JPS6229072A - Method and device for recovering valuable substance of run-down dry cell - Google Patents

Abstract

PURPOSE:To recover mercury, iron and a zinc material without causing pollution, by sorting run-down dry cells in terms of their form, size and weight, and using a rotary kiln as a roaster. CONSTITUTION:Run-down dry cells are sorted into unit-1 dry cells, unit-2 dry cells, unit-3 dry cells, manganese dry cells, alkali manganese dry cells and the like, in terms of their form, size and weight, by a form sorter 12 and a weight sorter 13 before the iron sheath of each dry cell is removed by a disassembly machine 14 and recovered as iron scrap by magnetic sorting. The remaining body of the dry cell is crushed by a crush/mix machine 15 so that contained substances such as the positive electrode depolarizing mix in the remaining body are separated and pulverised. The remaining substances are then charged into a rotary kiln 31 through a substance storage bin 16 so that mercury is evaporated below the melting point of zinc. the mercury is then treated by a condensation and waste gas disposal equipment and a waste water disposal equipment including a cyclone 41. Burnt remains are cooled by a cooler 32 so that iron scraps are recovered by a crusher 62 and a magnetic sorter 63, weighing is performed by a weighing bin 64 and zinc remains are recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for recovering valuables from used dry batteries, for recovering valuables from used dry batteries.

<Conventional technology> In recent years, with the technological advancement of electrical appliances, the use of dry cell batteries has been increasing year by year, not only in businesses but also in households. ,
The increase in the use of alkaline manganese dry batteries, which have little voltage fluctuation and are suitable for high rate discharge, is particularly remarkable.

Many of these dry batteries use zinc for the negative electrode, and hydrogen gas is generated from the negative electrode during discharge, but mercury or mercury compounds are used to suppress this. Waste dry batteries containing this harmful mercury are collected by local governments as waste from households and are either buried directly in landfills or incinerated along with combustible materials. As a result of this, recent research reports have found that soil contamination with mercury ranges from several ppm to several + ppnt in landfills, and even methylmercury has been detected in many of these landfills. Under these circumstances, there is a growing trend among local governments to separate and collect waste batteries, and in order to handle them, it is necessary to not only remove mercury and render them harmless, but also to remove the valuable materials that make up these batteries. It is necessary to collect it effectively.

Therefore, conventional methods for treating mercury-containing waste include roasting the mercury-containing waste in a vertical multi-stage roasting type Herreshof furnace, cooling the generated exhaust gas in a condenser, and recovering mercury. The collected exhaust gas is cleaned by chemical cleaning and electrostatic precipitator to remove mist, etc.
Excess water released into the atmosphere and generated during the treatment process was treated in an evaporation furnace. In addition, the slag left from the Herreshof furnace was humidified to suppress dust, and then disposed of in a buried reinforced concrete tank.

Conventionally, mercury has been recovered from recovered waste dry batteries using the above-mentioned method and apparatus for treating mercury-containing waste.

The conventional flow system is shown in FIG. 7, and the system diagram is shown in FIG. 8.

The collected waste dry batteries are stored in a warehouse 11, put into a crushing mixer 15 in various mixed state, crushed and crushed, and stored in a raw material storage bin 16. The raw material is fed from the raw material storage bin 16 into the Herreshof furnace 21 by a feeder (not shown). As shown in FIG. 9, the Herreshof furnace 21 has a cylindrical steel plate outer shell lined with refractory bricks, and a horizontal or slightly sloped brick shelf 21b is placed inside the shaft 21.
An arm 21c with teeth at each stage is protruded from d, and the raw material supplied from the raw material storage bin 16 and charged from the hopper 21a is stirred and horizontally moved on each stage of the brick shelf 21b. The raw material is continuously charged from the upper part, moves from the center of each brick shelf 21b while alternately repeating the circumferential direction and the opposite direction, falls to the lower part, and is discharged from the slag outlet 21h. A burner 21e is inserted near the center of the furnace to heat and roast the inside of the furnace. The secondary air is blown from the air 'll' 21f and is supplied to each stage through the shaft 21d. Exhaust gas is discharged from the top of the furnace in direction A. 21g is a prime mover that rotates the shaft 21d and the arm 21c attached thereto. The roasting equipment 20 shown in FIG. 8 is composed of a Herreshof furnace 21. The slag leaving the Herreshof furnace 21 is transported to a landfill site and reclaimed.

