RU2746836C1 - Method for separating unvulcanized rubber compound from metal cord in scrap / waste rubberized metal cord - Google Patents

Abstract

FIELD: rubber industry.

SUBSTANCE: invention relates to the rubber industry, in particular, to the industrial waste processing industry and to the rubber compound production industry. The essence of the claimed invention lies in the fact that the unvulcanized rubber mixture is separated from the metal cord in rubber products containing a rubberized metal cord, by acting on the rubber product with a water jet under a pressure of 500 to 3000 bar at a flow rate of 15 l / min and more using a reverse osmosis for water purification. The use of a reverse osmosis system for water purification ensures the preservation of the physicomechanical and physicochemical characteristics of the primary raw rubber compound.

EFFECT: increased economic efficiency with a high-quality separation of materials during processing, decreased wear of equipment for processing, decreased energy consumption, increased environmental safety, since the invention provides reduced waste and rejects in the rubber industry, the introduction of a returnable product in the rubber industry.

1 cl, 19 dwg

Description

The invention relates to the rubber industry, in particular, to the industrial waste processing industry and to the rubber compound production industry. The most effectively the proposed method can be used at industrial enterprises producing transport tires, rubber products (RTI), as well as at a local enterprise conducting economic activities through the processing of scrap / waste rubberized metal cord.

The problem of recycling scrap / waste rubberized with unvulcanized rubber compound metal cord has the task of maximizing the efficient use of valuable raw materials from which these products are made. The production of secondary raw materials is an important resource-saving direction in the context of the growing shortage of natural resources and the annual increase in the cost of primary raw materials.

The economic feasibility of processing this type of raw material is due to the fact that it does not lose its properties and can be used both for its intended purpose and in various sectors of the economy. The resulting secondary raw materials successfully replace expensive primary raw materials and do not differ in physical and mechanical (FMP) and physicochemical (FHP) indicators from the accepted standards for the production of rubber compounds.

Various methods of disposal / recycling of scrap / waste rubberized metal cord are known from the prior art.

The simplest method of disposal of scrap / waste rubberized metal cord is incineration.

The disadvantage is that this method is currently recognized as hazardous and harmful to the environment. The negative attitude of the population towards this type of disposal, the fines of the supervisory authorities have reduced this method to almost zero.

In addition, from the prior art of thermal utilization of rubberized metal cord, a processing method is known - pyrolysis (for example, RF patent for utility model No. 46222, IPC В29В 17/00, С10В 53/00, publ. 06/27/2005), which makes it possible to obtain from utilized / recycled rubber rubber soot, as well as a number of liquid and gaseous organic substances that can be used in the chemical industry and power engineering. Pyrolysis is carried out, as a rule, after preliminary destruction and grinding of products. Again, it should be noted that this method is applied to vulcanized scrap / waste rubber goods.

The disadvantage of pyrolysis is, first of all, the fact that its use does not allow solving the problem of processing a significant proportion of the total volume of waste products, in particular, rubberized metal cord, since the volume of consumption of pyrolysis products is limited at a significantly lower level. Also, the disadvantage is the high energy consumption of the process associated with the need to heat the processed products to high temperatures and is more than 1 kWh / kg. In the third stage, vulcanized scrap / waste is utilized / recycled in this way, which in turn does not allow returning the most valuable raw material - unvulcanized rubber compound - to the production cycle.

It is known from the prior art to use cryogenic technology to transfer rubber to an embrittled state by cooling to the glass transition temperature, which allows reducing energy costs for grinding and separating reinforcing elements from the product before mechanical processing of rubber (for example, RF patent for invention No. 2111859, IPC В29В 17 / 00, C08J 11/10, publ. 05/27/1998). This approach is implemented in the processing of rubber goods. It is also worth noting that this method is used for vulcanized scrap / waste rubber goods, which, in turn, does not allow returning the most valuable raw material - unvulcanized rubber mixture - to the production cycle.

The reason is that raw (uncured) rubber, due to its FMP and FHP, does not undergo a cooling process to the point of embrittlement.

