JPH06248367A - Method for recovering valuable metal from waste catalyst - Google Patents

Abstract

PURPOSE:To easily separate and recover valuable metals in a waste catalyst using alumina as the carrier, such as No, Ni, Co, V, Al, etc., in high yields by calcining the waste catalyst, dissolving it into sulfuric acid together with the catalytic metals to be dissolved and subjecting the resulting solution to extraction sulfiding and adsorption successively. CONSTITUTION:The waste catalyst using the carrier consisting essentially of alumina is defatted and calcined at 400 to 1000 deg.c. The resulting calcined material is dissolved into sulfuric acid together with the catalytic metals to be dissolved to obtain the original solution to be extracted. This original solution is extracted with an organic Mo extractant and Mo is recovered from the Mo contg. organic phase of the Mo extractant. Then the residual solution resulting from the Mo extraction is extracted with an organic V extractant and V is recovered from the V contg. organic phase of the V extractant by stripping it out. Further the residual solution resulting from the V extraction is brought into contact with gaseous H2S and the Ni and Co in the solution are recovered as their sulfides. The minute amounts of Ni and Co in the finally recovered solution are adsorbed and recovered with a chelate resin to obtain a high purity aluminum sulfate solution. Then the Ni and Co adsorbed on the chelate resin are liberated from it with sulfuric acid and the liberated solution is repeatedly returned to the above reduction and dissolution processes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering valuable metals from a spent catalyst using a carrier mainly composed of alumina.

[0002]

2. Description of the Related Art Hydrodesulfurization catalyst widely used in the organic chemical industry as a catalyst in which molybdenum, nickel, cobalt, etc. are supported as an active metal on a carrier made of alumina or a material obtained by adding a small amount of silica to alumina. There is. The hydrodesulfurization catalyst is poisoned by heavy metals such as vanadium and nickel carried in from the treated oil during use, and the catalytic activity gradually decreases. Then, after being used for a predetermined time, it is discarded as a so-called waste catalyst.

However, randomly discarding these spent catalysts has many problems not only in terms of environmental pollution but also in terms of resource saving and resource reuse. The recovery of valuable metals has been an essential issue, and various methods for recovering valuable metals from waste catalysts have been studied, proposed, and partially implemented in order to solve this problem.

These conventionally proposed methods are roughly classified,
There are a method of recovering only vanadium and molybdenum, and a method of recovering vanadium, molybdenum, nickel and cobalt. U.S. Patent No. as belonging to the former
There are methods described in 4,087,510 and JP-A-47-31892.
For example, the method described in U.S. Pat.No. 4,087,510 discloses the addition of caustic soda or sodium carbonate to a waste catalyst, and roasting vanadium and molybdenum into a water-soluble soda salt,
These are leached with water, and vanadium and molybdenum are separated and recovered from the obtained leachate.The method described in JP-A-47-31892 discloses a roasted product obtained by oxidizing and roasting a waste catalyst. Add caustic soda or sodium carbonate, roast soda,
Vanadium and molybdenum are made into a water-soluble soda salt, leached with water, and vanadium and molybdenum are separated and recovered from the obtained leachate.

In these two methods, nickel and cobalt in the spent catalyst form a complex oxide with alumina by heating and roasting at high temperature, or alumina itself produces γ-Al ₂ O ₃
The crystal structure of α-Al ₂ O ₃ (also known as corundum) is converted to extremely stable against acid and alkali, so that vanadium and molybdenum are selectively leached into the leachate. Therefore, from the viewpoint of recovering only vanadium and molybdenum, the above two methods can be said to be extremely ideal, but from the viewpoint of recovering all the valuable metals in recent years, they are completely useless. I can say.

The latter method of recovering vanadium, molybdenum, nickel and cobalt is suitable from the viewpoint of recent times, and a method proposed to solve this problem is disclosed in JP-A-47-21387. Publication, JP-A-54-10780
The method is described in Japanese Patent Application Laid-Open No. 1-73998.

