CN111945007A - A kind of method for recovering vanadium and molybdenum from waste catalyst containing vanadium and molybdenum - Google Patents

Abstract

The invention provides a method for recovering vanadium and molybdenum from a waste catalyst containing vanadium and molybdenum, which comprises the steps of firstly roasting to convert vanadium and molybdenum into a state easy to be leached by reaction with alkali, converting other elements into a state difficult to be leached by reaction with alkali, further carrying out mixed reaction of alkali solution to realize leaching of vanadium and molybdenum, further cooling and crystallizing to realize recycling of valuable metals, and simultaneously obtaining tailings rich in recovery value.

Description

A kind of method for recovering vanadium and molybdenum from waste catalyst containing vanadium and molybdenum

technical field

The invention relates to the technical field of solid waste recovery, in particular to a method for recovering vanadium and molybdenum from waste catalysts containing vanadium and molybdenum.

Background technique

Hydrodesulfurization (HDS) aluminum-based catalysts are widely used in the heavy oil hydrodesulfurization process in the petroleum refining industry. During the use process, due to the loss or denaturation of catalytically active substances and the deposition of carbon, sulfur, heavy metals, etc. deactivation. The service life of the catalyst used for the hydrodesulfurization of light crude oil is about 1-3 years, while the use of the heavy oil HDS catalyst is only 0.5-1 year. About 120,000 tons of waste HDS aluminum-based catalysts. If these waste catalysts are not treated, they will be directly landfilled as solid waste, which will cause great pollution to the environment; the content of valuable metals such as molybdenum, nickel, and vanadium in the waste catalysts is high, which has a high recovery value.

Therefore, it is of great significance to recover valuable metals from waste HDS catalysts, both from the perspective of the environment and from the perspective of resource utilization. At present, the metal in the waste catalyst is mainly recovered by the fire method, the wet method or the combination of the two. The fire method is usually to mix the waste catalyst raw materials and metal salts in a certain proportion and then convert the valuable metals into water-soluble by high-temperature roasting. The calcined product is directly immersed in water to obtain a leaching solution containing valent metals, and then the target metal product is obtained by chemical precipitation, ion exchange or solvent extraction. The wet method generally adopts the method of solution leaching directly. According to the difference in the solubility of different metals in acid and alkaline solutions, the separation and recovery of different elements or the recovery of all elements can be realized.

CN106282570A discloses a method for utilizing vanadium, nickel and molybdenum elements in waste catalysts by adopting high temperature melting (1550-1800°C) to form alloys.

CN101435027 discloses a method for crushing and pre-processing molybdenum-containing catalyst, mixing it with alkaline substance and magnesium oxide, and leaching and recovering molybdenum by solution leaching after high temperature roasting. This leads to the problem of lower recovery rate, but will produce harmful fumes that are difficult to handle during the roasting process.

CN102050492A, CN105274344A and CN1865460C disclose the recovery of valuable metals by a traditional sodium roasting-water leaching-extraction method, and further recovery of the reacted solid waste residue, thereby realizing efficient utilization of resources, reducing energy consumption and reducing pollution.

In order to improve the utilization efficiency of secondary resources, CN107435100A and CN102041388A etc. use fire-wet method to separate cobalt, nickel, molybdenum and other elements gradually by means of heat treatment, alkali leaching, acid leaching, etc. Although the recovery efficiency is high, the process is complicated. The amount of chemical reagents is large and the cost is high.

CN102041388A discloses a method for recovering metals from waste catalysts containing molybdenum and nickel. In the method, the waste catalysts are mixed and calcined with alkaline substances, and the calcined products are placed in a mixed acid leaching solution containing sulfuric acid, nitric acid and citric acid, leaching and filtration. Ammonia water is added to the filtrate for precipitation and recovery to obtain the ammonium molybdate product, and the pH value is continuously adjusted to obtain the precipitates of aluminum hydroxide and nickel successively. Compared with the above method, the process is simple and easy to implement and has high product purity, but the metal recovery efficiency is low.

