A method for recovering vanadium from waste nickel-aluminum powder for catalyst

Abstract

The present invention relates to the technical field of solid waste resource recycling and utilization, and specifically discloses a method for recovering vanadium from waste nickel-aluminum powder for catalyst. The method for recovering vanadium from waste nickel-aluminum powder for catalyst provided by the present invention comprises the steps of: making the waste nickel-aluminum powder into balls, and then roasting it in a microwave environment to obtain roasting slag; the roasting slag is pre-activated by ultrasonic wave, and then subjected to alkaline leaching treatment, and then solid-liquid separation to obtain vanadium-containing leaching solution and nickel-aluminum leaching slag respectively. The method of the present invention can realize the efficient leaching of vanadium from waste nickel-aluminum powder for catalyst, and the obtained leaching slag can be directly used as a raw material for catalyst preparation after simple treatment.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource recycling, and in particular to a method for recovering vanadium from waste nickel-aluminum powder used as a catalyst. Background Art

[0002] Vanadium metal is a rare metal with strategic significance and is widely used in a wide range of fields. For example, vanadium-containing steel has excellent properties such as high strength, high toughness, and good wear resistance. It is widely used in machinery, automobiles, shipbuilding, railways, aviation, bridges, electronic technology, defense industry and other industries, accounting for about 85% of vanadium consumption. Vanadium can also be used to produce titanium alloys required by the aerospace industry, giving titanium alloys good ductility and plasticity. In addition, vanadium can be used as a catalyst in the chemical industry. With the rapid development of various industries, the demand for metallic vanadium raw materials has increased year by year. Extracting vanadium from vanadium-containing ores alone can no longer meet the needs of production development. Therefore, the recycling and reuse of vanadium-containing secondary resources will be of great strategic significance.

[0003] Raney nickel catalyst is a solid heterogeneous catalyst composed of fine grains of nickel-aluminum alloy with a porous structure. It is obtained by activating nickel-aluminum alloy powder and is mainly used in catalytic hydrogenation reactions. After repeated use, the catalytic activity of Raney nickel catalyst decreases, and a large amount of waste nickel-aluminum powder is produced after deactivation. The waste nickel-aluminum powder for catalyst produced is an important secondary resource. In addition to nickel and aluminum metals, it is also rich in rare metals such as vanadium and molybdenum. But at the same time, waste nickel-aluminum powder also contains heavy metal elements. Waste nickel-aluminum powder for catalyst is a hazardous secondary resource with important economic value. Due to the complex composition of waste nickel-aluminum powder, it is difficult to handle. If it is randomly piled up without harmless treatment, it is easy to cause environmental pollution and waste of resources.

[0004] Therefore, under the current severe reality of decreasing mineral resources and worsening ecological environment damage, conducting research on the comprehensive recovery and utilization of vanadium in waste nickel and aluminum powder has both environmental and economic benefits. Summary of the invention

[0005] The main technical problem solved by the present invention is to provide a method for recovering vanadium from waste nickel-aluminum powder for catalyst, which can realize the effective leaching of vanadium in the waste nickel-aluminum powder for catalyst and improve the leaching rate of vanadium in the waste nickel-aluminum powder.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for recovering vanadium from waste nickel and aluminum powder for catalyst, comprising the steps of:

[0007] S1: making balls from waste nickel and aluminum powder, and then roasting them in a microwave environment to obtain roasted slag;

[0008] S2: The roasted slag is pre-activated by ultrasonic wave, then alkali leaching is performed, and then solid-liquid separation is performed to obtain vanadium-containing leaching solution and nickel-aluminum leaching slag respectively;

[0009] The roasting in a microwave environment includes two stages of roasting, the first stage of roasting is low-power and low-temperature roasting, and the second stage of roasting is high-power and high-temperature roasting;

[0010] Preferably, the roasting conditions of the first stage roasting treatment are: microwave power 300-500W, roasting temperature 100-150°C; the roasting conditions of the second stage roasting treatment are: microwave power 800-1100W, roasting temperature 700-900°C.