For example, in the method described in JP-A-47-21387, a waste catalyst is oxidized and roasted to remove organic substances and sulfur contained therein, and then ammonia water is used to apply atmospheric pressure to a pressure. By leaching under pressure, V, Mo, Ni, Co, etc. contained in the waste catalyst are leached and recovered. The method described in Japanese Patent Laid-Open No. 54-107801 discloses a method of removing waste catalyst from 300 After oxidizing and roasting at about 1000 ° C, chlorine gas is further added, and V, Mo, N contained in the waste catalyst is added.
I, Co, etc. are chlorinated to form a water-soluble chloride, and this chloride is leached out. The method described in JP-A-51-73998 discloses a method in which a waste catalyst is roasted in a steam atmosphere to produce a waste catalyst. After removing organic substances and the like adhering to the catalyst, V, Mo, Ni, Co, etc. contained in the waste catalyst are leached using a high-concentration acid. However, the leaching rate of nickel and cobalt is not sufficient in any of these methods,
In addition, as a result of the alumina being dissolved halfway, V, M
An aluminum solution containing o, Ni, and Co will be obtained as a leachate.

From such an aluminum solution, V, M
When attempting to separate and collect o, Ni, and Co, there is a problem that aluminum acts as an interfering element during the extraction operation, and half-finished distribution of each metal cannot be effectively separated and collected. Under such circumstances, V, which is still greater than the waste catalyst,
It can be said that a method capable of industrially separately collecting and recovering Mo, Ni, and Co has not been proposed.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a method for separating and recovering V, Mo, Ni, Co, and Al from a waste catalyst which is new and industrially practicable. With the goal.

[0010]

The method of the present invention for solving the above-mentioned problems comprises the following steps: a waste catalyst using a carrier containing alumina as a main component is deoiled if necessary, and then baked at 400 to 1000 ° C. ,
The obtained calcined product is dissolved in sulfuric acid together with a metal for a dissolution catalyst, the obtained solution is used as an extraction stock solution, and the extraction stock solution is brought into contact with an Mo extraction organic solution containing a predetermined amount of Mo extracting agent to extract molybdenum-containing organic solution. Phase and Mo extraction residual liquid, molybdenum is back-extracted from the organic phase using an alkaline solution to obtain a molybdate solution and regenerated Mo extracted organic, and regenerated Mo extracted organic is repeated in the molybdenum extraction step, Molybdenum is recovered from the molybdate solution, and the Mo extraction residual liquid is contacted with a V extraction organic liquid containing a predetermined amount of V extraction extractant to obtain an organic phase containing vanadium and a V extraction residual liquid. Vanadium is back-extracted from the phase using a mineral acid solution to obtain a vanadium-containing solution and a regenerated V-extracted organic substance, and the regenerated V-extracted organic substance is repeatedly subjected to the vanadium extraction step to bring the V-extraction residual liquid into contact with hydrogen sulfide gas. , V, the nickel and cobalt in the extraction residual liquid are recovered as sulfides, and the final recovered liquid is brought into contact with a chelate resin to adsorb a trace amount of nickel and cobalt in the separated liquid to the chelate resin to obtain high-purity aluminum sulfate. A solution is obtained, on the other hand, a small amount of nickel and cobalt adsorbed on the chelate resin is liberated using sulfuric acid, and the obtained liberated solution is repeated in the reducing and dissolving step, and more specifically, (1) reduction At the time of dissolution, the reaction temperature is set to 70 to 100 ° C., preferably 80 to 90 ° C. in a non-oxidizing atmosphere, and at least one of metal aluminum, metal nickel, and metal cobalt as a catalyst metal for dissolution, preferably metal aluminum. (2) when extracting molybdenum, the pH of the stock solution for extraction is set to 0 to 4, and the general formula R1-NH-R is used as an extracting agent.
2, at least one or more secondary amines in which R1 and R2 are each an alkyl group having 12 to 13 carbon atoms, preferably N-Dodecenyl (trialkylmethyl) amine and / or N-Lauryl (trialkylmethyl) amine And the diluent is at least one of aromatic hydrocarbons and paraffinic hydrocarbons, and a Mo-extracted organic compound obtained by mixing the extractant and the diluent in a weight ratio of 5:95 to 20:80. (3) When back-extracting molybdenum, at least one of 0.5 to 5 mol / l of caustic alkali solution or 0.5
Ammonia water of mol / l or more is used, (4)
When vanadium is extracted from the Mo extraction residual liquid, the pH of the Mo extraction residual liquid is set to 1 to 4, 2-ethylhexyl mono-2-ethylhexylphosphonate is used as an extracting agent, and aromatic hydrocarbons and paraffin hydrocarbons are used as diluents. Using V-extracted organic compound obtained by mixing the extractant and the diluent at a weight ratio of 20:80 to 60:40, using (5) reverse extraction of vanadium, A 0.05 to 2 mol / l mineral acid solution is used as the extract, and (6) when adsorbing nickel and cobalt on the resin, a chelating resin of iminodiacetic acid exchange group type and aminocarboxylic acid type is used in combination to obtain SV. 10 to 20, while nickel and cobalt adsorbed on the chelate resin are eluted with a similar SV using a 5 to 20 wt% sulfuric acid solution.

