Method for efficiently extracting tungsten from waste hydrogenation catalyst

Abstract

The invention relates to the technical field of resource recycling, in particular to a method for efficiently extracting tungsten from a waste hydrogenation catalyst. According to the method for efficiently extracting the tungsten from the waste hydrogenation catalyst, the tungsten in the waste hydrogenation catalyst is efficiently extracted by adopting a method of combining oxidizing roasting with silicon-adding high-pressure alkaline leaching, the highest leaching rate exceeds 99%, and compared with a direct alkaline leaching method and a conventional oxidizing roasting-alkaline leaching method, the leaching rate of the tungsten is high, and the yield of the tungsten is high. And aluminum in the waste hydrogenation catalyst forms sodium-silicon-aluminum slag, so that subsequent purification and separation of alkaline leaching liquid are facilitated, other valuable metals such as nickel are enriched in alkaline leaching slag, subsequent recovery is facilitated, and the problems that the tungsten leaching effect is poor and purification and separation are difficult due to the fact that a large amount of aluminum is leached in an existing process for recovering tungsten from the waste hydrogenation catalyst are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of resource recycling, and in particular to a method for efficiently extracting tungsten from a waste hydrogenation catalyst. Background Art

[0002] Tungsten, with its high melting point, high hardness, strong ductility, and excellent electrical conductivity, is widely used in aviation and aerospace, military equipment, medical devices, energy, and nuclear applications, earning it the nickname "the tooth of industry." However, tungsten ore resources have declined dramatically due to long-term, large-scale mining. As a strategic metal, tungsten's secondary resource recovery urgently warrants attention. With society's demanding requirements for oil quality, hydrogenation catalysts effectively remove impurities such as sulfur, oxygen, nitrogen, and metals from crude oil, highlighting their importance. However, over the life of a catalyst, poisoning, sintering, coking, and clogging can occur, altering its structure and composition, ultimately deactivating it and turning it into spent hydrogenation catalyst. Spent hydrogenation catalysts contain 3% to 20% tungsten, making them highly valuable for recovery. Spent hydrogenation catalysts primarily consist of valuable metal sulfides such as aluminum oxide, silicon oxide, tungsten, and nickel. Due to their relatively stable properties, these sulfides are difficult to directly leached with alkaline leaching.

[0003] Therefore, the current mainstream process is to first oxidize and roast the spent catalyst to convert the sulfides of valuable metals such as tungsten into oxides, facilitating subsequent alkaline leaching. However, the tungsten leaching rate of traditional alkaline leaching is still not very high, and some aluminum in the spent hydrogenation catalyst is also leached out during tungsten leaching, making it difficult to purify and separate the alkaline leaching liquid. Given the current problems of tungsten recovery from spent hydrogenation catalysts, such as poor leaching of valuable metals such as tungsten and the difficulty of subsequent purification and separation due to the large amount of aluminum leached out of the spent hydrogenation catalyst, there is an urgent need to develop an efficient and economical process for the recovery and extraction of spent hydrogenation catalysts. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a method for efficiently extracting tungsten from spent hydrogenation catalysts. The method uses oxidative roasting combined with silicon-added high-pressure alkaline leaching to efficiently extract tungsten from spent hydrogenation catalysts, with the highest leaching rate exceeding 99%.

[0005] The present invention provides a method for efficiently extracting tungsten from a spent hydrogenation catalyst, comprising the following steps:

[0006] S1. Taking the waste hydrogenation catalyst and performing oxidative roasting to obtain a roasting product;

[0007] S2. Mix silicon or a silicon compound with an alkaline solution to obtain a mixed solution;

[0008] S3. The roasted product and the mixed solution are mixed to carry out an alkali leaching reaction. After sufficient reaction, an alkali leaching product is obtained, which is filtered to obtain a tungsten-containing alkali leaching solution and an alkali leaching residue, respectively.