[0011] As an implementation scheme of the present invention, the waste nickel aluminum powder is mixed with water to form balls, and the ball diameter is controlled to be 1 to 3 cm.

[0012] As an embodiment of the present invention, the time of the first stage roasting treatment is controlled to be 2 to 5 minutes.

[0013] As an embodiment of the present invention, the time of the second stage roasting treatment is controlled to be 10 to 20 minutes.

[0014] As an embodiment of the present invention, the ultrasonic pre-activation comprises: treating the calcined slag with ultrasound at room temperature, with an ultrasound power of 400 to 600 W and a treatment time of 1 to 3 minutes. Room temperature refers to a temperature range of 20 to 40° C., preferably a temperature range of 25 to 35° C.

[0015] As an embodiment of the present invention, before the roasted slag is treated with ultrasound, water is first added to prepare a water-containing roasted slag material, and the liquid-to-solid ratio of the water-containing roasted slag material is 2.5-5.0 mL / g. Ultrasonic pre-activation treatment is to treat the water-containing roasted slag material with ultrasound at room temperature. The liquid-to-solid ratio refers to the ratio of the liquid volume (mL) of the water-containing roasted slag material to the mass (g) of the material contained.

[0016] As an embodiment of the present invention, the alkali leaching treatment comprises: heating the water-containing roasted slag material after ultrasonic pre-activation to 75-90° C., adding an alkali leaching agent, and stirring for 30-60 minutes.

[0017] As an embodiment of the present invention, the alkaline leaching agent is sodium carbonate and / or sodium hydroxide. For example, the alkaline leaching agent can be sodium carbonate, sodium hydroxide, or a mixture of sodium carbonate and sodium hydroxide. When the alkaline leaching agent is a mixture of sodium carbonate and sodium hydroxide, it is preferably mixed in a mass ratio of sodium carbonate: sodium hydroxide = 1:2.

[0018] As an embodiment of the present invention, the molar number of sodium ions in the alkaline immersion agent is 1.1 to 1.3 times the molar number of vanadium ions contained in the waste nickel and aluminum powder.

[0019] The vanadium-containing leaching solution obtained by the present invention has a mass percentage content of metallic vanadium of ≥98% based on the total mass of the metals contained (excluding sodium). The purity of the leaching solution is high, the subsequent purification process of vanadium is greatly simplified, and metallic vanadium can be obtained by simple treatment.

[0020] The nickel-aluminum leaching slag obtained by the present invention has a nickel-aluminum mass percentage content of ≥98% based on the total mass of the metals contained. The nickel-aluminum leaching slag has high purity and can be directly used as a raw material for preparing a Raney nickel catalyst after simple treatment.

[0021] The method for recovering vanadium from waste nickel-aluminum powder for catalyst provided by the present invention comprises the following steps: firstly, the waste nickel-aluminum powder is mixed with water to form balls, and then the balls are roasted in stages in a microwave environment to obtain loose and porous roasted slag; then, the roasted slag is treated with an ultrasonic pre-activation-alkali leaching process, and a leaching solution containing metallic vanadium and nickel-aluminum leaching slag are obtained after solid-liquid separation. The method of the present invention can achieve the recovery of insoluble NiV in waste nickel-aluminum powder for catalyst. 2 O 6 The effective leaching of vanadium in the physical phase greatly improves the leaching rate of vanadium in waste nickel and aluminum powder. At the same time, the leached residue obtained can be directly used as a raw material for catalyst preparation after simple treatment.

[0022] The vanadium in the raw material waste nickel aluminum powder treated by the present invention has a unique structure, mainly NiV 2 O 6 It exists in the form of insoluble phases. 2 O 6 Insoluble phases such as NiV are produced during the use of Raney nickel catalysts. The vanadium in this phase is difficult to recover using conventional processes, and the effective dissolution of vanadium in insoluble phases remains a difficult problem. 2 O 6 The effective dissolution of vanadium can only be achieved under the premise of decomposition of insoluble phases, and decomposition often requires high temperatures of more than 1000 degrees and long-term roasting. Therefore, the processing cost is extremely high and the equipment requirements are also very high.

[0023] The method for recovering vanadium from waste nickel-aluminum powder for catalyst provided by the present invention innovatively proposes a treatment scheme of microwave segmented roasting, wherein the first stage is low-power and low-temperature roasting, and the characteristic of microwaves for rapid heating of water is utilized, so that the water in the pellets is rapidly dried macroscopically, and the roasted slag is initially made to present a loose and porous structural appearance, and microscopically, the easily soluble vanadium-containing compounds under high-temperature roasting conditions are avoided to react with nickel to form new insoluble Ni-VO and other physical phases; the second stage is high-power and high-temperature roasting, and the special effect of microwaves on Ni-VO chemical bonds is utilized to achieve the destruction of Ni-VO chemical bonds under conditions below 1000 degrees, and macroscopically, the loose and porous structural appearance is further obvious under the high-power microwave field, providing conditions and channels for the in-depth destruction of microwaves, and microscopically, the Ni-VO chemical bonds are destroyed, so that the physical phase is transformed from insoluble to soluble, which is conducive to the subsequent leaching reaction. The study also found that the second high-power high-temperature roasting time should not be too long. If the time is too long, it will easily promote the reaction of soluble vanadium-containing compounds with nickel to form new insoluble Ni-VO and other phases. Therefore, controlling the roasting time is also very important. By controlling the microwave high-temperature roasting within the appropriate time, NiV 2 O 6 Effective dissolution of vanadium in insoluble phases such as vanadium.

[0024] The roasted slag obtained by microwave roasting is spherical (spherical diameter 1-3cm), and is treated by ultrasonic pre-activation-alkali leaching process, which abandons the process of grinding the roasted slag, and significantly reduces the process energy consumption. First, the roasted slag is added with water to prepare the water-containing roasted slag material, and then pre-activated by normal temperature ultrasonic wave. This step can break up the pelletized roasted slag macroscopically, so that the material and the leaching agent are evenly dispersed in the leaching process. Microscopically, due to the cavitation effect of ultrasonic wave, the surface particles of the roasted slag can be activated, which promotes the leaching reaction and greatly shortens the time of the alkali leaching process.

[0025] The leaching solution obtained by the method of the present invention has high vanadium content and extremely low nickel and aluminum content; the nickel and aluminum are mainly present in the leaching residue, and the mass percentage of nickel and aluminum in the leaching residue is above 98%, and the purity is high.

[0026] The method for recovering vanadium from waste nickel-aluminum powder provided by the present invention is designed for the unique insoluble composition and structure characteristics of vanadium in the raw material. Experiments show that the method of the present invention can be used to leach most of the vanadium in the waste nickel-aluminum powder, with a high recovery rate of vanadium. At the same time, the nickel-aluminum leaching rate is lower than 0.4%, the obtained leaching solution has high purity, and the subsequent purification process of vanadium is greatly simplified. The content of nickel and aluminum (calculated by the total weight of metal) in the leached residue after leaching is above 98%, with high purity, and the leached residue can be directly used as a catalyst preparation raw material after simple treatment.

[0027] The method for recovering vanadium from waste nickel-aluminum powder for catalyst provided by the present invention realizes efficient recovery of vanadium from waste nickel-aluminum powder, and has low processing cost, low labor intensity, short processing time, increased processing capacity of waste nickel-aluminum powder, and is more conducive to promoting resource processing and utilization of waste nickel-aluminum powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The NiV in the waste nickel aluminum powder treated in Example 1 of the present invention 2 O 6 SEM image of the insoluble phase;

[0029] Figure 2 This is a picture of the loose and porous calcined slag obtained by processing in step S1 in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is described in detail below through specific embodiments. The following embodiments are intended to further illustrate the content of the present invention in detail, but are not intended to limit the scope of protection of the claims of the present invention.

[0031] In the following examples, the pharmaceutical agents used are all commercially available products. Unless otherwise specified, the content percentages in each example are all mass percentages.