[0011]

When the catalyst to which the present invention is applied contains alumina as a main component as a carrier, and contains a large amount of oil depending on the conditions used or when discharged from the reaction system to the outside of the system. There is. In such cases,
If the used catalyst is roasted without removing the oil component, it becomes difficult to control the roasting temperature. Therefore, it is necessary to remove the oil component in advance to a level where there is practically no problem. As a method for removing this oil component, a method of washing with a low-molecular organic solvent that easily volatilizes may be adopted, or the oil may be removed by evaporation by heating in a neutral atmosphere or a non-oxidizing atmosphere.

[0012] In the method of the present invention, the roasting is performed at 400 ° C or higher and lower than 1000 ° C. The main purpose of this roasting is to remove one of the carbon content and one to make the valuable metal to be recovered mainly in the form of oxide, but of course a small amount of oil content It is also intended to remove sulfur, sulfur, etc., or to sulphate sulfur content.

The lower limit of the roasting temperature is 400 ° C. or higher,
This is because if the temperature is roasted at an excessively low temperature, the oxidation reaction rate of valuable metals and sulfur will be slowed down, the time for ensuring the oxidation will be long, and it will be disadvantageous in terms of economic efficiency.
1000 ° C means that when the roasting temperature exceeds 1000 ° C, the oxidation reaction rate of carbon, valuable metals, sulfur, etc. in the waste catalyst becomes fast and the oxidation becomes reliable, but it is generated like molybdenum. This is because the ratio of the generated oxide volatilized and scattered increases. In addition, formation of a complex oxide of a valuable metal and an alumina carrier is promoted. This is because if a complex oxide of a valuable metal and alumina is formed, the dissolution rate at the time of reduction dissolution in the next step becomes small and it becomes inefficient. Hereinafter, each step will be described.

(1) Reducing and Dissolving Step In the present invention, the calcined product obtained as described above is dissolved with sulfuric acid together with the metal for the dissolving catalyst. At this time, the pH of the liquid is preferably 4 or less in order to prevent the formation of hydroxide. This is because when the pH is high, aluminum or the like is hydrolyzed and precipitates as a hydroxide. However, p
If H is set too low, a large amount of acid will be used,
Not only is the economy impaired, but an alkali must be added to bring the pH to 0 or higher during the extraction of molybdenum in the next step, which is not preferable.

Metals that can be used as the catalyst metal for dissolution in the present invention include aluminum, tin, copper, zinc, iron, nickel, cobalt, magnesium, etc. However, considering the recovery symmetry of the present invention, aluminum, nickel, cobalt. It is necessary to use at least one of the above, and it is most preferable to use aluminum in terms of economical efficiency and availability.

Strictly speaking, the dissolution temperature is also related to the concentration of the acid used, but generally, if the temperature is less than 70 ° C., the dissolution rate will be low and the used catalyst will not be sufficiently dissolved, while at a high temperature, for example, above 100 ° C. At the temperature, the dissolution rate becomes extremely fast and the used catalyst can be completely dissolved. However, at the same time, the amount of the metal added for the dissolution catalyst to be dissolved by the acid also increases, resulting in an increase in the required amount of the dissolution catalyst metal and the amount of sulfuric acid, which not only impairs the economical efficiency but also greatly reduces the working environment. It deteriorates, and the equipment materials that can be used are also limited. Therefore, the melting temperature is 70 to 100 degrees.

The dissolution method is not particularly limited, but in order to efficiently solubilize the valuable metal and the alumina carrier in the waste catalyst, for example, the solution was obtained by dissolving in a cocurrent method or a countercurrent method. A method of obtaining a uniform solution sequentially or continuously, a method of dissolving using a reaction vessel equipped with a stirrer, or the like can be adopted.

