KR100770059B1 - METHOD FOR RECOVERING VALUABLE METAL FROM WASTE CONTAINING V, Mo AND Ni - Google Patents

Abstract

Provided is a method for stably and efficiently recovering Fe-Mo-Ni-based alloys and Fe-V-based alloys from wastes containing V, Mo, and Ni. The method for recovering valuable metals from V, Mo and Ni-containing wastes of the present invention reduces V, Mo and Ni-containing wastes to Fe to produce V-containing slag and Fe-Mo-Ni-based alloys, The process of leaving P component in V, Mo, and Ni-containing waste in Fe-Mo-Ni-based alloy, and separating said Fe-Mo-Ni-based alloy from said V-containing slag, and then said Fe-Mo-Ni-based alloy And a step of de-P'ing, and a step of adding a reducing agent to the V-containing slag to produce a Fe-V-based alloy.

Valuable metals, waste, reducing agents, recovery, slag, briquettes

Description

METHOD FOR RECOVERING VALUABLE METAL FROM WASTE CONTAINING V, MO AND Ni}

1 is a graph of standard generation free energy of oxide.

FIG. 2 is a view showing a flow of a valuable metal recovery method in one embodiment of the present invention. FIG.

3 is a diagram illustrating the flow of FIG. 2.

4 is a conceptual diagram showing changes over time of the Fe, Ni, and Mo components in the metal in the electric furnace and changes in the amount of molten metal in the electric furnace.

5 is a view showing another example of the flow of the recovery method of valuable metals.

The present invention relates to a method for recovering valuable metals from waste such as spent desulfurization catalyst, boiler ash, boiler sludge, nickel-based sludge and ammonium metavanadate.

For example, in a boiler using petroleum fuel as a power plant, heavy metals of Ni and V are condensed in the form of oxides in boiler sludge deposited on the bottom of the boiler and boiler ash captured by the dust collector. have. In the ammonium metavanadate obtained by wet alkali treatment of boiler ash, heavy metal of V is condensed in the form of oxide.

In the fields of petroleum refining, gas processing industry, etc., a desulfurization catalyst is provided in the purification process. In this spent desulfurization catalyst, heavy metals of Ni, Mo, and V are condensed in the form of oxides. It is desired to recover these oxides of Ni, Mo, and V in the form of metals as effective utilization of waste.

As one of such recovery techniques, the V-containing waste is heated to 450 to 950 ° C. to remove S, N and C in the waste, and then the waste is mixed with the iron source and the reducing agent and then pulverized. (V), and then heated to 1150 to 1350 ° C. to reduce the Fe, Ni, and Mo components in the raw materials into solid phase, and then charged into an electric furnace. Heating to produce a metal containing Fe, Ni, and Mo as a main component, and a flux rich in V. The metal containing Fe, Ni, and Mo as a main component is subjected to de-P treatment to reduce P. While obtaining an alloy, a method of obtaining a Fe-V alloy by reducing V in the flux by agitating a reducing material in a vessel having a steel stirring function while stirring the V-rich flux is disclosed. (See Patent Document 1 and Claim 1).

As another recovery technique, the first process for roasting V, Mo, Co, and Ni-containing wastes, and the metal equivalent of 50 to 120% of the chemical equivalent required to reduce the Mo, Ni, and Co oxides to the metals. The addition of Si and / or metal A1, heat reduction to dissolve, separates the Ca-A1 ₂ 0 ₃ slag from the Mo-Ni-based alloy or Mo-Co-based alloy or Mo-Ni-Co-based alloy. To the second step of recovering each other and the CaO-A1 ₂ 0 ₃ -based slag, at least a chemical equivalent of metal Si and / or metal A1 required to reduce the oxide of V contained in the slag to the metal; There is disclosed a method including a third step of separating and recovering a V-Si-based alloy or a V-A1-based alloy and CaO-A1 ₂ 0 ₃ -based slag by heating and reducing the solution (Patent Documents). 2, see claim 1).