<Problems to be Solved by the Invention> However, the above-mentioned conventional method and apparatus for recovering valuables from waste dry batteries have the following drawbacks.

(a) Since waste dry batteries of different types and sizes are simply crushed and mixed in the crushing mixer 15 and put into the Herreshof furnace 21, it is not possible to set appropriate roasting conditions depending on the mercury content, and the crushing and mixing Because the size of the processed raw materials is uneven,
It is difficult to uniformly transfer heat to materials containing mercury.

(b) Since waste dry batteries are covered with an iron shell, even if they are processed and separated in the crushing mixer 15, they cannot be processed in the Herreshof furnace 21.
When heated with materials containing mercury, zinc and iron can form zinc ferrite, making it unsuitable as a raw material. Furthermore, the steel plate on the outer skin has a negative effect on thermal efficiency.

(C) Since there is little movement of the raw material during roasting in the Herreshof furnace 21, the mercury on the surface of the raw material that receives heat evaporates;
Zinc is bonded by moderate melting from a state where it is in contact with each other,
Nodules tend to form, making it difficult for mercury to volatilize, and the residual rate of mercury in the slag containing zinc increases.

(d) The slag leaving the Herreshof furnace 21 is mainly composed of zinc and manganese dioxide, with a zinc content of almost 50%, but disposing of it in a landfill would throw away most of the valuables. Therefore, if the cost of buried tanks is included, it will lead to a loss of resources.

The present invention was made in view of the above-mentioned circumstances, and it processes waste dry batteries, removes the harmful mercury contained therein, and effectively uses mercury, iron layer, and zinc raw materials as valuable resources. The purpose of the present invention is to provide a method and device for recovering valuable materials from waste dry batteries that are operationally non-polluting and do not affect health and safety.

Means for Solving Problems> Therefore, the present invention provides a method for recovering valuables from waste dry batteries, in which mercury is recovered from exhaust gas obtained by roasting raw materials obtained by crushing and mixing waste dry batteries, using condensation/exhaust gas treatment equipment and wastewater treatment equipment. , the collected waste dry batteries are separated by type sorter based on differences in shape and size, then weight sorters are used to separate waste dry batteries of the same size into product types based on differences in principle, and the separated waste dry batteries are separated. The outer skin of the iron is removed and recovered using a crusher, and then crushed and mixed using a crushing mixer, and then roasted in a rotary kiln.The slag from the rotary kiln is cooled in a cooler, and then sent to the crusher. A method for recovering valuable materials from waste dry batteries, which is characterized by collecting iron scraps using a magnetic separator and recovering zinc slag containing remaining zinc, manganese dioxide, etc., and roasting raw materials obtained by crushing and mixing waste dry batteries. In a waste dry cell valuables recovery device that has a condensation/exhaust gas treatment facility that recovers mercury from burned exhaust gas and a wastewater treatment facility, there is a difference in weight between a shape sorter that separates the recovered waste dry F4 ponds by shape and size. Pre-treatment equipment consisting of a weight sorter for sorting, a disassembly machine for separating the outer shells of separated waste dry batteries from the main bodies, a crushing mixer for crushing and crushing the battery bodies discharged from the dismantling machine, and the above-mentioned disassembly. Roasting equipment consisting of a rotary kiln that roasts the main body of waste dry batteries treated with a mixer, a cooler that cools the slag that comes out of the rotary kiln, a crusher that crushes the slag that comes out of the cooler, and the cracker. Consisting of a device for recovering valuables from waste dry batteries, which is characterized by having a slag processing equipment consisting of a magnetic separator that separates iron scraps from the output of the crusher and recovers zinc slag containing zinc, manganese dioxide, etc. .

〉 Waste dry batteries are sorted according to the product type, shape, and size that differ in principle, and the iron shell is removed and put into the rotary kiln 31, so that the proper roasting conditions depending on the mercury content are determined. can be set, and in the rotary kiln 31 of the roasting furnace, the raw material rises to a certain position along with the inner wall of the furnace due to the rotation of the kiln, falls, and moves to the exit side with the slope of the furnace, so that it rises with the falling raw material. The raw materials collide and the raw materials do not bond with each other, but powder or constituents exist as single bodies, and the single bodies scratch the surfaces of each other.