[0032] Example 1

[0033] This embodiment provides a method for recovering vanadium from waste nickel-aluminum powder for catalysts. The processed raw waste nickel-aluminum powder is waste nickel-aluminum powder for catalysts provided by a chemical enterprise in Guangdong Province. It is a light green powder. Its main valuable metal chemical composition analysis is shown in Table 1 below, where the content of each element is in mass percentage. 2 O 6 The mass percentage of the insoluble phase in the vanadium-containing phase is 35%. 2 O 6 Phase diagram Figure 1 shown.

[0034] Table 1

[0035] element V Ni Al Mo Content, Wt% 10.23 12.36 58.86 1.23

[0036] The processing steps are as follows:

[0037] S1: Mix waste nickel and aluminum powder with water to make balls, and control the ball diameter within 1-3 cm. Then, perform two-stage roasting treatment in a microwave environment. The roasting conditions for the first stage are: microwave power 400 W, roasting temperature 125 ° C, and treatment time 4 min. The roasting conditions for the second stage are: microwave power 800 W, roasting temperature 800 ° C, and treatment time 20 min. Loose and porous roasted slag is obtained. See the photo. Figure 2 As shown;

[0038] S2: The calcined slag (spherical) is firstly added with water to prepare a hydrated calcined slag material, the liquid-solid ratio of the hydrated calcined slag material is 5.0 mL / g, and the hydrated calcined slag material is subjected to ultrasonic pre-activation treatment at room temperature (about 25°C), the ultrasonic power is 400 W, and the treatment time is 2 min; then, alkali leaching treatment is performed, the hydrated calcined slag material after ultrasonic pre-activation is heated to 85°C, and an alkali leaching agent, sodium hydroxide, is added, and the molar number of sodium ions added to the alkali leaching agent is 1.2 times the molar number of vanadium ions contained in the waste nickel-aluminum powder, and the mixture is stirred for 40 min, and then the solid-liquid is separated to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0039] After testing and analysis, most of the vanadium in the raw material waste nickel and aluminum powder entered the leaching solution, the vanadium recovery rate was 98%, and the nickel and aluminum leaching rate was 0.35%. The mass fraction of vanadium in the leaching solution (excluding sodium) was 98.76%, indicating that the main metal contained in the leaching solution was vanadium, and the purity was very high.

[0040] The mass percentage content of nickel and aluminum in the leaching residue (calculated based on the total mass of metals contained in the leaching residue) is 98.8%.

[0041] Example 2

[0042] This embodiment provides a method for recovering vanadium from waste nickel and aluminum powder for catalysts, and the processed raw waste nickel and aluminum powder is the same as that in Example 1. The processing steps are as follows:

[0043] S1: Mix waste nickel and aluminum powder with water to make balls, and control the ball diameter within 1-3 cm. Then, perform two-stage roasting treatment in a microwave environment. The roasting conditions of the first stage roasting treatment are: microwave power 500 W, roasting temperature 150° C., and treatment time 2 min. The roasting conditions of the second stage roasting treatment are: microwave power 1100 W, roasting temperature 900° C., and treatment time 10 min, to obtain loose and porous roasted slag;

[0044] S2: The calcined slag (spherical) is firstly added with water to prepare a hydrated calcined slag material, the liquid-solid ratio of the hydrated calcined slag material is 2.5 mL / g, and the hydrated calcined slag material is subjected to ultrasonic pre-activation treatment at room temperature (about 25°C), the ultrasonic power is 600 W, and the treatment time is 3 min; then, alkali leaching treatment is performed, the hydrated calcined slag material after ultrasonic pre-activation is heated to 90°C, and an alkali leaching agent, sodium carbonate, is added, the molar number of sodium ions added in the alkali leaching agent is 1.3 times the molar number of vanadium ions contained in the waste nickel-aluminum powder, and the mixture is stirred for 30 min, and then the solid-liquid is separated to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0045] After testing and analysis, most of the vanadium in the raw material waste nickel and aluminum powder entered the leaching solution, the vanadium recovery rate was 97%, and the nickel and aluminum leaching rate was 0.30%. Calculated by the total mass of metals in the leaching solution (excluding sodium), the mass fraction of vanadium was 99.15%, indicating that the main metal contained in the leaching solution was vanadium, and the purity was very high.