(2) Molybdenum Extracting Step The solution obtained as described above can usually be directly used as the Mo extracting stock solution. Molybdenum in the stock solution for extraction usually exists as hexavalent molybdic acid, and vanadium exists as tetravalent vanadyl sulfate. The pH of the leachate is adjusted to 0 to 4 if necessary. This is because if the pH is too low, the extraction efficiency will be deteriorated, and if the pH is too high, aluminum or vanadium in the stock solution will be hydrolyzed and hydroxide precipitates. As long as the pH of the undiluted solution is maintained within this range, there will be no phenomena that hinder the liquid-liquid phase separation such as the third phase generation and the clad generation.

The extractant used in the present invention is represented by the general formula R1-NH
-R2, wherein R1 and R2 each have 12 to 13 carbon atoms
The reason why the secondary amine, which is an alkyl group, is used is that the use of this extractant prevents the generation of the third phase, clad, etc. during the extraction operation for the first time, and the secondary amine is N-Dodecenyl (trialkylmethyl). ) amine and / or N-
The extraction state is better with Lauryl (trialkylmethyl) amine. Furthermore, when the diluent used in the present invention is at least one of aromatic hydrocarbons and paraffinic hydrocarbons, the extractant is more easily dissolved and the phase separation from the reducing sulfuric acid solution is good. This is because.

In the present invention, the above-mentioned extractant and diluent are mixed at a weight ratio of 5:95 to 20:80 and used as an organic extract, but when the ratio is out of this range, for example, when the extractant is small. The reason is that the extraction efficiency is lowered and the economic efficiency is impaired. For example, when the amount of the extractant is large, the viscosity of the organic phase after extraction is remarkably increased, and the phase separation takes too much time, which impairs the economical efficiency.

(3) Molybdenum Back Extraction Step In order to recover molybdenum from the organic phase in which molybdenum has been extracted from the extraction stock solution as described above, back extraction is performed using an alkaline aqueous solution. When caustic is used as the alkali to be used, its concentration should be 0.5 to 5 mol / l.
This is because the relationship between the back extraction efficiency and the phase separation due to the viscosity is similar to the above. When ammonia water is used as the alkali, its concentration can be 0.5 mol / l or more.
In this case, when the concentration is high, ammonium molybdate is produced in the back extraction liquid, but this does not hinder the operation in the reverse medium because ammonium molybdate precipitates very well in the reaction vessel without involving the organic phase. Because. The type of alkali used for back extraction may be selected depending on the form of the molybdate finally obtained. For example, ammonia water is used to obtain ammonium molybdate, and sodium hydroxide is used to obtain sodium molybdate. Use a solution.

(4) Vanadium Extraction Step In the Mo extraction residual liquid obtained by extracting and separating molybdenum in this manner, tetravalent vanadium exists as vanadyl sulfate.

If necessary in this step, p
Adjust H to 1-4. This is because if the pH is too low, the extraction efficiency will deteriorate, and if the pH is too high, the aluminum in the undiluted solution will be hydrolyzed and precipitate as hydroxide. As long as the pH of the stock solution is kept in this range,
Phenomena that hinder the liquid-liquid phase separation such as the third phase generation and the clad generation do not occur. Note that it is possible to omit the pH adjustment operation of the Mo extraction residual liquid by adjusting the amount of acid during the normal reduction extraction.

The extraction agent used in the present invention is 2-ethylhexyl mono-2-ethylhexyl phosphonate because vanadium can be back-extracted at a lower acid concentration by using the extraction agent, so that the third phase or This is because it is possible to prevent generation of clad and the like. Furthermore, when the diluent used in the present invention is at least one of aromatic hydrocarbons and paraffinic hydrocarbons, the extractant is more easily dissolved and the phase separation from the reducing sulfuric acid solution is good. This is because.

In the present invention, the above-mentioned extractant and diluent are mixed in a weight ratio of 20:80 to 70:30 and used as an extraction organic substance. The extraction efficiency is lowered and the economy is impaired.For example, when the extraction efficiency is high, the viscosity of the organic phase after extraction is remarkably increased, the phase separation takes too much time to impair the economy, and impurities are also entrained. Because.

(5) Vanadium back-extraction step In this way, vanadium is recovered from the extracted organic matter in which vanadium has been extracted from the stock solution for extraction by back-extraction using a solution of a mineral acid such as sulfuric acid or hydrochloric acid. The concentration of the mineral acid used
The amount of 0.05 to 2 mol / l is based on the relationship between the back extraction efficiency and the phase separation due to the viscosity, as in the above.

