JP4566684B2 - Method for recovering metallic Ni and / or Co - Google Patents

Description

  The present invention relates to a method for separating and recovering expensive metal Ni and / or Co from waste containing Ni and / or Co compounds.

Mills containing stainless steel, rolling scales, pickling sludge, plating sludge, etc. are discharged from factories that manufacture or process stainless steel materials, but at present, most of these are discarded and landfilled. It is.
In addition, from catalyst manufacturing plants that use Ni oxide and Co oxide as catalyst materials, raw material waste containing Ni and Co, waste catalyst, wastewater treatment sludge, etc. are discharged, and most of this is also discarded at present and landfilled Has been.

The reason for this is that these discarded dust and sludge contain Ni and Co as compounds such as oxides and hydroxides. In addition to Ni plating, wastewater from Cr plating is treated by the same wastewater treatment equipment in the plating process, so the sludge also contains Cr in addition to Ni hydroxide. This is because it is mixed as an oxide, and other neutralized products are also mixed in, so the quality of Ni is low and it cannot be used as it is as a Ni raw material.
This also applies to Co.

  Here, dust as well as sludge (usually dehydrated cake) is dried to form powder, and the present invention is a technique for selectively recovering metal Ni and metal Co from these powdered wastes. It is about.

  As a conventional technology, dust and sludge generated in a stainless steel manufacturing plant are mixed with carbon particles such as coke, added with a binder, granulated into bean charcoal, dried, charged into an electric furnace, and reduced There is a method in which a molten pool is formed by melting and the molten metal is discharged separately from the slag and taken out as a FeNiCr alloy.

Further, the present applicant has devised the following method as another method and disclosed it in a previous patent application (Japanese Patent Laid-Open No. 9-310126).
In this method, dust and dried sludge are melted by supplying them into the flame of an oxygen burner that uses liquid fuel or gaseous fuel as the heat source, and carbon powder is added in the molten pool at the bottom of the furnace to reduce part of the slag. Then, it is made into a metal and then discharged separately from the slag or simultaneously discharged and separated and recovered as an FeNiCr alloy.

However, the former method requires time and labor for granulation and drying, and in some cases firing, and it is unavoidable to perform batch operation to discharge metal and slag separately. There is a problem that the recovery cost is high because electric power is used as a heat source.
Further, the molten metal is an alloy of Fe and Cr and is not Ni simple substance, that is, the Ni quality (Ni concentration) is lowered, and there is a problem that it is difficult to use as a high quality Ni raw material.

In addition, since the latter method requires time for reduction in the furnace, the supply of dust and sludge, etc., must be interrupted or intermittent discharge is required, which inevitably results in batch operation, resulting in reduced productivity. .
In addition, the molten metal becomes an alloy with Fe and Cr, and the Ni quality decreases and chromium oxide, which is difficult to reduce, becomes slag and remarkably increases the viscosity of the slag. .
Therefore, it is necessary to add fluorite (CaF ₂ ) or the like in order to reduce the viscosity of the slag. In this case, there is a possibility that a problem of F elution that may hinder the safety of slag use may occur.

  Furthermore, since both the former and the latter dissolve most of the raw materials, there is a problem that a large amount of energy is used, and in addition, the quality of the produced metal Ni is low.

  The following Patent Document 1 and Patent Document 2 disclose that waste powder is treated using an oxygen burner. However, those disclosed in Patent Document 1 and Patent Document 2 are not solved by the present invention. The problems to be solved are different, and the object of processing and solution are also different from the present invention.

Japanese Patent No. 3271476 Japanese Patent No. 3277968

The method for recovering metal Ni and / or Co of the present invention has been devised against the background as described above, and the following points are to be solved.
I. First, metal Ni and Co can be selectively recovered at low cost. Do not use electric power for the melting heat source c. Even when using fuel, it is possible to avoid melting all the raw materials. The ability to recover metal Ni and / or Co continuously and high productivity. In other words, the product discharge should be continuous and continuous operation can be performed instead of batch operation. It is possible to eliminate the granulation and firing process as a previous process. To melt as much as possible by melting only the necessary parts without melting the whole raw material. There is no need for trouble to reduce the viscosity of the slag to facilitate the separation of molten slag and metal. Capable of recovering high-grade metal Ni and metal Co by melting only the target metal Ni and metal Co without reducing and melting even Fe and Cr contained in the raw material powder to be recovered

