KR102319523B1 - Separation and recovery of valuable metals from desulfurized waste catalyst - Google Patents

Abstract

The present invention provides a heating step for preparing a compound containing sodium aluminate by (1) mixing the spent desulfurization catalyst powder and solid sodium hydroxide in a furnace and reacting; (2) dissolving the compound containing the sodium aluminate into water to prepare an aqueous solution; (3) a first separation step of solid-liquid separation of nickel oxide not dissolved in the aqueous solution; (4) hydrolyzing sodium aluminate dissolved in the aqueous solution and precipitating aluminum hydroxide; (5) a second separation step of solid-liquid separation of the precipitated aluminum hydroxide; and (6) a recirculation step of reintroducing the solid sodium aluminate and solid sodium hydroxide remaining after separating water from the aqueous solution remaining after the second separation step to the (1) heating step; It relates to a method for separating and recovering valuable metals from

Description

Separation and recovery method of valuable metals from spent desulfurization catalysts

The present invention relates to a method for separating and recovering valuable metals from spent desulfurization catalysts. Specifically, it relates to a method for separating and recovering aluminum, nickel, etc. from a desulfurization spent catalyst in order to recycle valuable metals.

A catalyst is a material that activates the entire reaction at a high speed without reacting itself in any reaction system, and is an indispensable material in oil refining and petrochemical processes. The amount of catalyst used in the oil refining and petrochemical process is small compared to the FEED input to the process, but the amount of catalyst is gradually increasing due to the increase in oil refining and petrochemical plants.

In particular, various catalysts including valuable metals such as molybdenum, vanadium, nickel, and aluminum are used in oil refining and petrochemical plants. However, the catalysts containing the valuable metals are gradually reduced in performance over time and are eventually replaced. In the past, the waste catalyst at the end of its life was completely buried without a special treatment method, causing the problem of soil contamination that pollutes the groundwater due to the leaching of heavy metals. The problem of being abandoned has also been raised.

In order to minimize soil pollution and recycle high value-added valuable metals that depend on imports, a method of recovering valuable metals such as molybdenum and vanadium, which are precious metals, from spent desulfurization catalysts that have expired in oil refining and petrochemical processes has been proposed in various ways.

However, with respect to aluminum, there have been studies on a method of manufacturing aluminum hydroxide using liquid sodium hydroxide from a spent catalyst, but there is a problem in that it is difficult to design a reactor and operate the process stably due to operating conditions of high temperature and high pressure.

Due to the above problems, aluminum is not recovered from the spent catalyst and cannot be recycled, but is discarded as industrial waste, causing environmental pollution and causing great economic loss. In addition, aluminum has still been produced by the Bayer Process, which was proposed in 1888 by the German chemist Bayer. The Bayer method is a method of preparing aluminum hydroxide through the process of dissolving aluminum hydroxide by adding sodium hydroxide (NaOH) to bauxite ore, removing sludge and impurities, and precipitating aluminum hydroxide at a low temperature am.

Therefore, in order to prevent environmental pollution due to the burial of the spent catalyst and to recycle high value-added metals, high-purity aluminum hydroxide and nickel are separated from the desulfurized spent catalyst at the end of its lifespan to recover aluminum and nickel, which are valuable metals. Research is ongoing.

Republic of Korea Patent Publication No. 10-1187301, a method for recovering valuable metals from spent desulfurization catalysts with excellent recovery and separation efficiency

In order to separate and recover aluminum and nickel from the spent desulfurization catalyst, the present inventors use liquid sodium hydroxide (NaOH) as in the Bayer method to separate aluminum oxide (Al ₂ O ₃ ) contained in the spent catalyst and sodium aluminate (NaAlO). ₂ ) to dissolve it.

However, compared to bauxite containing aluminum hydroxide, aluminum oxide contained in the spent catalyst has low reactivity, so when reacting sodium hydroxide (NaOH) in a liquid phase, a high pressure of 20 bar or more and a high temperature of 240° C. or more are required inside the reactor. there was

In order to solve the above problem, the present inventors convert aluminum oxide contained in the spent catalyst into solid sodium aluminate by adding solid sodium hydroxide powder to the spent catalyst on a tunnel-type furnace, even under normal pressure, not high pressure. An object of the present invention is to provide a method for separating and recovering valuable metals from a spent desulfurization catalyst that produces high-purity aluminum hydroxide and separates nickel.

