HU181347B - Process and apparatus for separating special synthetic materials from waste materials produced with discovering old accumulators - Google Patents

Abstract

Low density plastics is separated from waste material obtained when dressing scrap accumulators by a sink-float process. The floating material may comprise polyethylene and polypropylene, and the sinking material may comprise hard rubber, polystyrene, PVC, glass and lead components. The material which sinks is tumbled by a rotating conveyor 12 while it is being transported to an outlet opening 18 in the bottom of the separating vessel 11. <IMAGE>

Description

The present invention relates to a process for the recovery of special plastics, in particular polyethylene and polypropylene, from waste material resulting from the digestion of old batteries. The invention also relates to an apparatus for carrying out the process. 5

In the recycling of old batteries, lead-containing components such as metallic lead, lead oxide and lead sulphate are recovered as valuable products, while the material of the battery casing and the inside of the batteries are waste products which have to be stored (1 224 935 Federal Publications Document). The battery housing is often made of hard rubber (commonly known as "ebonite") or polystyrene or polyethylene or polypropylene. Separator sheets are made essentially of PVC (polyvinyl chloride), and separators are also made of hardboard.

In addition to these materials, there are pieces of positive plates of certain batteries in the waste products from the processing of battery waste, which are made of glass fibers or plastic fibers and partially filled with lead oxide. The polyethylene (PE) and polypropylene (PP), low weight species ^{of 25,} toughness and certified resistance against sulfuric acid as a result of these two materials are increasingly used as the material of the battery housing. These PE and PP plastics belong to the chemical group of polyolefins and are manufactured from petroleum. As a result of the rise in oil prices, the recovery of PE and PP from waste products has increased significantly.

Accordingly, it is an object of the present invention to provide a process and apparatus for recovering the waste material that has been lost in the processing of old batteries, in particular the two valuable PE and PP plastics, in an economical way.

This problem is solved by the process of the kind mentioned in the introduction, according to the invention, by using a specific gravity sedimentation method for a floating material consisting of polyethylene (PE) and polypropylene (PP) and hard rubber, polystyrene, PVC, glass, fiberglass, lead materials. , and separating it into a pellet of similar material.

Since the specific gravity of the PE and PP plastics varies between 0.91 and 9.96 g / cm ³ , depending on the method of preparation, they can be obtained as a floating product using a water-settling process with a weight of 1.0 g / cm ³ . while polystyrene having a specific gravity of 1.05 g / cm, hard rubber (ebonite) having a specific gravity of about 1.39-1.40 g / cm ³ , and separators made of PVC having a specific gravity of about l , 30kg / cm ³ as sedimented material sinks to the bottom The sedimented material in which even part of PE and PP ³⁰ is trapped and closed, while in particular the fibrous webbing prevents the floating of lighter material - the A flotation-settling separation of the liquid separating medium, such as water and tumbled continuously simultaneously transmitted by ⁵ to the pelleted material entrained by PE and PP materials they become free and can rise again to the surface, and it is also possible to expose the portions of the lead sealed and trapped in the battery housing material and separators. ¹⁰ In this way, the waste shipped can be classified very well.

An apparatus according to the invention for carrying out the method is characterized in that it comprises a chopper unit, wherein the waste material is comminuted ¹⁵ smaller particle size than 100 mm, and whose discharge opening is connected to a wet classification apparatus and comprises latter fluid reservoir having a conveyor body rotating bottom, the pelleted material for rotating and conveying it to an outlet port ²⁰ , a discharge means is provided in the region of the upper edge of the container for carrying the floated material.

Detailed Description of the Invention The present invention will be described in more detail with reference to the accompanying drawings in which the drawings are described in more detail.

Fig. 1 is a longitudinal sectional view taken along line I-I in Fig. 2, showing the float settler classification apparatus of the present invention as the core of the apparatus for carrying out the process of the present invention.

Figure 2 is a sectional view taken along line II-II of Figure 1, Figure 3 is a sectional view taken along line III-III of Figure 1, and Figure 4 is a flow chart of the process of the invention.

An essential part of the process is the wet screening apparatus 10 shown in FIG. It comprises 11 containers, the bottom of which is cylindrical and extends upwards in cross-section. The cylindrical portion has a shaft 12 on which each blade-shaped conveyor means 13, 14, 15, 16 is disposed offset relative to one another along a thread. The conveying elements 13, 14, 15, 16 are inclined so that the sedimented material 50 submerged in the water level 17 and sinks to the bottom of the container 11 is simultaneously conveyed to the discharge opening 18 at the bottom of the container 11 when the shaft 12 the drive motor 19 rotates it. The outlet 18 for discharging the settled material is connected to the riser 55 by a siphon-like connection 55 connected to the container 11 and located outside the container 11. The riser 20 is provided with a conveyor auger driven by a conveyor, such as a motor 21, for transporting the sedimented material from the bottom upwards to an outlet 6C disposed about the water level 17 in the container 11, which creates an overflow of water 17 material. Thus, when the sedimented material 25 is discharged by the conveyor screw 22, on the one hand, the buoyancy of the liquid column in the riser 65 ² is utilized and, on the other hand, the discharged sediment 25 does not lose much liquid.

