JPS595422B2 - Method for removing iron from waste tires, etc. - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for processing waste tires.

BACKGROUND ART Generally known methods for processing waste tires include pulverizing the waste tires to recover rubber powder, and using the rubber powder as a raw material for products such as rubber mats or desulfurizing raw rubber.

As a specific method, a method as shown in FIG. 1 has conventionally been adopted.

That is, when processing waste tires, the iron bead wire portion is removed in advance in the bead removal process, and then sent to a crusher such as a cracker for coarse crushing (coarse crushing), and the crushed product is crushed. The particles are classified by particle size using a sieving device, coarse particles are returned to the crusher again to be coarsely crushed, and those with a predetermined particle size or less are sequentially subjected to a fiber removal process to remove the fiber content in the crushed material,
After that, it is finely ground using a crusher such as a grinding roll (
(finely pulverized) and extracted as rubber powder.

In such a case, in the conventional crusher and fine crusher, if iron is mixed in, there are various disadvantages such as damage to the crusher and fine crusher or a significant shortening of the machine life.

Therefore, in the conventional method described above, it is necessary to remove the iron content by pre-picking, and the target is limited to textile cord tires that do not contain iron other than the bead wire that can be removed by pre-picking in this way.

However, in recent years, as tire performance has improved, the prevalence of steel-cord tires that use steel not only for the bead wire but also for the cord has increased, and in the case of such tires, the steel cord must be removed in advance. That is almost impossible.

Therefore, when such steel cord tires are processed using the conventional method described above, a large amount of iron such as steel cords is sent to a cracker. In addition, even if the coarse crusher is used to coarsely crush the particles, the purpose of this crusher is to reduce the particle size, and the ability to dissociate rubber from iron such as steel cord is low. The crushed material contains a large amount of undissociated particles such as rubber and steel cord, so if this crushed material is fed to the crusher,
The life of the shredder will also be significantly reduced.

By the way, after the above-mentioned crushing, it is possible to remove the iron content using a magnetic separator, but since the ability of the coarse crusher to dissociate the rubber and iron content is low, only a small amount of the iron content can be removed.
A large amount of undissociated particles flows into the pulverizer, and it is difficult to reduce the load on the pulverizer.

In order to eliminate this drawback, if the magnetic force of the magnetic separator is strengthened to remove the undissociated particles from the system, the recovery rate of rubber becomes extremely poor.

For this reason, conventional technology has not been able to efficiently dispose of steel cord tires, and they have been left unchecked, leading to a pollution problem, and an early solution to this problem has been desired.

In view of these points, the present invention efficiently removes iron in the treatment process even if it contains iron, such as steel cord tires, and recovers rubber powder of the same quality as textile tires. We are trying to provide a way to obtain it.

The present invention involves crushing waste tires that contain iron such as steel cord tires using a crusher, and crushing them into pieces in which rubber particles that do not contain iron, undissociated particles of rubber and iron, and iron such as steel cords are mixed. material, and place the crushed material in a magnetically weak 1
The material is sequentially supplied to a secondary magnetic separator and a secondary magnetic separator with strong magnetic force, and the primary magnetic separator adsorbs only the iron content such as steel cords in the crushed material and discharges it out of the system, passing through the primary magnetic separator. A mixture of iron-free rubber particles and undissociated villages of rubber and iron is sorted by a secondary magnetic separator, and the undissociated villages of rubber and iron in the mixture are adsorbed and taken out. The particles are returned to the primary magnetic separator through a decomposer installed separately from the crusher, and during the reflux, the undissociated particles are sheared and crushed by the decomposer to remove iron such as steel cords and rubber. By dissociating the iron into grains and combining the dissociated mixture with the crushed material supplied from the crusher and performing the above sorting continuously, only the iron content such as steel cords is discharged from the system by the primary magnetic separator. This is a waste tire processing method characterized by sending out iron-free rubber particles from a magnetic secondary magnetic separator and supplying the iron-free rubber particles to a crusher to crush them.

Embodiments of the present invention will be described below with reference to FIG. 2 and subsequent figures.

First, the waste tires to be processed are crushed using a crusher.

At this time, as a crusher, use a rotary shearing type crusher, etc., which does not deteriorate performance even if iron content such as bead wire or steel cord is mixed in, and also reduce the crushed particle size as much as possible to increase the efficiency of the next process. is preferable.

Next, the crushed material crushed by the crusher is sent to a primary magnetic separator with relatively weak magnetic force.

At this time, the crushed materials are rubber particles A that do not contain iron (but do contain fiber) such as bead wires and steel cords, undissociated rubber and iron particles B, and 100 pieces of rubber particles that are free of bead wires and steel cords. There are three types of iron content C1 with % purity, and this primary magnetic separator specifically adsorbs and removes only the iron content C from among these crushed materials A-C.

As this primary magnetic separator, for example, a hanging magnetic separator or the like is used, and by adjusting its magnetic force weakly, only the iron content in C is adsorbed and separated from the other crushed materials A and B. becomes possible.

