is not a valuable metal to be recovered, the leaching is preferably stopped when the solution contains small amounts of phosphorus. Even in the case when this example is leached at 85 ⁰ C, the spent catalysts can still at any tem-

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temperature of the solution be leached between 75 ⁰ C and the boiling point, but the leaching is carried out preferably between 85 and 95 ⁰ C.

Example 2

This example shows another anunoniacal leach according to the present invention. 10

Spent hydrodesulfurization catalyst, which contains 1.4% by weight of cobalt, 6.3% by weight of molybdenum, 2.2% by weight of nickel and 4.2% by weight of vanadium, is kept at 427 ^° C. for 2 hours roasted in a gentle stream of air. After essentially all of the carbonaceous and sulfurous residue has been burned off, rusting is stopped. After the particles have been cooled, they are introduced into 1 l of a solution which has been prepared by dissolving 200 g (NH _{4 I 2} CO ₃ in 1 l of an aqueous 2M ΝΗ, ΟΗ solution.

The solution is analyzed for its metal content after 20 minutes and 180 minutes. The results are shown in Table II.
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Time (min)

20 30 1-.J0

Table II Metals i ^ *! % extracted (MO i n / A
■ ρ [CcI [mil ■; y
0 7 i'i 71
31 33

It can be seen that with a marked increase in the leaching time, more nickel, molybdenum and vanadium

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dium can be obtained, but the cobalt yield drops considerably.

Example 3

This is another example of one according to the invention ammoniacal leaching.

Spent Hydroprocessincj catalyst particles are roasted at various temperatures and then ₄ OH solution is introduced into a solution of 1M (NH ₄ J ₃ CO ₃ dissolved in a 22t NH, with the exception of the test at 850 ⁰ C, in which a 0, 5M (NH ₄ )., CC ^ solution is used in a 2M NH ₄ OH solution. Aliquots of the solutions are removed after 15 minutes and 180 minutes and examined for metal content by ICP. The results are shown in Table III.

Table III

Roasting temperature

25th Co
Mon
Ni
V 427 ° C. 600 ⁰ C 26th
74
46
73 760 ⁰ C 34
89
28
107 85 0 ° C. 15th 180 15th 180 15th 180 15th 180 metal min min min mm min min min min % Metals extracted 48
89
71
68 31
97
83
87 46
70
45
70 32
81
19th
103 32
52
8th
80 15th
62
21
81

The values represent % of the metals extracted into the solution compared to the metal content on the non-leached catalyst.

Nickel recovery suffers when the

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ture of the used Kataiysatorteilchen to values above 600 ⁰ C is increased. None of the metals in the solution are leached to a greater extent after roasting at temperatures greater than 427 ° C than is the case after roasting at 427 ° C. Cobalt extraction is in. generally better after 15 minutes at any roasting temperature than after 180 minutes at the same roasting temperature. It is generally most convenient to stop the leaching of the present invention after about 1 hour.

Example 4

This example shows the SO2 leaching of the present invention. 30.00 g of the spent catalyst from a pilot plant are leached for 6 0 min in 600 ml of a saturated aqueous S0 _o solution. The temperature of the leaching is 85 ^° C.

Fe

Table IV

Ni V

Al

Co

Lead ppm 6200 7200 21100 353900 14500 13500 Follow-up ppm 3900 6200 18300 372400 3900 13400 percentage

leached 49.38 '30, 71 30.21 17.65 78.36 20.13

Analysis of the forerunners, tailings and the final percentages of leaching are shown in Table IV.

Example 5

This is -} in another example of the S0 _o -suqung according to the present invention. 9 g of the consumed Ka; ; i-

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lysators from the pilot plant are leached in 170 ml of a saturated aqueous solution of SO ₂ at 88 ° C. for 180 minutes.

The analyzes of the foreruns, onward runs and the percentages of the leached metals can be found in Table V. emerged.