Thus, in the method for recovering metallic Ni and / or Co of the present invention, the fuel is burned with an oxygen burner under the condition that the ratio of oxygen to fuel is less than the stoichiometric ratio, thereby generating a reducing atmosphere together with the flame. The raw material powder containing Ni and / or Co compound is supplied into the flame through the internal flow path provided in the main body of the oxygen burner, and the Ni and / or Co compound is selectively reduced in the flame. Then, the fine metal Ni and / or Co is precipitated in the powder and subsequently melted and agglomerated by the heat of the flame, and then the powder treated with the flame is cooled and the molten metal Ni and / or Co is cooled. Is solidified in the powder and then separated and recovered from the others in the powder.

  According to a second aspect of the present invention, in the first aspect, a gas having an oxygen concentration of 90 vol% or more is used as a combustion-supporting gas of the oxygen burner.

  A third aspect of the present invention provides the fuel according to any one of the first and second aspects, wherein the oxygen is burned by the oxygen burner under the condition that the ratio of oxygen to the fuel is 0.4 to 0.9 of the stoichiometric ratio. It is made to burn.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the raw material powder is supplied to the flame after being dried to a moisture content of 10% by mass or less.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the raw material powder is adjusted so as to have a powder particle size of 50 μm or less and supplied into the flame.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the raw material powder is supplied into the flame by airflow conveyance using a gas having an oxygen concentration of 10 vol% or less.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, water vapor or water is supplied into the flame at 1% or more of the mass of the raw material powder .

Effects and effects of the invention

  As described above, the present invention allows the fuel to be burned under the condition that the ratio of oxygen to fuel is less than the stoichiometric ratio (the stoichiometric ratio is 1 when the fuel is completely burned), that is, under oxygen shortage. To produce a reducing atmosphere together with the flame, supply raw material powder of the waste into the flame, and selectively reduce Ni and / or Co compound in the flame to produce fine metal Ni and / or Co Is deposited in the powder, and is selectively melted and agglomerated by the heat of the flame, and then cooled to solidify them into particles in the powder, and then separated from the rest of the powder and recovered. To do.

In the present invention, the principle of separating and recovering metal Ni and / or Co from waste raw material powder is as follows.
In wastes such as dust and rolling scales generated at stainless steel manufacturing plants and wastewater sludge generated at plating plants and catalyst plants, Ni and Co are usually included in the form of hydroxides and oxides together with Fe and Cr. ing.
However, these hydroxides are easily decomposed into oxides at a low temperature.

FIG. 1 shows a known Ellingham diagram, where the horizontal axis represents temperature and the vertical axis represents standard free energy of formation.
The vertical axis represents the strength of affinity with oxygen, that is, the stability as an oxide. The lower the standard free energy of formation, that is, the lower the figure, the more stable the oxide, That is, it shows that the affinity with oxygen is large.

Referring to the figure, the oxides of Ni and Co are in the upper position in the figure compared to the oxides of Fe and Cr, and also H ₂ O and CO, and have a lower affinity for oxygen and are reduced than Fe and Cr. It can be seen that it is easy to be reduced by H ₂ O and CO.
The present inventor paid attention to this point, and obtained various ideas for the idea that Ni and Co in the powder could be selectively and preferentially reduced with respect to Fe and Cr.

  The problem is that even if Ni and Co compounds can be preferentially reduced with respect to other Fe and Cr compounds, the reduced Ni and Co metals in the powder are dispersed finely in the powder. How to separate from other materials, Ni and Co separation and recovery should be able to be separated easily, and the target metal while maintaining the processing object in the powder state It must be possible to carry out a process for separating and recovering Ni and Co.

  In the present invention, an oxygen burner is used as a means for that purpose, and the fuel is burned under oxygen-deficient conditions to produce a reducing atmosphere together with the flame, and the raw material powder is poured into the raw material powder in the flame. The oxide as a Ni or Co compound (hydroxide easily becomes an oxide by heat) is reduced.

  At this time, the oxides of Ni and Co in the raw material powder are selectively reduced with respect to the oxides of Fe and Cr and subsequently preferentially melted with respect to other oxides.

