JP2013001990A - Method for recycling waste battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recycling waste batteries, capable of suppressing cost and energy needed for recycling treatment and improving recovery percentage of lithium included in the waste batteries.SOLUTION: In a method for recycling waste batteries, crushed objects obtained by crushing waste batteries are subjected to a first heating treatment for heating the objects in a heating furnace, and a metal-containing substance is recovered from the crushed objects. In the method, crushed objects including lithium are used as the crushed objects, the first heating treatment is performed in conditions where the maximum temperature T1 (°C) is set at 730°C or above, and P/(P+P), which is represented by a COpartial pressure P(atm) and a CO partial pressure P(atm), and the COpartial pressure (atm) in an atmosphere satisfy predetermined expressions, and a lithium carbonate is recovered when the metal-containing substance is recovered. In the case, the lithium carbonate is preferably recovered from gas generated by the first heating treatment while the maximum temperature T1 is set at 1,320°C or above.

Description

  The present invention relates to a method for recycling a waste battery that recovers a metal-containing substance from a waste battery, and more particularly, to a method for recycling a waste dry battery that recovers lithium contained in the waste battery as lithium carbonate by heating in a heating furnace.

A used lithium battery generally contains lithium, manganese, cobalt, and nickel as metal components. The manganese dry battery contains manganese, zinc, and iron. The used alkaline manganese dry battery contains manganese, zinc, iron, and copper. As described above, used batteries such as lithium batteries, manganese dry batteries, and alkaline manganese dry batteries (hereinafter collectively referred to as “waste batteries”) contain various metal components, and some of these metal components are included. Is contained as an oxide such as lithium oxide (Li ₂ O) or manganese dioxide.

  Waste batteries are either discarded as non-combustible waste or collected separately in some local governments. Separately collected waste batteries are recovered from iron oxide, soft ferrite raw material, zinc, or the like by a recycling process.

  Regarding a method for recycling a waste battery, Patent Document 1 describes a method for recovering valuable metals by a wet method. According to the method described in Patent Document 1, after sorting manganese dry batteries and alkaline manganese dry batteries from various used batteries, the sorted dry batteries are crushed and classified to obtain iron oxide, plastic, paper agent, zinc on the sieve. Separated into cans, etc., under manganese dioxide, carbon, caustic potash, zinc chloride, etc. The top of the sieve is magnetically collected to collect iron, and the powder under the sieve is dissolved with dilute hydrochloric acid to dissolve caustic potash, zinc chloride, etc., and to recover residues mainly composed of manganese dioxide and carbon. .

  In the method described in Patent Document 1, a residue composed of iron, manganese dioxide, and carbon is recovered. However, since it is necessary to perform dissolution with dilute hydrochloric acid and subsequent drying, the cost required for recovery increases. Moreover, since zinc which is a valuable metal is discarded without being recovered, it cannot be said that resources are effectively utilized.

  Next, Patent Document 2 proposes a dry battery recycling method. In the method proposed by Patent Document 2, waste batteries are separated from waste, and manganese dry batteries and alkaline manganese dry batteries are selected from the sorted waste batteries. After the sorted dry batteries are crushed using a crusher equipped with a slit type screen, the powdered material containing zinc and copper under the sieve and metallic iron, zinc and copper are placed on the sieve by sieving. Classify into powder. By further magnetically selecting the top of the sieve, the powder is separated and recovered into a powdery material containing metallic iron and a powdery material containing zinc and copper.

  In the method proposed by Patent Document 2, the objects of recovery are metallic iron, zinc, and copper, and the manganese contained in the waste dry battery is discarded without being recovered.

  Further, Patent Document 3 discloses a method for recycling a waste battery for the purpose of recovering a soft ferrite raw material. In the method disclosed in Patent Document 3, a manganese dry battery and an alkaline manganese dry battery are selected from a variety of waste batteries, and further, are sorted by manufacturer. For each selected group, the waste batteries are crushed and sieved to obtain a powdery product mainly composed of metallic iron, zinc can, carbon rod, paper, plastic, etc. A powdery substance mainly composed of oxide and zinc oxide is obtained.

  After washing under water to remove impurities such as sodium and potassium compounds, calcining is performed in a heated furnace, and the manganese oxide and zinc content contained therein are manganese oxide (MnO) and zinc oxide (ZnO). Then, a soft ferrite raw material mainly composed of manganese oxide and zinc oxide is obtained by grinding. On the other hand, the paper and plastic are removed from the sieve by wind, and then separated by magnetic separation into a magnetic material mainly composed of iron oxide and a non-magnetic material mainly composed of a zinc can and a carbon rod. The magnetic material contains iron, and is recovered as an iron raw material. The non-magnetic material is crushed and washed with water, and then zinc and carbon are recovered by sieving.

  The method disclosed in Patent Document 3 can recover a soft ferrite raw material composed of manganese oxide and zinc oxide, iron, zinc, and carbon, but requires a large number of steps, so that processing time and processing cost are problematic. .

  As described above, various waste battery recycling methods have been proposed, but only a part of the collected waste dry batteries is subjected to the recycling process. This is because it requires more cost and energy to recover the metal by a conventional recycling method than to extract a metal such as metallic iron from the ore. Therefore, most of the waste batteries collected and collected are treated as non-combustible garbage without being recycled, despite containing metals such as metallic iron. For this reason, the recycling method of a waste dry battery which suppressed the cost and energy required for a process is awaited.

  Moreover, although a used manganese dry battery and an alkaline manganese dry battery contain much manganese and iron used as an iron-making raw material, even if harmful zinc is removed from a waste battery as a steel raw material, it is difficult to use it in the steel industry. This is because iron-making raw materials obtained from used manganese dry batteries and alkaline manganese dry batteries have a large proportion of manganese and iron contained in oxides and a small proportion of metals, so when used in blast furnaces and converters. In order to reduce these, it is necessary to input a large amount of fuel, which increases energy costs in the blast furnace and converter. Furthermore, it is difficult to implement industrially considering transportation costs and handling costs.

  In Patent Document 4, a carbon material such as coal is loaded on a moving bed in a movable hearth furnace (rotary hearth furnace), and heating is performed in a state where blast furnace dust, sintered powder, and a waste battery are loaded thereon. Thus, a method for recycling a waste battery is described in which a highly volatile metal such as zinc is volatilized and recovered from the exhaust gas of the furnace, and other low-volatile metal components are recovered on the moving bed.