CN109487075A discloses a method for realizing comprehensive recovery of valuable elements in aluminum-based petroleum refining catalysts by utilizing reducing gas. The method utilizes reduction heat treatment process to pretreat spent catalysts to generate alkali-soluble aluminum salts, acid-soluble elemental nickel-cobalt and The vanadium molybdenum suboxide, which is resistant to both acid and alkali, realizes the efficient separation and comprehensive recovery of various elements, but the experimental process is complicated and not suitable for industrial production.

CN104232902A discloses a method for recovering tungsten, molybdenum, aluminum and cobalt from waste catalyst by wet method. The method adopts 100g/L sodium hydroxide solution to leach molybdenum, aluminum, cobalt and other elements from waste catalyst at 120-155℃ , adding acid solution and magnesium chloride to the filtrate obtained by filtration and washing for several times to remove impurities by heating. Aluminum hydroxide is precipitated by adjusting the pH of the filtrate after removal of impurities, molybdenum sulfide is obtained by adding a vulcanizing agent, and tungsten is obtained by ion exchange. Compared with the pyrotechnic process, the reaction temperature and energy consumption are significantly reduced, but the subsequent impurity removal and element separation process are cumbersome and the recovery efficiency is low.

CN109652649A discloses a method for recovering molybdenum, cobalt, nickel and aluminum by leaching and recovering molybdenum, cobalt, nickel and aluminum with a mixed acid solution containing hydrofluoric acid. The acid leachate is difficult to handle and requires high corrosion resistance of the equipment, so it is not suitable for large-scale promotion and use.

CN109652651A discloses a method for activating and recovering cobalt and molybdenum from a waste cobalt-molybdenum-based hydrotreating catalyst. The method adopts the method of mechanical activation-nitric acid leaching to recover cobalt and molybdenum from the waste catalyst, and destroys the crystal structure of the sample by ball milling pretreatment. , greatly improved the leaching efficiency, the leaching rate of cobalt reached 98.3%, and the leaching rate of molybdenum reached 99.5%, but the concentration of nitric acid used was high, which was easy to cause equipment corrosion.

To sum up, there are various problems in the existing methods for recycling and processing waste catalysts. Therefore, it is necessary to develop a method for processing waste catalysts with low requirements on equipment corrosiveness, relatively low energy consumption and simple process flow.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides a method for recovering vanadium and molybdenum from waste catalysts containing vanadium and molybdenum. The method realizes the leaching of vanadium and molybdenum by first roasting and then mixing with an alkaline solution, and simultaneously obtains rich recovery. valuable tailings, and further recover vanadium and molybdenum through cooling crystallization, the cooling crystallization medium can be recycled back to the reaction stage, the extraction rate of vanadium and molybdenum is higher than 96% and 97% respectively, the process is simple and cost-effective.

For this purpose, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a method for recovering vanadium-molybdenum from a waste catalyst containing vanadium-molybdenum, the method comprising the steps of:

(1) waste catalyst containing vanadium molybdenum is roasted to obtain material after roasting;

(2) mixing and reacting the material after the roasting described in step (1) with the alkaline solution to obtain a reaction slurry;

(3) carrying out solid-liquid separation of the reaction slurry described in step (2) to obtain vanadium- and molybdenum-containing leachate and tailings;

(4) The leaching solution described in step (3) is crystallized by cooling to obtain a vanadium molybdenum product.

In the method for recovering vanadium and molybdenum from waste catalysts containing vanadium and molybdenum provided by the present invention, in the roasting process, vanadium and molybdenum are oxidized into high-value oxides that are easily soluble in alkali, while other elements such as alumina are converted into insoluble in the roasting process. Alkali-based alpha alumina; subsequent separation and recovery of vanadium, molybdenum and other elements through alkali leaching, and enrichment of other valuable elements in the tailings that do not react with alkali, which has high recycling value. The high-temperature roasting and alkali leaching of the waste catalyst in the method realizes the separation and efficient recovery of various valuable metals, is simple and easy to operate, and has low cost, and is an ideal method for comprehensive recovery of hazardous solid wastes.

The present invention does not limit the solid-liquid separation, and any method known to those skilled in the art that can be used for solid-liquid separation can be used, such as filtration, sedimentation, or centrifugation.