Fe Tabel V Co Mon 1914 Ni V 23000
2577
91.09 8800
7869
28.86 Flow ppm
Follow-up ppm
percentage
drained 8500
3064
71.28 13000
7527
53.94

Example 6

This example demonstrates the extent of metal precipitation from the SC ^ leaches that stem from the previous two examples. The metal sulfides are precipitated by bubbling H_S through the solutions, which have been cooled to room temperature and have a pH between 3.5 and 4.0. The percentage of metals removed from each SO ₂ leach liquor is shown in Table VI.

Table VT

Solution 1 2

Co

97.7
97.3

Mon

Ni

> 98.6
90.1

p-94.9

92.7 58.2

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¹ example 7

10

15th

This example shows a co-extraction of molybdenum and vanadium from an enriched liquid. The pH of the aqueous solution is varied. It is found that the most efficient extraction occurs at a pH of 10.4, which is the most practical value possible in an ammoniacal solution. An organic extraction solution consists of 10% aliquots ^& 336 in kerosene to which 10% dodecanol has been added. The aqueous feed solution has 2.4 g / l molybdenum, 3.1 g / l vanadium and a pH of approximately 10.1. The pH is increased by adding NH-OH and by adding H-SO. degraded. The aqueous phase and the organic phase are brought into contact at room temperature in a separatory funnel. The volume of the aqueous solution corresponds to the volume of the organic solution. The results are shown in Table VII.

pH 25 ^C

10.4

10.1

9.6

10.1

Contact time (min)

10 10 10 20

g / i

organic

1.06 0.86 0.60 0.88

Table VII
Mon

aqueous

"aq.

0.83
0.53
0.32
0.49

g / i g / i organically rig

2.83
2.97
3.11
3.14

0.43 0.40 0.43 0.41

aq.

7.1 7.4 7.8 7.8

30th

Example 8

35

This example shows the effect of varying the bicarbonate concentrations on the simplicity of the Stripping of metals from a solution of 10% Ali-

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quat ^iV 336 in 10% decanol and kerosene, loaded with both molybdenum and vanadium. Aqueous solutions with the concentrations of NH ₄ HCO- indicated below. are produced: 6.84, 13.68, 20.52, 100.0 and 200.0 g / l. An aqueous to organic ratio of 1: 1 is maintained for all concentrations.

The results of the tests are shown in Table VIII emerged.

pH Tabel VIII At the end pH 8.29 At the beginning Mon 8.73 [NH ₄ HCO-.]
fs -J 8.20 Md * aq. (g / l) 8.52 g / i 8.20 org. (g / l) org. (g / l) 0.26 8.42 6.84 8.21 3.3 2.9 0.68 8.07 13.68 8.34 . 3.3 2.5 1.1 8.41 20.52 3.3 2.1 2.9 100.00 3.3 0.4 3.7 200.0 pH 4.0 0.3 At the end pH 8.29 At the beginning V 8.62 [NH ₄ HCO ₃ ] 8.20 V * aq. (> g / l) 8.45 ■ g / l 8.20 org. (g / l) org. (g / l) 0.025 8.36 6.84 8.21 6.3 6.132 0.081 8.07 13.68 8.34 6.3 6.140 0.182 8.45 20.52 6.3 6.010 2.070 100.00 5.2 3.476 3.360 200.00 5.2 1.247

* The analysis of the metal concentrations in solution is carried out by atomic absorption.

Example 9

Two organic solutions, one with 3.3 67 g / l

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Molybdenum, loaded onto 10 I of Aliquat 336 in 10 "s decanol in kerosene, and the other with 6,292 g / l vanadium, loaded to 10% of Aliquat 336 in 10 ΐ decanol in kerosene and two other aqueous solutions, one with 20 g / l NH ₄ HCO ₃ and the other at 200 g / L NH ₄ HCO ₃ are made A variety of organic to aqueous ratios are selected and the results are shown in Tables IX and X.

pH 20 g / l NH ₄ Table IX HCO ₃ pH 200 g / l NH ₄ HCO ₃ 8.97 8.70 Relationship 8.93 org. (g / l) aq. (g / l) 8.52 org. (g / l) aq. (g nis 8.87 3.019 1.389 8.35 2.517 9.412 15/1 8.59 2.994 1.459 8.22 1.562 14,182 10/1 8.40 3.189 1,540 8.09 1.036 11,871 5/1 8.19 2.606 1,313 8.02 0.431 6.096 2/1 8.19 2.217 1.097 8.03 0.248 3.315 1/1 8.19 0.517 0.808 8.00 0.151 1.743 1/2 8.17 1.182 0.428 8.00 0.100 0.705 1/5 0.660 0.266 0.119 0.350 1/10 0.635 0.179 0.127 0.234 1/15

Table IX shows the values pens of the iMo solution.

regarding the strip

Table X

pH 20 g / l NH ₄ HQ) 3 aq. (g / l) BATH PH 200 g / l NH ₄ HCO ₃ aq. (g / l) COPY Relationship 9.03 0.162 8.52 * nis 8.97 org. (g / l) 0.175 8.35 org. (g / l) * 15/1 8.6 6.412 0.179 8.32 5.228 * 10/1 8.44 6.306 0.177 - 5.326 * 5/1 8.53 6.144 0.178 8.10 3,850 5,700 2/1 8.25 6.080 0.151 8.03 2,310. 0.251 1/1 8.17 6.104 0.137 8.00 0.743 1,112 1/2 8.17 5.715 0.112 8.02 0.800 1/5 8.20 5,690 0.100 7.99 0.186 0.385 1/10 * Precipitation '5.131 ORIGINAL 0.352 1/15 5.050 0.277 is available.

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Table X shows the values relating to the stripping of V from the organic solution. An unusual feature of the 200 g / l NH ₄ HCO ₃ stripping solution is a greenish color which is not predominant in the enriched aqueous solution that is present in the 20 g / l NH ₄ HCO ₃ solution. It is believed that this is due to the formation of a previously unknown vanadium compound. ■

Example 1 0

The greenish solution of Example 8 is determined by Raman spectroscopy analyzed.

Table XI

Transition energy (cm " ¹ ) 1063

1019 917 888 674 633 438 347

intensity

middle

very strong very strong

spicy

weak

weak

middle

weak

Assignment

CO.
j

HCO.

2-

2-

Vanadium V carbonate complex ρ

co / -

HCO ₃ "

Vanadium V carbonate complex Vanadium V carbonate complex

Raman spectroscopy strongly suggests vanadium-V-carbonate complexes. Table XI shows the Raman bands of some vanadium-containing solutions and their assignment. All solutions are brought to a pH of 8.8 adjusted using either nitric acid or sodium hydroxide. Sodium bicarbonate solutions, containing vanadium show intense Raman bands 923 cm and moderate bands at 4 35 cm and 35 4 cm, as can be seen from FIGS. 3B and D. Neither vanadium

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free sodium bicarbonate (Pig. 3C) nor bicarbonate free Metavanadate solutions (Fig. 3A) show these bands. It has also been found that vanadium bicarbonate solutions are usually are characteristically light green in color believed to be due to the complex.

Example 11

This example shows the results of stripping both Mo and V together from a loaded organic Solvent with 200 g / l NH4HCO, solution. An organic solution is made that contains 3 g / L molybdenum and 6 g / l vanadium dissolved in a kerosene solution containing 10% Aliquat® 336 and 10 3 decanol. Various proportions organic to aqueous are tried. The values are shown in Table XII below.

pH org. (g / l) Table XII org . (g / i) aq . (g / i) Relationship
nis 8.49 0.168 aq. (g / l) * 15/1 8.51 0.077 * 5.175 * 10/1 8.52 0.104 * 4.226 * 5/1 ■ 8.29 0.051 * 4.664 * 2/1 8.16 0.030 * 2.166 * 1/1 8.01 0.015 * 0.750 0, 321 3, 048 1/2 8.03 0.008 0.083 0, 234 1, 305 1/5 8.00 0.007 0.034 0, 211 0, 603 1/10 8.00 0.012 0.016 0, 349 0, 393 1/15 0.011

* Made insoluble ppt.