  Since the waste battery recycling method described in Patent Document 4 is loaded on the moving floor without crushing the waste battery, the low-volatile metal recovered from the moving floor also has a cylindrical shape and is transported when used. It causes difficulties. In this case, by raising the heating temperature in the mobile hearth furnace, the melting point of the low-volatile metal iron is lowered by carburization, and melted and different shapes are mixed together, making it easier to use. . However, in an embodiment in which iron of low volatility metal is melted by carburization, the heating temperature is as high as 1500 ° C., and the energy cost becomes a problem.

  In addition, since the waste battery is loaded on the moving bed and heated without being crushed, most of the oxides of manganese and iron contained in the waste battery are not reduced. For this reason, manganese and iron recovered from the moving bed have a high oxide content and are difficult to use in a blast furnace or converter.

  The recycling method of the waste battery described in Patent Document 4 is problematic even when the waste battery is a used lithium battery, because most of the manganese oxide contained in the lithium battery is not reduced. Moreover, since the metal lithium and lithium oxide contained in a lithium battery have a high boiling point and are loaded on the moving bed without being crushed, they are likely to remain on the moving bed without volatilization. Furthermore, even if some waste batteries are destroyed and metal lithium and lithium oxide volatilize, it is necessary to heat to high temperature, and it is difficult to implement industrially considering refractories and the like. From these, in the recycling method of the waste battery described in Patent Document 4, the recovery rate of lithium contained in the lithium battery is lowered.

JP 2007-12527 A JP 2004-871 A Japanese Patent Laid-Open No. 7-85897 JP 2009-256741 A

YE. Lee: Metallurgical and Materials Transactions B, 29B (1998), 397.

  As described above, the cost and energy required for the conventional waste battery recycling method are problematic, and can be applied only to a part of the separately collected waste batteries, and most of the waste dry batteries are treated as noncombustible waste. Yes. Moreover, by removing zinc from waste batteries, it is possible to obtain iron-making raw materials mainly composed of iron and manganese, but because of the high proportion of manganese and iron oxides, it is difficult to use them in blast furnaces and converters. It is. Furthermore, lithium contained in the waste battery has been studied by the waste battery recycling method described in Patent Document 4, but the lithium recovery rate is low.

  The present invention has been made in view of such a situation, and provides a recycling method of a waste battery that can reduce the cost and energy required for processing and can improve the recovery rate of lithium contained in the waste battery. It is aimed.

  In the treatment of dust and sludge generated in integrated steelworks and electric furnaces, a rotary kiln removes harmful zinc as a steel raw material and recovers it as coarse granular zinc oxide, while reducing iron oxide to obtain a steelmaking raw material Is used.

  The present inventors examined a method for recovering lithium from a crushed material obtained by crushing a lithium battery waste battery using a rotary kiln.

FIG. 1 shows the relationship between the temperature (° C.) and vapor pressure (atm) of metallic lithium, metallic manganese, lithium oxide (Li ₂ O), metallic cobalt, and metallic nickel related to metallic components contained in a used lithium battery. FIG. From the figure, the boiling point is 1330 ° C. for metallic lithium, 2060 ° C. for metallic manganese, 2600 ° C. for lithium oxide, 2927 ° C. for metallic cobalt, and 2920 ° C. for metallic nickel. It is confirmed that metal lithium can be recovered by evaporation.

  However, as a result of tests conducted by the present inventors, it has been found that lithium is difficult to recover by evaporation because it is liable to burn and become lithium oxide when heated. Since this lithium oxide has a boiling point as high as 2600 ° C. as shown in FIG. 1, it is difficult to recover it by evaporation. Moreover, since metallic lithium (Li) has a melting point of about 180 ° C., an attempt was made to recover lithium contained therein as a liquid by making the atmosphere reducible. However, in this case, since the liquid lithium reacts with other metals to form a compound, it is difficult to recover the liquid. Therefore, the present inventors have studied to recover lithium as lithium carbonate, which is an industrially important compound.

FIG. 2 is a diagram showing the relationship between the temperature at which the reaction by the metal component contained in the used lithium battery becomes equilibrium and the atmospheric conditions. In the figure, curve C1 shows the relationship between the temperature at which the reaction of producing lithium carbonate from lithium oxide is balanced and the CO ₂ partial pressure. Curve C2 shows the temperature at which the reaction of oxidizing metallic cobalt is in equilibrium, and CO ₂ partial pressure P _CO2 (atm) and P _CO2 / (P _CO2 + P _CO ) expressed by _CO partial pressure P _CO (atm). The relationship is shown. Curve C3 shows the relationship between the temperature at which the reaction of oxidizing metallic nickel is in equilibrium and P _CO2 / (P _CO2 + P _CO ). Further, as shown in the figure, P _CO2 / (P _CO2 + P _CO ) at which the reaction of oxidizing metal manganese is in equilibrium is almost 0 (zero).

From the figure, the present inventors can recover lithium oxide as lithium carbonate by heating the crushed material by setting the temperature, CO ₂ partial pressure, and P _CO2 / (P _CO2 + P _CO ) as predetermined conditions. I found out. Furthermore, it has been found that if the temperature is set to 1320 ° C. or higher when the crushed material is heated, the generated lithium carbonate can be easily separated and recovered by evaporation.

  Next, the present inventors examined a method for improving the reduction rate of manganese with a crushed material obtained by crushing a waste battery of a manganese dry battery and an alkaline manganese dry battery using a rotary kiln.

  FIG. 3 is a diagram showing the relationship between the temperature (° C.) and vapor pressure (atm) of metallic iron, metallic manganese, and metallic zinc related to the metallic components contained in a used manganese dry battery. From the figure, since the boiling points are 3070 ° C. for iron, 2060 ° C. for manganese, and 906 ° C. for zinc, it can be confirmed that zinc can be recovered by evaporation by heating the waste battery at 906 ° C. or higher.

FIG. 4 is a diagram showing the relationship between the oxygen partial pressure and the temperature at which the reduction reaction of manganese oxide and the reaction of generating carbon monoxide from graphite are in equilibrium. In the same figure, the graph shown with a solid line shows the relationship between the temperature and oxygen splitting when the reduction rate of manganese is 100% by mass in the reduction reaction of manganese oxide with graphite (C), and the graph shown with a dotted line is The relationship between the temperature at which the reaction for producing carbon monoxide from graphite shown in the following reaction formula (1) is balanced and the oxygen partial pressure is shown. Moreover, in the same figure, the graph shown with a dashed-dotted line shows the temperature and oxygen when the reduction rate of manganese becomes 1 mass%, 10 mass%, 20 mass%, or 50 mass% in the reduction reaction of manganese oxide by graphite. The relationship of partial pressure is shown respectively.
C + 1 / 2O ₂ = 2CO (1)

  From the graph showing the reduction reaction of manganese oxide by graphite and the graph showing the equilibrium of the reaction shown in the above (1) reaction formula, the oxygen partial pressure is a condition for the reaction shown in the above (1) reaction formula to be in equilibrium. When the atmosphere exceeds 1417 ° C., it can be confirmed that the reduction rate of manganese becomes 100% by mass due to the reduction reaction of manganese oxide by graphite. Here, the melting point of iron is 1538 ° C., but when iron is carburized, it melts at 1153 ° C. Since manganese oxide is dissolved and reduced in the carburized and melted iron, it is possible to reduce manganese oxide even at 1417 ° C. or lower.