FIG. 2 schematically shows this.
In the figure, 10 indicates one particle in the raw material powder of waste, which contains Ni and Co compounds (mainly hydroxides) in a mixed state together with Fe, Cr and other hydroxides. ing. That is, Ni and Co compounds form aggregates with other compounds to form one particle 10.
When the particles 10 in this powder are thrown into the flame of an oxygen burner, the hydroxide is easily decomposed by the heat into oxides.

For example, Ni
Ni (OH) ₂ → NiO + H ₂ O
And converted into an oxide.
Thus, Ni and Co that have become oxides in the particles 10 are reduced atmosphere generated by combustion under oxygen shortage by an oxygen burner, more specifically Fe, Cr and other oxides by the generated H ₂ and CO gas. Priority is given to such as.
Then, metal Ni or Co produced by the reduction precipitates in the particles 10 (see FIG. 2 ( b )).

As described above, Ni and Co finely precipitated by this reduction cannot be separated from surrounding Fe or Cr oxides as they are.
However, in the present invention, the fine metal Ni or Co thus produced is then selectively and preferentially melted from other oxides.

  Table 1 (a) shows melting points of various metals together with boiling points, and (b) shows melting points of various metal oxides together with boiling points.

Table 1 melting point of Ni as indicated in (b) is 1 4 55 ° C., a melting point of Co is a 1490 ° C., lower than the melting point of various metal oxides as shown in (b), Metals Ni and Co reduced under a high-temperature flame by an oxygen burner subsequently melt selectively and preferentially.
That is, only the fine metals Ni and Co are melted and the other surrounding oxides are not melted, and only Ni and Co are melted as a sphere and released from the surroundings.
In the figure, 14 represents Ni and Co metal particles which are separated from the surroundings and become independent as spheres.

  In the present invention, the oxygen burner is used instead of the air burner because it can generate a high-temperature flame necessary for melting the fine metal Ni and Co.

  However, if the heating temperature is too high, the metal may be evaporated. In this sense, the flame by the oxygen burner is at an appropriate temperature, and the deposited metal is not likely to evaporate due to the high temperature.

The metals Ni and Co selectively melted in this way are aggregated into one sphere by the surface tension together with other surrounding metals Ni and Co.
The molten metal spheres produced at that time vary in size depending on the amount of surrounding Ni and Co, but become small particles of about 5 to 50 μm.

In this way, the metal Ni or Co is melted and agglomerated in a granular form, so that it is separated from other surrounding oxides and released, and itself becomes a single state.
For this reason, when these metals Ni and Co are separated and recovered from the powder later, this can be easily performed.

  As described above, according to the present invention, the hydroxides of Ni, Co, Cr, and Fe are decomposed at a low temperature and become oxides in the temperature range related to the reduction, and the melting points of metal Ni and metal Co are 1455 ° C., It is relatively low at 1490 ° C., and it utilizes the fact that when they are selectively reduced from oxides, they are previously melted.

In addition, since fuel is used as a melting heat source, low cost can be realized, and in order to achieve high temperature, an oxygen burner is used and the fuel is burned under oxygen-deficient conditions to generate a reducing atmosphere, and the raw material is It can be reduced and melted continuously by a flame with an oxygen burner without granulation, and it can be processed from the supply of raw material powder to partial melting of Ni and Co while maintaining the powder state. can do.
Accordingly, the raw material can be processed as it is without granulating as in the conventional case, and the problem that it takes time for granulation can be solved.

  Moreover, it is possible to process the whole raw material through the entire process without melting the whole supplied raw material and without forming a molten pool, so that continuous processing is possible (not batch operation). Continuous operation), productivity can be increased as compared with the conventional case.

In addition, the present invention does not melt the entire raw material, but only partially melts Ni and Co contained in the powder in a dispersed state, so that the required energy can be reduced as much as possible. The processing cost can be reduced.

  In addition, it is not necessary to separate the molten slag from the metal as in the conventional method, and it is possible to solve the problem that the operation of lowering the viscosity of the slag is troublesome.

In particular, in the present invention, other components other than the target Ni and Co, in particular, Fe and Cr are not reduced, and the target Ni and Co can be separated and recovered as a single unit, resulting in high quality. It can be used as Ni raw material or Co raw material.
In the present invention, metal Fe and Cr can also be recovered from the remainder after recovering Ni and Co according to the conventional method.