[0046] The mass percentage content of nickel and aluminum in the leaching residue (calculated based on the total mass of metals contained in the leaching residue) is 98.1%.

[0047] Example 3

[0048] This embodiment provides a method for recovering vanadium from waste nickel and aluminum powder for catalysts, and the processed raw waste nickel and aluminum powder is the same as that in Example 1. The processing steps are as follows:

[0049] S1: Mixing waste nickel and aluminum powder with water to form balls, the ball diameter is controlled within 1-3 cm, and then two-stage roasting treatment is carried out in a microwave environment. The roasting conditions of the first stage roasting treatment are: microwave power 300W, roasting temperature 100°C, and treatment time 5min. The roasting conditions of the second stage roasting treatment are: microwave power 1000W, roasting temperature 850°C, and treatment time 15min, to obtain loose and porous roasting slag;

[0050] S2: The roasted slag (spherical) is firstly added with water to prepare a water-containing roasted slag material, the liquid-solid ratio of the water-containing roasted slag material is 3.0 mL / g, and the water-containing roasted slag material is subjected to ultrasonic pre-activation treatment at room temperature (about 25°C), the ultrasonic power is 500 W, and the treatment time is 2 min; then, alkali leaching treatment is performed, the water-containing roasted slag material after ultrasonic pre-activation is heated to 75°C, and an alkali leaching agent is added, the alkali leaching agent is a mixture of sodium carbonate and sodium hydroxide (wherein the mass of sodium carbonate: the mass of sodium hydroxide = 1:2), the total molar number of sodium ions added to the alkali leaching agent is 1.1 times the molar number of vanadium ions contained in the waste nickel-aluminum powder, the stirring treatment is performed for 60 min, and then the solid-liquid separation is performed to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0051] After testing and analysis, most of the vanadium in the raw material waste nickel and aluminum powder entered the leaching solution, the vanadium recovery rate was 96%, and the nickel and aluminum leaching rate was 0.38%. Calculated by the total mass of metals in the leaching solution (excluding sodium), the mass fraction of vanadium was 98.36%, indicating that the main metal contained in the leaching solution was vanadium, and the purity was very high.

[0052] The mass percentage content of nickel and aluminum in the leaching residue (calculated based on the total mass of metals contained in the leaching residue) is 98.5%.

[0053] Example 4

[0054] This embodiment provides a method for recovering vanadium from waste nickel and aluminum powder for catalysts, and the processed raw waste nickel and aluminum powder is the same as that in Example 1. The processing steps are as follows:

[0055] S1: Mix waste nickel and aluminum powder with water to make balls, and control the ball diameter within 1-3 cm. Then, perform two-stage roasting treatment in a microwave environment. The roasting conditions of the first stage roasting treatment are: microwave power 400 W, roasting temperature 150 ° C, and treatment time 3 min. The roasting conditions of the second stage roasting treatment are: microwave power 900 W, roasting temperature 700 ° C, and treatment time 15 min, to obtain loose and porous roasting slag;

[0056] S2: The calcined slag (spherical) is firstly added with water to prepare a hydrated calcined slag material, the liquid-solid ratio of the hydrated calcined slag material is 5.0 mL / g, and the hydrated calcined slag material is subjected to ultrasonic pre-activation treatment at room temperature (about 25°C), the ultrasonic power is 600 W, and the treatment time is 1 min; then, alkali leaching treatment is performed, the hydrated calcined slag material after ultrasonic pre-activation is heated to 80°C, and an alkali leaching agent is added, the alkali leaching agent is a mixture of sodium carbonate and sodium hydroxide (wherein the mass of sodium carbonate: the mass of sodium hydroxide = 1:2), the total molar number of sodium ions added to the alkali leaching agent is 1.2 times the molar number of vanadium ions contained in the waste nickel-aluminum powder, the stirring treatment is performed for 50 min, and then the solid-liquid separation is performed to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0057] After testing and analysis, most of the vanadium in the raw material waste nickel and aluminum powder entered the leaching solution, the vanadium recovery rate was 97%, and the nickel and aluminum leaching rate was 0.29%. The mass fraction of vanadium in the leaching solution (excluding sodium) was 98.18%, indicating that the main metal contained in the leaching solution was vanadium, and the purity was very high.

