JP3461300B2 - Method for recovering valuable resources from used lithium-manganese batteries - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to used lithium-
The present invention relates to a method of recovering valuable materials from a manganese battery. The lithium-manganese battery is used as a power source for mobile phones, PHSs, video cameras, notebook computers, etc. because of its features such as small size, light weight, and high energy density per volume.

The main components of a lithium-manganese battery are a steel case, a negative electrode plate made of copper foil, a positive electrode plate made by coating lithium manganate on an aluminum foil, and a separator made of polyethylene or the like.

[0003]

2. Description of the Related Art Several methods for recovering valuable metals such as Mo, Co and Ni from a Mo, Co or Ni Ni lithium battery have been proposed. According to Japanese Unexamined Patent Publication No. 6-322452, the crushed material of the used lithium secondary battery is magnetically separated and separated to remove the magnetic material such as metallic nickel. The crushed material is roasted in a non-oxidizing atmosphere or in a reducing atmosphere. It has been proposed that the roasted product is magnetically reduced and roasted and the obtained roasted product is magnetically selected. Roasting in a non-oxidizing atmosphere in the above method is a step for reducing a metal oxide by a carbonaceous material contained as a separator, carbon of a negative electrode material, and the last magnetic separation is nickel, cobalt. Is a process for separating from copper and the like. According to JP-A-6-346130, it is proposed to roast a used lithium battery to remove a binder, a solvent, etc., crush the roasted product, and sieve it to use the lower sieve as a raw material for smelting. Has been done.

[0004]

The above-mentioned conventional method is not a method for recovering valuable materials from a lithium manganate battery. Apart from this point, the above-mentioned Japanese Patent Laid-Open No. 6-3224.
In JP-A-52, the used lithium secondary battery is directly crushed, but this crushing is more difficult than the crushing of the roasted product. Further, in order to reduce the burden of roasting, the crushed material is directly magnetically selected without undergoing roasting, so magnetic separation for separating non-magnetic material and magnetic material is performed twice before and after roasting. . next,
In the method disclosed in Japanese Patent Laid-Open No. 6-346160, Ni and Co are recovered in the smelting process, and there is room for improvement in terms of heat energy. Similarly, although it is not a method of recovering a valuable material from a lithium manganate-based battery, it is obtained by roasting a used lithium-Mo, Co, Ni-based battery in JP-A-10-74539 by the present applicant. Valuable materials are recovered by crushing the roasted material and magnetically separating it into magnetic and non-magnetic materials. It is described that the roasting temperature of this method is preferably 800 to 1000 ° C. at which Al melts. When such high-temperature roasting is applied to a lithium-manganese battery, the recovered copper quality is lowered and effective separation of valuables is hindered, such as difficulty in separating Al. Lithium
When recovering Cu and Fe as valuable materials from a manganese-based battery, a particular problem is that if Mn accompanies the recovered Fe, Mn cannot be separated from Fe in the subsequent smelting. It is difficult. Therefore,
It is an object of the present invention to recover valuable metals from used lithium-manganese batteries in a way that facilitates crushing and only requires a single magnetic separation.

[0005]

According to the method of the present invention, a used lithium-manganese battery containing copper and iron as valuables is used in a temperature range of 500 to 750 ° C. and unburned carbon remains in the roasted product. Thus, the roasted product is crushed, the obtained roasted product is crushed, and magnetic separation is performed to separate into a magnetic product and a non-magnetic product, and a valuable material recovery method from a used lithium-manganese battery. Hereinafter, the method of the present invention will be described in detail.

First, in the method of the present invention, a used lithium-manganese battery is roasted to burn graphite and carbon powder, which are negative electrode active materials, and decompose organic substances such as polypropylene and n-methyl-2-pyrrolidone. ,
It burns and volatilizes, and at the same time generates CO as a reducing gas. If the roasting temperature is too low, the reduction of lithium metal oxide by the CO gas generated by the decomposition of organic matter will be insufficient and the burden of crushing will be large, so the roasting temperature is 500
℃ or more is required. On the other hand, if the temperature is too high, the aluminum will be melted and it will be difficult to crush it, and it will be difficult to recover the aluminum alone. .

The heating furnace for roasting is not limited,
It can be performed in a stationary furnace such as an electric furnace or a heavy oil furnace. In this case, an open flame heating stationary furnace under a stoker can be used. A used lithium-manganese battery is piled up on a stoker for one batch, and a flue gas passage is provided from the upper part of the furnace to perform roasting while appropriately discharging combustion gas. When the used lithium-manganese battery is roasted without being crushed, the above-mentioned carbon powder and organic substances are burned inside the battery, C
O 2 gas is generated, and the reduction of the oxide proceeds in the space inside the battery case. By this roasting, most of iron oxide and manganese oxide are reduced. If some of the carbon generated by the combustion of carbon or the decomposition of organic matter remains as unburned carbon, reoxidation of the once reduced metal is hindered. For example, when the temperature is raised to the roasting temperature with a burner, the temperature is rapidly raised while promoting combustion in an oxidizing atmosphere, and then the decomposition and reduction of organic substances proceed. If unburned carbon remains at the end of this stage, CO2
Since the reaction of + C → 2CO can be caused to increase the CO concentration in the furnace atmosphere, the furnace atmosphere shifts to the reducing side and prevents the reoxidation described above. After firing according to the present invention, the copper foil and the like maintain their metallic form, and the aluminum is present in the form of powder, lumps and the like.

The obtained roasted product was about 70 to 90% by weight of metal powder, agglomerate, and lithium-manganese battery.
A net, a foil, a plate, or a part of which maintains the bonding structure in the battery, or becomes a carbon powder.