Preferably, the vanadium-molybdenum-containing waste catalyst is a waste hydrodesulfurization aluminum-based petroleum catalyst.

The waste HDS aluminum-based petroleum catalyst mentioned in the present invention refers to the waste HDS catalyst whose service life has expired due to factors such as carbon deposition and sulfur deposition, metal element deposition and active factor deactivation in the process of petroleum hydrodesulfurization, wherein the vanadium content is between Between 0.5 and 15 wt %, the molybdenum content is about 3 to 12 wt %.

Preferably, the vanadium-molybdenum-containing spent catalyst also contains aluminum and nickel.

The waste catalyst of the present invention contains aluminum and nickel. Generally, aluminum is an active carrier, while nickel exists as a catalytically active substance. These two substances are enriched in the form of tailings during the recovery process, forming a high recovery value. of tailings.

Preferably, the molybdenum in the vanadium-molybdenum-containing spent catalyst is present in the form of molybdenum sulfide, preferably molybdenum disulfide.

Preferably, the aluminum in the vanadium molybdenum-containing spent catalyst is present in the form of alumina, preferably gamma-phase alumina.

The alumina in the catalyst generally exists in the form of a porous carrier, which is generally γ-phase alumina. Due to the existence of this phase, the direct use of alkaline solution mixed reaction leaching will lead to a large amount of aluminum leaching, which not only consumes alkali, but also makes it difficult to achieve elemental leaching. separation and recycling.

Preferably, the vanadium in the vanadium-molybdenum-containing waste catalyst exists in the form of vanadium oxide and/or vanadium sulfide, preferably including any one of V ₂ O ₅ , V ₂ O ₃ or V ₂ S ₃ or a combination of at least _two , where typical non _- limiting combinations are the combination _{of V2O5} and _V2O3 , the combination _{of V2O5 and V2S3} , the combination _{of V2O3} and _V2S3 .

Preferably, the nickel in the vanadium-molybdenum-containing spent catalyst is present in the form of nickel sulfides, preferably including NiS.

Preferably, the vanadium content in the vanadium-molybdenum-containing waste catalyst is 0.5-15wt%, such as 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt% , 9wt%, 10wt%, 11wt%, 12wt%, 14wt% or 15wt%, etc., are not limited to the above-mentioned specific values, and can be any value within the above-mentioned range, limited by space and for the sake of brevity, the present invention is not exhaustive enumerate.

Preferably, the molybdenum content in the vanadium-molybdenum-containing waste catalyst is 3-12wt%, such as 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt% or 12 wt %, etc., are not limited to the above-mentioned specific numerical values, and may be any numerical value within the above-mentioned range. Due to space limitations and for the sake of brevity, the present invention will not list them exhaustively.

Preferably, the nickel content in the vanadium-molybdenum-containing waste catalyst is 3-8wt%, such as 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt% , 7 wt %, 7.5 wt % or 8 wt %, etc., are not limited to the above-mentioned specific values, and can be any value within the above-mentioned range. Due to space limitations and for the sake of brevity, the present invention will not list them exhaustively.

Preferably, the aluminum content in the vanadium-molybdenum-containing waste catalyst is 15-35wt%, for example, it can be 15wt%, 20wt%, 25wt%, 30wt% or 35wt%, etc., not limited to the above specific values, but can be within the above range Any value of , due to space limitations and for the sake of brevity, the present invention will not list them exhaustively.

Preferably, the roasting temperature in step (1) is 750-1200°C, for example, it can be 750°C, 780°C, 800°C, 820°C, 850°C, 880°C, 900°C, 920°C, 950°C, 980°C °C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, etc., preferably 900 to 1100°C.

In the present invention, the roasting temperature needs to be strictly controlled to be 750-1200°C. Within this temperature range, the vanadium, molybdenum sulfides and low-valent oxides in the raw materials are oxidized to high-valent oxides that are easily soluble in alkalis, and at the same time, the alumina undergoes a phase change. It changes from the porous γ-phase alumina (active phase) that is easily soluble in acid and alkali into α-alumina (stable phase) that is difficult to be dissolved by acid and alkali. The separation and recovery of elements are realized by alkali leaching. Taking molybdenum as an example, The molybdenum in the raw material is converted into molybdenum dioxide, which is insoluble in alkali during the roasting process within this temperature range; while the alumina carrier is generally an amphoteric oxide, which can obtain enough energy within this temperature range and overcome the energy barrier. , the irreversible phase transformation of the lattice reconstruction type occurs to form a stable phase of α-alumina, which is almost insoluble in acid and alkali, and is concentrated in the tailings.

Preferably, the roasting time is 3-5h, for example, it can be 3h, 3.2h, 3.5h, 3.8h, 4h, 4.2h, 4.5h, 4.8h or 5h, etc., not limited to the above-mentioned specific values, can be the above-mentioned Any value within the range is not exhaustively listed in the present invention due to space limitations and for the sake of brevity.

Preferably, the alkaline solution in step (2) is a sodium hydroxide solution.

Preferably, the mass concentration of the sodium hydroxide solution is 20-45wt%, such as 20wt%, 21wt%, 22wt%, 23wt%, 25wt%, 27wt%, 28wt%, 30wt%, 32wt%, 35wt% , 38wt%, 40wt%, 42wt% or 45wt%, etc., preferably 25 to 35wt%, not limited to the above specific values, can be any value within the above range, limited space and for the sake of simplicity, the present invention does not List exhaustively.

Preferably, the liquid-solid ratio of the sodium hydroxide solution to the vanadium-molybdenum-containing waste catalyst is 3 to 12:1, such as 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, 10.5:1, 11:1, or 12: 1, etc., preferably 5 to 10:1, is not limited to the above-mentioned specific numerical values, and can be any numerical value within the above-mentioned range. Due to space limitations and for the sake of brevity, the present invention will not list them exhaustively.

Preferably, the temperature of the mixing reaction in step (2) is 90-150°C, for example, it can be 90°C, 92°C, 95°C, 100°C, 105°C, 110°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C or 150°C, etc., preferably 110-140°C, not limited to the above specific values, can be any value within the above range, limited by space and for the sake of brevity, the present invention is not exhaustive enumerate.

Preferably, the mixing reaction time is 1-8h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h h or 8h, etc., preferably 3-6h, is not limited to the above-mentioned specific values, and can be any value within the above-mentioned range. Due to space limitations and for the sake of brevity, the present invention will not list them exhaustively.

Preferably, the vanadium- and molybdenum-containing leaching solution in step (3) contains Na ₃ VO ₄ and Na ₂ MoO ₄ .

Preferably, the vanadium and molybdenum-containing leachate contains sodium hydroxide.

Preferably, the tailings contain aluminum and nickel.

In the invention, the tailings are enriched with a large amount of valuable metals such as aluminum and nickel, and have high recovery value

Preferably, the temperature of the cooling crystallization in step (4) is 20-50°C, for example, it can be 20°C, 21°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40° C., 42° C., 45° C., 48° C. or 50° C., etc., are not limited to the above-mentioned specific values, and may be any value within the above-mentioned ranges. Due to space limitations and for the sake of brevity, the present invention will not list them exhaustively.

Preferably, the crystallization mother liquor of cooling crystallization is recycled to step (2) for mixing reaction.

In the present invention, the crystallization mother liquor can be recycled, which saves energy consumption and reduces alkali consumption.

Preferably, the vanadium molybdenum product is Na ₃ VO ₄ and Na ₂ MoO ₄ crystals.

As a preferred technical solution of the present invention, the method comprises the following steps:

(1) the waste catalyst containing vanadium and molybdenum is calcined at 750～1200 ℃ for 3～5h to obtain the calcined material;

(2) according to the liquid-solid ratio of 3～12:1, the material after the roasting described in step (1) and the sodium hydroxide solution whose mass concentration is 20～45wt% are mixed and reacted at 90～150 ℃ for 1～8h, and the reaction is obtained slurry;

(3) performing solid-liquid separation on the reaction slurry in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel;

(4) In step (3), the leaching solution is cooled and crystallized at 20-50° C. to obtain crystals of Na ₃ VO ₄ and Na ₂ MoO ₄ , and the crystallization mother liquor of said cooling and crystallization is circulated to step (2) for mixing reaction.