  In the present invention, dry dust can be made into powder simply by adjusting the particle size, and sludge such as plating sludge can be dried and adjusted in particle size, and then charged into the flame of an oxygen burner. Can be processed in a powder state consistently from discharge to discharge and further to subsequent separation and recovery.

In this invention, raw material powder is supplied in a flame through the internal flow path provided in the main body of the oxygen burner.
As a method for supplying the raw material powder into the flame of the oxygen burner, the raw material powder is supplied into the flame H through an external flow path 18 provided outside the oxygen burner 16 as shown in FIG. Although it is possible, the raw material powder is preferably supplied into the flame H through the internal flow path 20 provided in the main body of the oxygen burner 16.

In the present invention, a gas having an oxygen concentration of 90 vol% or more can be used as the combustion-supporting gas of the oxygen burner (claim 2).
By doing in this way, flame temperature can be made high temperature and appropriate temperature.

In the present invention, it is also preferable that the oxygen burner be burned under the condition that the ratio of oxygen to fuel is 0.4 to 0.9 of the stoichiometric ratio.
If it is less than 0.4, a lot of soot is generated and oxides other than Ni and Co are easily reduced by C.
On the other hand, if the amount of oxygen is 0.4 or more with respect to the stoichiometric ratio, no soot will be generated, and the flame temperature of the oxygen burner will be higher than the melting temperature of Ni or Co. Can be high.
On the other hand, the upper limit is preferably set to 0.9 or less in order to generate a good reducing atmosphere .

The addition material powder in the present invention, after drying to less than 10% moisture so as not to give rise to clogging (mass%) in the conveying path, it is desirable to make so as to supply into the flame (claim 4).

Furthermore, it is desirable to adjust the particle size so that the powder particle size in the raw material powder is 50 μm or less and to supply the raw material powder into the flame (claim 5 ).
By setting the powder particle size of the raw material powder to 50 μm or less, it is possible to quickly raise the temperature when it is thrown into the flame, and the penetration and diffusion of the reducing gas into the powder particles is good. The reduction reaction can be promoted.
For this reason, it is desirable to adjust the particle size by pulverizing and sieving the raw material powder in advance.

The pneumatic conveying using also the raw material powder oxygen concentration 10% (vol%) or less of gas in the present invention, it is desirable to make so as to supply into the flame (claim 6).
By doing in this way, raw material powder can be smoothly supplied in a flame. Moreover, oxygen can be prevented from being excessively supplied by setting the oxygen concentration of the gas to 10% or less.

In the present invention, it is also desirable to supply water vapor or water into the flame at 1% or more of the raw material powder mass (claim 7 ).
By so doing to, with a stronger reducing power H _{2 O} can be generated much compared to the CO, also to be able to reduce the likely C to reduce oxides such as Fe and Cr, the objective It becomes easy to obtain an appropriate reducing atmosphere.

In the present invention, a specific treatment method of the powder after treatment with the flame, the powder after treatment with their in the flame, then water砕固of charged into water or water flow, the metal in a subsequent Ni And / or Co can be separated and recovered from the others.
In this way, the metal Ni and Co in the powder discharged from the flame of the oxygen burner can be rapidly cooled without being reoxidized, and the particles of the metal Ni and Co are thermally expanded with the surrounding oxide by water granulation. Due to the difference, it shrinks greatly and is well-edged from the other, making it easier to separate and recover.

Hand, may be cooled powder after treatment in a flame with an oxygen concentration 5 vol% in the following gas atmosphere (cooled in an atmosphere in which the oxygen concentration for reoxidation prevention low), the gas in this case Cooling in the atmosphere makes it possible to shrink and solidify the molten metal Ni and Co particles.
According to how the Matako, its in the powder is entrained in the gas used in the cooling, which was collected by the dust collector downstream as it separates the metal Ni and / or Co other therefrom, collected can do.

That is, it is possible to perform subsequent processing while maintaining the powder after processing in the flame in the same powder state.
Metals Ni and / or Co contracted and solidified by cooling in the powder as a means for separating from other, this by utilizing a bulk density difference or magnetic differences in the present invention is separated from the other, also be made to recover it can.
Metals Ni and Co have a higher specific gravity than oxides, and furthermore, they are stronger in magnetism than oxides, so that they can be separated and recovered well from others using them.
In this case, it is possible to use centrifugal separation based on a difference in specific gravity, pressurized flotation separation, or the like, or separation by magnetic separation based on a magnetic difference between metal and oxide.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 4 shows an example of a process in the case of processing a raw material having a moisture content of 40 to 80%, such as wastewater sludge from a catalyst manufacturing plant or wastewater sludge from a plating plant.