The liquid-liquid contact method is not particularly limited, but vanadium can be continuously extracted with a solvent by using a pulse column, a mixer-settler, or a centrifugal extraction type liquid-liquid contact device. It will be possible and industrially applicable.

(6) Sulfidation Step The method of converting nickel and cobalt into sulfides with hydrogen sulfide is a known method having a long history, and the description of conditions and the like will be omitted.

In the present invention, hydrogen sulfide gas is used as the V extraction residual liquid to convert nickel and cobalt into sulfides.
V It is for precipitating and removing a trace amount of copper, arsenic and iron coexisting in the extraction residual liquid as a sulfide, thereby obtaining a high-purity aluminum sulfate solution, and an ionic resin in the next step. This is to reduce the load when adsorbing nickel and cobalt on.

(7) Adsorption Step of Nickel and Cobalt on Ion Exchange Resin In the present invention, a trace amount of nickel and cobalt in the final solution after recovery of nickel and cobalt as sulfides are treated with iminodiacetic acid exchange groups. It is adsorbed and removed by using the resin having it and the resin having the aminocarboxylic acid exchange group. These resins may be separately brought into contact with the final recovery solution, or these resins may be mixed and then brought into contact with the final recovery solution.

The resin having an iminodiacetic acid exchange group used in the present invention is a valuable metal element (Ni) in a divalent valence state.
2+, Co2 +, Fe2 +, Cu2 +, and VO2 +) are selectively adsorbed, and a resin having an aminocarboxylic acid exchange group is preferable because of its ability to selectively adsorb valuable metal elements (Mo6 +, V5 +, Fe3 +). Not only
The acid used to elute the valuable metal from the chelate resin and regenerate the chelate resin can be recycled to the step of dissolving the waste catalyst, and the operating cost can be reduced.

The adsorption and desorption conditions on the resin are SV of 10 to
It is best for the adsorption and desorption efficiency to be 20 and the sulfuric acid concentration of the sulfuric acid solution used for desorption be 5 to 20% by weight.

Other than the above conditions, each unit operation can be arbitrarily selected within a range that is common sense. According to the method as described above, molybdenum and vanadium can be respectively recovered as salts, nickel and cobalt can be recovered as sulfides, and are good raw materials for nickel smelting, and aluminum is a high-purity aluminum sulfate solution. It can be recovered and used as a good alumina raw material. In order to achieve the object of the present invention, if pH adjustment is performed,
It is recommended to use calcium carbonate and / or calcium hydroxide as modifier. For example,
If sodium hydroxide or sodium carbonate is used, sodium is mixed in the sulfuric acid-reducing reductive extraction residual liquid, resulting in a decrease in the purity of the recovered valuable metal product, which is not preferable. Further, when calcium carbonate is used, calcium sulfate can be precipitated and removed by simple solid-liquid separation, and there is an advantage that the purity of the valuable metal product to be recovered is not adversely affected.

[0034]

EXAMPLES The method of the present invention will be described in more detail below with reference to examples. Unless otherwise stated,% is based on weight. (Example 1) Two kinds of metal-containing desulfurization waste catalysts having a carrier mainly composed of deoiled alumina as a carrier and a copper catalyst were mixed and inserted into an external heating type rotary kiln, and roasting temperature was 550 ° C for 2 hours. It heated and the baked product was obtained. The analytical values were as follows. Ni 3.15% Co 1.22% Mo 5.81% V 7.80% S 1.06% Cu 2.89% Fe 0.55% Al 30.8% C 0.11%

A) Complete dissolution step 140 g of the burned material and 1 g of a strip of metal aluminum (waste aluminum can) cut into strips were 560 ml of 10% sulfuric acid solution.
The mixture was heated and dissolved at a temperature of 90 ° C. while aerated with carbon dioxide gas. Further, water was added to make the total amount 1000 ml. The stirring speed in the dissolution tank was 300 rpm. The analytical values of the obtained solution are as follows. (Unit: g / l) Ni 4.4 Co 1.7 Mo 8.1 V 11.1
Cu 4.0 Fe 0.7 Al 43.6 pH 1.5 Standard oxidation-reduction potential 157mV