The prior art knows the processing of scrap / waste rubberized metal cord by mechanical methods - crushing (crushing equipment), cutting (shredder) and grinding (using rollers) (for example, RF patent for invention No. 2325995, IPC В29В 17/00, publ. 27.12. 2007). This method is used for vulcanized scrap / waste rubber goods, which, in turn, does not allow returning the most valuable raw material - unvulcanized rubber mixture - to the production cycle.

The disadvantage is that the processing of scrap / waste rubberized metal cord and the production of rubber crumb from them by mechanical methods is not used, since the viscosity of raw / uncured rubber does not allow crushing, cutting and grinding the presented material.

Thus, the processing of scrap / waste rubberized metal cord (unvulcanized rubber) and high-quality separation of materials is a complex technical problem. An ecologically and economically satisfactory solution has not yet been found worldwide.

To use the rubber compound in the production of rubberized metal cord in the tire industry, for the production (after vulcanization of the rubber compound) consumer goods or special-purpose products manufactured for various sectors of the economy, it is necessary to fulfill certain technical quality requirements, including, in particular , limitation on the content of volatile components (metal, dust, moisture, chemical impurities, etc.) in the material. For this, it is necessary to ensure the separation of rubber and metal fragments of the reinforcing frame. The viscosity of raw rubber, the absence of a chemical bond with the metal, the properties of rubber in aggressive environments not to lose their original properties were the basis for a deep study of this problem and led to a positive result in solving the problem of obtaining expensive secondary raw materials.

The essence of the claimed invention lies in the fact that the unvulcanized rubber mixture is separated from the metal cord in rubber products with the preservation of FMP and FHP of the primary unvulcanized rubber mixture, by exposing the rubber product to a water jet under pressure from 500 to 3000 bar with a flow rate of 15 l / min and above using a water reverse osmosis system or a similar water purification system, as well as the possibility of heating technical (used to separate the raw rubber compound from the metal cord) water up to 150 ° C.

The technical result is an increase in economic efficiency with high-quality separation of materials during processing, a decrease in the wear of equipment for processing by this method, a decrease in energy consumption, and an increase in environmental safety. The use of the invention ensures the reduction of waste and rejects in the production of the tire and rubber industry, the introduction of a return product into the tire and rubber industry, the introduction of a new product as a masterbatch for various industries producing both consumer goods and specialized products (oil and gas production and processing complex, transport industry , the automotive industry, the aerospace and aircraft industry, etc.).

The invention is illustrated by the following drawings.

FIG. 1 shows a general view of scrap / waste of rubberized metal cord (uncured rubber compound).

FIG. 2 shows the recovered green rubber fragments.

FIG. 3 shows the recovered metal reinforcing elements (threads) of the metal cord.

FIG. 4 shows the division of the input material into metal reinforcements and rubber fragments.

FIG. 5 shows the rubber compound after treatment.

FIG. 6 shows a diagram of a device for separating unvulcanized rubber mixture from a metal cord in scrap / waste, where: 1 - working chamber, 2 - automatic gates for loading incoming raw materials and unloading processed products, 5 - cleaning system, 6 - work table, 8 - pipe flowing water of a water supply system with a water reverse osmosis system, 11 - a control panel for a purification system, 12 - a water tank.

FIG. 7 shows a diagram of a device for separating unvulcanized rubber mixture from a metal cord in scrap / waste, where: 1 - working chamber, 4 - high-pressure apparatus, 7 - circulating water system, 8 - flowing water pipe of the water supply system, 11 - system control panel cleaning, 12 - a tank with water.

FIG. 8 shows a diagram of a device for separating unvulcanized rubber mixture from a metal cord in scrap / waste, where: 1 - working chamber, 4 - high-pressure apparatus, 7 - circulating water system, 8 - flowing water pipe of the water supply system, 9 - reverse osmosis system water, 11 - control panel for the cleaning system.

FIG. 9 shows a diagram of a device for separating an unvulcanized rubber mixture from a metal cord in scrap / waste, where: 1 - working chamber, 2 - automatic gates for loading incoming raw materials and unloading processed products, 4 - high-pressure apparatus, 5 - cleaning system, 6 - work table, 7 - circulating water system, 8 - flowing water pipe of the water supply system, 12 - water tank.

FIG. 10 shows a diagram of a device for separating an unvulcanized rubber mixture from a metal cord in scrap / waste, where: 1 - working chamber, 4 - high pressure apparatus, 5 - cleaning system, 6 - work table, 7 - circulating water system, 8 - flow pipe water supply system, 9 - reverse osmosis water system, 11 - control panel for the purification system, 12 - water tank.

FIG. 11 shows a photograph of a device for separating unvulcanized rubber mixture from a metal cord in scrap / waste, where: 1 - working chamber, 4 - high-pressure apparatus, 5 - cleaning system.

FIG. 12 shows a photograph of a device for separating unvulcanized rubber mixture from metal cord in scrap / waste, where: 2 - automatic gates for loading incoming raw materials and unloading processed products, 3 - ventilation and electric lighting system, 6 - work table.

FIG. 13 shows a photograph of a device for separating an unvulcanized rubber mixture from a metal cord in scrap / waste, where: 7 is a circulating water system, 8 is a water supply system, 9 is a water reverse osmosis system, 10 is a fine water filtration system.

FIG. 14 shows a photograph of a device for separating unvulcanized rubber mixture from metal cord in scrap / waste, where: 11 - control panel of the cleaning system.

FIG. 15 shows a photograph of a working device for separating green rubber compound from metal cord in scrap / waste.

FIG. 16 is a table showing FMP and FHP of unvulcanized rubber mixture obtained as a result of carrying out the method.

The rubberized metal cord (metal cord) contained in a rubber product consists of a brass-plated (brass spraying) carbon wire (metal) and a raw (unvulcanized) rubber compound based on natural rubber in a ratio of 50/50 (Fig. 1). In the process of processing steel cord, it is divided into raw (unvulcanized) rubber mixture and metal.

When implementing the invented method, a water jet is applied to the rubberized metal cord of a rubber product (waste or scrap), due to which the metal is separated from the unvulcanized (raw) rubber mixture without the slightest violations of the FMP and FHP of the crude rubber mixture. FMP and FHP remain at the level of the primary crude rubber compound used for the production of rubberized steel cord. As a result, rubber fragments are obtained - a crude rubber mixture (Fig. 2) and "metal" - metal reinforcing elements (threads) of a metal cord, consisting of brass-plated carbon wire (Fig. 3).

The rubber compound used for rubberizing the steel cord contains natural rubber (rubber content 52%), a modifying system for attachment to metal, as well as adhesion promoters, chemical antioxidants, and a vulcanizing group.

The method uses the effect of water under high pressure, which destroys the bond between rubber and metal in a rubberized steel cord, and the stressed state of the material significantly increases the speed of separation. A moderate amount of energy is spent on the creation and maintenance of the deformed state of the product, and a small amount of physical impact is required to remove the rubber, which provides low energy consumption for processing products by the proposed method, which is less than 1 kWh / kg and can be reduced to optimal parameters. The loads applied to the processed product are significantly less than the loads required to break the bond between rubber and metal in a rubberized steel cord. When processing scrap / waste, no aggressive action is carried out, namely, cutting, tearing or rapid abrasion of rubber. Due to this, equipment for processing scrap / waste in this way wears out significantly less than traditional equipment for mechanical processing. The reinforcing elements are completely separated from the uncured (raw) rubber without contaminating it with their fragments. This makes it possible to obtain pure rubber unvulcanized (raw) chips and rubber-free metal without complex multi-stage schemes for separating rubber from small fragments of reinforcing elements and equipment for removing rubber residues from the metal cord wire and textile yarns. This increases the yield of the finished product and reduces the amount of scrap / production waste.