According to a first aspect of the invention,

(1) a heating step of mixing the spent desulfurization catalyst powder and solid sodium hydroxide, then putting it in a furnace and reacting it to prepare a compound containing sodium aluminate; (2) dissolving the compound containing the sodium aluminate into water to prepare an aqueous solution; (3) a first separation step of solid-liquid separation of nickel oxide not dissolved in the aqueous solution; (4) hydrolyzing sodium aluminate dissolved in the aqueous solution and precipitating aluminum hydroxide; (5) a second separation step of solid-liquid separation of the precipitated aluminum hydroxide; and (6) a recirculation step of reintroducing the solid sodium aluminate and solid sodium hydroxide remaining after separating water from the aqueous solution remaining after the second separation step to the (1) heating step; It provides a method for separating and recovering valuable metals from

In one embodiment of the present invention, in step (1), 80 to 150 parts by weight of solid sodium hydroxide are mixed with respect to 100 parts by weight of the spent desulfurization catalyst powder.

In one embodiment of the present invention, the method further includes a powdering step of crushing or milling to prepare a powdered desulfurization spent catalyst prior to step (1).

In one embodiment of the present invention, the furnace is operated at a temperature of 400 to 1100 °C, and is a continuous furnace in the form of a conveyor belt.

In one embodiment of the present invention, the alumina-based material included in the spent desulfurization catalyst powder is a material containing gamma-alumina.

In one embodiment of the present invention, in step (2), 400 to 1000 parts by weight of water are used based on 100 parts by weight of the spent desulfurization catalyst powder.

In one embodiment of the present invention, after the step (3), the step of separating the nickel hydroxide through a process of drying and leaching the nickel oxide; further includes.

In one embodiment of the present invention, the hydrolysis reaction of step (4) proceeds in a sedimentation tank, the sedimentation tank includes any one or more of a swash plate and an impeller.

In one embodiment of the present invention, the precipitation of step (4) is performed using aluminum hydroxide seeds.

In one embodiment of the present invention, the step (6) comprises the steps of removing water using a vacuum distiller at a temperature of 50 to 90 ℃; and condensing the removed water through a heat exchanger.

In one embodiment of the present invention, the method further comprises the step of re-introducing the separated water to the dissolving step (2) after the step (6).

In one embodiment of the present invention, the precipitated aluminum hydroxide has a purity of 95% or more.

In one embodiment of the present invention, the spent desulfurization catalyst powder includes aluminum oxide.

The method for separating and recovering valuable metals from spent desulfurization catalysts according to the present invention separates and recovers components such as aluminum and nickel that were previously buried to recycle valuable metals with high added value, and environmental pollution caused by landfilling of spent catalysts It has the effect of reducing the problem.

In addition, with respect to the instability of the process due to the high-pressure operating conditions of the existing method for producing aluminum hydroxide from the spent catalyst, the difficulty in reactor design, and the increase in investment cost, the separation of valuable metals from the spent catalyst according to the present invention and The recovery method is effective in producing high-purity aluminum hydroxide even under economical and stable process conditions, especially under atmospheric pressure, using a tunnel-type furnace and powdered solid sodium hydroxide. The high-purity aluminum hydroxide is suitable for use as a material for printed circuit boards used in various electronic products, as a raw material for high-purity alumina, as a raw material for special ceramics, and as a raw material for polyaluminum chloride (PAC, Polyaluminum Chloride) as a water treatment agent.

1 is a diagram illustrating a furnace used in Embodiment 1 of the present invention.
2 is a view for explaining the operating principle of the furnace used in Embodiment 1 of the present invention.
3 is a view showing an XRD pattern of aluminum hydroxide precipitated according to Example 1 of the present invention.

The embodiments provided according to the present invention can all be achieved by the following description. It is to be understood that the following description is to be understood as describing preferred embodiments of the present invention, and the present invention is not necessarily limited thereto.

Hereinafter, a method for separating and recovering valuable metals from a spent desulfurization catalyst according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As a result of the experiments of the present inventors, the method of dissolving sodium aluminate by adding liquid sodium hydroxide to separate and recover valuable metals such as aluminum and nickel from the conventional spent desulfurization catalyst is a method of reactor design and process due to high temperature and high pressure conditions. There was a problem that it was difficult to apply it to an actual process because it was difficult to operate stably. For this reason, there was a need for research on a process for stably separating and recovering valuable metals such as aluminum and nickel from spent desulfurization catalysts.