  However, when reducing manganese oxide at 1417 ° C. or lower, the amount of manganese dioxide dissolved is limited by temperature, so the reduction rate of manganese is also limited. From the graph showing the reduction rate of manganese of 50% by mass, 20% by mass, and 10% by mass in the same figure, and the graph showing the equilibrium of the reaction shown in the above (1) reaction formula, the reduction rate of manganese is 1390. It can be confirmed that the temperature is limited to 50% by mass at 20 ° C., 20% by mass at 1333 ° C., and 10% by mass at 1293 ° C.

  As a result of intensive studies based on these results, the present inventors have made manganese and pulverized materials containing manganese and oxygen by setting the temperature and the oxygen partial pressure of the atmosphere to predetermined conditions when heat-treating in a heating furnace. It was found that the reduction rate of iron can be improved.

  The present invention has been completed on the basis of these findings, and has the gist of the following (1) to (6) waste battery recycling methods.

(1) A waste battery recycling method in which a crushed material obtained by pulverizing a waste battery is subjected to a first heat treatment that is heated in a heating furnace, and a metal-containing material is recovered from the crushed material, the crushed material containing lithium as the crushed material In the first heat treatment, the maximum temperature T1 (° C.) is set to 730 ° C. or higher, and the atmosphere is expressed by CO ₂ partial pressure P _CO2 (atm) and CO partial pressure P _CO (atm). _{When CO2} / (P _CO2 + P _CO ) satisfies the following formula (1) and CO ₂ partial pressure P _CO2 (atm) satisfies the following formula (2), carbon dioxide is collected when the metal-containing substance is recovered. A method of recycling a waste battery characterized by recovering lithium (hereinafter also referred to as “the recycling method of the first embodiment of the present invention”).
P _CO2 / (P _CO2 + P _CO ) <1 / (1 + exp (−ΔG ⁰ _A /(R·(T1+273.15))) (1)
P _CO2 > exp (ΔG ⁰ _B /(R·(T1+273.15)) (2)
However,
ΔG ⁰ _A = (− 468200 + 140.98 (T1 + 273.15)) / 2 − (− 565160 + 172.03 (T1 + 273.15)) / 2 (3)
ΔG ⁰ _B = −153750 + 85.87 (T1 + 273.15) (4)
R: Gas constant

(2) The waste according to (1) above, wherein the maximum temperature T1 is set to 1320 ° C. or higher, and lithium carbonate is recovered from the gas generated by the first heat treatment when the lithium carbonate is recovered. How to recycle batteries.

(3) In the recycling method for waste batteries described in (1) or (2) above, any one or more of manganese, iron, cobalt, and nickel is recovered from the crushed material that has undergone the first heat treatment. A method for recycling waste batteries characterized by the above.

(4) By heating the crushed product obtained by crushing the waste battery in a heating furnace, the low boiling point metal contained in the crushed product is evaporated and the oxide of the high boiling point metal contained in the crushed product is reduced. Further, the waste battery recycling method includes a second heat treatment for recovering low-boiling point metal from the generated gas and a recovery process for recovering high-boiling point metal from the crushed material that has undergone the second heat treatment, The object contains manganese, and the second heat treatment is performed under the condition that the maximum temperature T2 (° C.) is 1200 ° C. or more and the oxygen partial pressure P _O2 (atm) of the atmosphere satisfies the following expression (3). A featured recycling method for waste batteries (hereinafter also referred to as “the recycling method of the second embodiment of the present invention”).
log (P _O2 ) ≦ 0.008 · T2-26.6 (5)

(5) A crushed material obtained by crushing a waste battery, wherein the crushed material containing lithium and manganese is treated by the method for recycling a waste battery according to any one of the above (1) to (3), and then the above ( A method for recycling a waste battery, characterized by being treated by the method for recycling a waste battery described in 4).

(6) The method for recycling a waste battery according to any one of (1) to (5) above, wherein a rotary kiln is used as the heating furnace.

In the present invention, the “high boiling point metal” refers to a metal having a boiling point of 1200 ° C. or higher, for example, manganese, iron and nickel. The “low boiling point metal” means a metal having a boiling point of less than 1200 ° C. and includes a metal having a vapor pressure of 10 ⁻⁵ atm or more at 1200 ° C. Examples of the low boiling point metal include zinc, mercury, and lead. However, lithium has a vapor pressure at 1200 ° C. of 10 ⁻⁵ atm or more, but is not included in the low boiling point metal because it is easily combusted when heated to a high temperature.

  According to the method for recycling a waste battery of the present invention, by subjecting a crushed material containing lithium to a first heat treatment, lithium can be recovered as lithium carbonate and the lithium recovery rate can be improved. Moreover, by applying the second heat treatment to the crushed material containing manganese, it is possible to reduce the oxides of manganese and iron and improve the reduction rate of the recovered manganese and iron.

Is a diagram illustrating a relationship using metallic lithium associated with the metal component contained in the used lithium batteries, manganese metal, lithium oxide (Li ₂ O), metallic cobalt, metallic nickel temperature (℃) and vapor pressure (atm) . It is a figure which shows the relationship between temperature and atmospheric conditions in which the reaction by the metal component contained in a used lithium battery equilibrates. It is a figure which shows the relationship between the temperature (degreeC) and vapor pressure (atm) of metallic iron, metallic manganese, and metallic zinc relevant to the metallic component contained in a used manganese dry battery. It is a figure which shows the relationship between the temperature and oxygen partial pressure at which the reduction reaction of manganese oxide and the reaction in which carbon monoxide is generated from graphite are in equilibrium. It is a figure explaining the example of a processing flow of the waste battery by the recycling method of the waste battery of this invention. It is a figure which shows the example of a processing flow in an Example.

1. Treatment of Crushed Material Containing Lithium As described above, the recycling method according to the first embodiment of the present invention performs the first heat treatment of heating the crushed material obtained by pulverizing the waste battery in a heating furnace, from the crushed material, the metal-containing material. Waste battery recycling method that uses lithium crushed material as a crushed material, the first heat treatment is performed at a maximum temperature T1 (K) of 730 ° C. or higher, and the atmosphere is CO ₂ partial pressure P P _CO2 / (P _CO2 + P _CO ) expressed by _CO2 (atm) and CO partial pressure P _CO (atm) satisfies the above equation (1), and the CO ₂ partial pressure P _CO2 (atm) is (2 The lithium carbonate is recovered when the metal-containing material is recovered under the conditions satisfying the above formula.

  If the waste battery is heat-treated without being crushed, the metal such as lithium and its oxide contained in the waste battery are contained in a sealed container, so that the reaction does not proceed easily and is recovered by evaporation. Becomes difficult. In this case, the reaction temperature and recovery by evaporation can be promoted by increasing the maximum temperature in the heat treatment, but the energy cost and the equipment cost required for the heating furnace become problems. For this reason, in this invention, a waste battery is crushed and made into a crushed material, and this crushed material is heat-processed. Thereby, the progress of the reaction in the heating furnace and the recovery by evaporation can be promoted. The crushing of the waste battery may be appropriately performed to such an extent that a metal such as lithium and its oxide existing in the container of the waste battery can react with the atmosphere or evaporate. The waste battery can be crushed by, for example, a double roll crusher or a hammer crusher.

The maximum temperature T1 is set to 730 ° C. or higher, and the atmosphere is expressed by the equation (1) where P _CO2 / (P _CO2 + P _CO ) expressed by CO ₂ partial pressure P _CO2 (atm) and CO partial pressure P _CO (atm) And the crushed material containing lithium is subjected to heat treatment under the condition that the CO ₂ partial pressure P _CO2 (atm) satisfies the above-mentioned formula (2). In other words, the conditions are such that the atmosphere is within the region sandwiched between the curves C1 and C2 shown in FIG. 2 (the hatched region in FIG. 2), that is, an oxidizing atmosphere. Thereby, liquid or gaseous lithium carbonate produces | generates from the lithium oxide contained in a crushed material. On the other hand, when the maximum temperature T1 is less than 730 ° C., the melting point of lithium carbonate is 723 ° C., so that it is difficult to recover the generated lithium carbonate as a liquid or gas.

  When the maximum temperature T1 is less than 1320 ° C., the generated lithium carbonate is a liquid, so that lithium contained as an oxide in the crushed material can be recovered as lithium carbonate from the crushed material after the first heat treatment. On the other hand, when the maximum temperature T1 is 1320 ° C. or higher, the generated lithium carbonate evaporates into a gas, so that lithium contained as oxides in the crushed material is recovered as lithium carbonate from the gas generated in the first heat treatment. can do.

  In addition, lithium contained as a metal in the crushed material can be recovered as lithium carbonate by setting the maximum temperature T1 to 730 ° C. or higher as described above and making it an oxidizing atmosphere.

  As shown in FIG. 2, cobalt mainly contained as a metal in a crushed material obtained by crushing a used lithium battery remains as metallic cobalt without being oxidized by heat treatment. Moreover, nickel mainly contained as a metal in a crushed material obtained by crushing a used lithium battery remains as metallic nickel without being oxidized by heat treatment. Manganese contained mainly as an oxide in the crushed material obtained by crushing a used lithium battery remains an oxide without being reduced.

  In the recycling method of the first embodiment of the present invention, it is preferable that the maximum temperature T1 is set to 1320 ° C. or higher, and lithium carbonate is recovered from the gas generated by the first heat treatment when recovering lithium carbonate. This is because lithium carbonate can be efficiently recovered. On the other hand, if the maximum temperature is set too high, equipment costs and maintenance costs for preventing melting loss of the heating furnace become problems, and therefore it is preferable that the maximum temperature T1 be less than 1400 ° C.

  Since iron contained in the crushed material as an oxide or metal has a high boiling point, it remains in the crushed material without evaporating.

  Zinc contained as an oxide in the crushed material reacts with carbon monoxide gas or hydrogen gas generated in the heating furnace, and is reduced to be metallized. Since the reduced zinc and zinc contained as a metal in the crushed material have a boiling point as low as 907 ° C., they evaporate when the maximum temperature T1 is 1320 ° C. or higher. The evaporated zinc reacts with oxygen in the atmosphere and is oxidized to become zinc oxide (ZnO) particles, which can be recovered from the gas generated by the first heat treatment.

  Lead contained as oxides in the crushed material reacts with carbon monoxide gas or hydrogen gas generated in the heating furnace, and is reduced to be metallized. Lead contained in the crushed metal as a metal has a boiling point as high as 1749 ° C., but since the vapor pressure is high at a temperature near the boiling point of zinc (907 ° C.), it tends to evaporate when the maximum temperature T1 is 1320 ° C. or higher. . Therefore, the reduced lead and the lead contained as a metal in the crushed material are evaporated by raising the temperature, oxidized by reaction with the atmosphere to become particles, and can be recovered from the gas generated by the first heat treatment.

  Thus, by performing 1st heat processing to a crushed material, it can collect | recover from the gas which generate | occur | produces zinc and lead including lithium contained in a crushed material. On the other hand, the crushed material that has undergone the first heat treatment includes metals and oxides of cobalt, nickel, iron, and manganese. For this reason, the recycling method of 1st Embodiment of this invention can collect | recover manganese, iron, cobalt, and nickel from the crushed material which passed through 1st heat processing further.

  Since some manganese batteries contain mercury, the crushed material obtained by crushing manganese batteries may contain mercury. Since mercury has a low boiling point of 356 ° C., the reduced mercury and mercury contained as a metal in the crushed material evaporate when the temperature rises. The evaporated mercury reacts with the atmosphere and is oxidized to form mercury oxide particles. Therefore, the recycling method of the first embodiment of the present invention can recover mercury contained in the crushed material as mercury oxide from the gas generated by the first heat treatment, and can also treat manganese dry batteries containing mercury.

  In the recycling method of the first embodiment of the present invention, a used lithium battery can be used as a waste battery. The recycling method of the first embodiment of the present invention can be processed without sorting even if the waste battery includes a used manganese dry battery, an alkaline manganese dry battery, and a nickel primary battery in addition to the used lithium battery.

2. As described above, the recycling method according to the second embodiment of the present invention evaporates low boiling point metal contained in the crushed material by heating the crushed material obtained by crushing the waste battery in a heating furnace. In addition, the high boiling point metal oxide contained in the crushed material is reduced, and the second boiling heat treatment recovers the low boiling point metal from the generated gas, and the high boiling point metal is recovered from the crushed material after the second heat treatment. The waste battery recycling method includes a recovery process, wherein the crushed material contains manganese, the second heat treatment is performed at a maximum temperature T2 (° C) of 1200 ° C or higher, and an oxygen partial pressure P _O2 ( atm) is performed as a condition satisfying the expression (5).