[0009] According to the method for efficiently extracting tungsten from a waste hydrogenation catalyst provided by the present invention, the temperature of the oxidative roasting in S1 is 300-1000° C., and the time of the oxidative roasting is 0.5-5 h.

[0010] According to a method for efficiently extracting tungsten from a waste hydrogenation catalyst provided by the present invention, the content of WO3 in the waste hydrogenation catalyst in S1 is 3-20%, and the content of Al2O3 is 10-70%.

[0011] According to a method for efficiently extracting tungsten from a waste hydrogenation catalyst provided by the present invention, the silicon compound in S2 is any one of silicon dioxide, sodium silicate or sodium silicate nonahydrate, and the alkaline solution is sodium hydroxide or sodium carbonate, and the concentration of the alkaline solution is 0.5 to 10 mol / L.

[0012] According to the method for efficiently extracting tungsten from a waste hydrogenation catalyst provided by the present invention, the amount of silicon or silicon compound added in S2 is 0.4 to 3 times the molar amount of aluminum atoms in the waste hydrogenation catalyst in S1.

[0013] According to a method for efficiently extracting tungsten from a waste hydrogenation catalyst provided by the present invention, the liquid-solid ratio of the calcined product in S3 to the alkaline solution, silicon or silicon compound in the mixed solution in S2 is 1:1 to 10:1, the temperature of the alkaline leaching reaction in S3 is 80 to 140°C, and the time of the alkaline leaching reaction is 0.2 to 4 hours.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] The present invention provides a method for efficiently extracting tungsten from spent hydrogenation catalysts. The method adopts an oxidation roasting method combined with silicon-added high-pressure alkaline leaching to efficiently extract tungsten from the spent hydrogenation catalysts, with a maximum leaching rate exceeding 99%. Compared with direct alkaline leaching and conventional oxidation roasting-alkaline leaching methods, the tungsten leaching rate is high, and aluminum in the spent hydrogenation catalyst forms sodium-silicon-aluminum slag, which is convenient for subsequent purification and separation of the alkaline leaching liquid. Other valuable metals such as nickel are enriched in the alkaline leaching slag, which is convenient for subsequent recovery. This method solves the problems of poor tungsten leaching effect and difficulty in purification and separation caused by large amounts of aluminum leached in existing processes for recovering tungsten from spent hydrogenation catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A flow chart of a method for efficiently extracting tungsten from spent hydrogenation catalysts;

[0018] Figure 2 This is the XRD diffraction pattern of the alkali leaching product in Example 1 of the present invention. DETAILED DESCRIPTION

[0019] An embodiment of the present invention provides a method for efficiently extracting tungsten from a spent hydrogenation catalyst, comprising the following steps:

[0020] S1. Take 4-8 kg of spent hydrogenation catalyst and place it in a high-temperature furnace at 300-1000° C. for oxidation roasting for 0.5-5 h to obtain a roasted product;

[0021] The content of WO3 in the spent hydrogenation catalyst is 3-20%, and the content of Al2O3 is 10-70%;

[0022] S2, according to the molar ratio of silicon or silicon compound to aluminum in the spent hydrogenation catalyst of 0.4 to 3:1, preferably 0.5 to 2 times, taking the silicon compound and the alkaline solution of concentration and mixing them uniformly to obtain a mixed solution;

[0023] The silicon compound can be any one of silicon dioxide, sodium silicate or sodium silicate nonahydrate, and the alkaline solution can be sodium hydroxide or sodium carbonate, wherein the concentration of the alkaline solution is 0.5 to 10 mol / L;

[0024] S3. The roasted product and the mixed solution are mixed to carry out alkali leaching reaction. The alkali leaching temperature is 80-140° C. and the leaching is carried out under high pressure for 0.2-4 h. After sufficient reaction, an alkali leaching product is obtained. After filtration, tungsten-containing alkali leaching solution and alkali leaching residue are obtained respectively. The alkali leaching temperature is preferably 90-130° C. The solid-liquid ratio of the roasted product, the alkali solution and the silicon or its compound is controlled in the range of 1:1-10:1, preferably 1:1-4:1, and the leaching time is preferably 0.5-2 h.