In order to solve the above problems, the inventors of the present invention mixed solid sodium hydroxide with a spent desulfurization catalyst and heated in a continuous furnace to obtain solid sodium aluminate under atmospheric pressure, and based on this, high-purity aluminum hydroxide To provide a method for separating and recovering valuable metals from a spent desulfurization catalyst that recycles aluminum by manufacturing.

The method for separating and recovering valuable metals from the spent desulfurization catalyst according to the present invention comprises (1) mixing the spent desulfurization catalyst powder and solid sodium hydroxide, then putting it in a furnace and reacting, a compound containing sodium aluminate heating step to prepare; (2) dissolving the compound containing the sodium aluminate into water to prepare an aqueous solution; (3) a first separation step of solid-liquid separation of nickel oxide not dissolved in the aqueous solution; (4) hydrolyzing sodium aluminate dissolved in the aqueous solution and precipitating aluminum hydroxide; (5) a second separation step of solid-liquid separation of the precipitated aluminum hydroxide; and (6) recirculating the solid sodium aluminate and solid sodium hydroxide remaining after separating water from the aqueous solution remaining after the second separation step into the (1) heating step.

Hereinafter, each step will be described in detail.

(1) heating step

The method for separating and recovering valuable metals from spent desulfurization catalyst according to the present invention comprises mixing the spent desulfurization catalyst powder and solid sodium hydroxide, then putting it in a furnace and reacting, to prepare a compound containing sodium aluminate heating step;

The spent desulfurization catalyst powder may include aluminum oxide (Al ₂ O ₃ ).

In the heating step, aluminum oxide (Al ₂ O ₃ ) contained in the spent desulfurization catalyst is mixed with solid sodium hydroxide (NaOH) and then continuously reacted under high temperature and atmospheric pressure conditions in a furnace to convert aluminum oxide to sodium aluminate (NaAlO ₂ ) A compound containing sodium aluminate is prepared through the reaction of Scheme 1 below.

[Scheme 1]

2Al ₂ O ₃ (s) + 4NaOH(s) → 4NaAlO ₂ (s) + 2H ₂ 0(l)

In the heating step, 80 to 150 parts by weight of solid sodium hydroxide, preferably 95 to 135 parts by weight, more preferably 110 to 120 parts by weight, may be mixed with respect to 100 parts by weight of the spent desulfurization catalyst powder. When the solid sodium hydroxide is less than 80 parts by weight, there is a problem in that the amount of sodium hydroxide is not sufficient to react with the total amount of aluminum oxide contained in the spent desulfurization catalyst. In addition, when the solid sodium hydroxide exceeds 150 parts by weight, sodium aluminate in a very hard solid state is generated after the heating step, making it difficult to handle.

The method may further include a powdering step of crushing or milling to produce a powdered desulfurization spent catalyst before the heating step. Through the crushing or grinding process, the average particle size of the powdered desulfurization spent catalyst may be 20 to 50 μm. When the average particle size of the powdered spent desulfurization catalyst is less than 20 μm, there is a problem in that it may be filtered during the dissolution step due to the small average particle size. In addition, when the average particle size of the powdered spent desulfurization catalyst exceeds 50 μm, there is a problem in that the extraction rate of the extract containing the aluminum component is lowered. The average particle size is calculated from a value measured by a particle size analyzer (Beckman Coulter (USA), LS 13 320) (a cumulative 70% point in the average diameter distribution of particles).

The furnace may be operated at a temperature of 400 to 1100 °C, 450 to 900 °C, and 500 to 700 °C. When the temperature of the furnace is 400° C. or less, the reaction of Scheme 1 in which aluminum oxide is converted into sodium aluminate is difficult to occur because the heating temperature is low. In addition, when the temperature of the furnace is 1100° C. or higher, there is a problem in that equipment and process operation costs are greatly increased.

1 and 2 , the furnace may be a continuous furnace in the form of a conveyor belt. The furnace is a tunnel-type furnace and may be operated so that the spent desulfurization catalyst powder and solid sodium hydroxide continuously react under a high-temperature condition through a conveyor belt. In addition, the furnace can be operated under normal pressure conditions as an open type.

The alumina-based material included in the spent desulfurization catalyst powder may be a material containing gamma-alumina. Gamma-alumina is characterized by a porous structure, has a large specific surface area, has excellent processing rate and moldability, and can be used as a catalyst or catalyst carrier.

The compound containing the sodium aluminate may include sodium hydroxide, sodium aluminate, water, sodium carbonate, and other impurities.

(2) dissolution step

The method for separating and recovering valuable metals from the spent desulfurization catalyst according to the present invention includes a dissolution step of preparing an aqueous solution by adding the compound containing the sodium aluminate to water.

In the dissolution step, in order to separate nickel oxide insoluble in water, a compound containing sodium aluminate is added to water to dissolve solid sodium aluminate in water.

In the dissolution step, 400 to 1000 parts by weight, preferably 400 to 800 parts by weight, more preferably 400 to 600 parts by weight of water based on 100 parts by weight of the spent desulfurization catalyst powder may be used. When the water is used in less than 400 parts by weight, the amount of water may be insufficient to dissolve the compound including sodium aluminate. In addition, when the water is used in excess of 1000 parts by weight, the concentration of the aqueous solution containing sodium aluminate is lowered, the aluminum hydroxide precipitation rate is lowered, and the amount of water to be removed to recover solid sodium hydroxide in the recirculation step is There is a problem in that the economic feasibility of the process decreases due to the increase.

(3) first separation step

The method for separating and recovering valuable metals from a spent desulfurization catalyst according to the present invention includes a first separation step of solid-liquid separation of nickel oxide not dissolved in the aqueous solution.

Nickel oxide (NiO) does not dissolve in water, but dissolves in hydrochloric acid or nitric acid at high temperature. For this reason, in the dissolution step, the solid sodium aluminate is dissolved in water, but the solid nickel oxide is not dissolved in water and remains in the solid phase.

Solid-liquid separation can be performed between sodium aluminate, which is liquid dissolved in water, and solid nickel oxide, which is not dissolved in water, by using the phase difference. In the first separation step, the solid-liquid separation may be preferably performed using a filter press, but is not limited thereto.

The first separation step may further include washing the nickel oxide. After solid-liquid separation through a filter press, the solid nickel oxide may have a moisture content of about 50%. Accordingly, in order to wash the nickel oxide with water corresponding to at least twice the mass of water hydrated in the solid nickel oxide, preferably, the solid nickel oxide may be washed twice with water equivalent to the mass of the solid nickel oxide.

The method may further include a step of separating nickel hydroxide through a process of drying and leaching the nickel oxide after the first separation step.

In order to separate nickel hydroxide, first, hydrochloric acid (HCl) may be added to a mixture containing the nickel oxide to form a nickel chloride. Thereafter, an alkali is added to the nickel chloride to precipitate and remove other metal impurities while increasing the pH, and nickel hydroxide is precipitated from the nickel chloride at about pH 6, separated and dried to obtain nickel hydroxide.

(4) hydrolysis step

The method for separating and recovering valuable metals from the spent desulfurization catalyst according to the present invention includes a hydrolysis step of hydrolyzing sodium aluminate dissolved in the aqueous solution and precipitating aluminum hydroxide.

_{In the hydrolysis step, aluminum hydroxide (Al(OH) 3} ) is generated from sodium aluminate dissolved in the aqueous solution remaining after solid-liquid separation through the hydrolysis reaction of Scheme 2 below, and then the temperature condition is lowered to precipitate solid aluminum hydroxide. make it

[Scheme 2]

NaAlO ₂ (aq) + 2H ₂ 0(l) → Al(OH) ₃ (s) + NaOH(l)

The hydrolysis reaction may be carried out at a temperature of 50 to 80 ℃, preferably 55 to 70 ℃, more preferably 55 to 65 ℃. When the temperature condition is less than 50° C., the hydrolysis reaction for forming aluminum hydroxide may proceed at a very slow rate. In addition, when the temperature condition exceeds 80 ℃, the solubility increases, the precipitation rate is lowered, the reverse reaction may occur, and there is a difficulty in selecting a material in the design of the reactor due to the reaction including a high-temperature base.

The hydrolysis reaction of the hydrolysis step may proceed in a precipitation tank. In addition, the settling tank may include any one or more of a swash plate and an impeller. The swash plate can increase the sedimentation efficiency by shortening the sedimentation time of the particles, and the impeller can control the particle size through the number of revolutions per minute (rpm).

The precipitation of the hydrolysis step may be performed through alumina seeds or aluminum hydroxide seeds, preferably aluminum hydroxide seeds. The aluminum hydroxide seeds are added to perform the role of crystal nuclei, grow aluminum hydroxide having a small crystal size, and can bring about an improvement in the extraction rate of crystals and uniformity of crystal sizes.