The floating material 24 is discharged from the reservoir 11 of the wet grading device 10 by means of a propeller 27 driven by a drive motor 26. In order to guide the PE and PP containing floating material 24 to the impeller 27, a spray device 28 is arranged at water level 17 such that the spray water guides the floating material to the impeller 27. This problem could also be solved by employing a plurality of vane-driven impellers 27 on the water level 17 of the container 11.

Disposed waste material 29, which is formed as a product from the recycling of old batteries, is fed into the hopper 30 of the container 11 located behind the spray device 28. During heavy subsidence, some of the PE and PP, which is enclosed in the settled material, is carried and sinks. By rotating the material at the bottom of the container 11, these entrained portions of PE and PP are released and reintroduced to the water surface.

In order to transfer the sedimented material to the wet screening unit 10 and the subsequent riser pipe 20 without difficulty, and to release the trapped or trapped lead material in the battery housing material and separators, it is necessary that the waste material to be treated is 100 mm. less than 80 mm, preferably less than 80 mm.

Disposed waste material 29 is a mixture of metal particles, various plastics, plastic fibers, glass particles and the like. Shredding this heterogeneous mixture is difficult to accomplish on cutting machines designed for plastics. It turned out that this mixture can be crushed very well in a hammer mill. To make the crushing of plastics better, the crushing must be done wet; the water is then used as a refrigerant to dissipate the heat generated by the comminution and also serves as a slurry-forming medium.

Figure 4 schematically illustrates the process of recovering PE and PP from the waste product 31 produced during the recycling of old batteries. The waste material 31 is conveyed by a conveyor belt 32 to a hammer mill 33. At the same time, water is fed to the hammer mill 33 through the pump 34 and the line 35 shown in barcode. The shredded waste material is passed through a dewatering screen 36 to an intermediate container 37. A scrap belt 38 and a conveyor 39 feed the waste material according to Figures 1-3. 1 to 4, the wetting device 10 shown in more detail therein. The purified PE and PP mixture, which is the floating material 24, and the waste products obtained as the sedimented material 25 are dewatered in a central screen 40. The screen 40 may be provided with a spray device 42 connected to the power line 41.

-2181347

The purified PE and PP mixture is fed to conveyor belt 43 by means of conveyor belt 43 and reduced to a particle size of less than 7 mm. The comminuted product 45 is suitable for example being fed to an extruder to form a plastic granulate from the product.

The waste material from the process of Figure 4 can be further classified by means of a second float settler separation (not shown) using a heavy slurry having a density greater than 1.0. Heavy slurry can be produced, for example, by using magnetite suspended in water or by weight slurry.

The present invention provides essentially the following advantages.

Simple and clean separation of PE and PP materials from waste material, which is produced as a product in the recycling of old batteries. Water is normally used as the separating medium for the screening device.

The float-settling separation will result in max. LOOmm in size. By conveying the sedimented material through a conveyor with inclined conveyor elements, a good recycling of the waste material is possible. Water consumption is low as the water required for the entire process is recirculated through line 47, balancing tank 48 and pump 34. Energy consumption is also low. Industrial water may also be used as a separating medium for the screening process. Both the PE and PP products forming the float material 24 and the waste product as the sediment material 25 can be repeatedly rinsed through the dewatering screen 40. This yields pure PE and PP for further processing and yields a disposable waste product that does not contain soluble lead. The screening device can also be used as a float settler for the screening of higher specific gravity materials by using a heavy slurry having a higher specific gravity so that a higher specific gravity floating material can be recovered while the separating medium is regenerated and recycled.

Claims (6)

Patent claims: A process for the recovery of special plastics, in particular polyethylene and polypropylene, from waste material resulting from the digestion of old batteries, characterized in that the float-deposition process of waste material comprises polyethylene and polypropylene floating material and hard rubber, polystyrene, and separated into a settled material consisting of the like. 2. The method of claim 1, wherein the sedimented material of the waste material is continuously circulated and simultaneously conveyed in a liquid separation medium of the float-settling process. 3. A process according to claim 1 or 2, characterized in that the waste material is comminuted to a particle size of less than 100 mm prior to introduction into the sludge settling process, preferably by using a hammer mill in the wet state. . 4. The process of claim 1, wherein the first waste float settler is separated from the waste material using a water separator, polyethylene and polypropylene as floating material, and from the first float settling bed sedimented material. a second float-settling separation in a heavy slurry having a specific gravity greater than 1, such as 1.50 g / cm ² , and the floating material being hard rubber, polystyrene and PVC. Apparatus for extracting special plastics, in particular polyethylene and polypropylene, from waste products from the digestion of old batteries, characterized in that it comprises a shredder, such as a hammer mill (33), with an outlet opening connected to a wet screening device (10). comprising a rotatable conveyor (12) for recirculating the sedimented material and for transferring it to the delivery port (18), and a delivery port (27) for transferring the floated material (24) to the delivery port in the upper edge region of the liquid container (11). arranged. An embodiment of the device according to claim 5, characterized in that the outlet (18) for the sedimented material at the bottom of the container (11) of the wet screening device (10) is siphonically connected to a riser (20) located outside the wet screening device. a conveyor, such as a conveyor screw (22) or a bucket conveyor, for transferring sedimented material from below to a discharge port (23), while the discharge port (23) is at a height of the liquid level - water level (17) in the container (11) is provided with a suitable overflow.