[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-204420

[Patent Document 2] Japanese Patent Application Laid-Open No. 2001-214423

However, in the recovery method described in Patent Document 1, finely divided coal or coks are used as a reducing agent for solid-phase reduction of Fe, Ni, and Mo components in the raw material (Patent Document 1, paragraph 0022). For this reason, carbon will remain in the metal which has Fe, Ni, and Mo as a main component. Since carbon is easy to bind to Fe-Mo, Fe-Ni, etc. in metal, it becomes difficult to remove carbon in a subsequent process. In addition, there is also a problem that the Mo component sublimes in the kiln during the solid phase reduction, and the recovery yield of the Mo component deteriorates. Furthermore, there is a problem that the process is long and the equipment cost increases.

In the recovery method described in Patent Document 2, in the first step, the waste is roasted as powder without being pellet (see Patent Document 2, paragraph 0010). For this reason, there exists a problem that a waste does not flow and sinters in a kiln.

In addition, in the second step, since the waste is dissolved as a powder, the furnace situation is deteriorated, for example, bridging or blowing occurs in the melting furnace. The deterioration of the furnace situation may lead to deterioration of the power unit or operation instability. Further, in the second step, since the metal Si and / or the metal A1 is used as the reducing agent, there arises a problem that separation of the V component, Mo, and Ni component becomes difficult. In other words, when the amount of metal Si and / or metal A1 is reduced to reduce the amount of metal, the yield of the Mo and Ni components deteriorates, and the Mo and Ni components enter the V-containing slag. On the other hand, when the steel is reduced, not only the reduced V component enters the Mo-Ni-based alloy, but also Si and / or A1 reducing agent enters the Mo-Ni-based alloy. In particular, when A1 is used as the reducing agent, Al reacts with oxygen in the atmosphere, and the loss of oxide is also large.

The present invention has been made in view of the above circumstances, and an object thereof is a method capable of stably recovering a Fe-Mo-Ni-based alloy and a Fe-V-based alloy from a V, Mo and Ni-containing waste stably. To provide.

This inventor paid attention to the oxygen affinity of Ni, Mo, and V in melt reduction temperature 1400 degreeC-1800 degreeC. As shown in Fig. 1 (graph of the standard free energy of oxide generation), Fe is stronger in oxygen affinity than Ni and Mo and weaker than V. When Fe is used as a reducing agent, V-containing slag and Fe It was found that the Mo-Ni-based alloy can be separated in a good yield.

That is, the invention described in claim 1 reduces V, Mo, and Ni-containing wastes to Fe to produce V-containing slag and Fe-Mo-Ni-based alloys, and also, in the V, Mo and Ni-containing wastes, A step of leaving the component in the Fe-Mo-Ni-based alloy, separating the Fe-Mo-Ni-based alloy from the V-containing slag, and then performing P removal of the Fe-Mo-Ni-based alloy; The above-mentioned subject is solved by the recovery method of valuable metals characterized by including the process of adding a reducing agent to V containing slag and producing a Fe-V type alloy.

In addition, the invention described in claim 2 is a method for recovering valuable metals from wastes containing V, Mo, and Ni, and includes the following steps: roasting the wastes containing V, Mo, and Ni; The V, Mo, and Ni-containing waste, Fe, and flux as a reducing agent are charged to a heating furnace, and heated and reduced to produce V-containing slag and Fe-Mo-Ni-based alloys, and the V, Mo, and Ni-containing alloys. Leaving P component in the waste in the Fe-Mo-Ni-based alloy; Separating the Fe-Mo-Ni-based alloy from the V-containing slag and then performing de-P of the Fe-Mo-Ni-based alloy; A1 reducing agent was added to the V-containing slag to form a Fe-V-based alloy and CaO-Al ₂ O ₃ It can also be configured as a step of generating slag.

The invention described in claim 3 is a method for recovering valuable metals from V, Mo and Ni-containing wastes according to claim 1 or 2, wherein the V-containing slag and the Fe-Mo-Ni-based alloy are produced. An iron bath is formed in advance, and the V, Mo, and Ni-containing wastes are charged into the iron bath to perform a melt reduction reaction.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described. In this embodiment, the waste containing V, Mo, and Ni is used as a raw material. Specifically, at least one of spent desulfurization catalyst (direct desulfurization catalyst, indirect desulfurization catalyst), boiler ash, boiler sludge, nickel-based sludge, ammonium metavanadate, or a mixture thereof is used as a raw material. Table 1 shows an example of the component for every raw material.

For example, in the desulfurization catalyst, there are many Ni, Mo, and V components, and many C and S components. The boiler ash contains about 80% of the C component, for example, but does not contain the Mo component. Carbon-type sludge contains 50% of moisture, for example. Thus, the waste which has various components is used as a raw material. The raw material is in a state in which heavy oil or water adheres.

Table 2 shows an example of the product standard finally obtained.

For the Fe-V alloy, for example, a standard equivalent to JIS No. 2 is required. In this standard, it is necessary to adjust V component to 45-55 mass%, to suppress C, Si, P, S component, etc. low, and to suppress Ni, Mo, and A1 component low. In addition, the Fe-Ni-Mo alloy has a standard when used in steel, for example, and according to this standard, P and S components need to be kept low.

Fig. 2 shows the flow of the valuable metal recovery method, and Fig. 3 shows this flow. First, raw materials such as a desulfurization catalyst (direct desulfurization catalyst, indirect desulfurization catalyst), boiler ash, carbon sludge, nickel sludge, heavy oil gasification sludge and the like are dried (S1). In this drying process, a raw material is heated to a temperature of about 120 degreeC, for example with a rotary dryer, and is dried. In a raw material, moisture exists as a volatile matter about 30 to 40%, for example. If the water proceeds to the next step as it is, there is too much water to prevent briquetting. Furthermore, since the desulfurization catalyst and the coke boiler ash are originally low in moisture, they may be added after the drying step.

Next, the dry V, Mo and Ni-containing waste is pulverized (S2). For example, V, Mo, and Ni-containing wastes are ground by a milling mill. When pulverized, various raw materials are mixed and made uniform.

Next, the ground waste is coarsely formed into briquettes (S3). For example, the pellet is shaped into pellet or briquette briquettes by pelletizer or briquet. If you proceed to the next step as a powder without molding the raw material into briquettes, the raw material is sintered in the kiln to be roasted, or bridging or blow-up phenomenon occurs in the furnace that melt-reduces. The situation may worsen as a result.

Next, the raw material which briquettes are roasted (S4). In this step, the briquette raw material is heated to, for example, 800 to 900 ° C in a kiln. By this roasting, the S and C components in the waste are thermally decomposed and removed as SO _X , CO _2, or the like. The temperature of 800 ° C or higher is suitable for removing heavy oil or C powder as an oxide, and the temperature of 950 ° C or lower is to prevent Mo from sublimation and the recovery rate drops.

Next, the roasted raw material, Fe as a reducing agent, and lime as a flux are charged into an electric furnace as a heating furnace. Then, these are heated and reduced to about 1700 ° C. to produce V-containing slag and Fe-Mo-Ni-based alloy (S5).

In this step (S5), the roasted raw material, Fe, and flux may be charged into the electric furnace at the same time, or an iron bath may be generated in advance, and the melt reduction reaction may be performed by charging the raw material and lime into the iron bath. If the iron bath is generated in advance, the reaction efficiency of the reduction reaction can be improved, and the thermal efficiency can be further improved.

Reduction of the Mo oxide and Ni oxide in the raw material is performed with Fe. The amount of Fe as the reducing agent is set approximately equal to the chemical equivalents required to reduce the Mo and Ni oxides in the V, Mo and Ni-containing waste to the metal.

After reducing the raw material to Fe, an A1 reducing agent is added to the molten metal, and the Fe oxide produced by Fe reduction and the Fe oxide in the raw material are reduced to the A1 reducing agent. The reduction with the A 1 reducing agent is for returning the Fe oxide produced by the reduction reaction to the metal as the iron source of the Fe-Mo-Ni-based alloy and for adjusting the Fe content in the V-containing slag. The A1 reducing agent can be used auxiliary for the component adjustment of Fe content to the last. As the reducing agent for the Fe oxide, any one of metal A1, metal Si, ferro silicon, carbon or the like, or a combination thereof can be used.

It is also possible to reduce all the Fe reducing agents without adding the A 1 reducing agent, by adding the powder as the iron source of the Fe—Mo—Ni alloy to the amount of Fe as the reducing agent. However, in this step, the Fe content in the V-containing slag becomes too large, and it becomes difficult to reduce the V component. When there is much Fe content in the V-containing slag, V ₂ 0 ₅ Or ammonium metavanadate needs to be charged.

Next, after the Fe-Mo-Ni-based alloy is separated into a V-containing slag, de-S, de-P and de-C of the Fe-Mo-Ni-based alloy are performed (S6, S7). The P component in the raw material remains in the Fe-Mo-Ni-based alloy. Since the S component has a strict standard, it is necessary to remove the S component, and the C component needs to be removed because there is also charcoal from the electrode.

In this step, the Fe-Mo-Ni-based alloy is first tapped with a ladle furnace as a heating container (S6). Next, lime, CaO-A1 ₂ O ₃ -based flux, CaO-A1 ₂ O ₃ -FeO-based flux, and the like are charged, followed by de-S, P, and C (S7). As the CaO-A1 ₂ 0 ₃ -based flux, slag generated by Al reduction of the V-containing slag described later may be used. Ar gas or 0 ₂ gas blowing (using bubbling) is effective. Finally, the Fe-Mo-Ni-based alloys with de-S, de-P and de-C are injected into the mold.

On the other hand, the V-containing slag is also poured into the ladle furnace serving as a heating container (S8). The ladle furnace is also charged with A 2 reducing agent, lime and V ₂ 0 _{5 for} adjusting the V component, thereby containing V. Fe-V-based alloy and CaO-Al ₂ 0 ₃ from slag Slag generates Ladle furnace used for de-S, de-P and de-C for Fe-Mo-Ni-based alloys, and ladle furnace used for A1 reduction of V-containing slag for the purpose of minimizing the installation here. Is common.

4 is a conceptual diagram showing changes over time of molten metal and metal Fe, Ni, and Mo components in an electric furnace. By Fe reduction, Fe component in a metal decreases with time, Ni and Mo component increase, and can stabilize after that. In addition, when the V-containing slag becomes a predetermined amount, the metal is left in the furnace as it is, and the V-containing slag only taps into the ladle furnace. Then, the V-containing slag is reduced in the ladle furnace. On the other hand, the Fe-Mo-Ni-based alloy is tapped into the same ladle furnace once in a plurality of batches in which the V-containing slag taps into the ladle furnace. Then, de-S, de-P and de-C are refined in the same ladle furnace.

The amount of Fe—Mo—Ni based alloy produced is very small compared to V containing slag. By frequently tapping the V-containing slag, the thermal efficiency of the electric furnace is improved. In addition, productivity is also improved as compared with the case of tapping the Fe-Mo-Ni-based alloy for each batch for tapping the V-containing slag.

Figure 5 shows another example of the flow of the recovery method of valuable metals. In this flow, the drying process and the roasting process of the pretreatment process are performed together, and the process is simplified.

First, raw materials such as desulfurization catalyst (direct desulfurization catalyst, indirect desulfurization catalyst), boiler ash, carbon sludge, nickel sludge and heavy oil gasification sludge are roasted (S1 '). In this step, for example, the rotary kiln is heated to, for example, 800 to 900 ° C. By this roasting, the water in the waste evaporates and the S and C minutes are removed.

Next, the raw material which becomes powder is bridging (S3 '). For example, the raw material is molded into pellet or briquette briquettes by a pelletizer or briquette. Depending on the raw material, the briquettes are easily brittle, so the grinding step may be performed before briquetting (S2). What is not powder may be loaded as it is without briquetting. Raw material, Fe as a reducing agent, and lime as a flux are charged to an electric furnace as a heating furnace (S5). Since subsequent processes are the same as the flow of the recovery method shown in FIG. 2, the same reference numerals are used, and the description thereof is omitted.

Example 1

The composition of Table 3 was obtained by roasting the mixed material of the desulfurization catalyst, the boiler ash, and the nickel-based sludge with a drier.

DRY (%) Ni MO V Co Al ₂ O ₃ SiO ₂ Roasting material       3.0 2.3 3.4 0.08 16.2 1.0

Next, 100 kg of dry raw material, 14 kg of quicklime and 7 kg of Fe were charged to a 500 KVA electric furnace, and these were heated to about 1700 ° C. and subjected to melt reduction reaction. 10 kg of the Fe-Mo-Ni alloy of the composition shown in Table 4 and V-rich slag was produced.

      MO Ni Co V (%) Fe-Mo-Ni      20.0 29.0 0.8 0.2

The 57 kg of slag separated and recovered was kept at 1600 ° C. in a high frequency furnace, 5 kg of metal A1 and 5 kg of lime, V ₂ 0 ₅ as a reducing agent. 7 kg was added to recover 10 kg of the Fe-V alloy shown in Table 5.

