Conventionally, two different methods have been used for the treatment of cable material, depending on the cable material.

For the treatment of so-called dry cables, a method has been successfully used, in which the cable material is crushed, granulated and sieved, whereby the mechan¬ ical treatment results in separation of the metal and non-metal materials of the cable material from each other. These dry cables, such as electric cables or the like, comprise an electroconductive core material which is covered by a dry, insulating casing material. In the casing material, a rubber or plastic casing or the like can be used as the insulating material; the cable can thus also comprise a powderized or solid mass, such as textile fibres or the like.

Previously, a method based on melting or combusting has been primarily used for the treatment of so-called jelly-filled cables. Thus, the cable material is e.g. first preheated in a heating apparatus, such as an oven, whereby the casing, insulating and filling materials covering the metal core material of the cable melt or burn, and the core material remaining

solid can be removed from the heating apparatus. After this, an afterburning apparatus with a very high temperature is generally used for securing the burn-out of non-metal materials, such as plastics, rubbers or the like. In this connection, the term jelly-filled cables is used to denote to cables in which a viscous, fat-, oil-, wax-based or the like filling material in a fluid or solid state, such as an insulator, impregnant or lubricant, is used as part of the material.

An advantage of the first method is its environmental safety, whereby the method as such causes no direct environmental risks. However, the method is not applicable for the treatment of so-called jelly-filled cables, because the apparatus does not function in connection with these cables due to their viscous filling materials, such as vaselin, bitumen or paraf¬ fin. The filling material induces thus arching of both granulating and sieving apparatuses, in which case the conveyor apparatuses will be clogged or there will be an overflow in the process. These test runs have also not even in the early stages given a sufficiently pure sieving result, due to the con- taminating effect of the filling material.

The second method presented comprises both direct and indirect environmental risks due to the combustion of cables. Depending on the plastic materials used in the cables, the method may also cause actual damage to the environment in the form of smoke and smell. In addition, there are special regulations for certain plastics, whereby their combustion is possible at appropriate refuse incineration plants only. One such particularly harmful substance is PVC. Therefore, using a method based on combustion, the cable material to be burnt must be sorted out according to burnabili- ty, whereby problem wastes, such as cables containing

, mus e e vere o e appropr a e p an s. n practice, however, this sorting is not possible without a chemical analysis of the cable material to be treated. Thus in practice, when a method based on combustion is used, the quality of all burnable material is never fully checked out, whereby the risk of the development of so-called super-poisons is always present in connection with the combustion. For minimizing the security risks, the application of the method requires continuous control of such processes as well as assay of discharges at certain intervals.

Consequently, the methods currently in use do not make it possible to apply the treatment of cable materials or the like in a manner that is both tech¬ nically and economically advantageous and gives good results by environmentally safe means.

It is an aim of the method according to the present invention - to attain a decisive improvement to the drawbacks presented above and thus to raise substan¬ tially the level of prior art in the field. For achieving this aim, the method according to the invention is primarily characterized in that par- ticularly for the treatment of a cable material or the like, in which a viscous, fat-, oil-, wax-based or the like filling material in a fluid or solid state, such as an insulator, impregnant, lubricant and/or the like is used as part of the material, the said filling material is absorbed during the treatment into a medium, whereby the treatment results in separation of the filling material of the cable material or the like absorbed into the medium.

The most important advantages of the method according to the invention are the simplicity and reliability of the principle and of the apparatus and process applying the method. Further, the method and the

apparatus according to the invention are also ad¬ vantageous in comparison with the methods currently in use from the environmental aspect and the aspect of occupational safety. The apparatus for applying the method according to the invention or the process in the same do not induce any risks to the environment nor to occupational safety which would be directly or indirectly caused e.g. by the combustion process in methods based on combustion. Particularly compared with combustion units, the apparatus applied in the method according to the invention is also substantially less expensive with respect to total costs, thanks to the lesser internal power consumption required in the process.

Advantageous embodiments of the method according to the invention are presented in other dependent claims.

In the following description, the invention is il- lustrated- in detail with reference to the appended drawings, in which

Fig. la shows a cross-sectional view of a so- called dry cable,

Fig. lb shows a cross-sectional view of a so- called jelly-filled cable, and

Fig. 2 shows a schematic view of the process in the apparatus for applying the method according to the principle.

The method according to the invention is applied for the treatment of a cable material 1 or the like, whereby the cable material 1 or the like is crushed A, granulated B and sieved C. The treatment results in the separation of at least part of the submaterials contained in the cable material 1 or the like, such

as the casing material la based on plastics, rubber, wood or the like, and the core material lb based on metal. For treatment of a so-called jelly-filled cable or the like according to the invention, part of the material containing a viscous filling material lc in a fluid or solid state, the said filling material lc is absorbed during the processing into a medium 2, whereby the treatment results in the separation of the filling material lc of the cable material 1 or the like absorbed into the said medium 2.

Figure la shows a cross-sectional view of a so-called dry cable as an example. The cable is thus formed of metal conduits lb (e.g. copper, aluminum, brass), plastic casings la covering them, and of mass Id placed between the plastic casings la of the con¬ duits lb and the outer casing of the cable, such as textile fibres or the like.