In this case, it is possible that some of the undissociated particles of rubber, etc. and iron will be adsorbed, but since the magnetic force of this primary magnetic separator is weakened, even if undissociated particles of rubber and iron are adsorbed, However, the amount of rubber, etc. attached to the iron content is extremely small, and therefore does not significantly affect the subsequent recovery rate of rubber powder.

After that, the remaining crushed materials that were not adsorbed and removed by the primary magnetic separator, that is, rubber particles A that do not contain iron and undissociated particles B of rubber and iron, are sent to a secondary magnetic separator with a strong magnetic force. sort,
Separate both A and B and take them out individually.

At this time, a magnetic separator similar to the above-mentioned primary magnetic separator is used as the secondary magnetic separator, but by making the magnetic force stronger than that of the primary magnetic separator, undissociated particles containing even a small amount of iron can be removed. It can be taken out by adsorption and separation, and therefore rubber particles A containing no iron can be obtained as the remainder.

The rubber particles A obtained in this way are then sent to a crusher or the like, where they are passed through a process similar to the conventional process shown in FIG. 1 to finally obtain rubber powder of a predetermined particle size.

Note that when the above-mentioned secondary magnetic separator adsorbs and separates undissociated fiB from rubber and iron, adsorption leakage may occur, but since the magnetic force of the secondary magnetic separator is made strong, even if adsorption leakage occurs. Even if it occurs, it is very small, and therefore,
Even if the rubber particles are sent to the next pulverizing process, the iron content contained in the rubber particles is extremely small, and there is no risk of adversely affecting the pulverizer or the like.

The undissociated particles adsorbed and separated by magnetic force and the above-mentioned secondary magnetic separator are
The iron is sent to a decomposer to separate iron and its deposits.

At this time, the purpose of the decomposer is not to reduce the size of the particles; in short, the purpose of the decomposer is to loosen the iron and rubber by using shear crushing force, so a well-known crusher is used as the decomposer. Even if one uses one, it is possible to adopt one with a structure that is not easily affected by wear.

In this way, after the iron content and its deposits are dissociated by the decomposer, they are sent to the primary magnetic separator again, and then passed through the primary and secondary magnetic separators in the same manner as above. While the secondary magnetic separator successively adsorbs and separates only the iron content, the rubber particles that do not contain iron are sequentially sent out from the secondary magnetic separator and sent to the next crusher etc. for pulverization, and undergoes the fiber removal process. After that, fibers are removed, and rubber powder of a predetermined particle size is finally extracted.

In the above process, when the rubber particles and iron content dissociated by the decomposer are fed again to the primary magnetic separator, new crushed pieces are also fed from the crusher to the primary magnetic separator, so this processing system When operations are stable at , the following relationship holds true.

That is, Diamond processing amount (crusher processing amount): Wi iron content taken out by the primary magnetic separator: Ws iron content sent out from the secondary magnetic separator: W.

If the amount recirculated via the decomposer is: WR, then Wi = Wo + Ws, and the throughput of the primary magnetic separator: Wi + VVR The throughput of the secondary magnetic separator: Wi + WR - the throughput of the Ws decomposer
:WR Processing amount of crushing process :W.

becomes.

Therefore, by selecting equipment that satisfies the above conditions, rubber powder and iron can be efficiently separated and extracted.

Next, an experimental example of the method of the present invention will be explained with reference to FIGS. 3 to 5.

Experimental Example Equipment A rotary shearing type crusher (nominally 30φ or less) was used as the crusher.

As the primary magnetic separator, as shown in Fig. 4, a belt conveyor 2 for iron separation using a magnetic pulley 2a in an underfeed manner is installed near the outlet of the belt conveyor 1 that conveys the crushed material sent out from the crusher. The magnetic pulleys 2a and the crushed materials are provided facing each other, and the magnetic force can be adjusted by appropriately adjusting the distance between the magnetic pulley 2a and the crushed materials, so that iron with a low mixing rate of rubber and other crushed materials can be separated and taken out.

As a secondary magnetic separator, as shown in Fig. 5, a magnetic pulley 3a is used in an overfeed manner at the delivery end of the belt conveyor 3, and the crushed material sent out from the primary magnetic separator is separated into rubber containing even a small amount of iron. It is now possible to separate and extract undissociated particles of iron and rubber particles that do not contain iron.

A single-rotor rotary crusher was used as the decomposer.

Material samples used: Steel cord tires for Nidrak buses (iron content: approx. 20% by weight) Samples: Steel cord tires for passenger cars (iron content: approx. 8% by weight) Experimental method The test is carried out using a formula, the weight is measured each time, and 100% of the amount goes out of the system.
Next time, new material was replenished in an amount corresponding to the purity iron content Ws1 and the iron-free rubber content WR2, and the test was repeated.

In addition, in FIGS. 3 to 5 and Tables 1 and 2 described later, W: Tire fragments crushed by a crusher (nominal 30
φ or less) Wsl: Iron content with a purity of 100% WR1: A mixture of rubber content that does not contain iron and rubber content and undissociated rubber iron content WS2: Undissociated rubber iron content (reflux content) WR2: Contains no iron content It shows the rubber content.