Here, the oxygen burner 16 is disposed vertically, a vertical reaction furnace 26 is attached to the lower side thereof, and a granulated and solidified device 28 is disposed below the reaction furnace 26. A conveyor 30 is provided in the water tank of the granulated solidification device 28.
In FIG. 4A, reference numeral 32A denotes a dryer main body, and the dryer main body 32A and the hot air generating furnace 32B form a dryer.

Reference numeral 36 denotes a pulverizer, and a cyclone 34 is provided between the pulverizer 36 and the dryer main body 32A.
Reference numeral 40 denotes a quantitative cutting device, and a cyclone 38 is provided between the quantitative cutting device 40 and the pulverizing device 36.
The hot air generating furnace 32B secondarily burns unburned gas from the oxygen burner 16 and generates hot air there, which serves as a heat source for drying the raw material in the dryer body 32A.

FIG. 4B shows the processing process of this example as a block diagram.
In this process example, drying is essential for conveying the raw material by air flow, and therefore, unburned exhaust gas from the oxygen burner 16 is subjected to secondary combustion in the hot air generating furnace 32B to serve as a heat source for drying.

The raw material powder after drying and pulverization is air-flowed from the outlet of the quantitative cutting device 40 by the fuel gas and supplied to the oxygen burner 16.
Here, oxygen is produced from the atmosphere with an oxygen concentration of 93% by an oxygen generator using an adsorbent, and is supplied to the oxygen burner 16 at a ratio that provides an LPG fuel and a necessary reducing atmosphere.

  The raw material powder is supplied into the flame H through the internal flow path in the main body of the oxygen burner 16, Ni oxide or Co oxide is selectively reduced to metal, and further melted thereafter. Separated and precipitated from the oxide.

The reaction furnace 26 prevents the temperature of the flame H from decreasing and prevents the atmosphere from entering the reaction space to ensure the necessary atmosphere and reaction time.
The reaction-treated product is subjected to granulation and solidification by the granulation and solidification device 28, then pulverized, and centrifuged to separate the metal Ni and Co from others.

The example of FIG. 5 is a process example in the case of processing a raw material having a water content of less than 10%, such as dust generated from a refining furnace of a stainless steel manufacturing plant.
In this process example, the oxygen burner 16 is disposed sideways, and a horizontal reaction furnace 26 is attached to the tip side thereof.

In FIG. 5 (a), 44 is a pulverizing device for pulverizing the raw material powder in a dry state, 46 is a sieve, and 40 is a quantitative cutting device.
48 is an exhaust gas cooling cylinder, 50 is a bag dust collector, 52 is a crusher, and 56 is a centrifuge. A cyclone 54 is provided between the centrifugal separator 56 and the crusher 52.

58 is a secondary combustion cylinder for secondary combustion of the exhaust gas from the oxygen burner 16.
FIG. 5B shows the processing process of this example as a block diagram.

In the process example shown in FIG. 5, since the raw material is in a powder state and drying is not necessary, when the unburned gas is burned in the secondary combustion tower, heat recovery is performed using hot water (not shown) or the like.
Further, the powder composed of dust and treated with the flame H is introduced into the exhaust gas cooling tower 48 along with the exhaust gas.
The dried and pulverized raw material powder is air-flowed from the quantitative cutting device 40 by nitrogen gas and supplied to the oxygen burner 16.

Here, oxygen is produced from the atmosphere with an oxygen concentration of 93% by an oxygen generator using an adsorbent, and is supplied to the oxygen burner 16 at a ratio that provides an LPG supply amount and a necessary reducing atmosphere.
The raw material powder is supplied into the flame H through an internal flow path in the main body of the oxygen burner 16, and Ni oxide or Co oxide is selectively reduced to metal and melted, and separated and precipitated from other oxides.