Manganese, iron, copper, and nickel contained as metals in the crushed material have a high boiling point. Therefore, even if heating is performed in a rotary kiln, most of them do not evaporate and remain in the crushed material as they are. On the other hand, in used manganese dry batteries, carbon rods, plastics, and papers used as current collecting rods on the positive electrode side contain graphite (C), and this graphite causes the reaction shown in the reaction formula (1) by heat treatment. Then, carbon monoxide gas (CO) and hydrogen gas (H ₂ ) are generated. With the carbon monoxide gas and hydrogen gas generated by this reaction, a part of manganese, iron, copper and nickel contained as oxides in the crushed material is reduced to become metal.

Here, according to the recycling method of the second embodiment of the present invention, the maximum temperature T2 (° C.) is set to 1200 ° C. or higher and the atmospheric oxygen partial pressure P _O2 (atm) is set to the above (5). The second heat treatment is performed as a condition satisfying the formula. Here, the condition that the oxygen partial pressure satisfies the equation (5) means that the oxygen partial pressure is a hatched region on the straight line shown as the equation (5) in FIG.

  As described above, iron contained as an oxide in the crushed material is carburized by graphite, the melting point is lowered, and it melts at about 1153 ° C. For this reason, the maximum temperature T2 is set to 1200 ° C. or higher in the second heat treatment, and the oxygen partial pressure of the atmosphere satisfies the above formula (5), so that it is included as oxide in the carburized and melted iron. Manganese is dissolved and reduced to metallic iron, manganese, and carbon dioxide. By the reduction reaction of manganese oxide by the carburized iron, manganese and iron contained as oxides in the crushed material are reduced. As a result, the reduction rate of manganese and iron contained in the crushed material after the second heat treatment is reduced. It can be improved.

In the recycling method of the second embodiment of the present invention, it is preferable to perform the second heat treatment under the condition that the oxygen partial pressure of the atmosphere satisfies the following formula (6). The condition that the oxygen partial pressure satisfies the following equation (6) means that the oxygen partial pressure is set to a hatched region on the straight line shown as the equation (6) in FIG. Thereby, the reduction rate of manganese and iron contained in the crushed material which passed through the 2nd heat processing can be improved more. Further, if the maximum temperature is too high, the equipment cost and maintenance cost for preventing the melting loss of the heating furnace become problems, so the maximum temperature T2 is preferably less than 1450 ° C.
log (P _O2 ) ≦ 0.0154 · T2-36.5 (6)

  Zinc contained as an oxide in the crushed material reacts with carbon monoxide gas or hydrogen gas generated in the heating furnace, and is reduced to be metallized. Since this reduced zinc and zinc contained as a metal in the crushed material have a boiling point as low as 907 ° C., they evaporate when the temperature rises. The evaporated zinc reacts with oxygen in the atmosphere and is oxidized to become zinc oxide (ZnO) particles, which can be recovered from the gas generated by the second heat treatment.

  Lead contained as oxides in the crushed material reacts with carbon monoxide gas or hydrogen gas generated in the heating furnace, and is reduced to be metallized. Lead contained in the crushed metal as a metal has a high boiling point of 1749 ° C., but the vapor pressure is high at a temperature near the boiling point of zinc (907 ° C.), so the second heat treatment with the maximum temperature T2 of 1200 ° C. or higher is performed. Easy to evaporate. Therefore, the reduced lead and the lead contained as a metal in the crushed material are evaporated by the temperature rise, oxidized by the reaction with the atmosphere to become particles, and can be recovered from the gas generated by the second heat treatment.

By subjecting the crushed material to the second heat treatment in this manner, low boiling point metals such as zinc and lead contained in the crushed material can be recovered from the generated gas. Moreover, since high boiling point metals such as manganese and iron contained in the crushed material remain in the crushed material, they can be recovered from the crushed material subjected to the second heat treatment. As described above, in the second embodiment of the present invention, in the second heat treatment, the maximum temperature T2 (° C.) is set to 1200 ° C. or more, and the oxygen partial pressure P _O2 (atm) of the atmosphere is expressed by the equation (5). By applying as satisfying conditions, the reduction rate of recovered manganese and iron can be improved.

  Since some manganese batteries contain mercury, the crushed material obtained by crushing manganese batteries may contain mercury. Since mercury has a low boiling point of 356 ° C., the reduced mercury and mercury contained as a metal in the crushed material evaporate when the temperature rises. The evaporated mercury reacts with the atmosphere and is oxidized to form mercury oxide particles. Therefore, the recycling method of the second embodiment of the present invention can recover mercury contained in the crushed material as mercury oxide from the gas generated by the second heat treatment, and can also treat manganese dry batteries containing mercury.

  In the recycling method of the second embodiment of the present invention, a used manganese dry battery, an alkaline manganese dry battery, a lithium battery, or a nickel primary battery can be used as a waste battery. The recycling method of the second embodiment of the present invention is not limited to one type of waste battery to be treated, and without sorting out used batteries in which used manganese dry batteries, alkaline manganese dry batteries, lithium batteries, or nickel primary batteries are mixed. Can be processed.

3. Process Flow Examples and Preferred Embodiments A process flow example according to a method for recycling a waste battery of the present invention and an embodiment that is preferably employed in the present invention will be described below with reference to the drawings.

  FIG. 5 is a diagram for explaining an example of the processing flow of the waste battery by the waste battery recycling method of the present invention. In the example of the processing flow shown in the figure, the crusher 2 that crushes the waste battery 1 that is input into a crushed material, the first conveyor 31 that transports the crushed material discharged from the crusher, and the crushed material that is supplied. The first recycling device 91 that mainly recovers lithium, the second conveyor 32 that transports the crushed material processed by the first recycling device 91, and the second that increases the reduction rate of manganese contained in the supplied crushed material. The recycling apparatus 92 is shown.

  The first recycle device 91 and the second recycle device 92 are respectively a rotary kiln 41 or 42 that heats the crushed material supplied as a heating furnace, and a cyclone that collects coarse particles from the gas discharged from the rotary kiln 41 or 42. 51 or 52 and a bag filter 61 or 62 for collecting fine particles from the gas processed by the cyclone 51 or 52.

  The rotary kiln 41 or 42 provided in the first recycling device 91 and the second recycling device 92 has a hollow cylindrical shape, is disposed slightly inclined from the horizontal, and is rotatably supported. One end of the rotary kiln 41 or 42 is provided with an inlet 41a or 42a, and the other end is provided with an outlet 41b or 42b. Although not shown, a burner is arranged at the center of rotation on the outlet side of the rotary kiln. In the rotary kiln 41 or 42 having such a configuration, the crushed material supplied to the input port 41a or 42a is heated by the burner, and is rotated and inclined on the lower wall surface (lower part) of the rotary kiln to the discharge port side. It moves and is discharged from the discharge port 41b or 42b.

