TW201702388A - A method for recovering a metal alloy from an al-containing waste catalyst - Google Patents

Abstract

A method for recovering a metal alloy from an Al-containing waste catalyst includes mixing an Al-containing waste catalyst with a reductant, a fluxing medium and an iron powder to obtain a mixture; heating the mixture at a temperature of 1450-1650 DEG C for 1-4 hour under non-oxygen environment to obtain an aluminum flux and an alloy solution; removing the aluminum flux; and cool down the alloy solution to obtain a metal alloy. As such, the aluminum oxide existed in the Al-containing waste catalyst is removed, and the heavy metals existed in the Al-containing waste catalyst can be recovered in the form of a metal alloy.

Description

Method for recovering metal alloy from aluminum waste catalyst

The present invention relates to a method for recovering metals from waste catalysts, and more particularly to a method for recovering metal alloys from aluminum-based waste catalysts.

Aluminum-based catalysts are often used in chemical industrial processes to accelerate the catalysis of products containing aluminum oxide and heavy metals such as vanadium, molybdenum, tungsten, nickel, and cobalt. The above-mentioned components have high usability. For example, if the alumina contained in the aluminum-based waste catalyst is separated from the remaining heavy metals, the obtained alumina can be used as a cement additive, and the metal alloy composed of the above-mentioned heavy metals can be used. Used to make alloy steels with better mechanical properties.

Conventional aluminum-based waste catalyst recovery methods are mostly treated by wet method (acid leaching or alkali leaching). Taking the acid leaching method as an example, the heavy metal component contained in the aluminum-based waste catalyst is decanted by the acid solution, and the alumina is not easily dissolved in the acid solution, but is separated from the remaining heavy metal components. However, the heavy metal components obtained are formed in the form of compounds (metal salts), so it is necessary to reduce the metal salts to form metal alloys, increasing the complexity of the process and reducing the metal recovery rate (about 70%). ). In addition, recovery by acid leaching requires a large amount of high-concentration acid solution, which causes water and air pollution, and requires a long working time, which takes at least one day.

In view of the above, it is necessary to propose a method for recovering a metal alloy from an aluminum-based waste catalyst, which can improve the above problems.

The main object of the present invention is to provide a metal recovery from an aluminum-based waste catalyst. The gold method can separate the alumina contained in the aluminum-based waste catalyst and directly recover the heavy metal in the aluminum-based waste catalyst in the form of a metal alloy.

Still another object of the present invention is to provide a method for recovering a metal alloy from an aluminum-based waste catalyst which does not require the use of an acid liquid.

The invention provides a method for recovering a metal alloy from an aluminum-based waste catalyst, comprising: mixing an aluminum-based waste catalyst with a reducing agent, a slagging agent and an iron powder to obtain a mixture, wherein each kilogram The aluminum-based waste catalyst is mixed with 0.05 to 0.3 kg of the reducing agent; the mixture is placed in an anaerobic environment, and the mixture is reacted at a temperature of 1450 to 1650 ° C for 1 to 4 hours to form a Aluminum slag and an alloy solution; removing the aluminum slag; and cooling the alloy solution to obtain a metal alloy.

The method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, wherein the reducing agent is coke, ferroniobium, aluminum particles, cerium carbide or a combination thereof.

The method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, wherein the waste catalyst is mixed with 0.1 to 1 kg of the slag-forming agent per kg. .

The method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, wherein the slag-forming agent is a calcium-containing compound or a combination of several calcium-containing compounds.

The method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, wherein the waste catalyst is mixed with 0.1 to 0.5 kg of the iron powder per kg.

The method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, further comprising: mixing the aluminum-based waste catalyst with the reducing agent, the slagging agent and the iron powder at a temperature of 150 to 800 ° C The heavy oil contained in the aluminum-based waste catalyst is volatilized to remove the heavy oil contained in the aluminum-based waste catalyst.

The method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention further comprises: before cooling the alloy solution, mixing a phosphorus removal agent into the alloy solution to form a phosphorus slag, and continuously removing the phosphorus slag to remove the The phosphorus component contained in the alloy solution.

a method for recovering a metal alloy from an aluminum-based waste catalyst of the present invention, wherein the The phosphorus agent is calcium oxide, magnesium oxide, calcium chloride, magnesium chloride or a combination thereof.