B) Step of extracting molybdenum The above-mentioned solution is used as a Mo extraction stock solution and N-Lauryl is used as an extractant.
A xylene solution containing 5% of (trialkylmethyl) amine was used as Mo-extracted organic, and the Mo-extracted stock solution and Mo-extracted organic were mixed at a ratio of 1: 1 and shaken for 5 minutes to extract molybdenum into an organic phase. . The molybdenum concentration in the obtained Mo extraction residual liquid was as follows. Mo ion concentration less than 0.01g / l As an extractant, N-Dodecenyl (trialkylmethyl) amine
The same operation was attempted by using to obtain a Mo extraction residual liquid, and the molybdenum concentration thereof was measured, and was similarly less than 0.01 g / l.

C) Back-extraction of molybdenum Back-extraction of Mo from the Mo-containing extraction organic solvent was carried out using 2 mol / l aqueous ammonia to obtain an ammonium molybdate solution and regenerate the extraction organic solvent.

D) Step of extracting vanadium Next, calcium carbonate is added to the Mo extraction residual liquid obtained in B) to adjust the hydrogen ion concentration to a range of 2 to 3, and calcium sulfate (gypsum) produced at that time. Was solid-liquid separated. Then, the obtained filtrate was used as a V extraction stock solution, and 50% of 2-ethylhexylphosphonate mono-2-ethylhexyl was used as an extractant.
The xylene solution contained in a ratio of 1% was used as V-extracted organic, the V-extracted stock solution and the V-extracted organic were mixed at a ratio of 1: 1 and shaken for 5 minutes to extract V into the organic phase. The V ion concentration in the obtained V extraction residual liquid was less than 0.02 g / l.

E) Step of Back-Extracting Vanadium Back-extraction of V from the extracted organic solvent containing V was carried out using a sulfuric acid solution having a concentration of 5% by weight to obtain a vanadyl sulfate solution and to regenerate the extracted organic solvent.

F) Step of Obtaining Ni, Co, Cu, and Fe Sulfide Slime The above V extraction residual liquid was heated to 40 ° C., and hydrogen sulfide was bubbled through the liquid. The generated sulfide was subjected to solid-liquid separation to obtain sulfide slime. The concentrations of nickel, cobalt, copper and iron in the recovered final liquid after solid-liquid separation were as follows. Ni 0.51 g / l Co 0.10 g / l Cu less than 0.01 g / l Fe less than 0.01 g / l The obtained sulfide was sufficiently usable as a nickel smelting raw material.

G) Step of Obtaining High-Purity Aluminum Sulfate Solution The mixed final solution obtained in the step F) was mixed with a resin having an iminodiacetic acid exchange group and a resin having an aminocarboxylic acid exchange group (trade name). Sumichelate MC30 and Sumichelate M
C75 mixed bed (Sumitomo Chemical Co., Ltd.) was passed through a packed column filled with an H-type chelate resin at SV = 15. The analytical value of the obtained passing liquid (aluminum sulfate aqueous solution) is
It was as follows. Al 43.1g / l Ni <0.001g / l Co <0.001g / l Mo <0.001g / l V <0.001g / l Cu <0.001g / l Fe <0.001g / l

H) Elution of nickel and cobalt. On the other hand, in order to elute a trace amount of heavy metal adsorbed on the chelate exchange resin, SV = 15 was eluted using a 10% sulfuric acid solution.
The elution could be done completely. I) Regenerated Mo-extracted organic matter and regenerated V-extracted organic matter were repeatedly used, and the chelating resin eluent was repeatedly subjected to the reducing and dissolving step to repeat the above-mentioned test to find operational problems. The phase separation was good, and the formation of the third phase and the clad was not observed. In the reduction dissolution step, the fired product was always completely dissolved.

