KR100322038B1 - Recovery of valuable metals from waste batteries using plasma - Google Patents

Abstract

The present invention relates to a method for recovering valuable metals from waste manganese batteries that are frequently used for home use or industrial use and are discarded after use. The present invention relates to a plasma generation furnace by applying a power source between a cathode rod and an anode. The furnace is heated to 1200 to 1400 ° C. by heat to dissolve the waste battery.

In the present invention, the mercury volatilized by the heat applied to the waste battery is recovered through a mercury recovery apparatus at 350 to 450 ° C.

Description

Recovery of Valuable Metals from Waste Battery Using Plasma

The present invention relates to a method for recovering valuable metals from a waste battery using plasma, and more particularly, to recover ferro manganese and mercury using plasma from waste manganese batteries that are frequently used for home use or industrial use and disposed of after use. It is about.

Waste battery recycling technology uses a rotary roaster to vaporize mercury and residues to recover iron by magnetic screening, and recovers iron and manganese by wet method after volatilizing mercury in low temperature electric furnace. Law).

However, the prior art recovers iron and manganese through a very complicated process including pretreatment and post-treatment, and since most processes involve magnetic screening or wet treatment for post-treatment, the process is expensive and has a treatment process. The site must be large and there is a secondary contamination problem due to sulfuric acid solution, especially for wet treatment.

The present inventors have studied to solve the above problems of the prior art, and as a result, the plasma used as the heat source is excited by the specific energy and is present in the state separated from the atom, thus distinguishing it from gas, liquid, and solid. When this plasma state is reached, it retains very high energy in latent heat, but it is placed in an unstable state, and it is ionized locally by removing the system that maintains the unstable state or by leaving it. Although it is in an electrically neutral state, the focus of the plasma is estimated to be about 10,000 to 20,000 degrees in the center and an external temperature of about 3000 to 4,000 degrees.

When argon, which is an inert gas, is used as a plasma gas, a high temperature can be obtained as a clean heat source, and when a gas such as hydrogen, nitrogen, and carbon monoxide is used as a plasma gas, compounds that are difficult to manufacture by a general method can be synthesized.

In addition, metallurgy is not widely used due to the cost increase due to the large use of electricity and gas, but the possibility of plasma use in the smelting process has been steadily reviewed, and some practical applications have been made mainly in northern Europe, where electricity prices are low.

At this time, the plasma is used as a clean heat source, and since heat transfer starts from the bottom of the melt, compared to other heat sources that must transfer heat from the surface of the melt to the inside, a relatively high thermal efficiency can be expected and the stirring effect of the melt is excellent and the heat distribution is even. Has an advantage.

The present invention has been made to solve the problems of the prior art described above, a method of recovering valuable metals from a waste battery by facilitating the reduction of iron oxide and manganese oxide by giving a sufficient amount of heat to a waste battery loaded using plasma as a heat source. The purpose is to provide.

1 is a view schematically showing an apparatus for practicing the present invention,

2 is a view showing the recovery of ferro manganese according to the elevated temperature of the furnace,

3 shows mercury recovery.

<Explanation of symbols for main parts of drawing>

1: raw material charging device 2: furnace 3: cathode electrode 4: anode

5: mercury recovery unit 6: power supply unit 7: exhaust gas treatment unit

21: mercury outlet 22: hot water outlet 31: plasma gas supply passage

Method for recovering valuable metals from the waste battery of the present invention for achieving the above object comprises the steps of charging the waste battery into the furnace; Supplying nitrogen gas into the furnace where the waste battery is charged; Generating a plasma from nitrogen gas by applying a voltage of 1500 to 1800 A and 150 to 170 V between the cathode and the anode of the furnace; By using the heat generated in the step of generating the plasma to raise the internal temperature of the furnace to 1200 ~ 1400 ℃ by melting and reducing the waste battery while melting the mercury is volatilized and slag is excluded to recover the ferro manganese made It is a structure characterized by the above-mentioned.

In the present invention, the mercury volatilized by the heat applied to the waste battery is recovered through a mercury recovery apparatus at 350 to 450 ° C.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments.

First, an apparatus for recovering valuable metals from a waste battery for implementing the present invention will be described with reference to FIG. 1.

The anode electrode 4 is provided at the bottom of the furnace 2 for generating plasma, and the cathode electrode rod 3 on which the plasma gas supply passage 31 is formed extends vertically through the center of the furnace 2. In the furnace 2, a raw material charging device 1 for introducing waste batteries into the furnace 2 is provided at the upper part of the furnace, and a mercury outlet for recovering volatilized mercury is disposed at the center of the upper sidewall of the furnace 2. 21) is provided in the lower part of the furnace side wall is provided with a hot water outlet 22 for separating and recovering the obtained ferro-manganese and slag.

