JP2000127161A - Method for separation wastes plastic by dry specific gravity and shape separation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate chlorine-containing plastics from waste plastics in general and industrial wastes. SOLUTION: The waste plastic is comminuted, and granulated to a semi-fused state by a melt granulating apparatus in a temperature higher than a melting point of an olefin plastic 11 and lower than a melting point of a chlorine- containing plastic 12. Thus, the plastic 11 becomes a shape different from that of the chlorine-containing plastic. Then, the waste plastic of the semi-fused state is introduced into a dry separator 1. In the separator 1, the plastic 11 is separately recovered from a small specific gravity matter discharge side 7 and the plastic 12 is separately recovered from a large specific gravity matter discharge side 8 according to a specific gravity difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the separation of waste plastics in general and industrial wastes, and more particularly to a method for separating chlorine-containing plastics from waste plastics.

[0002]

2. Description of the Related Art Plastic wastes in general and industrial wastes are incinerated in the treatment of the wastes.
C), polyvinylidene chloride (PVDC), etc.). Toxic gas is discharged. Also, when blowing into a blast furnace, the allowable content of chlorine-containing plastic must be 1% or less. Cannot be used. In landfill, a large land area is required due to the large floor area ratio.

[0003] As a method for separating mixed waste plastics,
There are known a wet separation method such as a sink float, a liquid cyclone, a wet vertical separation device and a centrifugal separation device, and a dry separation method using absorption of near infrared rays or X-rays. In the wet separation method, the specific gravity of polyethylene (P
It is possible to separate E) or polypropylene (PP) from polystyrene (PS), PVC, paper or the like, which has a higher specific gravity than water, but it is impossible to separate PVC from paper, which has a higher specific gravity than water, and paper. (In order to separate PS by flotation, a heavy liquid having a specific gravity of about 1.2 must be used). For this reason, PVC and paper are currently landfilled. Furthermore, since a specific gravity liquid such as water is used for wet separation, wastewater treatment is indispensable, and drying of the separated plastic is required.

[0004] On the other hand, in the case of dry separation, it is difficult to align film-based plastics, and the throughput is low. In the case of wind separation and dry separation such as a vibrating sieve, it is possible to separate materials having a large difference in specific gravity, such as plastic and metal, but the same plastics, PE and PV, can be used.
It is difficult to separate materials having close specific gravities such as C.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to separate waste plastics having the above-mentioned problems, particularly to remove chlorine-containing plastics contained in general and industrial wastes by the difference in specific gravity and shape. It is to provide a method for dry separation from other plastics.

[0006]

According to the first aspect of the present invention,
The waste plastic is granulated to a semi-molten state using a predetermined melting temperature by a melt granulator, and then a vibrating sieve that can vibrate substantially horizontally in a predetermined vibrating direction, and a rising air flow from the lower surface of the vibrating sieve Using a dry specific gravity shape separation device having an injecting means for injecting the vibrating sieve and a plurality of baffles arranged on the vibrating sieve in substantially the same direction as the vibrating direction and in parallel with each other. Tilting in the direction and also inclining even in the horizontal direction orthogonal to the vibration direction, vibrating the vibrating sieve in the predetermined vibration direction, and injecting the rising air flow by the injection means. Thus, the semi-molten granules are separated into heavy specific gravity waste plastic and light specific specific gravity waste plastic by the dry specific gravity separator.

[0007] The crushed waste plastic is made into a semi-molten state by using a melting granulator at a temperature of about 160 ° C. Next, the waste plastic in the semi-molten state is separated into a chlorine-containing plastic and an olefin-based plastic by a dry separator. Alternatively, after the components are disintegrated by some method, they are brought into a semi-molten state by a melt granulation device. Next, the mixture is separated by a dry separator.

An olefin plastic represented by polyethylene (PE) or polypropylene (PP) has a melting point of 107 to 160 ° C.
A chlorine-containing plastic represented by VC) has a melting point of 220 ° C., which is higher than that of an olefin-based plastic. Therefore, these mixtures are melt-granulated using a temperature higher than the melting point of the olefin-based plastic to less than the melting point of the chlorine-containing plastic. When granulated by the apparatus, the olefin-based plastic having a low melting point melts first. For this reason, the olefin-based plastic has a distinctly different shape compared to the chlorine-containing plastic.