  On the other hand, although not shown, the rotary kiln 41 or 42 includes an intake port on the upper side on the discharge port side and an exhaust port on the upper side on the input port side. Thereby, an atmosphere flow from the discharge port side to the input port side is created at the upper part of the rotary kiln, and the gas generated by the heat treatment can be discharged from the exhaust port. By treating the exhaust gas with the cyclone 51 or 52 and the bag filter 61 or 62, the metal-containing substance can be recovered from the gas generated by the heat treatment.

  The waste battery recycling method of the present invention is a crushed material obtained by crushing a waste battery, as shown in the processing flow example of the figure, and the crushed material containing lithium and manganese is recycled according to the first embodiment of the present invention. After the treatment by the method (first heat treatment), it is preferable to further carry out the treatment by the recycling method (second heat treatment) of the second embodiment of the present invention (see solid line arrow in the figure).

  In this case, lithium, zinc, lead, and mercury can be recovered from the crushed material containing lithium and manganese by the first heat treatment of the first embodiment. On the other hand, the crushed material that has undergone the first heat treatment includes manganese, iron, metallic cobalt, and metallic nickel. By performing the second heat treatment of the second embodiment on the crushed material that has undergone the first heat treatment, the reduction rate of manganese and iron contained in the crushed material that has undergone the second heat treatment can be improved. Moreover, the recovery rate of low boiling point metal can be improved by evaporating and recovering zinc, lead, and mercury remaining in the crushed material without evaporating in the first heat treatment, in the second heat treatment.

  After processing by the recycling method of the first embodiment of the present invention, when further processing by the recycling method of the second embodiment of the present invention, a used lithium battery can be used as a waste battery. In this case, even if the waste battery includes a used manganese dry battery, an alkaline manganese dry battery, or a nickel primary battery in addition to the used lithium battery, it can be processed without sorting.

  The waste battery recycling method of the present invention can employ a rotary kiln or a rotary hearth furnace as a heating furnace for subjecting the crushed material to the first heat treatment or the second heat treatment. Thus, it is preferable to employ a rotary kiln. In the rotary kiln, the crushed material subjected to heat treatment by rotation is stirred and the reaction is promoted by increasing the chance of contact with the atmosphere. Therefore, the recovery rate of lithium and the reduction rate of iron and manganese can be further improved. , Processing time can be shortened.

In the first heat treatment, P _CO2 / (P _CO2 + P _CO ) represented by the CO ₂ partial pressure P _CO2 (atm) and the CO partial pressure P _CO (atm) in the atmosphere is set to a predetermined condition, or in the second heat treatment When the oxygen partial pressure P _O2 (atm) of the atmosphere is set to a predetermined condition, for example, it can be performed by a method of adjusting the chemical composition of the atmosphere supplied to the heating furnace. The recycling method of the waste battery according to the present invention is such that when the atmosphere is set to a predetermined condition, the carbon material is subjected to a heat treatment together with the crushed material, and the atmosphere is set to the predetermined condition by adjusting an input amount of the carbon material. preferable.

When the carbon material burns, it reacts with oxygen in the heating furnace to become carbon monoxide or carbon dioxide. Therefore, the oxygen partial pressure of the atmosphere can be adjusted by increasing or decreasing the input amount of the carbonaceous material. Further, the adjustment of P _CO2 / (P _CO2 + P _CO ) and the CO ₂ partial pressure can be performed by increasing or decreasing the input amount of the carbonaceous material.

  Moreover, when heat-treating a carbonaceous material with a crushed material in heat processing, the atmosphere in a heating furnace can be heated up using the energy by combustion of a carbonaceous material, and energy cost can be reduced. In addition, when carbonaceous materials are heated, some of them are pyrolyzed into carbon and hydrogen, so reducing the manganese and iron oxides with this carbon and hydrogen can increase the reduction rate of iron and manganese. it can.

  As a carbon material, what generates carbon and hydrogen by thermal decomposition can be used, for example, quiche carbon, which is graphite precipitated from molten pig iron, wood powder, and coke powder.

4). Next, the reason why the maximum temperature and the atmospheric condition of the first heat treatment are defined as described above in the recycling method according to the first embodiment of the present invention will be described.

The reaction in which lithium oxide (Li ₂ O) reacts with carbon dioxide (CO ₂ ) to become lithium carbonate (Li ₂ CO ₃ ) is represented by the following equation (2), and the standard free energy change is represented by the following equation (a). Is done.
Li ₂ O (s) + CO ₂ (g) = Li ₂ CO ₃ (2)
ΔG ⁰ ₍₂₎ = − 153750 + 85.87T (a)
However, in the above formula (a), 993K <T <1300K.
Here, ΔG ⁰ _(i) is the standard free energy change (J) in the reaction formula (i), and T is the temperature (K).

When the reaction represented by the above reaction formula (2) is in equilibrium, the following formula (b) is established.
ΔG ⁰ ₍₂₎ = − RTln (α _Li2CO3 / (α _Li2O · P _CO2 )) (b)
Here, R is a gas constant, α _Li2CO3 is the activity of Li ₂ CO ₃ , α _Li2O is the activity of Li ₂ O, and P _CO2 is the partial pressure (atm) of CO ₂ .

Here, _assuming that α _Li2CO3 = 1 and α _Li2O = 1 in the above equation (b), the following equation (c) is derived.
P _CO2 = exp (ΔG ⁰ ₍₂₎ / (R · T)) (c)
When the calculation is performed using the standard free energy change of the equation (a) in the equation (c), the curve C1 of FIG. 2 is obtained. In the above formula (c), the formula (2) is obtained by using the standard free energy change of the formula (a) and further setting the thermodynamic temperature (K) to the Celsius temperature (° C.).

On the other hand, reactions in which the metals Co, Ni, and Mn are oxidized to become CoO, NiO, and MnO, respectively, are represented by the following reaction formulas (3) to (6). Moreover, the standard free energy change of the reaction represented by the following reaction formulas (3) to (6) is represented by the following formulas (d) to (g).
2Co (s) + O ₂ (g) = 2CoO (s) (3)
ΔG ⁰ ₍₃₎ = − 468200 + 140.98T (d)
However, in the above equation (d), 298K <T <1768K.
2Ni (s) + O ₂ (g) = 2NiO (s) (4)
ΔG ⁰ ₍₄₎ = − 468580 + 169.44T (e)
However, in the above equation (e), 298K <T <1728K.
2Mn (s) + O ₂ (g) = 2MnO (s) (5)
ΔG ⁰ ₍₅₎ = − 76565060 + 148.96T (f)
However, in the above formula (f), 298K <T <1519K.
2Mn (l) + O ₂ (g) = 2MnO (s) (6)
ΔG ⁰ ₍₆₎ = − 801100 + 173.02T (g)
However, 1519K <T <2083K in the above equation (g).