The method for recovering a metal alloy from an aluminum-based waste catalyst according to the present invention, wherein the aluminum-based waste catalyst is mixed with the reducing agent, the slagging agent and the iron powder, and is 1450 to 1650 ° C in the closed reaction furnace. The mixture is heated at a temperature for 1 to 4 hours, and the alumina in the aluminum-based waste catalyst can be separated, and the remaining heavy metals can be directly recovered in the form of a metal alloy, thereby achieving the functions of simplifying the recovery step and shortening the time required for recovery.

In the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, the mixing ratio of the aluminum-based waste catalyst and the reducing agent can effectively reduce heavy metals and separate the unreduced alumina to enhance the metal. The effect of recovery rate.

Since the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention directly reduces the heavy metal into an alloy solution by using a reducing agent and separates the alumina by density, it is possible to achieve a reduction in recovery cost without using a large amount of acid solution. To avoid environmental pollution and other effects.

The above and other objects, features and advantages of the present invention will become more <RTIgt; The method for recovering the metal alloy in the medium is to mix an aluminum-based waste catalyst with a reducing agent, a slagging agent and an iron powder to form a mixture, and continue heating the mixture to form an aluminum slag and an alloy solution.

In detail, the aluminum-based waste catalyst comprises an alumina component, and may further comprise one or more heavy metal components of vanadium, molybdenum, tungsten, nickel, and cobalt. For example, the aluminum-based waste catalyst may be a waste nickel catalyst (DNi), a nickel-molybdenum waste catalyst (HDS), or a vanadium-molybdenum-nickel waste catalyst (RDS), but is not limited thereto.

More specifically, the present invention mixes 0.05 to 0.3 per kilogram of the aluminum-based waste catalyst. The reducing agent of kilograms. By the above ratio, the heavy metal component in the aluminum-based waste catalyst can be reduced, but the alumina contained therein is not reduced, thereby separating the alumina and the heavy metal component. Further, depending on the strength of the reducing ability required, the reducing agent may be selected from coke, ferroniobium, aluminum or tantalum carbide. Among them, the reduction power of coke is the strongest, while the reduction of carbonization is weak. Niobium iron has the composition of iron, which can reduce the amount of iron powder added, and the niobium oxide formed by oxidation is mixed in the aluminum slag; the aluminum granule can form alumina after oxidation, and the recovery is convenient.

The slag forming agent is a calcium compound such as calcium oxide, calcium fluoride, calcium chloride or calcium carbonate, or may be a combination of a plurality of calcium compounds, which is not limited in the present invention. The calcium component contained in the slag-forming agent can form aluminum slag with the alumina contained in the aluminum-based waste catalyst and float on the alloy solution to accelerate the efficiency of removing the aluminum slag. In this embodiment, 0.1 to 1 kg of the slag-forming agent is mixed per kg of the aluminum-based waste catalyst, which can save the amount of the slag-forming agent and at the same time effectively achieve the effect of helping the aluminum slag to float.

In addition, in the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, by adding the iron powder, the heavy metal component contained in the aluminum-based waste catalyst can be mixed with iron to facilitate subsequent alloy steel. Production. In this embodiment, 0.1 to 0.5 kg of the iron powder is mixed per kilogram of the aluminum-based waste catalyst to meet the ratio of the common alloy steel.

More specifically, the aluminum-based waste catalyst is mixed with the reducing agent, the slagging agent and the iron powder to form a mixture, and the mixture is continuously placed in an anaerobic environment to avoid the aluminum-based waste contact. The metal component contained in the medium is reoxidized during heating. The oxygen-free environment herein can be achieved by various conventional means, such as introducing high-pressure nitrogen to remove oxygen in the reaction environment, or placing the mixture in a closed reactor and using the reducing agent to remove the oxygen-free atmosphere. Oxygen or the like present in the closed reactor.

In the present invention, the mixture is reacted at a temperature of 1450 to 1650 ° C for 1 to 4 hours. If the reaction temperature is lower than 1450 ° C, the vanadium and the like in the aluminum-based waste catalyst and the iron powder may not be melted; When the temperature is higher than 1650 ° C, it may cause heavy weight in the aluminum waste catalyst. The metal component evaporates to reduce the recovery. In the present invention, the reducing agent reduces the heavy metal component in the aluminum-based waste catalyst to form the alloy solution by the difference in activity; the alumina is not reduced to maintain the oxidation state, and forms a density with the slag forming agent. The lighter aluminum slag floats above the alloy solution. The closed reaction furnace can prevent the alloy solution from reacting with oxygen. The above closed reactor can be a three-way electric arc furnace (EAF), which has the advantages of stable temperature and large operation amount, but the invention is not limited.

Then, the aluminum slag can be removed from the closed reaction furnace, and the aluminum slag can be used as a cement additive after being cooled. The alloy solution can be cooled to form a metal alloy for alloy steel. Thereby, the present invention can achieve the purpose of separating the components from the alumina and the remaining heavy metals, and the above heavy metal components can be directly formed into a metal alloy for recycling, thereby achieving the effect of simplifying the production.

In addition, in the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, the heavy oil in the aluminum-based waste catalyst may be removed in advance, for example, heating the aluminum-based waste in a reaction furnace at a temperature of 150 to 800 ° C. The medium volatilizes the heavy oil to remove the heavy oil attached to the aluminum-based waste catalyst. The aluminum-based waste catalyst is continuously mixed with the reducing agent, the slagging agent and the iron powder to prevent heavy oil from entering the alloy solution and affecting the progress of the reduction reaction.

In the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, before cooling the alloy solution to form the metal alloy, a phosphorus removal agent may be added to remove the phosphorus component contained in the alloy solution to avoid The phosphorus component enters the alloy steel, reducing the strength and toughness of the alloy steel. The phosphorus removal agent may be calcium oxide, magnesium oxide, calcium chloride or magnesium chloride, and combined with phosphorus to form phosphorus slag, and the removed phosphorus slag may be used for the manufacture of refractory bricks and the like.

In order to confirm that the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention can separate the alumina and the remaining heavy metals, and recover the heavy metal component contained in the aluminum-based waste catalyst in the form of a metal alloy, the following experiment is carried out.

(A) Effect of reducing agent ratio

Each 1000 kg of HDS waste catalyst contains 301 kg of aluminum, 161 kg of molybdenum and 35 kg of nickel as the aluminum-based waste catalyst of Groups A1 to A5. As shown in the first table below, different amounts of coke are added as the reducing agent, and 500 kg of slag-forming agent (calcium oxide) and 300 kg of iron powder are added respectively, and 1450 to 1650 ° C in a three-way electric arc furnace. The temperature was heated for 2 hours to form the aluminum slag and the alloy solution. After the aluminum slag is taken out, phosphorus is removed by magnesium chloride, and the alloy solution is cooled to obtain the metal alloy. The recoveries of aluminum, molybdenum and nickel were recorded as follows:

As shown in the first table, in the group A1 to A4, the reducing agent is mixed with 0.05 to 0.3 kg per kg of the aluminum-based waste catalyst, and the alumina and the remaining heavy metals (molybdenum and nickel) can be effectively separated. And the recovery rate of molybdenum and nickel is more than 95%, and the recovery rate of aluminum can even reach more than 99%. As shown in the group A5, if the aluminum-based waste catalyst is mixed with more than 0.3 kg of the reducing agent per kilogram, since the concentration of the reducing agent is too high, part of the alumina is also reduced and mixed to the alloy solution. In the middle, the recovery rate of aluminum is reduced.

Therefore, from the above experimental results, it is understood that the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention can surely separate the alumina and recover the remaining heavy metal in the form of a metal alloy. In addition, the optimum recovery effect can be achieved by mixing 0.05 to 0.3 kg of the reducing agent per kilogram of the aluminum-based waste catalyst.

(B) Effect of heating time

Take 1000 kg of the same HDS waste catalyst as the above experiment, and add 175 kg of coke, 500 kg of calcium oxide and 300 kg of iron powder as the B1~B4 group, and 1450~1650 in the three-way electric arc furnace. The temperature of °C is heated for 1 to 4 hours, and the remaining steps are the same as above. The recoveries of aluminum, molybdenum and nickel were recorded as follows:

As shown in the second table, the heating of the B1 to B4 groups for 1 to 4 hours can effectively achieve the purpose of separating the components from the alumina and recovering the metal alloy. Among them, heating for more than 2 hours can achieve a better recovery effect, and the best effect is obtained by heating for 4 hours. Therefore, it can be seen from the above experiment that it is possible to obtain the separated alumina and metal alloy from the aluminum-based waste catalyst by heating at a temperature of 1450 to 1650 ° C for 1 to 4 hours.