To achieve the final goal, scrap / waste of rubberized steel cord (scrap / waste of rubber goods) is exposed to a jet of water (industrial water is used up to 60 ° C, with some recommendations, industrial water is used up to 45 ° C (depending on pressure modes)) under high pressure from 500 to 3000 bar with a flow rate from 15 to 250 l / min, as well as above 250 l / min, i.e. with a flow rate of more than 15 liters of water per minute, which leads to a complete separation of the rubber by violating the integrity of the incoming material (plate and asymmetric chips).

When using industrial water, it is recommended to use an industrial reverse osmosis system or a similar system that increases the properties of the supplied water. This system softens industrial water, eliminating excess hardness salts, removing chlorine. The outlet of the reverse osmosis system is pure water that meets the production needs of the equipment used to completely separate the rubber. Also, industrial water after using the reverse osmosis system, as well as another method of filtration from impurities when using the method of complete separation of rubber from the reinforcing element (metal), increases the efficiency of the equipment and has a positive effect on the outgoing material. Third-party volatile substances do not enter the outgoing material, which has a positive effect on the FMP and FHP of the raw rubber mixture, as well as the reinforcing element (metal). FIG. sixteen.

It is also possible to heat industrial water up to 150 ° C, which allows not only to quickly cope with the complete separation of rubber by violating the integrity of the incoming material, but also to degrease and disinfect the surface of the scrap / waste of rubberized steel cord. Moreover, the speed of rubber separation by violating the integrity of the incoming material increases. This effect leads to an increase in the volume of the input material and, accordingly, to an increase in the volume of the finished product (raw rubber compound and metal).

When the resulting rubber fragments are deformed in an aqueous medium, they can be crushed to the required size (for example, from 10 to 400 mm).

FIG. 6-10 show the diagrams and FIG. 11-14 are photographs of a batch device for separating green rubber from scrap metal cord. The device includes a working chamber (1), an automatic gate for loading incoming raw materials and unloading processed products (2), a ventilation and electric lighting system (3), a high-pressure apparatus (4), a cleaning system (5), a work table (6 ), a circulating water system (7), a water supply system (8), a water reverse osmosis system (9), a fine water filtration system (10), a purification system control panel (11), a water tank (12).

In the working chamber (1), incoming raw materials are processed - scrap or waste of rubberized steel cord. The working chamber (1) is equipped with an automatic gate for loading incoming raw materials and unloading processed products (2) and is equipped with a ventilation system and electric lighting (3). The air temperature in the working chamber is maintained at least + 5 ° C and is regulated by the ventilation system.

The method is carried out as follows.

A) Incoming material - scrap or waste of rubberized steel cord in the form of plates or asymmetric pieces is located with rigid fixation on the working table (6). The material is placed on stainless steel grates. The mesh size of the lattice depends on the technical condition of the final product - raw rubber compound.

B) The working chamber (1) is closed.

C) The operator of the high-pressure apparatus (4) starts the equipment, determining the required pressure power, which is from 500 to 3000 bar, and also starts the water supply system after reverse osmosis of water or similar water purification (9).

D) The operator of the cleaning system (5) starts the cleaning system and turns on the ventilation system (3) of the working chamber, checking the temperature regime in the working chamber at the time of starting the system (1).

E) The cleaning system (5), controlled by the operator by means of the remote control (11), moving in 2D / 3D mode at an angle from 0 to 360 degrees (Fig. 15), runs over the entire surface of the working table (6). The incoming material, thanks to the automatic mode of the cleaning system (5) with a set passage limit (from 1 to 60 minutes), is smoothly divided over the entire surface into two fractions: unvulcanized (raw) rubber compound and metal (see Fig. 4).

E) The finished product - unvulcanized (raw) rubber compound and metal - is removed from the surface of the working table (6) mechanically or automatically (for example, the use of mechanical rake grates to extract unvulcanized rubber compound). The metal is removed from the work table (6) using a magnetic separator system included in the cleaning system (5).

G) Ready uncured (raw) rubber mixture in the form of chips or asymmetric pieces is placed in a drying chamber or on drying shelves.