Also in this process example, the horizontal reaction furnace 26 prevents the flame temperature from decreasing and prevents the intrusion of the atmosphere, and ensures the necessary atmosphere and reaction time.
After the reaction, the powder and the combustion exhaust gas are rapidly cooled by an exhaust gas cooling tower 48 using a low O ₂ cooling gas, and the powder is collected by a bag dust collector 50, and then a pulverizer 52 and a centrifugal separator 56. Metal Ni and Co are separated and recovered from the other.
The combustion exhaust gas is discharged after secondary combustion.

Next, examples of the present invention will be described below.
[Example 1]: Example of metal Ni recovery from plating sludge
The example which collect | recovered metal Ni by the process of FIG. 5 from the sludge after the waste water treatment of the plating factory which is performing Ni plating and Cr plating is shown.
The fuel used was LPG with 10 m ³ N / h, and oxygen with 93 vol%.
Here, the metal Ni recovery rate is
Metal Ni recovery rate = ((recovered amount × metal Ni concentration) / (raw material amount × Ni concentration in raw material)) × 100.
The results are shown in Table 2 along with the processing conditions.

As shown in Table 2, in each of the present process examples, the metal Ni could be recovered satisfactorily.
Table 3 shows the component composition in the recovered material in Example 2 together with the component composition of the raw material.

  As shown in Table 3, most of the recovered material was Ni, which was high quality.

[Example 2]: Example of recovery from Ni, Co catalyst wastewater sludge
Both the examples which collect | recovered metal Ni and Co by the process shown in FIG. 4 from the wastewater sludge of a Ni and Co catalyst manufacturing factory are shown.
Use 10m ³ N / h of LPG fuel, 93vol% of oxygen,
Metal Ni recovery rate = ((recovered amount × metal Ni concentration) / (raw material amount × Ni concentration in raw material)) × 100,
Metal Co recovery rate = ((recovered amount × metal Co concentration) / (raw material amount × Co concentration in raw material)) × 100.
The results are shown in Table 4 along with the processing conditions.

As shown in Table 4, in this process example, metal Ni and metal Co could be separated and recovered at a high recovery rate.
Table 5 shows the component composition of the recovered product in Example 2 together with the component composition of the raw material.

  As shown in Table 5, high-quality Ni and Co are also obtained in this example.

  Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be implemented in variously modified forms without departing from the spirit of the present invention.

It is a figure showing the Ellingham diagram. It is explanatory drawing which represented the solution principle of this invention typically. It is explanatory drawing which showed the supply method of the raw material powder in the flame of an oxygen burner. It is explanatory drawing of the collection | recovery method of one Embodiment of this invention. It is explanatory drawing of the collection | recovery method of other embodiment of this invention.

10 Particles of raw material powder 14 Metal particles 16 Oxygen burner
H flame

Claims (7)

Under the condition that the ratio of oxygen to fuel is less than the stoichiometric ratio, the fuel is burned with an oxygen burner to generate a reducing atmosphere together with the flame, and raw powder containing Ni and / or Co compound in the flame Is supplied through an internal flow path provided in the main body of the oxygen burner, and Ni and / or Co compounds are selectively reduced in the flame to precipitate fine metal Ni and / or Co in the powder. Then, the powder after being melted and agglomerated with the heat of the flame and then treated with the flame is cooled to solidify the molten metal Ni and / or Co in the powder, A method for recovering metallic Ni and / or Co, wherein the metallic Ni and / or Co are separated and recovered from others.   The method for recovering metal Ni and / or Co according to claim 1, wherein a gas having an oxygen concentration of 90 vol% or more is used as a combustion-supporting gas of the oxygen burner.   The fuel according to any one of claims 1 and 2, wherein the fuel is burned by the oxygen burner under a condition in which a ratio of oxygen to the fuel is 0.4 to 0.9 of the stoichiometric ratio. A method for recovering metallic Ni and / or Co. In any one of claims 1 to 3, the method of recovering metals Ni and / or Co, and supplying to the flame in terms of the raw material powder was dried below 10 wt% moisture. In any one of claims 1-4, the method of recovering metals Ni and / or Co, and supplying the raw material powder into the flame adjusted to such a powder particle diameter is 50μm or less. 6. The method for recovering metal Ni and / or Co according to any one of claims 1 to 5 , wherein the raw material powder is supplied into the flame by airflow conveyance using a gas having an oxygen concentration of 10 vol% or less. In any one of claims 1 to 6, the metal Ni and / or Co collection methods, characterized by supplying steam or water into the flame at least 1% of the mass of the raw material powder.

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