Therefore, the surfaces of components such as zinc containing mercury are activated, and the mercury easily absorbs heat, and the volatilization surface becomes large, so that volatilization is effectively performed.

Furthermore, the slag leaving the rotary kiln 31 is stored in a cooler 3.
2 and then crushed by a crusher 62, iron scraps are separated by a magnetic separator 63, so that zinc slag containing zinc, manganese dioxide, etc. can be recovered.

<Example> Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 is a flow system diagram for recovering valuable materials from waste dry batteries showing an embodiment of the present invention, and FIG. 2 is a diagram showing the same system.

The collected waste dry batteries are stored in a warehouse 11 and sent to a type sorter 12 in various mixed forms. As shown in FIG. 3, in this type sorter 12, waste dry batteries supplied to an alignment feeder 12a are sent forward through the grooves of the alignment feeder 12a by electromagnetic vibration and fall into a sorting feeder 12b.

At this time, the number of small waste dry batteries of button type and AAA type is 1.
It falls and is collected below the slit between the two bars shown as 2e. Next, the AA type falls below the slit 12d, the single Z type falls below the slit 12e, and the AA type falls below the slit 12f, and is collected. Finally, when the single type is collected,
Other large box-shaped waste batteries are sorted into the sorting feeder 12b.
It falls from the tip and is collected. The above sorting feeder 12b
The waste batteries are fed by an electromagnetic vibrating feeder 12g, similar to the alignment feeder 12a.

The button type and AAA type 4.5 type separated by the slit 12e are further distinguished by a type sorter (not shown) having the same structure as above.

Of the waste dry batteries that are sorted by shape and size by the type sorter 12, most of the cylindrical AA, AA, and AA cylindrical batteries are of two types: manganese batteries and alkaline manganese batteries. Even if they are of the same shape, they have different weights due to differences in constituent materials, so weight sorting is performed by weight sorter 13 for each of the same shapes. FIG. 4 shows a perspective view of the weight sorter.

The waste dry batteries are fed from a feeder 13a and placed on a weighing conveyor 13c by a conveyor 13b. If it is specified that a certain range of weight is to be detected, the weighing conveyor 13c detects the weight of each piece using a load cell, and the sorting conveyor 13d sorts the weights into the respective weights. Sorting devices include a set of flippers and an air jet type.

Shape,
Waste dry batteries sorted by size and weight are, for example, AA batteries,
The outer skin of the iron is removed by disassembling machine 14 shown in FIG. 5 for each type such as AA and AA and mild type such as manganese and alkali manganese. In order to remove the outer skin, in order to prevent the method of cutting the outer skin using a blade or a grindstone, the heat generated by cutting causes mercury to scatter, which has a negative impact on the working environment.
A dismantling machine 14 shown in the figure is used. In this structure, the waste batteries are arranged in the same direction, and the receivers are mounted on support rods 14a from both sides of the stand.
is pushed out by pressure and supports the waste dry battery 14b,
The dismantling mold 14c comes out from both sides along the support rod 14a, and the dismantling mold 14c is applied to the part that presses the electrode plate of the waste dry battery 14b, and the dismantling mold 14c is opened as shown by the chain line in the figure. The outer skin 14d is expanded outwardly by the dismantled mold 14c to form the main body 14.
Separate from e. These are dropped and the outer skin 14d is collected as iron scrap by magnetic separation.

The raw material, which is a collection of the remaining bodies 14e from which the outer skin has been removed in the dismantling machine 14, is crushed and crushed in a crushing mixer 15, and the substances contained in the cylindrical body, such as the positive electrode mixture, are removed from the cylinder. Separate and crush. The main body 14e of the waste dry battery is surrounded by a zinc cylinder in the case of a manganese dry battery, and zinc is placed in an iron cylinder in the case of an alkaline manganese dry battery. The crushing mixer 15 is called a paddle type, and as shown in FIG. 6, has a rectangular top surface that is open, and has a groove-shaped main body 15a in which 29 shafts 15b with blades 15c are disposed. . These shafts 15b, 15b are connected to a pair of gears 15d, 15d.
They rotate in opposite directions, and are driven by a motor (not shown). The main body of the waste dry cell is charged from the right direction in FIG. 6 in the direction of the arrow, crushed and pressed together by the blades 15c rotating in opposite directions, and is pushed out from the lower outlet 15e in the direction of the dashed arrow on the left.