The precipitated aluminum hydroxide may have a purity of 95% or more, preferably 98% or more, more preferably 99% or more. The high-purity aluminum hydroxide can be used as a material for printed circuit boards used in various electronic products, as a raw material for high-purity alumina, as a raw material for special ceramics, and as a raw material for polyaluminum chloride (PAC, Polyaluminum Chloride) as a water treatment agent.

(5) second separation step

The method for separating and recovering valuable metals from the spent desulfurization catalyst according to the present invention includes a second separation step of solid-liquid separation of the precipitated aluminum hydroxide.

Solid-liquid separation can be performed using the phase difference between the precipitated solid aluminum hydroxide and the liquid sodium aluminate/sodium hydroxide solution. In the second separation step, the solid-liquid separation may be preferably performed using a filter press. However, the present invention is not limited thereto.

(6) recirculation step

In the method for separating and recovering valuable metals from the spent desulfurization catalyst according to the present invention, the solid sodium aluminate and solid sodium hydroxide remaining after separating water from the aqueous solution remaining after the second separation step are used in the (1) heating step. It includes; a recirculation step of re-inputting.

The recycling step separates water from an aqueous solution in which sodium aluminate and sodium hydroxide remaining after separating the aluminum hydroxide precipitated through the second separation step is dissolved, and the water is a dissolution step, solid sodium aluminate and solid phase Sodium hydroxide is recycled to the heating step to increase the efficiency of the process.

The recirculation step may include; removing water using a vacuum distiller at a temperature of 50 to 90°C, preferably 60 to 80°C, more preferably 65 to 75°C. When the temperature of the recirculation step exceeds 90° C., the process operating cost may increase due to an increase in energy consumption. In addition, when the temperature of the recirculation step is less than 50 ℃, the process efficiency may decrease due to an increase in the reduced pressure distillation process time.

The recirculation step may include condensing the removed water through a heat exchanger. The condensed water can be fed back to the dissolution step and used to dissolve the sodium aluminate.

In addition, it may further include the step of re-injecting the separated water to the dissolution step (2) after the recirculation step. The separated water may be added back to the dissolution step and used to dissolve the sodium aluminate.

Hereinafter, preferred examples are presented to help the understanding of the present invention, but the following examples are only provided for easier understanding of the present invention, and the present invention is not limited thereto.

Example: Preparation of aluminum hydroxide

[Example 1]

100 g of spent desulfurization catalyst powdered to an average particle size of 50 μm and 115 g of sodium hydroxide in the form of solid powder were put into a mixer and mixed. Thereafter, the solid mixture was put into a continuous tunnel-type furnace in the form of a conveyor belt (Taeyoung Electric Heat Co., Ltd., Tunnel Furnace) and heated at 600° C. for 2 hours.

The compound obtained through the heating reaction was put into 500 g of water at a temperature of 80° C. and stirred, and solid sodium aluminate (NaAlO ₂ ) was dissolved in water. At this time, the undissolved nickel oxide (NiO) was separated into solid-liquid using a filter press (Korea Filter Co., Ltd.), washed twice with water equal to the mass of the separated nickel oxide, and then the nickel oxide was recovered.

In addition, an aqueous solution containing sodium aluminate separated through the solid-liquid separation process is put into a precipitation tank, 25 g of aluminum hydroxide is added as a seed, and then stirred at 60° C. for 72 hours to carry out a hydrolysis reaction and hydroxylate Aluminum was deposited.

Thereafter, the precipitated solid aluminum hydroxide was separated from solid and liquid using a filter press (Korea Filter Co., Ltd.), washed with water at 90° C., and dried at 120° C. to prepare aluminum hydroxide.

At this time, the aqueous solution remaining after the solid-liquid separation of the solid aluminum hydroxide was put into a convection oven (Jeio tech, ON-22GW) and dried at 120° C. to obtain solid sodium aluminate and solid sodium hydroxide. .

In addition, the solid sodium aluminate and solid sodium hydroxide were recycled and used in the process of introducing the solid mixture into the furnace.

[Comparative Example 1]

100 g of a powdered desulfurized spent catalyst with an average particle size of 50 μm and 800 g of a 50% concentration sodium hydroxide solution were put into the reactor, and reacted at a temperature of 240 ° C and a pressure of 20 bar to contain liquid sodium aluminate and solid nickel oxide An aqueous solution was prepared. Except for preparing the aqueous solution, nickel hydroxide was separated, hydrolyzed, and recycled in the same manner as in Example 1 to prepare aluminum hydroxide.