[0058] The mass percentage content of nickel and aluminum in the leaching residue (calculated based on the total mass of metals contained in the leaching residue) is 98.8%.

[0059] It can be seen from the above examples that the method of the present invention is used to treat waste nickel and aluminum powder, the recovery rate of vanadium is high, the nickel and aluminum leaching rate is low, the obtained leaching solution is of high purity, and the metal vanadium content is above 98%. The nickel and aluminum content in the leached residue after leaching is greater than 98%, and the purity is high.

[0060] Comparative Example 1

[0061] This comparative example provides a method for recovering vanadium from waste nickel and aluminum powder for catalysts, and the processed raw waste nickel and aluminum powder is the same as that in Example 1. The processing steps are as follows:

[0062] S1: Mixing waste nickel and aluminum powder with water to form balls, the ball diameter is controlled within 1-3 cm, and then calcining in a microwave environment. The calcining conditions are: microwave power 1000 W, calcining temperature 900 ° C, and treatment time 30 min to obtain calcined slag;

[0063] S2: The roasted slag (spherical) is firstly added with water to prepare a water-containing roasted slag material, the liquid-solid ratio of the water-containing roasted slag material is 5.0 mL / g, and the water-containing roasted slag material is subjected to ultrasonic pre-activation treatment at room temperature (about 25°C), the ultrasonic power is 500 W, and the treatment time is 3 min; then, alkali leaching treatment is performed, the water-containing roasted slag material after ultrasonic pre-activation is heated to 90°C, and an alkali leaching agent is added, the alkali leaching agent is a mixture of sodium carbonate and sodium hydroxide (wherein the mass of sodium carbonate: the mass of sodium hydroxide = 1:2), the total molar number of sodium ions added to the alkali leaching agent is 1.3 times the molar number of vanadium ions contained in the waste nickel-aluminum powder, the stirring treatment is performed for 60 min, and then the solid-liquid separation is performed to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0064] After testing and analysis, the vanadium recovery rate is 63%, and the nickel-aluminum leaching rate is 5.49%. Calculated by the total mass of metals in the leaching solution (excluding sodium), the mass fraction of vanadium is 84.36%. The leaching solution mainly contains metal vanadium and aluminum. The leaching solution has a complex composition, which increases the difficulty of subsequent process treatment.

[0065] The mass percentage content of nickel and aluminum in the leaching residue (calculated based on the total mass of metals contained in the leaching residue) is 89.9%.

[0066] The analysis shows that the loose and porous structure of the slag without the first low-power and low-temperature roasting treatment is not as good as that after the second-stage roasting treatment, and it is harder. Microscopically, the soluble vanadium-containing compounds directly react with nickel under high-temperature roasting conditions to easily form new insoluble Ni-VO and other phases, resulting in a significant decrease in the vanadium recovery rate.

[0067] By selecting a two-stage roasting treatment, the low-power and low-temperature roasting in the first stage and the high-power and high-temperature roasting in the second stage work synergistically. The second stage roasting can make the loose and porous structure of the first stage roasting slag more obvious, providing conditions and channels for the deep destruction of microwaves, which is conducive to improving the recovery rate of vanadium.

[0068] Comparative Example 2

[0069] This comparative example provides a method for recovering vanadium from waste nickel and aluminum powder used as a catalyst, and the processed raw waste nickel and aluminum powder is the same as that in Example 1. The processing steps are as follows:

[0070] S1: waste nickel aluminum powder is mixed with water to form balls, the ball diameter is controlled within 1-3 cm, and then two-stage roasting treatment is carried out in a microwave environment. The roasting conditions of the first stage roasting treatment are: microwave power 400 W, roasting temperature 125 ° C, and treatment time 4 min. The roasting conditions of the second stage roasting treatment are: microwave power 800 W, roasting temperature 800 ° C, and treatment time 20 min, to obtain loose and porous roasting slag;