The reaction in which the metal (Me) is oxidized to form an oxide (MeO) as in the reaction formulas (3) to (6) can be represented by the following reaction formula (7). In addition, the reaction in which carbon monoxide (CO) gas and oxygen (O ₂ ) gas react to form carbon dioxide (CO ₂ ) gas can be expressed by the following reaction formula (8). Is represented by the following formula (h).
2Me + O ₂ (g) = 2MeO (7)
2CO (g) + O ₂ (g) = 2CO ₂ (g) (8)
ΔG ⁰ ₍₈₎ = − 565 160 + 172.03T (h)
However, in the above equation (h), 298K <T <3000K.

When a new reaction equation is obtained from the reaction equations (7) and (8) and O ₂ is eliminated, the following equation (9) is obtained. When the reaction shown by the following reaction formula (9) is in equilibrium, the following formula (i) is established.
Me + CO ₂ (g) = MeO + CO (g) (9)
ΔG ⁰ ₍₉₎ = − RTln (α _MeO ² · P _CO / (α _Me ² · P _CO2 )) (i)
Here, alpha _MeO the activity of MeO, the alpha _Me activity of Me, P _CO is the partial pressure of CO (atm).

Assuming that α _MeO = 1 and α _Me = 1 in the above equation (i), the following equation (j) is derived. Here, P _CO2 / (P _CO2 + P _CO ) = 1 / (1 + P _CO / P _CO2 ). When the following formula (j) is used for this formula, the following formula (k) is obtained.
P _CO / P _CO2 = exp (−ΔG ⁰ ₍₉₎ / (R · T)) (j)
P _CO2 / (P _CO2 + P _CO ) = 1 / (1 + exp (−ΔG ⁰ ₍₉₎ / (R · T))) (k)
When calculation is performed using the standard free energy change of the equation (d) or (e) and the standard free energy change of the equation (h) in the equation (k), the curve C2 or the curve C3 in FIG. can get. Further, the formula (1) is the above formula (k), using the standard free energy change of the formulas (d) and (h), and the thermodynamic temperature (K) as the Celsius temperature (° C.). is there.

Further, in the above equation (k), when the calculation is performed using the standard free energy change of the equation (f) or (g) and the standard free energy change of the equation (h), the oxidation reaction of manganese is balanced. Although the conditions are obtained, when the temperature T is 1400 ° C. or lower, P _CO2 / (P _CO2 + P _CO ) ≈0 as shown in FIG.

5. Next, the reason why the maximum temperature and the atmospheric condition of the second heat treatment are defined as described above in the recycling method according to the second embodiment of the present invention will be described.

Reactions in which metal Mn is oxidized to become oxides of MnO are represented by the reaction formulas (5) and (6). The standard free energy change of the reaction represented by the reaction formulas (5) and (6) is represented by the formulas (f) and (g). When the reaction represented by the reaction formula (5) or (6) is in equilibrium, the following formula (l) is established.
ΔG ⁰ ₍₅₎ or ΔG ⁰ ₍₆₎ = − RTln (α _MnO · P _CO / (α _Mn · P _O2 )) (1)
Here, α _MnO is the activity of MnO, α _Mn is the activity of Mn, and P ₀₂ is the partial pressure (atm) of O ₂ .

In the above formula (l), assuming that α _MnO = 1, and using γ _Mn which is an activity coefficient of Fe—C—Mn based _Mn and x _Mn which is the molar concentration of _Mn , the following formula (m) is obtained. Led.
ΔG ⁰ ₍₅₎ or ΔG ⁰ ₍₆₎ = − RTln (γ _Mn · x _Mn · P _O2 ) (m)
Here, γ _Mn is expressed by the following equation (n) as described in Non-Patent Document 1.
γ _Mn = (− 0.4822 + 576.7 / T) x _C + (5.1498-10842 / T) × _C ² + (− 25.821 + 8289.7 / T) x _C ³ −4943.8 × _C ⁴ x _Fe ⁵ ... (n)
However, x _c is the molar concentration of C, and x _Fe is the molar concentration of Fe.

On the other hand, the reaction in which carbon (C) and oxygen (O ₂ ) react to form carbon monoxide (CO) is represented by the following reaction formula (10). Moreover, the standard free energy change of reaction represented by the following (10) reaction formula is represented by the following (o) formula.
2C (s) + O ₂ (g) = 2CO (g) (10)
ΔG ⁰ ₍₁₀₎ = − 221840-178.02T (o)
However, in the above equation (o), 298K <T <3000K.
Each of the curves shown in FIG. 4 can be obtained by the above equations (m) and (n) and the above equations (f), (g) and (o) indicating the standard free energy change.

  In order to verify the effect of the waste battery recycling method of the present invention, a test was performed in which the crushed material obtained by crushing the waste battery was subjected to a heat treatment using a rotary kiln.

1. Test using waste batteries as used lithium batteries [Test method]
FIG. 6 is a diagram illustrating an example of a processing flow in the embodiment. As shown in the figure, in this test, the waste battery 1 was crushed by the crusher 2 to obtain a crushed product, and the crushed product was supplied to the rotary kiln 4 by the conveyor 3 and subjected to heat treatment. A used lithium battery was used as a waste battery. In the heat treatment in this test, the atmosphere in the rotary kiln was heated by supplying a burner provided on the discharge port side of the rotary kiln 4 and burning it by supplying a mixed gas of fuel and oxygen.

At that time, the atmosphere temperature (maximum temperature) in the vicinity of the discharge port that became the highest temperature in the rotary kiln and the lower part of the rotary kiln was set to 1385 ° C. In addition, by adjusting the input amount of carbon material, the atmosphere near the discharge port and below the rotary kiln is P _CO2 / (P _CO2 + P _CO ) = 0.7 and the CO ₂ partial pressure is 0.7 atm. It was. The time and the time required for the crushed material to be discharged after being put into the rotary kiln were adjusted to 4 hours by adjusting the inclination and rotation speed of the rotary kiln.

  During the heat treatment, the gas generated in the rotary kiln 4 was discharged from the exhaust port provided on the inlet side. Coarse particles were collected from the exhaust gas by the cyclone 5, and the exhaust gas treated by the cyclone 5 was passed through the bag filter 6 to collect fine particles. The particles recovered by the cyclone 5 and the bag filter 6 were selected to recover lithium carbonate. On the other hand, the crushed material discharged from the rotary kiln was selected to collect metal cobalt, metal nickel, and manganese metal and oxide.