       V Al Mo Ni (%) Fe-V      46.0 1.0 0.9 0.5

Example 2

After drying the desulfurization catalyst, boiler sludge, nickel-based sludge, boiler ash, etc., add 2% of bentonite as a binder, and then wet and grind it to 200 mesh or less using a rotary ball mill. It was molded into pellets having a diameter of about 10mm. Then, it roasted in 800 degreeC and 3 hours in the water-type kiln, and the roasted thing shown in Table 6 was obtained.

(%) CS Mo Ni Co V SiO ₂ Al ₂ O ₃ Roast     0.1 0.4 5.5 7.5 0.2 8.4 2.4 40.0

17 kg of Fe was melted in advance in a Magnesia Lining 500 KVA electric furnace, 100 kg of the roasted material and 32 kg of quicklime and A1 were added thereto, followed by stirring to blow Ar gas, which is shown in Table 7. 24 kg of a Fe-Mo-Ni alloy was obtained.

    Mo Ni Co V Si P S C (%) Fe-Mo-Ni    20.0 29.0 0.8 0.2 0.1 0.5 0.3 0.1

Furthermore, the Fe-Mo-Ni-based alloy was heated and maintained at a high frequency furnace to remove S, P, and C. Table 8 shows the results.

     P S C Fe-Mo-Ni     0.04 0.03 0.05

138 kg of the V-rich slag separated and recovered were kept at about 1600 ° C and stirred with Ar gas. As the reducing agent, 25 kg of the metal A1, 21 kg of V ₂ 0 ₅ , and 25 kg of lime were added to recover 39 kg of the Fe-V alloy shown in Table 9.

     Ni Al Mo Ni Si P (%) Fe-V     46.8 0.1 0.9 0.5 0.4 0.05

The slag component is composed of CaO 31%, A1 ₂ 0 ₃ 52%, SiO ₂ 2%, MgO 8%, FeO 8.8%.

As described above, according to the present invention, since Fe is used as the reducing agent, Fe-Mo-Ni-based alloys and Fe-V-based alloys can be stably recovered from the V, Mo and Ni-containing wastes in a stable yield.

According to the invention according to claim 1 or 2, Fe is used as a reducing agent, so that Fe-Mo-Ni-based alloys and Fe-V-based alloys can be recovered stably and with good yield from V, Mo and Ni-containing wastes. have. In addition, the P component in the e-Mo-Ni-based alloy and the Fe-V-based alloy can be reduced.

According to the invention described in claim 3, the reaction efficiency of the reduction reaction can be improved, and the thermal efficiency can also be improved. Moreover, continuous operation of a heating furnace is also possible.

Claims (3)

V, Mo, and Ni-containing wastes are reduced to Fe to produce V-containing slag and Fe-Mo-Ni-based alloys, and the P component in the V-, Mo- and Ni-containing wastes is contained in the Fe-Mo-Ni-based alloys. Residual process, Separating the Fe-Mo-Ni-based alloy from the V-containing slag and then performing de-P of the Fe-Mo-Ni-based alloy; A method for recovering valuable metals from V, Mo and Ni-containing wastes, comprising the step of adding a reducing agent to the V-containing slag to form a Fe-V-based alloy. As a method for recovering valuable metals from wastes containing V, Mo and Ni, Roasting V, Mo and Ni-containing wastes; The V, Mo, and Ni-containing waste, Fe, and flux as a reducing agent are charged to a heating furnace, and heated and reduced to produce V-containing slag and Fe-Mo-Ni-based alloys, and the V, Mo, and Ni-containing alloys. Leaving P component in the waste in the Fe-Mo-Ni-based alloy; Separating the Fe-Mo-Ni-based alloy from the V-containing slag and then performing de-P of the Fe-Mo-Ni-based alloy; A1 reducing agent was added to the V-containing slag to form a Fe-V-based alloy and CaO-Al ₂ O ₃ A method for recovering valuable metals from V, Mo and Ni-containing wastes, comprising the step of producing slag. The method according to claim 1 or 2, In the step of producing the V-containing slag and the Fe-Mo-Ni-based alloy, an iron bath is generated in advance, and the V, Mo and Ni-containing waste is charged into the iron bath to perform a melt reduction reaction. A method for recovering valuable metals from wastes containing V, Mo and Ni.

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