3) Depending on the order of the end consumer, unvulcanized (raw) rubber mixture can go through the process of rolling, refining or calendering, and also go through the process of rubber mixing in a rubber mixer, extruder (see Fig. 5).

As the equipment used in the method for separating the unvulcanized rubber composition from the scrap metal cord, the following is used.

A) Working chamber (1):

- PVC profile,

- double-glazed window single-chamber / double-chamber,

- sandwich panels (for example, 28 mm),

- partition (for example, 3200 × 2959 mm) - 2 pcs. (top, bottom - sandwich panel from 28 mm, middle - single-chamber / double-chamber double-glazed window (for example, 28 mm) (2 glasses))),

- partition (for example, 2500 × 2950 mm) - 1 pc. (top, bottom - sandwich panel from 28 mm, middle - single-chamber / double-chamber double-glazed window (for example, 28 mm) (2 glasses))),

- partition (for example, 3200 × 2950 mm) - 2 pcs. (top, bottom, middle - sandwich panel (for example, 28 mm)),

- partition (for example, 2500 × 2500 × 2950 mm) - 1 pc. (top - sandwich panel (for example, 28 mm)),

- ceiling - (for example, 16 m ² ) (frame - guides for gypsum plasterboard (for example 67 × 28 mm), sandwich panel finish)),

- self-adhesive strip - (for example, 40 running meters).

The parameters of the Working chamber and the materials for its manufacture can be changed in accordance with the requirements, as well as with the volume of processing scrap / waste rubberized steel cord.

B) Ventilation equipment (3): according to their design features, the ventilation systems of car washes are divided into:

- a system that provides an air flow in the amount of 8-10 times air exchange, and

- stretching (output to the outside) in the amount of 10-12 times air exchange.

C) The lighting system of the working chamber (3): the luminous flux power - from 600 to 2000 lumens, the presence of the "flickering" effect is excluded, the uniformity of light scattering, the absence of "blind spots", shaded or dimly lit areas, preferably additional portable lighting light calibration close to natural, for the spectral sensitivity of the eye, the color rendering level must correspond to bright daylight (sunlight) illumination, the color rendering index is at least 80, the lamps used must be resistant to mechanical damage, vibrations, temperature extremes and high pressures.

D) Water reverse osmosis system (9). The design is based on a simple technological scheme. The source water is supplied to the reverse osmosis element (reverse osmosis membrane) due to the design of the membrane, the flow is divided into permeate (clean, purified water) and concentrate (dirty water, that is, water with a high content of contaminants). Clean water is supplied to a high-pressure apparatus, and dirty (concentrate) is discharged into the treatment plant system. FIG. nineteen.

E) Water circulation system (7): complete set: frame, filter column, tank for clean water 2000 l, pressure boosting module (stainless steel), submersible pump, control panel, quartz sand, tank overflow sensors, fine filter, three-way valve, additional cartridge filter.

E) Work table (6): AISI stainless steel or similar metal.

G) High pressure washer (4): strong steel frame, electric motor from 20 to 500 kW, frequency drive of the motor, belt drive of the pump with guard, three-plunger pump or five-plunger pump with built-in lubrication and plunger cooling system, booster centrifugal pump, storage tank 300 l with coarse filter, high pressure safety valve, high pressure pump (HP) dry-running protection, motor control uses a soft starter or frequency drive, industrial stainless steel filter with 5 or 10 micron bag-type cartridge, pressure gauges in high and low pressure lines, the high-pressure apparatus is accompanied by an operating manual, a certificate or declaration of the vehicle, a warranty card, recommendations on safety and labor protection.

H) Cleaning system (5): mechanized system with controlled movement for cleaning flat surfaces at an angle from 0 to 360 degrees, maximum pressure 100-5000 bar, minimum flow rate 15 l / min - maximum flow rate 1000 l / min, rotation speed 10- 1000 rpm, travel speed 2-12 m / min, travel speed control, independent rotational and travel speed controllers, universal box rails, movable limit switches, interchangeable accessories, XY system configuration for work in different planes, cleaning surfaces in specified directions.