The extruded raw material is stored in a raw material storage bin 16 by a supply conveyor (not shown). FIG. 2 shows the pretreatment equipment 10 from the shape sorter 12 to the raw material storage bin 16.

In the raw material storage bin 16, raw materials obtained by crushing and crushing the main bodies of waste dry batteries are stored according to type, size, and type depending on the difference in constituent materials, and are charged into the rotary kiln 31 by a quantitative feeder (not shown).

Of the charged raw materials, most of the mercury volatilizes at a boiling point of 360°C before reaching the melting point of zinc, 419°C, and passes through a duct (not shown) installed at the inlet of the rotary kiln 31 to other combustible materials. It is treated as exhaust gas together with the combustion gas and volatile components or moisture in the condensation/exhaust gas treatment membrane 4II40 below the cyclone 41 and the wastewater treatment equipment 50 shown in FIGS. 1 and 2. The condensation/exhaust gas treatment membrane [40] and wastewater treatment equipment 50 are the same as in the conventional flow system diagram shown in FIG.

The exhaust gas that has passed through the duct passes through a cyclone 41 that removes dust and a dry electrostatic precipitator 42, and then a condenser 43.
guided by. In the condenser 43, the temperature of the exhaust gas is lowered to room temperature, so mercury vapor having a pressure higher than mercury vapor pressure at room temperature is condensed, and mercury is recovered. Air pollutants such as chlorides in the exhaust gas are removed in the next gas scrubbing tower 44 by gas-liquid contact with an appropriate chemical solution. Also, for mist, etc., use a wet electrostatic precipitator 45.
However, some of the mercury is gasified, so the activated carbon tank's de-M tower 46 is impregnated with Kir-1 resin that adsorbs mercury.
It is released into the atmosphere as exhaust gas. The equipment from the cyclone 41 to the de-M tower is shown in FIG. 2 as a condensation/exhaust gas treatment equipment 40. In this way, the exhaust gas is discharged in a state compatible with environmental protection, so that no problem of environmental pollution occurs. In addition, the water used for the chemical solution is recycled, and the mercury absorbed therein is recovered by being treated with a mercury fixative through the waste water treatment PA 52 and the filter 53.

In addition, since some of the salts in the chemical solution also contain some zinc, a dryer 54 is used to recover this and to prevent water from being discharged, and a boiler 55 is provided for this purpose. The cooling tower 51 is used to lower the temperature of the chemical solution used in the gas scrubbing tower.

The equipment from the cooling tower 51 to the boiler 55 is shown in FIG. 2 as a drainage equipment 50.

The above-mentioned rotary kiln is equipped with a seal to prevent the leakage of harmful mercury gas, but the other structure is the same as that commonly used. The raw material charged from the furnace entrance is heated by the heat of combustion of fuel by a burner (not shown), the slag is discharged along with the slope of the furnace, and the exhaust gas is discharged to the above-mentioned duct. Since the slag leaving the rotary kiln has a height of m, a cooler 32 consisting of a rotary cooler 32a and a Guring conveyor 32b is used.
First, the rotary cooler 32a exchanges heat with air to cool the slag, and while the slag moves to the outlet side, the
The temperature drops to 00 to 400°C, and the cooling conveyor 32b is charged.

The air heated by the heat exchange is transferred to the rotary kiln 31.
Save energy by using it as secondary air. The cooling conveyor 32b is a saking conveyor (vibration conveyor) equipped with a jacket for cooling from the outside, and the slag is cooled during movement. Above rotary kiln 31, rotary cooler 3
The 2a1 cooling conveyor 32b is shown in FIG. 2 as the combustion equipment 30. The slag cooled by the cooling conveyor 32b is temporarily put into the slag storage tank 61.