In a second aspect, the present invention provides a method for treating waste hydrodesulfurization aluminum-based petroleum catalysts, which includes the method for recovering vanadium and molybdenum from a waste catalyst containing vanadium and molybdenum according to the first aspect.

The method for treating the waste hydrodesulfurized aluminum-based petroleum catalyst provided by the invention can efficiently separate vanadium and molybdenum, and obtain tailings rich in recovery value, and has high separation efficiency, simple operation and high industrial application value.

Compared with the prior art, the present invention at least has the following beneficial effects:

(1) the method for recovering vanadium and molybdenum from the waste catalyst containing vanadium and molybdenum provided by the invention realizes the efficient leaching of vanadium and molybdenum without leaching other elements, the extraction rate of vanadium is ≥ 51wt%, and the extraction rate of molybdenum is ≥ 28wt%, Under optimal conditions, the leaching rate of vanadium and molybdenum is as high as 96wt% and 97wt%, respectively, and the components of the leaching solution are simple and easy to separate later;

(2) vanadium and molybdenum in the method for reclaiming vanadium-molybdenum from the waste catalyst containing vanadium-molybdenum provided by the invention are easy to separate and the separation mode is simple and easy, and the tailings are enriched with a large amount of valuable metals such as aluminum and nickel, which have Higher recycling value.

Detailed ways

In order to facilitate the understanding of the present invention, examples of the present invention are as follows. It should be understood by those skilled in the art that the embodiments are only for helping the understanding of the present invention, and should not be regarded as a specific limitation of the present invention.

1. Example

Example 1

The present embodiment provides a method for recovering vanadium-molybdenum from a waste catalyst containing vanadium-molybdenum, the method comprising the steps of:

(1) The waste catalyst containing vanadium and molybdenum is waste HDS aluminum-based petroleum catalyst, and the composition includes: V ₂ O ₅ : 10.51wt%, Al ₂ O ₃ : 22.15wt%, MoO ₃ : 2.96wt%, NiO: 2.94wt% ;

The waste catalyst containing vanadium and molybdenum enters the muffle furnace and is calcined at 800°C for 3 hours to obtain the calcined material;

(2) mixing and reacting the calcined material described in step (1) with a sodium hydroxide solution with a mass concentration of 25wt% at 90° C. for 3h at a liquid-solid ratio of 5:1 to obtain a reaction slurry;

(3) filtering and separating the reaction slurry described in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel;

(4) In step (3), the leaching solution is cooled and crystallized at 50° C. to obtain crystals of Na ₃ VO ₄ and Na ₂ MoO ₄ , and the crystallization mother liquor of said cooling and crystallization is recycled to step (2) for mixing reaction.

Example 2

The present embodiment provides a method for recovering vanadium-molybdenum from a waste catalyst containing vanadium-molybdenum, the method comprising the steps of:

(1) The waste catalyst containing vanadium and molybdenum is waste HDS aluminum-based petroleum catalyst, and the composition includes: V ₂ O ₅ : 8.32wt%, Al ₂ O ₃ : 25.22wt%, MoO ₃ : 3.07wt%, NiO: 2.35wt% ;

The waste catalyst containing vanadium and molybdenum enters the muffle furnace and is calcined at 900°C for 4 hours to obtain the calcined material;

(2) mixing and reacting the calcined material described in step (1) with a sodium hydroxide solution with a mass concentration of 30wt% at 100° C. for 4h at a liquid-solid ratio of 7:1 to obtain a reaction slurry;

(3) filtering and separating the reaction slurry described in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel;

(4) In step (3), the leaching solution is cooled and crystallized at 40° C. to obtain crystals of Na ₃ VO ₄ and Na ₂ MoO ₄ , and the crystallization mother liquor of said cooling and crystallization is recycled to step (2) for mixing reaction.

Example 3

The present embodiment provides a method for recovering vanadium-molybdenum from a waste catalyst containing vanadium-molybdenum, the method comprising the steps of:

(1) The waste catalyst containing vanadium and molybdenum is waste HDS aluminum-based petroleum catalyst, and the composition includes: V ₂ O ₅ : 9.76wt%, Al ₂ O ₃ : 20.21wt%, MoO ₃ : 2.32wt%, NiO: 3.23wt% ;

The waste catalyst containing vanadium and molybdenum enters the muffle furnace and is calcined at 1000°C for 5 hours to obtain the calcined material;

(2) mixing and reacting the calcined material described in step (1) with a sodium hydroxide solution with a mass concentration of 35wt% at 110° C. for 5h at a liquid-solid ratio of 10:1 to obtain a reaction slurry;

(3) filtering and separating the reaction slurry described in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel;

(4) In step (3), the leaching solution is cooled and crystallized at 30° C. to obtain Na ₃ VO ₄ and Na ₂ MoO ₄ crystals, and the crystallization mother liquor of the cooling crystallization is recycled to step (2) for mixing reaction.

Example 4

The present embodiment provides a method for recovering vanadium-molybdenum from a waste catalyst containing vanadium-molybdenum, the method comprising the steps of:

(1) The waste catalyst containing vanadium and molybdenum is waste HDS aluminum-based petroleum catalyst, and the composition includes: V ₂ O ₅ : 10.44wt%, Al ₂ O ₃ : 23.86wt%, MoO ₃ : 3.37wt%, NiO: 2.07wt% ;

The waste catalyst containing vanadium and molybdenum enters the muffle furnace and is calcined at 1100°C for 5 hours to obtain the calcined material;

(2) mixing and reacting the calcined material described in step (1) with a sodium hydroxide solution with a mass concentration of 40 wt % at 120° C. for 6 h at a liquid-solid ratio of 11:1 to obtain a reaction slurry;

(3) centrifuging the reaction slurry described in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel;

(4) The leaching solution in step (3) is crystallized by cooling at 20° C. to obtain Na ₃ VO ₄ and Na ₂ MoO ₄ crystals.

Example 5

The present embodiment provides a method for recovering vanadium-molybdenum from a waste catalyst containing vanadium-molybdenum, the method comprising the steps of:

(1) The waste catalyst containing vanadium and molybdenum is waste HDS aluminum-based petroleum catalyst, and the composition includes: V ₂ O ₅ : 9.03wt%, Al ₂ O ₃ : 20.75wt%, MoO ₃ : 3.11wt%, NiO: 2.57wt% ;

The waste catalyst containing vanadium and molybdenum enters the muffle furnace and is calcined at 1200°C for 4 hours to obtain the calcined material;

(2) mixing and reacting the calcined material described in step (1) with a sodium hydroxide solution with a mass concentration of 45wt% at 130° C. for 6h at a liquid-solid ratio of 12:1 to obtain a reaction slurry;

(3) centrifuging the reaction slurry described in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel;

(4) The leaching solution in step (3) is crystallized by cooling at 20° C. to obtain Na ₃ VO ₄ and Na ₂ MoO ₄ crystals.

Example 6

The present embodiment provides a method for recovering vanadium and molybdenum from waste catalysts containing vanadium and molybdenum. In the method, except that "45wt% NaOH solution" is replaced with "15wt% NaOH solution" in step (1), the rest are the same as Example 5 is the same.

Example 7

The present embodiment provides a method for recovering vanadium-molybdenum from a vanadium-molybdenum-containing waste catalyst. In the method, except that "the roasting time is 5h" is replaced with "the roasting time is 2h" in step (1), the rest are the same as the Example 3 is the same.

Example 8

The present embodiment provides a method for recovering vanadium and molybdenum from waste catalysts containing vanadium and molybdenum. In the method, except that "1200 ℃ roasting for 4 hours" is replaced with "650 ℃ roasting for 4 hours" in step (2), the rest are the same as Example 5 is the same.

Example 9

The present embodiment provides a method for recovering vanadium and molybdenum from a waste catalyst containing vanadium and molybdenum. In the method, except that in step (2), "1200°C roasting for 4 hours" is replaced by "1400°C roasting for 4 hours", the rest are the same as Example 5 is the same.

2. Comparative ratio

Comparative Example 1

The present comparative example provides a method for recovering vanadium and molybdenum from a waste catalyst containing vanadium and molybdenum. The method is the same as in Example 5 except that the method is directly mixed and reacted with an alkaline solution without roasting.