Experimental example: X-ray diffraction analyzer (XRD, X-Ray Diffraction) and X-ray fluorescence analyzer (XRF, X-ray Fluorescence Spectrometer) measurement

The crystal structure of the precipitate of Example 1 was analyzed through an X-ray diffraction analyzer (XRD) (SHIMADZU, XRD-7000). Referring to FIG. 3 showing the XRD analysis result, it was confirmed that aluminum hydroxide was included in the precipitate by comparing the _{raw data showing the XRD peak and the card data corresponding to the reference data of Al(OH) 3 .}

In addition, the results of evaluating the content of each component through an X-ray fluorescence analyzer (XRF) (SHIMADZU, XRF-1800) are shown in Table 1 below. Through this, it was found that the purity of aluminum hydroxide in Example 1 prepared by reacting solid sodium hydroxide with a spent catalyst and reacting under atmospheric pressure was 99.4%, which was higher than Comparative Example 1.

ingredient(%) Al(OH) ₃ Na ₂ O SiO ₂ etc Example 1 99.4259 0.3470 0.1637 0.0634 Comparative Example 1 66.3157 31.3416 0.9663 1.3764

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will become apparent from the appended claims.

Claims (13)

(1) a heating step of mixing the spent desulfurization catalyst powder and solid sodium hydroxide, then putting it in a furnace and reacting it to prepare a compound containing sodium aluminate;
(2) dissolving the compound containing the sodium aluminate into water to prepare an aqueous solution;
(3) a first separation step of solid-liquid separation of nickel oxide not dissolved in the aqueous solution;
(4) hydrolyzing sodium aluminate dissolved in the aqueous solution and precipitating aluminum hydroxide;
(5) a second separation step of solid-liquid separation of the precipitated aluminum hydroxide; and
(6) a recirculation step of reintroducing the solid sodium aluminate and solid sodium hydroxide remaining after separating water from the aqueous solution remaining after the second separation step to the (1) heating step;
The step (1) is a method for separating and recovering valuable metals from the spent desulfurization catalyst, in which 80 to 150 parts by weight of solid sodium hydroxide are mixed with respect to 100 parts by weight of the spent desulfurization catalyst powder.
delete The method of claim 1,
The method of separating and recovering valuable metals from the spent desulfurization catalyst, further comprising; a powdering step of crushing or milling to prepare a powdered spent desulfurization catalyst prior to the step (1).
The method of claim 1,
The furnace is operated at a temperature of 400 to 1100 ℃, a continuous furnace in the form of a conveyor belt, a method for separating and recovering valuable metals from the desulfurization waste catalyst.
The method of claim 1,
The alumina-based material contained in the spent desulfurization catalyst powder is a material containing gamma-alumina, a method for separating and recovering valuable metals from the spent desulfurization catalyst.
The method of claim 1,
The step (2) is a method for separating and recovering valuable metals from the spent desulfurization catalyst, using 400 to 1000 parts by weight of water based on 100 parts by weight of the spent desulfurization catalyst powder.
The method of claim 1,
Separating the nickel hydroxide through a process of drying and leaching the nickel oxide after the step (3); further comprising a method for separating and recovering valuable metals from the desulfurization spent catalyst.
The method of claim 1,
The hydrolysis reaction of step (4) proceeds in a precipitation tank, wherein the precipitation tank includes any one or more of a swash plate and an impeller.
The method of claim 1,
The precipitation of step (4) is performed using aluminum hydroxide seeds, a method for separating and recovering valuable metals from the desulfurization spent catalyst.
The method of claim 1,
The step (6) is a step of removing water using a vacuum distiller at a temperature of 50 to 90 ℃; and condensing the removed water through a heat exchanger.
The method of claim 1,
The method of separating and recovering valuable metals from the desulfurization waste catalyst, further comprising the step of re-injecting the separated water to the (2) dissolution step after the step (6).
The method of claim 1,
The method for separating and recovering valuable metals from the desulfurization spent catalyst, wherein the precipitated aluminum hydroxide has a purity of 95% or more.
The method of claim 1,
The method for separating and recovering valuable metals from the spent desulfurization catalyst, wherein the spent desulfurization catalyst powder includes aluminum oxide.

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