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Example 12

This example shows the preparation of a cobalt (II) solution from an aqueous solution initially containing both nickel and cobalt. '

Spent catalyst particles from a pilot hydrodesulfurization plant containing cobalt and molybdenum as catalytic metals are used, which particles have been in contact with a feedstock containing high levels of vanadium and nickel as impurity metals. The catalyst particles are leached with an aqueous ammonium carbonate / ammonia solution at a pH of approximately 10.5. After heating the solution to evaporate sufficient ammonia so that ammonia plus ammonium equals approximately 25 g / l at a pH of 9, nickel is extracted with LIX * ^ 64N in kerosene. The solution is then passed through a column with cobalt meal and containing the raffinate from this column, 2.975 g / l cobalt, extracted with 5% by volume LIX ^5- 5 1% in 10% decanol, and 85 Kermac® 470B at 50 ⁰ C . The organic solution obtained is stripped with 2 molar ammonium carbonate solution in 15 molar ammonia solution, the pH of which has been adjusted to 10.27 by adding sulfuric acid. Approximately 25% of the cobalt from the LIX 51 is removed during each contact with the ammonia stripping solution. After a few countercurrent extractions, the cobalt (II) carbonate solution obtained is evaporated to give a cobalt-containing brown powder which is believed to consist of a mixed oxide / carbonate salt.

The cobalt (II) carbonate solution can be sent directly to the catalyst manufacturer delivered or processed to produce a cobalt product.

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Example 13

Various organic solutions containing cobalt in LIX " ¹ 51 solution are stripped with aqueous solutions of ammonia and ammonium carbonate, the organic solutions are 5% LIX® '51, 85% Kermac ^" 470B and 10% decanol. The concentration of cobalt in the organic phase is 2.65 g / l in the case of 3M and 5M ammonia and 3.1 g / l in the case of 15M ammonia. The volume ratio organic (O) / aqueous (A) is varied. The results are shown in Table XIII.

Table XIII .

Cobalt stripping with ammonia solution Organic phase: 5 2 LIX " ^V 51, 85 ο KERMAC ^ 4 7 0B and 10% DECANOL, temperature 50 ⁰ C, organic concentration / aqueous concentrate (g Co / 1)

Stripping solutions 5 58 5 3 , 05 3 , 08 / 0.23 , 88 / 0.045 , 73 / 0.025 ■ NH ₃ M 15 2.5 2.5 1.5 , 81 3 , 04 / 0.31 2.82 / 0.028 (NH ₄ ) ₂ CO ₃ M 2 , 42 , 47 3 , 02 / 0.16 2 Kjeldahl NE ₅ 206
(g / i) ' ^Δ 27 10 ,: , 31 10.4 10.27 , 28 3 .01 / 0.12 pHpjp 10, , 51 , 17th 2.86 / 0.081 Volume phases
ratio (O / A) 2.72 / 0 , 53 , 094 2 15/1 2.69 / 0 , 97 2.98 / 1.21 3.0 / 1 , 015 10/1 2.45 / 0 , 30 2.94 / 0.82 2.98 / 0 , 03 5/1 2.28 / 0 , 23 2.83 / 0.52 2.86 / 0 2/1 2.00 / 0 , 15 2.84 / 6.32 2 ', 82/0 • 1/1 1.74 / 0 , 22 2.67 / 0.21 2.77 / 0 1/2 1.49 / 0 BATH 2.45 / 0.12 2.52 / 0 1/5 1.32 / 0 2.34 / 0.077 2.97 / 0 1/10 1.05 / 0 2.06 / 0.06 2.61 / 0 1/15 ORIGINAL

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The values show that the cobalt passes more easily into the aqueous phase from the organic phase in the case of 1SM ammonia than in the case of 5M or 3M ammonia. Therefore, at a higher concentration of ammonia stripped more cobalt if the pH was kept at about 10.5.