Since the comparative example 1 has not been roasted, a large amount of molybdenum cannot be dissolved in the sodium hydroxide solution when it is mixed and reacted with the sodium hydroxide solution, and a large amount of aluminum is dissolved in the alkali, so the separation of vanadium, molybdenum and other elements cannot be realized. The leaching efficiency is extremely low.

3. Results

Test method: utilize ICP method to detect the vanadium content and molybdenum content in the vanadium-molybdenum product in the above embodiment and comparative example, and calculate the extraction rate of vanadium and molybdenum according to the content in the raw material, and the results are shown in Table 1.

Table 1

Vanadium extraction rate Molybdenum extraction rate Example 1 51wt% 43wt% Example 2 72wt% 56wt% Example 3 96wt% 97wt% Example 4 94wt% 95wt% Example 5 94wt% 95wt% Example 6 60wt% 49wt% Example 7 59wt% 41wt% Example 8 82wt% 28wt% Example 9 65wt% 48wt%

The following points can be seen from Table 1:

(1) It can be seen from the comprehensive examples 1 to 10 that the method for recovering vanadium and molybdenum from the waste catalyst containing vanadium and molybdenum provided by the invention can better realize the extraction of vanadium and molybdenum, and the extraction rate of vanadium is ≥ 51wt%, which is relatively Under optimal conditions, it can reach more than 94wt%, the highest can reach more than 96wt%, the extraction rate of molybdenum is ≥28wt%, and it can reach more than 95wt% under better conditions, and the highest can reach more than 97wt%. To the tailings, the process economy is high;

(2) Comprehensive Example 5 and Example 6 can be seen, adopting 25wt% NaOH solution in Example 5, compared to adopting 15wt% NaOH solution in Example 6, the extraction rate of vanadium and molybdenum in Example 5 They are 94wt% and 95wt% respectively, while the extraction rates of vanadium and molybdenum in Example 6 are only 60wt% and 49wt%, respectively, which shows that the present invention improves the concentration of sodium hydroxide solution by controlling the concentration within a specific range. The extraction rate of vanadium and molybdenum;

(3) comprehensive embodiment 3 and embodiment 7 can be found out, in embodiment 3, calcination time is 5h, compared to 2h in embodiment 7, the extraction rate of vanadium and molybdenum is respectively 96wt% and 97wt%, while the extraction rates of vanadium and molybdenum in Example 7 are only 59wt% and 41wt%, respectively, which shows that the present invention improves the extraction rates of vanadium and molybdenum by controlling the roasting time within a specific range. , and can effectively inhibit the leaching of other elements;

(4) Comprehensive Example 5 and Examples 8 to 9 can be seen that the calcination temperature in Example 5 is 750 ℃, compared with the calcination temperature in Example 8 and Example 9, which are respectively 650 ℃ and 1400 ℃, The extraction rates of vanadium and molybdenum in Example 5 were 94wt% and 95wt% respectively, while the extraction rates of vanadium and molybdenum in Example 8 and Example 9 were lower than those in Example 5, which indicated that the present invention was controlled by optimal The roasting temperature increases the extraction rate of vanadium and molybdenum.

To sum up, the method for recovering vanadium and molybdenum from a waste catalyst containing vanadium and molybdenum provided by the present invention converts vanadium and molybdenum into a state that is easy to react with alkali by first roasting, and converts other elements into a state that is not easy to react with alkali. In the state of leaching, under the optimal conditions of a combination of specific roasting temperature, roasting time and alkali concentration, the extraction rate of vanadium is above 94wt%, the extraction rate of molybdenum is above 95wt%, and even the extraction rate of both can reach 96wt% % or more, the economic benefit is higher.