Figure lb shows a so-called jelly-filled cable, in which conduits lb are covered e.g. by an impregnated paper layer lp covered by a plastic casing la. Mass Id is placed between the outer casing of the cable and the plastic casings la of the conduits lb. As an in- sulator and impregnants in the paper layers lp covering the conduits lb, filling material lc based on fat, oil, wax or the like is used, such as bitumen, vaselin or paraffin. Also the mass Id is usually impregnated with a corresponding substance.

According to the process shown in Fig. 2, the filling material lc is absorbed into the medium 2 by bringing the medium 2 and the cable material 1 into contact with each other at the crushing stage A, whereby the absorption of the filling material lc into the medium 2 takes place during the treatment as the cable mate¬ rial 1 and the medium 2 are mixed with each other.

At the crushing stage A, the medium 2 is supplied by the supply equipment 3, such as a pneumatic, mechanic or corresponding conveyor, to the crushing equipment 4, formed in the presented embodiment by one crusher, and to the intermediate depot 5 placed after the crushing equipment 4. The intermediate depot 5 is intended for balancing the mass flow of the crushed cable material 1 passing from the crushing stage A to the granulation stage B. In connection with the crushing stage A, ferrous substances lFe are removed from the cable material 1 by means of a metal eliminat¬ ing means 6, such as an electromagnetic actuator or the like, placed between the crushing equipment 4 and the intermediate depot 5. The filling material lc absorbed into the medium 2 is removed at the sieving stage C by separating equipment 7 which in the present embodiment is a wind sieve based on the differences in the specific weights of the partial materials of the cable material 1 to be treated.

In the test runs of the process according to the method, the medium 2 was primarily horticultural peat, which has a specific weight of ca. 100 kg/m ³ , humidity of ca. 20%, a mineral soil content in dry substance of ca. 3%, and a particle size (dimension in one direction) of ca. 8 mm, with a ca. 50% content of particles with a size smaller than 1 mm.

It is naturally possible to use a variety of substances as the vegetable medium; results from continuous development indicate that husk from barley can be used as such or in a suitable mixture. Thus the specific weight of the medium is 50-200 kg/m ³ , the humidity is lower than 30%, and the particle size (dimension in one direction) is 0.1 to 20 mm, and the content of particles smaller than 5 mm in size is 30 to 70%.

In the process shown in Fig. 2, the cable material 1 is transferred at the crushing stage A by a lifting apparatus 9 to the crusher 4. The crusher 4 is supplied with medium 2 from the medium depot 10 by the first supply means 3a. The cable material 1 crushed in the crusher 4 as well as the medium 2 supplied to the crusher to mix with it are transferred by the first conveyor 11 to the intermediate depot 5. The electro¬ magnetic actuator 6 arranged in connection with the first conveyor 11 removes ferrous particles lFe from the crushed material flow 1, 2 carried on the con¬ veyor 11 to a container 12. Medium 2 is supplied by a second supply means 3b to the intermediate depot 5. Good mixing is achieved at the intermediate depot 5; also the volume of the crushed material flow 1, 2 passing to the granulation stage B is balanced at the intermediate depot 5.

At the granulation stage B, the crushed material flow 1, 2 -carried from the intermediate depot 5 by a second conveyor 13a is supplied to successive granula- tors 14. The number of granulators 14 used in the process can be varied according to the quality of the cable material 1 to be treated.

At the sieving stage C, the granulated material flow 1, 2 is supplied to a first separator 15a functioning on the principle of a shaking sieve, a wind sieve 7 being arranged to function in connection with the same. Upon passing through the sieve surface, the air flow carries away the part of the granulated material l, 2 with the lowest specific weight, i.e. the medium, such as the horticultural peat 2 and the viscous filling material absorbed in it, such as fat lc and part of the mass Id, which is conveyed to a cyclon 16. The first separator 15a is used for separating the core material with the highest specific weight, such as copper lb, to a container 17, and the casing material

with a lower specific weight, such as plastic la and part of the mass Id, to further processing. The material flow carried to further processing may also contain particles of the core material lb, which in the presented embodiment are separated in a second separator 15b. The fine screening in the second separator 15b is used for final separation of the casing material la and part of the mass Id from the core material lb. The casing material la can be carried e.g. by a conveyor to suitable further processing. Consequently, pure copper lb, fatty horticultural peat 2, lc. Id and casing material la and mass Id with specific weights between those of the above- mentioned are given as a result of the process applying the method.

The method according to the invention can thus be used for separation of the core material lb from the cable material 1 for environmentally fully safe recycling.- The fatty horticultural peat removed from the cyclon 16 is also e.g. decomposable as such, and the casing material la from the second separator 15b can be reutilized in one form or another.

It is clear that the invention is not restricted to the embodiment presented above but it can be modified within the basic idea even to a great extent because of the wide total range of the process for applying the method. The apparatus for applying the method according to the invention can comprise devices which vary from those presented in number and principles of function. Consequently, constructions related to the supply and discharge of the medium can be made in a number of different ways, whereby the medium can be mixed e.g. with a fluid before or in connection with mixing with the cable material.