Experimental result The experimental results for Sample I are shown in Table 1.

From Table 1 above, it can be seen that from the third time onwards, the balance becomes extremely stable.

The rubber recovered through this process is 60% of the tire processing amount.
Before and after.

The remaining 40 or so pieces were disposed of as iron.

In such a case, in the conventional non-batch method, only the rubber fraction WR2 that does not contain iron, which is extracted in the first step, becomes the total recovered rubber fraction, and the rest is the iron fraction (actually, the rubber fraction WR2 contains a large amount of undissolved iron). However, the recovery rate for the rubber content is 63%, as is clear from Table 1 above.
/177.8=35.4%.

Therefore, according to the method of the present invention, since the recovery rate of the rubber component is around 60% as described above, it can be said that the recovery rate of the rubber component can be increased compared to the conventional method.

The experimental results for sample ① are shown in Table 2.

In this case, it can be seen that from the 5th time onwards, the balance will be much lower.

The amount of rubber to be recovered is approximately 80%.

In addition, in the conventional non-batch method, only the iron-free rubber fraction WR2 extracted in the first step is the total rubber fraction recovered.
Since the remaining undissociated component Ws2 from the rubber is discarded out of the system together with the iron component Ws1, the recovery rate of the rubber component is calculated as above and becomes 25.1159.5=42.3%.

Therefore, according to the method of the present invention, even in the case of sample ①, the above sample I
As in the case of , it can be said that the recovery rate of the rubber component can be dramatically increased compared to the conventional method.

As explained above, when processing waste tires according to the present invention, there is no need to remove the bead wire part as in the conventional method, and even waste tires containing a large amount of iron such as steel cord tires can be left as they are. Since N processing can be performed, work can be streamlined.

Moreover, among the crushed materials crushed by the crusher, only the iron content such as bead wires and steel cords is discharged to the outside of the yarn by one magnetic flux separator, and only the rubber powder is sent out by two magnetic flux separators to be supplied to the crusher and crushed. As a result, the load on the crusher can be greatly reduced and the life of the machine can be improved. In addition, undissociated rubber and iron particles are taken out to the reflux side by two magnetic flux separators and refluxed to one magnetic flux separator. During reflux, it is dissociated into rubber powder and iron by a decomposer, and by repeating this several times, the undissociated particles can be almost completely dissociated into rubber powder and iron, which can then be individually sorted. Therefore, the iron content can be efficiently separated and removed without reducing the recovery rate of the rubber content.

In the conventional treatment method, where a magnetic separator is simply installed to remove iron, steel cord tires often have an intermediate state of undissociated rubber and iron, so the iron removal rate is low. If the rubber content is increased, the undissociated particles of the rubber and iron will be mixed into the iron side, and the amount of rubber content on the iron side will become very large, resulting in an extremely low recovery rate of the rubber content. However, in the present invention, Since there is no direct relationship between iron removal rate and rubber recovery rate, operating conditions that satisfy both conditions can be obtained.

[Brief explanation of the drawing]

Figure 1 is a process explanatory diagram showing the conventional tire processing process;
The figure is a process explanatory diagram showing the tire treatment process according to the present invention, FIG. 3 is a process explanatory diagram based on an experimental example of the present invention, and FIG.
The figure is a schematic front view showing an example of the 1 magnetic flux sorter, and Figure 5 is a 2
FIG. 2 is a schematic front view showing an example of a magnetic flux sorting machine. 1...1 Belt conveyor for transporting crushed materials of the magnetic separator, 2... Belt conveyor for iron separation, 2a
...Same magnetic pulley, 3...2
Belt conveyor of magnetic feed sorter, 3a... Same magnetic pulley.

Claims (1)

[Claims] 1. A waste tire containing iron such as a steel cord tire is crushed as is using a crusher to produce a crushed product containing a mixture of iron-free rubber particles, undissociated rubber and iron, and iron such as steel cord. The crushed material is sequentially supplied to a primary magnetic separator with a weak magnetic force and a secondary magnetic separator with a strong magnetic force, and the primary magnetic separator only adsorbs iron such as steel cords in the crushed material and discharges it out of the system. Then, a mixture of iron-free rubber particles that have passed through the first magnetic separator and undissociated villages of rubber and iron is sorted by a secondary magnetic separator to remove undissociated villages of rubber and iron in the mixture. At the same time as being adsorbed and taken out, the undissociated villages are refluxed to the primary magnetic separator through a decomposer provided separately from the crusher, and during the reflux, the undissociated villages are sheared and crushed by the decomposer. , by dissociating the iron content of the steel cord etc. and rubber particles, and combining the dissociated mixture with the crushed material supplied from the crusher to continuously perform the above-mentioned sorting, 1.
The secondary magnetic separator discharges only iron from steel cords, etc., out of the system, while the secondary magnetic separator sends out rubber particles that do not contain iron, and these iron-free rubber particles are fed to a crusher and crushed. A waste tire processing method characterized by: