JPH0585624B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for treating waste dry batteries, particularly waste dry batteries containing mercury. [Prior Art and Problems] Conventionally, the treatment of waste dry batteries, particularly waste dry batteries containing mercury, has been a problem. This problem is becoming more and more serious as alkaline batteries containing large amounts of mercury come into widespread use. Conventional methods for disposing of this type of waste dry cell batteries include (1) throwing them into a garbage incinerator and incinerating them with trash, (2) fixing them in cement and burying them, and (3) separating them and burying them as is. etc. are being carried out. However, in method (1), metals such as mercury and zinc evaporate during incineration, polluting the air, and in method (2), heavy metals such as mercury and zinc are leached from cement, causing secondary pollution. Of course, in method (3), mercury, zinc, etc. are more likely to be eluted than in method (2), and what is even more important is that in the case of (2) and (3), the eluted mercury may react in the soil. This means that organic mercury, such as methylmercury, can be easily taken up by living organisms. [Means for Solving the Problems] The present invention, as a means for solving the above conventional problems, involves heating the mercury-containing crushed material obtained by sieving the mechanically crushed material of waste mercury-containing dry batteries in two stages. The main purpose of this method is to evaporate heavy metals such as mercury and zinc, and to collect the mercury and heavy metals, respectively. The invention will be explained in detail below. The waste mercury-containing dry batteries that are the object of the present invention include waste of dry batteries that contain mercury, such as manganese dry batteries, alkaline cylindrical batteries, alkaline button batteries, silver oxide batteries, and mercury batteries. In the case of mixed waste with mercury-free dry batteries such as lithium batteries and lithium batteries, it is desirable to manually sort out and remove the mercury-free dry batteries such as lithium batteries, for example. The mercury-containing dry batteries sorted in this way are cut and mechanically crushed to separate the crushed outer shell (iron shell or zinc can) and the crushed contents, and the contents are crushed by sieving. It is desirable to collect only the mercury-containing powder from the material and treat it. According to the above-mentioned sieving process, waste dry batteries are separated into (1) crushed iron shells, zinc cans, and carbon electrodes, and (2) mercury-containing crushed pieces. The collected mercury-containing crushed material is first heated to 100 to 400°C to evaporate the mercury contained therein. Evaporated mercury is condensed and recovered by cooling with a condenser, stripping with water, etc. When heated at the above temperature, zinc, cadmium, lead, etc. remain in the crushed material after treatment, so in order to recover them, the crushed material is heated at a temperature lower than 950°C to evaporate the zinc.
Evaporated zinc is condensed and recovered by cooling with a condenser, stripping with water, etc., just like mercury. [Function] In the present invention, since the waste mercury-containing dry cell is crushed mechanically, the battery does not explode and is safe. Furthermore, since the crushed material is sieved and only the mercury-containing crushed material is heated to evaporate and remove mercury from the crushed material, and the evaporated mercury is collected, the mercury recovery efficiency is increased. Further, by further heating the crushed material after mercury evaporation, heavy metals such as zinc are evaporated, and the evaporated heavy metals such as zinc are also collected. [Effect] Therefore, in the present invention, the treatment process is carried out safely and there is no leakage of mercury, zinc, cadmium, lead, etc. to the outside world from the treatment process, and environmental pollution due to heavy metals such as mercury is completely prevented. Not only will it be used, but it will also be turned into a resource. [Example] The method of the present invention will be explained in more detail with reference to an example shown in the drawings. In FIG. 1, the sorted waste dry batteries D are put into a hopper 1, but at this time, the waste dry batteries D in the hopper 1 are oriented in the same direction as shown in FIG. A slide lid 3 that is opened and closed by an air cylinder 2 is arranged at the lower end of the hopper 1, and by opening and closing the slide lid 3 by the air cylinder 2, the waste batteries D in the hopper 1 are sequentially transferred onto the conveyor 4. supplied to The conveyor 4 is provided with guides 41 in the lateral direction, and the waste dry batteries D are fitted one by one between each guide 41 and aligned. A cutter 5 is disposed on the conveyor 4, and the waste batteries D are transferred by the conveyor 4 moving in the direction of the arrow A, and the cutter 5 rotates in the opposite direction of the arrow A by a motor 51, as shown in FIG. disconnected. The waste dry batteries D thus cut are further transferred to the net conveyor 7 by the chute 6.
The net conveyor 7 is also provided with guides 71 so that the cut waste dry batteries D are fitted between the guides 71 and lined up one by one. A crusher 8 is disposed on the net conveyor 7 and is moved up and down by air cylinders 81 and 82 to crush the cut waste dry batteries D on the net conveyor 7. As shown in FIG. 4, a vibrator 72 is inserted into the net conveyor 7, and the net conveyor 7 is vibrated by the vibrator 72 to crush mercury-containing crushed waste batteries D. The material _D1 is sieved by the net conveyor 7 and supplied onto the conveyor 9. The net conveyor 7 is moving in the direction of the arrow B, and the uncrushed materials D ₂ such as iron shells, zinc cans, carbon electrodes, etc. are thrown into the container 10 . The conveyor 9 moves in the direction of arrow C and throws the crushed material D ₁ into the hopper 11 . The crushed material D ₁ charged into the hopper 11 is supplied onto the conveyor 13 in the furnace 12 via the valve 111 . The furnace 12 consists of a first heating furnace 121 heated to 100 to 400°C and a second heating furnace 122 heated to below 950°C _. 1st
It enters a heating furnace 121, where the mercury contained therein is evaporated. The evaporated mercury is stripped in the collection chamber 14 by water from the shower 141 above, cooled to about 40°C, condensed and accumulated at the bottom of the collection chamber 14, and taken out to the outside together with the water. . Further, in order to prevent leakage of mercury vapor from the collection chamber 14, a filling layer 16 of activated carbon, chelate resin, etc. is interposed in the exhaust pipe 15 extended from the collection chamber 14. The crushed material D ₁ from which mercury has been removed in this way enters the second heating furnace 122 where the heavy metals such as zinc contained therein are evaporated, and the evaporated heavy metals such as zinc are collected and condensed in the condenser 17. It is taken out from the bottom of the condenser 17. The crushed material D ₁ from which heavy metals such as zinc have been removed in this manner is mainly composed of manganese dioxide and carbon powder and does not contain harmful substances, so it is taken out of the furnace 12 as is. When we conducted an elution test on these crushed materials, we obtained the following results and were able to safely dispose of them by landfilling.

[Table] For heating the furnace 12, general heating means such as an electric heater, a radiant tube, and a burner are used.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the apparatus used in the method of the present invention, FIG. 2 is a plan view of the hopper 1, FIG. 3 is a partial front view of the cutter, and FIG. 4 is a partial front view of the crusher. In the figure, 8...crusher, 12...furnace, 12
1...First heating furnace, 122...First heating furnace, 14
... Collection chamber, 17 ... Condenser, D ... Waste dry battery, D ₁ ... Crushed material containing mercury, D ₂ ... Uncrushed material.

Claims (1)

[Claims] 1 Mechanically crush a waste mercury-containing dry battery, sieve the crushed material into a crushed outer shell and electrode material, and a mercury-containing crushed material, and heat the mercury-containing crushed material to 100 to 400°C to evaporate the mercury. , further after collecting the mercury
Heating at below 950℃ evaporates heavy metals such as zinc,
A method for treating waste mercury-containing dry batteries, which comprises collecting heavy metals such as zinc.