The test conditions in this test are as follows.
Rotary kiln: furnace inner diameter 1m, furnace length 10m,
Input amount of crushed material: 1500 kg / day,
Fuel used: Coke open gas 200Nm3 / Hr,
Oxygen supply amount: 6 Nm3 / Hr

[Test results]
In this test, particles collected by the cyclone 5 and the bag filter 6 were selected, and the resulting lithium carbonate had a purity of 99% or more. It was 2 mass% when content of lithium was confirmed about the crushed material discharged | emitted from the rotary kiln. Therefore, it became clear that the recycling method of 1st Embodiment of this invention can collect | recover most lithium contained in a waste battery as lithium carbonate by performing 1st heat processing to a crushed material.

2. Test of using waste batteries as used manganese batteries [Test method]
In this test, a used manganese dry battery was used as a waste battery, and the waste battery was crushed and supplied to the rotary kiln 4 according to the process flow example shown in FIG. At that time, the ambient temperature (maximum temperature) in the vicinity of the discharge port that was the highest temperature in the rotary kiln and the lower part of the rotary kiln was set to 1400 ° C. Further, by adjusting the input amount of the carbon material, the oxygen partial pressure P _O2 in the vicinity of the discharge port and under the rotary kiln was set to 10 ⁻¹⁷ atm (log (P _O2 ) = − 17).

  During the heat treatment, the gas generated in the rotary kiln 4 was discharged from the exhaust port provided on the inlet side. Coarse particles were collected from the exhaust gas by the cyclone 5, and the exhaust gas treated by the cyclone 5 was passed through the bag filter 6 to collect fine particles. The particles recovered by the cyclone 5 and the bag filter 6 were selected to recover zinc. On the other hand, the crushed material discharged from the rotary kiln was selected under a nitrogen atmosphere to recover manganese and iron metals and oxides.

The test conditions in this test are as follows.
Rotary kiln: furnace inner diameter 1m, furnace length 10m,
Input amount of crushed material: 1500 kg / day,
Fuel used: Coke open gas 135Nm ³ / Hr,
Oxygen supply amount: 6 Nm ³ / Hr

[Test results]
The crushed material subjected to the heat treatment of this test was selected, the contents of the obtained manganese and iron metals and oxides were confirmed, and the reduction rate, which is the percentage of the mass of the metal contained relative to the total mass, was calculated. As a result, the obtained manganese and iron both had a reduction rate of 90% or more. Therefore, the recycling method of the second embodiment of the present invention reduces the manganese and iron oxides contained in the waste battery by subjecting the crushed material to the second heat treatment, and reduces the resulting reduction rates of manganese and iron. It became clear that it could be improved.

  According to the method for recycling a waste battery of the present invention, by subjecting a crushed material containing lithium to a first heat treatment, lithium can be recovered as lithium carbonate and the lithium recovery rate can be improved. Moreover, by applying the second heat treatment to the crushed material containing manganese, it is possible to reduce the oxides of manganese and iron and improve the reduction rate of the recovered manganese and iron.

  Therefore, the lithium carbonate recovered by the method for recycling a waste battery of the present invention can be used for the production of a positive electrode active material for glass products, cement, or lithium ion secondary batteries. Further, the recovered manganese and iron are useful as a steel raw material used for a blast furnace and a converter because zinc which is harmful as a steel raw material is removed and the reduction rate of the contained manganese and iron is high. For this reason, the waste battery recycling method of the present invention can greatly contribute to the effective use of resources.

1: Waste battery, 2: Crusher,
3, 31 and 32: conveyor, 4, 41 and 42: rotary kiln,
4a, 41a and 42a: inlet, 4b, 41b and 42b: outlet,
5, 51 and 52: Cyclone, 6, 61 and 62: Bag filter,
7: Crushed material after heat treatment, 91: First recycling device,
92: Second recycling device

Claims (6)

A waste battery recycling method in which a first heat treatment is performed on a crushed material obtained by crushing a waste battery in a heating furnace, and a metal-containing material is recovered from the crushed material,
Using a crushed material containing lithium as the crushed material,
In the first heat treatment, the maximum temperature T1 (° C.) is set to 730 ° C. or more, and the atmosphere is expressed as P _CO2 / (P expressed by CO ₂ partial pressure P _CO2 (atm) and CO partial pressure P _CO (atm). _CO2 + P _CO ) satisfies the following formula (1) and CO ₂ partial pressure P _CO2 (atm) satisfies the following formula (2).
A method for recycling a waste battery, wherein lithium carbonate is recovered when the metal-containing material is recovered.
P _CO2 / (P _CO2 + P _CO ) <1 / (1 + exp (−ΔG ⁰ _A /(R·(T1+273.15))) (1)
P _CO2 > exp (ΔG ⁰ _B /(R·(T1+273.15)) (2)
However,
ΔG ⁰ _A = (− 468200 + 140.98 (T1 + 273.15)) / 2 − (− 565160 + 172.03 (T1 + 273.15)) / 2 (3)
ΔG ⁰ _B = −153750 + 85.87 (T1 + 273.15) (4)
R: Gas constant The maximum temperature T1 is set to 1320 ° C. or higher,
2. The method for recycling a waste battery according to claim 1, wherein when recovering the lithium carbonate, the lithium carbonate is recovered from a gas generated by the first heat treatment.   3. The waste battery recycling method according to claim 1, wherein at least one of manganese, iron, cobalt, and nickel is recovered from the crushed material that has undergone the first heat treatment. 4. How to recycle batteries. By heating the crushed material obtained by crushing the waste battery in a heating furnace, the low boiling point metal contained in the crushed material is evaporated, and the oxide of the high boiling point metal contained in the crushed material is reduced and further generated. A second heat treatment for recovering the low boiling point metal from the treated gas;
A waste battery recycling method including a recovery process for recovering a high-boiling point metal from the crushed material that has undergone the second heat treatment,
The crushed material contains manganese,
The second heat treatment is performed with a maximum temperature T2 (° C.) of 1200 ° C. or more and an oxygen partial pressure P _O2 (atm) of the atmosphere as a condition satisfying the following expression (3): Recycling method.
log (P _O2 ) ≦ 0.008 · T2-26.6 (5)   The waste battery according to claim 4, which is a crushed product obtained by crushing a waste battery, wherein the crushed product containing lithium and manganese is treated by the waste battery recycling method according to claim 1. A recycling method for waste batteries, characterized by being treated by a recycling method.   The method for recycling a waste battery according to claim 1, wherein a rotary kiln is used as the heating furnace.

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