[0009] The chlorine-containing plastic can be separated from other plastics by separating the waste plastics crushed by the melt granulator at a temperature of about 160 ° C and semi-molten by a dry separator. Further, the melt granulation apparatus and the dry separation apparatus are not particularly limited as long as they are of any known type.

For example, as a dry separator, a vibrating sieve and an ascending air flow are combined as shown in FIG. 1 according to a first embodiment described later, and a plurality of baffles are provided on the vibrating sieve. A dry separator in which the vibrating sieve is appropriately inclined in the vibration direction and the transverse direction of the vibration direction can be used.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. The crushed waste plastic is brought into a semi-molten state by a melt granulator at a temperature of about 160 ° C. Next, the waste plastic in the semi-molten state is separated into a chlorine-containing plastic and an olefin-based plastic by a dry separator.

FIG. 1 is a perspective view showing an outline of a dry separation apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view illustrating a structure, and FIG. 3 is a perspective view illustrating a separation state of waste plastic. It is. Air table type separation device 1 is shown in FIGS.
As shown in FIG. 1, a bottom plate (vibrating sieve) 2, two side plates 3 provided on both sides of the bottom plate 2, and a plurality of side plates 3 provided on the bottom plate 2 in parallel with each other across the side plates 3 In this case, seven baffles (ruffles) 4 are provided. Bottom plate 2
Has a large number of net-like or suitably sized uniform holes for flowing an appropriate amount of airflow from the bottom. The baffle 4
Several mm to several c depending on the size of the plastic to be separated
m (about 1 to 10 times the size of the plastic). The bottom plate 2 has an inclination angle of 1 as shown in FIG.
(Symbol 5) side slope and inclination angle 2 (symbol 6)
It has an end slope and is inclined. The bottom plate 2 vibrates in a vibration direction 9 in the lateral direction (the direction of the side plate). The bottom plate 2 injects the upward air flow 10 upward from the injection holes on the lower surface. When the bottom plate 2 vibrates in the vibration direction 9 and an appropriate air flow flows upward from the lower surface of the bottom plate 2 into the semi-molten mixed plastic 13, the waste plastic on the bottom plate 2 is caused to have a specific gravity difference. The chlorine-containing plastic 12 is separated and recovered from the light specific substance discharge side 8 and from the heavy specific substance discharge side 8.

[0013]

Next, the present invention will be described with reference to embodiments.
About 8 PVC and PVDC in general and industrial waste
% Mixed plastic is crushed, and then the crushed waste plastic is melted at about 160 ° C.
A semi-molten state was obtained using this temperature. Next, the chlorine-containing plastic was separated from the waste plastic in the semi-molten state using a dry separator. As a result, it was possible to obtain a plastic having a content of PVC and PVDC of 0.4% or less and a content of not more than an allowable content as a raw material for blowing a blast furnace or the like.

[0014]

As described above, according to the present invention, the following useful effects can be obtained. (1) By making waste plastic in general or industrial waste into a semi-molten state, it is possible to separate chlorine-containing plastics with high efficiency by a dry separator, and to use plastics with a content below the allowable content as raw materials for blast furnace blowing etc. Can be obtained. (2) The amount of waste landfilled can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a dry separation device according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating the structure of the dry separation device according to the embodiment of the present invention.

FIG. 3 is a perspective view illustrating a state of separation of waste plastic according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air table type separation apparatus 2 Bottom plate (vibrating sieve) 3 Side plate 4 Baffle plate (ruffle) 5 Incline angle 1 6 Incline angle 2 7 Light specific gravity discharge side 8 Heavy specific gravity discharge side 9 Vibration direction 10 Ascending air flow 11 Olefin Plastics 12 Chlorine-containing plastics

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[Procedure amendment]

[Submission date] December 8, 1998 (1998.12.
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Iwa ▲ saki ▼ Toshihiko 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. (Reference) 4D004 AA07 AA08 AA46 AB06 BA03 CA04 CA08 CA14 CA29 4D021 FA09 FA17 FA18 GA08 GA20 GA23 HA10 4F301 AA12 AA16 AD02 BA21 BD01 BD05 BD42 BE15 BF09 BF11 BF15

Claims (1)

[Claims] 1. A method for separating a waste plastic into a dry specific gravity shape, wherein the waste plastic is granulated to a semi-molten state at a predetermined melting temperature by a melt granulation apparatus.