The slag includes cylindrical iron products for alkaline manganese dry batteries and some iron products that are included in the raw materials.Since these have other constituent substances such as zinc and manganese attached, they are separated by a crusher 62. The iron scrap is collected by the Ti1 sorter 63. The crusher 62 used is of a cage mill type. The slag from which iron has been removed is placed in a weighing bin 64 and weighed, and then recovered as zinc slag.

This zinc slag is mainly composed of zinc and manganese dioxide, and the zinc content is nearly 50%. The equipment from the slag storage tank 61 to the weighing pin 64 is shown in FIG. 2 as the slag processing equipment 60.

<Effects of the Invention> According to the method and apparatus for recovering valuables from waste dry batteries of the present invention described in detail above, the following effects are achieved.

■ Use pre-treatment equipment to separate waste dry batteries by shape, size, and constituent materials, treat each battery separately, and recover the outer skin as scrap iron, making it possible to reliably remove and collect harmful mercury even though it is a valuable item.

■ Since a rotary kiln is used for the roasting equipment, mercury is effectively volatilized and recovery efficiency is high.

■ Slag processing equipment that combines a crusher and magnetic separator can recover valuable materials such as iron scrap, zinc, and manganese dioxide that can be recycled from waste dry batteries.

[Brief explanation of the drawing]

Fig. 1 is a flow system diagram for recovering valuables from waste dry batteries showing an embodiment of the present invention, Fig. 2 is a diagram of the same system, and Fig. 3 is a perspective view of a type sorter used in the valuables recovery device of the present invention. Figure, 4th
The figure is a perspective view of the same weight sorter, Figures 5(a) and (b) are a plan view and side view showing the dismantling operation of the same dismantling machine, respectively, and Figure 6 is a perspective view of the same crushing mixer. Figure 7 is a flow diagram of a conventional waste dry battery valuable collection flow system, Figure 8 is a diagram of the same system,
FIG. 9 is a longitudinal sectional view of a conventionally used Herreshof furnace. 10. Pretreatment equipment, 11. Warehouse, 12.. Shape sorter, 13.. Weight sorter, 14. Dismantling machine, 14d. Shell, 14e. Main body, 15. Crushing mixer, 20, 30. Roasting equipment, 21. Herreshof. Furnace, 31 ・Rotary kiln, 32 ・Cooler, 32a
・Rotary cooler, 32b Cooling conveyor, 40 ・Condensation/exhaust gas treatment equipment, 50 ・Wastewater treatment equipment, 60 Slag treatment equipment, 62 ・
Crushing machine, 63 ・Magnetic separator,

Claims (2)

[Claims] (1) In the method for recovering valuables from waste dry batteries, in which mercury is recovered from the exhaust gas obtained by roasting raw materials made by crushing and mixing waste dry batteries, using condensation/exhaust gas treatment equipment and wastewater treatment equipment, the collected waste dry batteries are passed through a mold sorter. They are sorted according to differences in shape and size, and then put into a weight sorter to separate waste dry batteries of the same size into product types based on differences in principle. The outer skin is removed and collected, then crushed and mixed in a crushing mixer, and then roasted in a rotary kiln. The slag from the rotary kiln is cooled in a cooler, passed through a crusher, and iron scraps are recovered by a magnetic separator. , a method for recovering valuables from waste dry batteries, characterized by recovering zinc slag containing remaining zinc, manganese dioxide, etc. (2) The recovered waste dry batteries are separated by shape and size in the waste dry cell valuables recovery equipment, which has condensation/exhaust gas treatment equipment and wastewater treatment equipment to recover mercury from the exhaust gas produced by roasting raw materials made by crushing and mixing waste dry batteries. A weight sorter separates waste dry batteries based on differences in weight, a dismantling machine separates the outer shells of separated waste dry batteries from the main body, and a crushing mixer crushes and crushes the main bodies of the batteries discharged from the dismantler. a rotary kiln for roasting the main body of the waste dry battery treated with the crushing mixer; a torrefaction equipment comprising a cooler for cooling the slag leaving the rotary kiln; and a roasting equipment for the slag leaving the cooler. A waste dry battery characterized by having a slag processing equipment comprising a crusher for crushing the battery, and a magnetic separator for separating iron scraps from the discharge of the crusher and recovering zinc slag containing zinc, manganese dioxide, etc. valuables recovery equipment.