[0025] Example 1

[0026] This embodiment provides a method for efficiently extracting tungsten from spent hydrogenation catalyst, comprising the following steps:

[0027] S1. Take 4 kg of spent hydrogenation catalyst and place it in a high-temperature furnace at 700 ° C for 2 hours to obtain a calcined product;

[0028] The content of WO3 in the spent hydrogenation catalyst is 15% and the content of Al2O3 is 50%;

[0029] S2, according to the molar ratio of silicon dioxide to aluminum in the spent hydrogenation catalyst being 2:1, taking silicon dioxide and a sodium hydroxide solution with a concentration of 4 mol / L and mixing them evenly, the sodium hydroxide solution and silicon dioxide are mixed to obtain a mixed solution;

[0030] S3, mixing the roasted product and the mixed solution to carry out alkali leaching reaction, wherein the solid-liquid ratio of the roasted product, the alkali solution and the silicon or its compound is 1:4:1, the alkali leaching temperature is 140 ° C, and the high pressure leaching is carried out for 2 hours. After sufficient reaction, the alkali leaching product is obtained. The alkali leaching product is mainly a sodium aluminum silicon slag ternary phase, and its XRD diffraction pattern is as follows Figure 2 As shown, after filtration, tungsten-containing alkaline leaching solution and alkaline leaching residue are obtained respectively;

[0031] The tungsten content in the alkaline leaching residue is 0.11%, the aluminum content is 39%, the tungsten leaching rate is 99.22%, and the aluminum leaching rate is only 7%.

[0032] Example 2

[0033] This embodiment provides a method for efficiently extracting tungsten from spent hydrogenation catalyst, comprising the following steps:

[0034] S1. Take 6 kg of spent hydrogenation catalyst and place it in a high-temperature furnace at 800°C for oxidative roasting for 2.5 hours to obtain a roasted product;

[0035] The content of WO3 in the spent hydrogenation catalyst is 10% and the content of Al2O3 is 60%;

[0036] S2. According to the molar ratio of sodium silicate to aluminum in the spent hydrogenation catalyst of 2:1, sodium silicate and a 3 mol / L sodium hydroxide solution were mixed to obtain a mixed solution;

[0037] S3, mixing the roasted product and the mixed solution to perform an alkali leaching reaction, wherein the solid-liquid ratio of the roasted product, the alkali solution and the silicon or its compound is 1:1:1, and the alkali leaching temperature is 120° C. and high pressure leaching is performed for 1 hour. After sufficient reaction, an alkali leaching product is obtained, which is filtered to obtain a tungsten-containing alkali leaching solution and an alkali leaching residue, respectively;

[0038] The tungsten content in the alkaline leaching residue is 0.13%, the aluminum content is 48%, the tungsten leaching rate is 99.32%, and the aluminum leaching rate is only 10%.

[0039] Example 3

[0040] This embodiment provides a method for efficiently extracting tungsten from spent hydrogenation catalyst, comprising the following steps:

[0041] S1. 8 kg of spent hydrogenation catalyst was placed in a high-temperature furnace at 600°C for oxidative roasting for 1.5 h to obtain a roasted product;

[0042] The content of WO3 in the spent hydrogenation catalyst is 18% and the content of Al2O3 is 47%;

[0043] S2. According to the molar ratio of sodium silicate nonahydrate to aluminum in the spent hydrogenation catalyst of 1.5:1, sodium silicate nonahydrate was mixed with a 5 mol / L sodium hydroxide solution to obtain a mixed solution;

[0044] S3, mixing the roasted product and the mixed solution to perform an alkali leaching reaction, wherein the solid-liquid ratio of the roasted product, the alkali solution and the silicon or its compound is controlled to be 1:7:1, and the alkali leaching temperature is 110° C. and high pressure leaching is performed for 1.5 hours. After sufficient reaction, an alkali leaching product is obtained, which is filtered to obtain a tungsten-containing alkali leaching solution and an alkali leaching residue, respectively;

[0045] The tungsten content in the alkaline leaching residue is 0.15%, the aluminum content is 38%, the tungsten leaching rate is 98.78%, and the aluminum leaching rate is only 15%.