The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow. Process flow can be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. a method for reclaiming vanadium-molybdenum from the waste catalyst containing vanadium-molybdenum, is characterized in that, described method comprises the steps: (1) waste catalyst containing vanadium molybdenum is roasted to obtain material after roasting; (2) mixing and reacting the material after the roasting described in step (1) with the alkaline solution to obtain a reaction slurry; (3) carrying out solid-liquid separation of the reaction slurry described in step (2) to obtain vanadium- and molybdenum-containing leachate and tailings; (4) The leaching solution described in step (3) is crystallized by cooling to obtain a vanadium molybdenum product. 2. method according to claim 1, is characterized in that, the waste catalyst of described vanadium-containing molybdenum is waste hydrodesulfurization aluminum-based petroleum catalyst; Preferably, the vanadium-molybdenum-containing waste catalyst also contains aluminum and nickel; Preferably, the molybdenum in the vanadium-molybdenum-containing waste catalyst exists in the form of molybdenum sulfide, preferably molybdenum disulfide; Preferably, the presence of aluminum in the vanadium-molybdenum-containing waste catalyst includes alumina, preferably γ-phase alumina; Preferably, the vanadium in the vanadium-molybdenum-containing waste catalyst exists in the form of vanadium oxide and vanadium sulfide, preferably including any one or at least V ₂ O ₅ , V ₂ O ₃ or V ₂ S ₃ . a combination of the two; Preferably, the nickel in the vanadium-molybdenum-containing spent catalyst is present in the form of nickel sulfides, preferably including NiS. 3. The method according to claim 1 or 2, wherein the vanadium content in the waste catalyst containing vanadium molybdenum is 0.5 to 15wt%; Preferably, the molybdenum content in the vanadium-molybdenum-containing waste catalyst is 3-12 wt%; Preferably, the nickel content in the vanadium-molybdenum-containing waste catalyst is 3-8wt%; Preferably, the aluminum content in the vanadium-molybdenum-containing waste catalyst is 15-35 wt%. 4. The method according to any one of claims 1 to 3, wherein the roasting temperature in step (1) is 750-1200°C, preferably 900-1100°C; Preferably, the roasting time is 3-5h. 5. The method according to any one of claims 1 to 4, wherein the alkaline solution in step (2) is a sodium hydroxide solution; Preferably, the mass concentration of the sodium hydroxide solution is 20-45wt%, preferably 25-35wt%; Preferably, the liquid-solid ratio of the sodium hydroxide solution to the vanadium-molybdenum-containing waste catalyst is 3-12:1, preferably 5-10:1. 6. The method according to any one of claims 1 to 5, wherein the temperature of the mixing reaction in step (2) is 90-150°C, preferably 110-140°C; Preferably, the mixing reaction time is 1-8 h, preferably 3-6 h. 7. The method according to any one of claims 1 to 6, wherein the leaching solution containing vanadium and molybdenum described in step (3) contains Na ₃ VO ₄ and Na ₂ MoO ₄ ; Preferably, the vanadium- and molybdenum-containing leachate contains sodium hydroxide; Preferably, the tailings contain aluminum and nickel. 8. The method according to any one of claims 1 to 7, wherein the temperature of the cooling crystallization in step (4) is 20 to 50 °C; Preferably, the crystallization mother liquor of the cooling crystallization is circulated to step (2) for mixing reaction; Preferably, the vanadium molybdenum product is Na ₃ VO ₄ and Na ₂ MoO ₄ crystals. 9. The method according to any one of claims 1 to 8, wherein the method comprises the following steps: (1) the waste catalyst containing vanadium and molybdenum is calcined at 750～1200 ℃ for 3～5h to obtain the calcined material; (2) according to the liquid-solid ratio of 3～12:1, the material after the roasting described in step (1) and the sodium hydroxide solution whose mass concentration is 20～45wt% are mixed and reacted at 90～150 ℃ for 1～8h, and the reaction is obtained slurry; (3) performing solid-liquid separation on the reaction slurry in step (2) to obtain a leaching solution containing Na ₃ VO ₄ and Na ₂ MoO ₄ and tailings containing aluminum and nickel; (4) In step (3), the leaching solution is cooled and crystallized at 20-50° C. to obtain crystals of Na ₃ VO ₄ and Na ₂ MoO ₄ , and the crystallization mother liquor of said cooling and crystallization is circulated to step (2) for mixing reaction. 10. A processing method for waste hydrodesulfurization aluminum-based petroleum catalyst, characterized in that the processing method comprises the method for recovering vanadium and molybdenum from a waste catalyst containing vanadium and molybdenum as claimed in any one of claims 1 to 9 .