[0071] S2: The calcined slag (spherical) is first added with water to prepare a water-containing calcined slag material, the liquid-solid ratio of the water-containing calcined slag material is 5.0 mL / g, and the calcined slag material is directly alkali leached. The water-containing calcined slag material is heated to 85°C, and an alkali leaching agent is added. The alkali leaching agent is a mixture of sodium carbonate and sodium hydroxide (wherein the mass of sodium carbonate: the mass of sodium hydroxide = 1:2), and the total molar number of sodium ions added to the alkali leaching agent is 1.3 times the molar number of vanadium ions contained in the waste nickel-aluminum powder. The mixture is stirred for 60 minutes, and then the solid-liquid is separated to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0072] After testing and analysis, the vanadium recovery rate of this comparative example was only 53%.

[0073] The analysis shows that directly using stirring method to alkali-leach the spherical roasted slag will result in uneven dispersion of the material and the alkali leaching agent, resulting in a decrease in the vanadium leaching rate. If the roasted slag is ground and then leached, although the vanadium leaching rate can be improved to a certain extent, it will increase energy consumption and easily cause the loss of raw materials during the grinding process, thus affecting the recovery rate of metal vanadium.

[0074] Comparative Example 3

[0075] This comparative example provides a method for recovering vanadium from waste nickel and aluminum powder used as a catalyst, and the processed raw waste nickel and aluminum powder is the same as that in Example 1. The processing steps are as follows:

[0076] S1: waste nickel aluminum powder is mixed with water to form balls, the ball diameter is controlled within 1-3 cm, and then two-stage roasting treatment is carried out in a muffle furnace. The roasting conditions of the first stage roasting treatment are: roasting temperature 125°C, treatment time 5min, and the roasting conditions of the second stage roasting treatment are: roasting temperature 700°C, treatment time 60min, to obtain roasting slag;

[0077] S2: The roasted slag (spherical) is firstly added with water to prepare a water-containing roasted slag material, the liquid-solid ratio of the water-containing roasted slag material is 5.0 mL / g, and the water-containing roasted slag material is subjected to ultrasonic pre-activation treatment at room temperature (about 25°C), the ultrasonic power is 500 W, and the treatment time is 3 min; then, alkali leaching treatment is performed, the water-containing roasted slag material after ultrasonic pre-activation is heated to 90°C, and an alkali leaching agent is added, the alkali leaching agent is a mixture of sodium carbonate and sodium hydroxide (wherein the mass of sodium carbonate: the mass of sodium hydroxide = 1:2), the total molar number of sodium ions added to the alkali leaching agent is 1.3 times the molar number of vanadium ions contained in the waste nickel-aluminum powder, the stirring treatment is performed for 60 min, and then the solid-liquid separation is performed to obtain a vanadium-containing leaching solution and a nickel-aluminum leaching slag, respectively.

[0078] The calcination temperature of the second calcination treatment in step S1 of this comparative example was changed from 700°C to 800°C, 900°C, 1000°C, and 1100°C, respectively, while the treatment time remained unchanged. Experiments were carried out to obtain the metal vanadium recovery rates at the corresponding temperatures. The results are shown in Table 2.

[0079] Table 2

[0080] The second stage of calcination temperature, °C 700 800 900 1000 1100 Vanadium recovery rate, % 39 52 63 89 87

[0081] It can be seen from the above table that the NiV in the waste nickel aluminum powder is calcined in a muffle furnace. 2 O 6 It is difficult to decompose the insoluble vanadium-containing phases below 1000 degrees, which also shows that their chemical bonds can only be broken under high temperature conditions. When the temperature is below 1000 degrees, the vanadium recovery rate is below 65%.

[0082] Experimental Example 1

[0083] This experimental example mainly investigates the influence of different second stage roasting treatment time on vanadium recovery rate. The treated raw material waste nickel and aluminum powder is the same as that in Example 1.