The average recovery rate of each valuable metal recovered in the above embodiment is shown below. Mo 98.5% (Product form; ammonium molybdate) V 99.5 or more. (Product form; vanadyl sulfate) Al 100% (Product form; sulfuric acid band (Al ₂ O ₃ min.
8.1%) Aqueous solution) Ni 100% (as raw material for non-ferrous scouring; NiS slime form) Co 100% (as raw material for non-ferrous scouring; CoS slime form) Cu 100% (as raw material for non-ferrous scouring; CuS slime form)

[0044]

According to the method of the present invention, vanadium, molybdenum, nickel, cobalt and aluminum can be reliably and easily separated and recovered with a high recovery rate, and the method of the present invention is basically a closed system. It is also effective from the standpoint of pollution prevention and is industrially significant.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C01G 39/00 A 51/00 Z C22B 3/26 23/00 34/22 34/34 (72) Inventor Masaaki Shimizu 1400-2 Takano, Katsuta City, Ibaraki Prefecture

Claims (4)

[Claims] 1. A waste catalyst using a carrier containing alumina as a main component is deoiled, if necessary, and then roasted at 400 to 1000 ° C., and the obtained calcined product is dissolved with sulfuric acid together with a catalyst metal for dissolution, The obtained solution is used as an undiluted solution, and the undiluted solution is brought into contact with a Mo-extracting organic compound containing a predetermined amount of Mo-extracting agent to obtain a molybdenum-containing organic phase and a Mo-extraction residual liquid. Is back-extracted with an alkaline solution to obtain a molybdate solution and a regenerated Mo-extracted organic matter, and the regenerated Mo-extracted organic matter is repeated in the molybdenum extraction step to recover molybdenum from the molybdate solution, And a V extraction organic containing a predetermined amount of V extraction extractant are contacted to obtain an organic phase containing vanadium and a V extraction residual liquid, and vanadium is back-extracted from the organic phase using a mineral acid solution, Vanadium solution and regenerated V extraction organic The regenerated V-extracted organic matter is repeated in the vanadium extraction step, and the V-extracted residual liquid and hydrogen sulfide gas are contacted to recover nickel and cobalt in the V-extracted residual liquid as sulfides, and the final recovered liquid is a chelate. By adsorbing a small amount of nickel and cobalt in the separated liquid in contact with the resin to the chelate resin to obtain a high-purity aluminum sulfate solution, a small amount of nickel and cobalt adsorbed to the chelate resin is admixed with sulfuric acid. A method for recovering valuable metal from a waste catalyst, which comprises liberating and repeating the obtained liberating solution in the reducing and dissolving step. 2. A method for recovering valuable metal from a waste catalyst, wherein each step in the method according to claim 1 is defined under the following conditions. (1) At the time of reducing and dissolving, in a non-oxidizing atmosphere, the reaction temperature is set to 70 to 100 ° C., and at least one of metallic aluminum, metallic nickel, and metallic cobalt is used as a catalytic metal for dissolution, and (2) molybdenum is used. At the time of extraction, the pH of the undiluted solution is set to 0 to 4 and at least a secondary amine represented by the general formula R1-NH-R2, in which R1 and R2 are each an alkyl group having 12 to 13 carbon atoms, is used as an extracting agent. At least one of aromatic hydrocarbons and paraffinic hydrocarbons is used as the diluent, and the extractant and the diluent are mixed in a weight ratio of 5:95 to 20:80. Using the obtained Mo-extracted organic matter, (3) at the time of back-extracting molybdenum, at least one of the 0.5 to 5 mol / l caustic alkali solution was used as the back-extracting solution, and (4) Mo-extracting residual solution was used. When extracting vanadium, H is set to 1 to 4, 2-ethylhexyl mono-2-ethylhexylphosphonate is used as an extractant, and at least one kind of aromatic hydrocarbon and paraffin hydrocarbon is used as a diluent, and an extractant and a diluent are used. The weight ratio is 20:80
Using the V-extracted organic compound obtained by mixing at a ratio of -60: 40, (5)
For vanadium back-extraction, 0.05-
(6) When adsorbing nickel and cobalt onto the resin using a 2 mol / l mineral acid solution, a chelate exchange resin of iminodiacetic acid exchange group type and aminocarboxylic acid type is used together, and SV is set to 10 to 20. On the other hand, nickel and cobalt adsorbed on the chelate exchange resin are eluted with the same SV using a 5 to 20 wt% sulfuric acid solution. 3. The method for recovering valuable metal from the spent catalyst according to claim 1, wherein 0.5 mol / l or more of ammonia water is used as a back extraction liquid in the back extraction of molybdenum. 4. N-Dodeceny as a molybdenum extractant
l (trialkylmethyl) amine and / or N-Lauryl (trialky
l-methyl) amine is used, Claims 2-4 characterized by the above-mentioned.
A method for recovering valuable metal from any of the waste catalysts described.