The present examples illustrate the invention without restricting it.

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Claims (16)

Patent claims INSPECTtU 1. Process for the recovery of metals from used up Hydroprocessing catalyst particles, the metals being selected from at least one metal selected from the group VIII of the Periodic Table of the Elements and at least one metal from the group consisting of the Belong to groups Vb and VIb of the Periodic Table of the Elements, characterized in that (a) the particles are roasted in an atmosphere containing molecular oxygen at a temperature between 400 and 600 ^{0 C,} (b) Particles with a first aqueous solution containing ammonia and ammonium salt at a Temperature to be leached, which is lower than dot: atmospheric boiling point of the first aqueous solution, a first being enriched ϋ * 8000 Munich 2 Isartorplatz 6 POB 26 02 47 D-8000 Munich 26 Cable: Telephone Telecopier Infotec 6400 B Ti Muebopat 089 / 221483-7 GII + III (089) 229643 5- Liquid and once leached particles are produced, (c) the particles once leached from the first
separated from the enriched solution, (d) the once leached particles are leached with a second aqueous solution containing sulfur dioxide with a second enriched liquid and twice leached particles, (e) separating the second enriched liquid from the twice leached particles, (f) Metal sulfides precipitated from the second enriched liquid by adding hydrogen sulfide will, (g) the precipitated metal sulfides with fresh consumed Roasted catalyst in stage (a) will, (h) the Group Vb and VIb metals contained in the first enriched liquid into one
first organic solution are transferred by liquid ion exchange, (i) the metals from the first metallic solution be stripped with a first aqueous stripping solution, (j) the metals separated by successive precipitation will, (k) selectively the metals of Group VIII of the Periodic Table of the Elements of the first enriched Liquid into at least one second organic solution by series liquid ion exchange be convicted and (1) each of the second organic solutions stripped
are obtained, aqueous solutions are obtained,
which contain individual metals. 2. The method according to claim 1, characterized in that the spent hydroprocessing catalysts deposited on alumina. 3. The method according to claim 1, characterized in that the first aqueous solution has a pH between 9.5 and 11 and the concentrations of ammonia plus ammonium do not exceed a value of 6 molar. 4. The method according to claim 1, characterized in that the pH of the second aqueous solution is between 2.5 and 3 is held. 5. The method according to claim 1, characterized in that that vanadium is the Group Vb metal and bicarbonate in the first aqueous stripping solution and one greenish solution is generated in step (i) with a Raman spectrum of FIG. 3B. 6. The method according to claim 1, characterized in that that the metals of groups V and VI include oxyanions of the group of metals consisting of molybdenum, Tungsten and Vanadium are made. 7. The method according to claim 1, characterized in that the first liquid ion exchange using a quaternary alkyl ammonium salt is carried out as a phase transfer agent. 8. The method according to claim 1, characterized in that the first stripping solution contains bicarbonate ions. ORIGINAL INSPECTED -A- 9. The method according to claim 2, characterized in that vanadium is precipitated in stage C and the Stripping solution is cooled. ° 10. The method according to claim 4, characterized in that that the molybdenum is precipitated by reducing the volume of the stripping solution. 11. The method according to claim 1, characterized in that the metals of Group VIII of nickel and cobalt exist. 12. The method according to claim 1, characterized in that that the nickel is in a divalent state and the cobalt. is in a trivalent state. 13. The method according to claim 12, characterized in that in step D the nickel is extracted with an extractant selected from the group which consists of dioximes and hydroxyoximes. 14. The method according to claim 13, characterized in that that the trivalent cobalt is reduced to divalent cobalt and the divalent cobalt with an extractant which is selected from the group consisting of dioximes, hydroxyoximes as well ß-diketones. 15. The method according to claim 1, characterized in that the aqueous solution containing the metals also contains ammonium and ammonia, the first stripping solution Contains ammonium ions and the majority of stripping solutions contain ammonium ions and ammonia. 16. The method according to claim 15, characterized in that that ammonia is removed by distillation before step (d).