In addition, a mercury recovery device 5 for recovering mercury through the mercury discharge port 21 adjacent to the furnace 2 is provided, from which the exhaust gas treatment device 7 and the stack 8 are installed.

The cathode electrode 3 and the anode 4 installed in the furnace 2 are supplied with a high-voltage power source such as 1500 to 1800 A and 150 to 170 V from the power supply device 6 to generate a plasma between the anode and the cathode. It is configured to.

This is because such application of power is most suitable for generating plasma through nitrogen gas.

Referring to the process of recovering the ferro-manganese from the waste battery using the plasma generating apparatus of the above configuration, nitrogen to the plasma gas supply passage 31, such as nitrogen gas formed in the center of the cathode electrode rod (3) While supplying power to the cathode rod (3) and the anode (4) to generate an arc at the electrical contacts to plasma the nitrogen gas to dissolve the dust first, the waste battery through the raw material charging device (1) through the furnace (2) In the case of charging, the waste battery is directly heated by the heat of plasma to volatilize mercury first, and metallic mercury is recovered in the mercury recovery apparatus 5 in the range of 350 to 450 캜.

Subsequently, the temperature of the furnace 2 is adjusted to a temperature of 1200 to 1400 ° C., and the temperature is raised to dissolve the waste battery. The molten ferro-manganese and slag collected at the bottom are separated and tapped through the hot water outlet 22 to ferro-manganese. Recover.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example

The charge amount of the waste battery as a raw material was 100 g, and 30 g of electrolytic iron was charged together to generate plasma smoothly. The reduced temperatures of the spent batteries were in the range of 1100 ° C. to 1450 ° C., 1100 ° C., 1200 ° C., 1300 ° C., 1400 ° C., and 1450 ° C., respectively. 2 shows the recovery rate of ferro-manganese by temperature by measuring the amount of recovered ferro-manganese and slag. The ferromangan recovery was calculated by the chemical analysis as shown in Table 1, the amount recoverable in 100 g of the input material. The theoretical recovery amount of ferro-manganese is obtained by the following equation.

Theoretical recoverable amount = loading amount × {(iron component ratio + MnO ₂ component ratio ×

(Mn Molecular Weight / Manganese Oxide Molecular Weight)}

TABLE 1

As can be seen from FIG. 2, it can be seen that as the temperature of the furnace 2 increases, the recovery amount of ferro manganese increases. This is because the slag amount decreases because iron oxide is more likely to become metal as the temperature increases, and the recovery amount of ferro-manganese seems to increase.

3 shows the amount of mercury recovered when the temperature of the mercury recovery device 5 is fixed at 300 ° C, 400 ° C, and 500 ° C, respectively. Since the mercury component contained in the battery is in a metal state in its entirety, the theoretical recoverable amount of mercury is obtained as follows.

Theoretical recoverable amount = charged amount × mercury content ratio

As can be seen from FIG. 3, the amount of mercury recovered has a parabolic shape, so an appropriate recovery section exists. Maximum recovery was obtained at a mercury recovery unit temperature of about 400 ° C.

However, as the temperature of the furnace increases, it is easier to reduce the valuable metals such as iron and manganese to the metal state.However, as the temperature increases, the volume of the gas increases to increase the flow rate in the furnace, thereby increasing the temperature of the mercury recovery system. It is difficult to control, so it can be seen that it is economical to recover mercury in conjunction with the temperature of the furnace in the appropriate temperature range of 350 ~ 450 ℃.

Therefore, according to the present invention as described above, in the closed melting furnace, the plasma is used as a heat source and the waste battery is heated to a high temperature at the time of treating the waste battery to dissolve the waste battery to recover ferro-manganese as well as to recover mercury, thereby to discard the waste battery. Useful for recycling

Claims (1)

As a method for recovering valuable metals from waste batteries, Charging the waste battery into the furnace 2 and charging the waste battery; Supplying nitrogen gas into a furnace (2) in which a waste battery is charged; Generating a plasma from nitrogen gas by applying a voltage of 1500 to 1800 A and 150 to 170 V between the cathode electrode rod 3 and the anode 4 of the furnace 2; Using the heat generated in the step of generating the plasma to raise the internal temperature of the furnace (2) to 1200 ~ 1400 ℃ melting and reducing the waste cell while melting the mercury is volatilized and slag is excluded to recover the ferro-manganese A valuable metal recovery method from a waste battery using a plasma comprising a.