(C) Impact of aluminum-based waste catalyst types

Take the same amount of waste nickel catalyst (DNi), nickel-molybdenum waste catalyst (HDS) and vanadium molybdenum nickel waste catalyst (RDS) as the C1~C3 group, and operate the invention according to the conditions of the same group B2. The method for recovering metal alloys from aluminum waste catalysts and measuring the recovery rates of aluminum, molybdenum and nickel are as follows:

As shown in the third table, the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention can be used for various aluminum-based waste catalysts, separating the alumina components contained therein, and recovering the remaining in the form of a metal alloy. Heavy metal. Among them, the recovery rate of molybdenum and nickel can be about 95%, and the recovery rate of aluminum is more than 99%, which is significantly higher than that of acid leaching.

In summary, in the above method for recovering a metal alloy from an aluminum-based waste catalyst, the aluminum-based waste catalyst is mixed with the reducing agent, the slagging agent and the iron powder, and is sealed in the closed reaction furnace at 1450~ The mixture is heated at a temperature of 1650 ° C for 1 to 4 hours, and the alumina in the aluminum-based waste catalyst can be separated, and the remaining heavy metals can be directly recovered as a metal alloy to achieve a simplified recovery step and a shorter recovery time.

Furthermore, in the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention, the mixing ratio of the aluminum-based waste catalyst and the reducing agent can effectively reduce the heavy metal and separate the unreduced alumina. Achieve the effect of improving metal recovery.

In addition, since the method for recovering a metal alloy from the aluminum-based waste catalyst of the present invention directly reduces the heavy metal into an alloy solution by using a reducing agent and separates the alumina by the density, it is possible to achieve a reduction without using a large amount of acid liquid. Recycling costs, avoiding environmental pollution and other effects.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

Claims (8)

A method for recovering a metal alloy from an aluminum-based waste catalyst comprises: mixing an aluminum-based waste catalyst with a reducing agent, a slagging agent and an iron powder to obtain a mixture, wherein the aluminum per kilogram The waste catalyst is mixed with 0.05~0.3 kg of the reducing agent; the mixture is placed in an anaerobic environment, and the mixture is reacted at a temperature of 1450 to 1650 ° C for 1 to 4 hours to form an aluminum slag and An alloy solution; removing the aluminum slag; and cooling the alloy solution to obtain a metal alloy. A method for recovering a metal alloy from an aluminum-based waste catalyst according to claim 1, wherein the reducing agent is coke, ferroniobium, aluminum particles, cerium carbide or a combination thereof. A method for recovering a metal alloy from an aluminum-based waste catalyst according to the first aspect of the patent application, wherein the waste catalyst is mixed with 0.1 to 1 kg of the slag-forming agent per kg. A method for recovering a metal alloy from an aluminum-based waste catalyst according to claim 3, wherein the slag-forming agent is a calcium-containing compound or a combination of several calcium-containing compounds. A method for recovering a metal alloy from an aluminum-based waste catalyst according to the first aspect of the patent application, wherein the waste catalyst is mixed with 0.1 to 0.5 kg of the iron powder per kilogram. The method for recovering a metal alloy from an aluminum-based waste catalyst according to any one of claims 1 to 5, further comprising mixing the aluminum-based waste catalyst with the reducing agent, the slagging agent, and the iron Before the powder, the heavy oil contained in the aluminum-based waste catalyst is volatilized at a temperature of 150 to 800 ° C to remove the heavy oil contained in the aluminum-based waste catalyst. The method for recovering a metal alloy from an aluminum-based waste catalyst according to claim 6 of the patent application, further comprising: mixing a phosphorus-removing agent in the alloy solution to form a phosphorus slag, and continuing to move before cooling the alloy solution; The phosphorus slag is removed to remove the phosphorus component contained in the alloy solution. A method for recovering a metal alloy from an aluminum-based waste catalyst according to claim 7, wherein the phosphorus-removing agent is calcium oxide, magnesium oxide, calcium chloride, magnesium chloride or a combination thereof.