[0046] Example 4

[0047] This embodiment provides a method for efficiently extracting tungsten from spent hydrogenation catalyst, comprising the following steps:

[0048] S1. Take 7 kg of spent hydrogenation catalyst and place it in a high-temperature furnace at 600°C for oxidative roasting for 1.5 hours to obtain a roasted product;

[0049] The content of WO3 in the spent hydrogenation catalyst is 7% and the content of Al2O3 is 38%;

[0050] S2. According to the molar ratio of sodium silicate nonahydrate to aluminum in the spent hydrogenation catalyst being 1:1, sodium silicate nonahydrate was mixed with a 5 mol / L sodium hydroxide solution to obtain a mixed solution;

[0051] S3, mixing the roasted product and the mixed solution to perform an alkali leaching reaction, wherein the solid-liquid ratio of the roasted product, the alkali solution and the silicon or its compound is 1:10:1, and the alkali leaching temperature is 110° C. and high-pressure leaching is performed for 1.5 hours. After sufficient reaction, an alkali leaching product is obtained, which is filtered to obtain a tungsten-containing alkali leaching solution and an alkali leaching residue, respectively;

[0052] The tungsten content in the alkaline leaching residue is 0.15%, the aluminum content is 38%, the tungsten leaching rate is 98.78%, and the aluminum leaching rate is only 20%.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for efficiently extracting tungsten from spent hydrogenation catalysts, characterized in that: The following steps are involved: S1. Taking the waste hydrogenation catalyst and performing oxidative roasting to obtain a roasting product; S2. Mix silicon or a silicon compound with an alkaline solution to obtain a mixed solution; S3. The roasted product and the mixed solution are mixed to carry out an alkali leaching reaction. After sufficient reaction, an alkali leaching product is obtained, which is filtered to obtain a tungsten-containing alkali leaching solution and an alkali leaching residue, respectively.

2. The method for efficiently extracting tungsten from spent hydrogenation catalyst according to claim 1, characterized in that: The temperature of the oxidation roasting in S1 is 300-1000° C., and the time of the oxidation roasting is 0.5-5 h.

3. The method for efficiently extracting tungsten from spent hydrogenation catalyst according to claim 1, characterized in that: The content of WO3 in the spent hydrogenation catalyst in S1 is 3-20%, and the content of Al2O3 is 10-70%.

4. The method for efficiently extracting tungsten from spent hydrogenation catalyst according to claim 1, characterized in that: The silicon compound in S2 is any one of silicon dioxide, sodium silicate or sodium silicate nonahydrate, and the alkaline solution is sodium hydroxide or sodium carbonate, and the concentration of the alkaline solution is 0.5 to 10 mol / L.

5. The method for efficiently extracting tungsten from spent hydrogenation catalyst according to claim 1, characterized in that: The amount of silicon or silicon compound added in S2 is 0.4 to 3 times the molar amount of aluminum atoms in the spent hydrogenation catalyst in S1.

6. The method for efficiently extracting tungsten from spent hydrogenation catalyst according to claim 1, characterized in that: The liquid-to-solid ratio of the calcined product in S3 to the alkaline solution, silicon or silicon compound in the mixed solution in S2 is 1:1 to 10:1, the temperature of the alkali leaching reaction in S3 is 80 to 140° C., and the time of the alkali leaching reaction is 0.2 to 4 hours.

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