[0084] The experimental steps are as follows:

[0085] S1: waste nickel aluminum powder is mixed with water to form balls, the ball diameter is controlled within 1-3 cm, and then two-stage roasting treatment is carried out in a microwave environment. The roasting conditions of the first stage roasting treatment are: microwave power 400 W, roasting temperature 125 ° C, and treatment time is 4 min. The roasting conditions of the second stage roasting treatment are: microwave power 800 W, roasting temperature 800 ° C, and the treatment time is set to 5 min, 10 min, 15 min, 20 min, 25 min, and 30 min, respectively, to obtain loose and porous roasting slag;

[0086] The several roasted slags obtained in step S1 were subjected to ultrasonic pre-activation-alkali leaching treatment respectively, and the treatment steps were the same as step S2 in embodiment 1 of the present invention. Vanadium-containing leaching solution and nickel-aluminum leaching slag were obtained respectively, and the vanadium recovery rate was calculated. The specific results are shown in Table 3.

[0087] Table 3

[0088]

[0089] From the above experiments, it can be seen that during microwave high-temperature roasting, the roasting time has a significant effect on the leaching of vanadium. Too short or too long a time is not conducive to the leaching of vanadium in waste nickel-aluminum powder. If the time is too short, the roasting is incomplete, and if the time is too long, it is easy to promote the reaction of soluble vanadium-containing compounds with nickel to form new insoluble Ni-VO and other phases. Therefore, it is very important to control the roasting time, so it is preferred that the second stage of high-power high-temperature roasting treatment time is controlled to 10 to 20 minutes.

[0090] The above examples illustrate that the method of the present invention can achieve the recovery of insoluble NiV in waste nickel and aluminum powder for catalyst. 2 O 6 The effective leaching of vanadium can significantly improve the recovery rate of vanadium; the obtained leaching solution has high purity, and the leaching residue can be directly used as a raw material for catalyst preparation after simple treatment.

[0091] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for recovering vanadium from waste nickel and aluminum powder for catalyst, characterized in that: Includes steps: S1: making balls from waste nickel-aluminum powder, and then calcining them in a microwave environment to obtain calcined slag; the vanadium in the waste nickel-aluminum powder mainly exists in the form of NiV2O6 insoluble phase; S2: The roasted slag is pre-activated by ultrasonic wave, then alkali leaching is performed, and then solid-liquid separation is performed to obtain vanadium-containing leaching solution and nickel-aluminum leaching slag respectively; The roasting in a microwave environment includes two stages of roasting, the first stage of roasting is low-power and low-temperature roasting, and the second stage of roasting is high-power and high-temperature roasting; The roasting conditions of the first roasting treatment are: microwave power 300-500W, roasting temperature 100-150°C, and the time of the first roasting treatment is controlled to be 2-5min; the roasting conditions of the second roasting treatment are: microwave power 800-1100W, roasting temperature 700-900°C, and the time of the second roasting treatment is controlled to be 10-20min.

2. The method according to claim 1, characterized in that The waste nickel aluminum powder is mixed with water to form balls, and the ball diameter is controlled to be 1 to 3 cm.

3. The method according to claim 1, characterized in that: The ultrasonic pre-activation comprises: treating the calcined slag with ultrasonic waves at room temperature, with the ultrasonic wave power being 400-600W and the treatment time being 1-3 minutes.

4. The method according to claim 3, characterized in that Before the calcined slag is treated with ultrasound, water is first added to prepare a water-containing calcined slag material, and the liquid-to-solid ratio of the water-containing calcined slag material is 2.5-5.0 mL / g.

5. The method according to claim 4, characterized in that The alkali leaching treatment comprises: heating the water-containing roasted slag material after ultrasonic pre-activation to 75-90° C., adding an alkali leaching agent, and stirring for 30-60 minutes.

6. The method according to claim 5, characterized in that The alkaline leaching agent is sodium carbonate and / or sodium hydroxide.

7. The method according to claim 6, characterized in that The molar number of sodium ions in the alkaline leaching agent is 1.1 to 1.3 times the molar number of vanadium ions contained in the waste nickel and aluminum powder.

8. The method according to claim 1, characterized in that The mass percentage content of metallic vanadium in the vanadium-containing leaching solution is ≥98% based on the total mass of the metals contained; and / or, The mass percentage content of nickel and aluminum in the nickel and aluminum leaching slag is ≥98%.

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