Next, the roasted product is crushed. This crushing has the various forms described above, and the roasted products of various sizes are arranged in appropriate sizes, and those that maintain the structure of the battery are separated into material forms such as powder, plate, and foil. It is an operation that facilitates the separation into a magnetic substance and a non-magnetic substance by the magnetic separation of. The crusher is not limited, but a uniaxial crusher or the like can be preferably used. In addition, crushing is JIS
It is preferable that the standard sieve of Z 8801 has a size of less than 20 mm. After crushing, the sieve can be subjected to roasting treatment again to collect valuables. In the crushing after roasting according to the method of the present invention, the battery itself is not crushed directly, but is crushed to some extent by thermal expansion during roasting, rupture due to the pressure of combustion gas in the case, and the weight is reduced. The load of crushing is reduced to crush. In addition, since most of the roasted material is metal and there is almost no carbon or organic matter that is difficult to crush, the burden of crushing is also reduced in this respect. The last step of the present invention is a step for performing magnetic separation to separate iron in the battery case, which is a magnetic substance, from non-magnetic substances.

Further, when it is necessary to separate the magnetic material into iron and other accompanying substances, for example, if the magnetic material is sieved to less than 2 mm or more, it becomes an iron scrap piece on the screen and
It becomes powder of carbon, copper, aluminum, etc. that is mechanically attached to iron. Iron scrap is recycled as normal iron scrap. Similarly, when sieving the non-magnetic material, a mixture of copper foil with a small amount of aluminum debris adhered on the screen,
Under the sieve, powder of copper, aluminum, manganese, carbon, etc.,
These are sintered products. This separation is possible because the crushed material after roasting generally has a copper foil shape. Since the copper quality on the sieve is 75% or more, it can be regenerated by treating it in a converter of a copper smelting plant. The sieve bottom is used as a raw material for a flash furnace of a copper smelting plant to recover copper.

A more detailed description will be given below with reference to the flow charts for carrying out the present invention. A used lithium-manganese battery is used as a raw material 1, and 400 kg, for example, is charged into a roasting furnace 3 such as an electric furnace or a heavy oil furnace. When the roasted valuable metal-containing material reaches several tons, it is crushed by the crusher 2 to a size suitable for magnetic separation. The crushed pieces are separated into a magnetic substance M and a non-magnetic substance NM by two conveyors 5 and 9 and magnetic separators 7 and 8 each having an electromagnet as an element. The magnetic substance M and the non-magnetic substance NM are separately separated by the sieving machine 8 into an upper screen and a lower screen. 4 is a suction fan, 9 is a portable conveyor, 10 is a sieve container bag, 11 is a sieve container bag, and 12 is a dust collecting facility. The present invention will be described in more detail with reference to the following examples.

[0012]

Example: Used lithium whose metal composition is as shown in Table 1
Seven manganese batteries (1716 g) were used as raw materials and treated in a pilot plant.

[0013]

[Table 1]

When the raw material was roasted at an average temperature of 680 ° C. for about 30 minutes in a heating furnace directly below equipped with a heavy oil burner furnace,
Although the weight was reduced by 25.8%, the metal composition did not change. About 100 g of carbon was present in the roasted product.
Next, crushing was performed using a crusher with a cutting blade, and magnetic separation was performed using a hanging iron piece separator for 900 g excluding 373 g of the residue remaining in the crusher.
640 g of non-magnetic material was obtained.

Subsequently, the magnetic material was sieved with a sieving machine (2 mm), and 176 g of pure iron as the sieve top and the sieve shown in Table 2 (8
4 g) was obtained.

[0016]

[Table 2]

Finally, the non-magnetic material was sieved by a sieving machine (2 mm), and 239 g of a mixture of copper foil and aluminum scraps (copper grade 75%) and a sieve shown in Table 3 (401 g) on the sieve were used.
Got

[0018]

[Table 3]

As described above, according to the present invention, iron and copper can be recovered as valuable resources.

[0020]

EFFECTS OF THE INVENTION (1) A valuable material can be recovered by crushing a used lithium-manganese battery once. (2) Since the entire amount of the used lithium-manganese battery is not crushed, the burden of crushing is reduced. (3) Fe recovered in Fe is less mixed with Mn
Due to its high purity, it can be used as any iron source. (4) The copper content recovered as the non-magnetic material becomes a raw material for copper smelting in a converter, a flash smelting furnace and the like. However, since Mn and the like are less mixed on the sieve and the copper quality is high, it is preferable to use it as a raw material for the copper converter in terms of smelting operation. (5) Despite the high purity of valuable metals among the recovered materials as described above, the magnetic separation can be performed only once. (6) In summary, when the method of the present invention is carried out, the running cost is low, only one crusher and one magnetic separator are required, so the equipment investment cost is also low, and the recovered material is also very valuable, and the material manufacturer, steel It is suitable for sale to manufacturers and non-ferrous smelting industries.

[Brief description of drawings]

1 is a flow sheet of a method of practicing the method of the present invention.

[Explanation of symbols]

1 raw material 2 crusher 3 roasting furnace 7 Magnetic separator

Claims (3)

(57) [Claims] 1. A used lithium-manganese battery containing copper and iron as valuables is roasted in a temperature range of 500 to 750 ° C. so that unburned carbon remains in the roasted product. A method for recovering valuable materials from a used lithium-manganese battery, which comprises crushing a calcinated product and magnetically separating it into a magnetic substance containing iron and a non-magnetic substance containing manganese and copper . 2. The magnetic material separated by the magnetic separation is sieved to recover iron on the sieve.
A method for recovering valuable materials from the used lithium-manganese battery described. 3. The used lithium-manganese battery according to claim 1 or 2, wherein the non-magnetic substance separated by the magnetic separation is sieved to recover copper as a sieve and manganese as a sieve . Valuables collection method.