I) The cleaning system uses nozzles. The applied nozzles, including rotary ones, have special nozzles through which high-pressure water acts on the incoming material, separating the unvulcanized (raw) rubber from the reinforcing element (metal) without mechanical cutting or crushing. FIG. fifteen.

K) Metal separation system: the most effective for additional cleaning of the finished unvulcanized rubber compound from the remaining volatile material (finely dispersed metal fractions) is a vibrating magnetic separator or a similar device. Technical parameters: capacity from 5 kg / h, magnetic tape shaft diameter (for example - 295 mm, magnetic tape shaft speed 35 m / min, magnet width 500 mm, magnet height 130-160 mm, motor power 0.75KW x 2, external dimensions (L × W × H) 3300 × 2000 × 1700 mm)).

L) After the separation stage, the production personnel (operators of technical post-treatment), using specialized protective chain mail gloves Fig. 17, modifies the resulting crude rubber mixture to finished / marketable appearance.

M) Further, the crude rubber mixture enters the drying chamber, where the complete evaporation of water condensate occurs and the unvulcanized rubber mixture finds its primary FMP and FHP. Installed electrical power of air movement systems - for example, no more than 5 kW (reversible fans, kW - 0.75 × 3 = 2.25; exhaust fan, kW - 1.5, drive - up to 1 kW). Drying of the raw rubber compound can also be done in other ways: air drying, heat drying, natural drying of uncured rubber compound in special storage areas, as well as in other places designated for drying / drying purposes. FIG. eighteen.

The parameters of the equipment used in the method of separating the uncured rubber mixture from the metal cord in scrap / waste rubberized metal cord can be changed in accordance with the requirements, as well as with the volume of processing scrap / waste rubberized steel cord.

FMP and FHP of the finished product - unvulcanized rubber mixture obtained as a result of the method, are shown in the table in Fig. 16. The warranty period for preserving these indicators is up to 3 months (under normal storage conditions: humidity no more than 75%, temperature 10-35 ° C). It is allowed to transport the rubber mixture at temperatures (minus 30 ° C - plus 35 ° C), followed by warming up before use in a warm room to room temperature until condensation on the surface is eliminated. Method of transportation: rubber mixture, in the form of sheets 5-10 mm thick, laid with plastic wrap on a wooden pallet.

Thus, the invention provides an increase in economic efficiency in high-quality separation of materials. The economic efficiency is due to the fact that the raw rubber compound does not lose its properties (the rubber compound is separated from the metal cord in the rubber product while preserving the FMP and FHP of the primary raw rubber compound used for the production of rubberized steel cord). In particular, the preservation of FMP and FHP of the primary rubber compound is achieved by using a water reverse osmosis system or a similar water purification system.

In addition, heating industrial water to 150 ° C allows not only to quickly cope with the complete separation of rubber by violating the integrity of the incoming material, but also to degrease and disinfect the surface of the scrap / waste of rubberized steel cord, which also contributes to the preservation of FMP and FHP of the primary rubber mixture. Moreover, the speed of rubber separation by violating the integrity of the incoming material increases. This effect leads to an increase in the volume of the input material and, accordingly, to an increase in the volume of the finished product (raw rubber compound and metal). This indicator increases the economic efficiency of an economic entity.

The resulting crude rubber mixture can be used for the production of new materials for both technical purposes (tire industry, transport industry, machine-building industry, oil and gas industry, etc.) and in widespread consumption - the mixture is modified to an economy class by mixing rubber and the production of rubber goods economy class. In addition, the invention provides a decrease in equipment wear, a decrease in energy consumption, and an increase in safety for the environment.

Claims (1)

A method for separating an unvulcanized rubber mixture from a metal cord in a scrap / waste rubberized metal cord while maintaining the physical and mechanical characteristics of the primary rubber mixture and the physicochemical characteristics of the primary rubber mixture, including the impact on the rubber product with a water jet under pressure from 500 to 3000 bar with a flow rate of 15 l / min and more using a reverse osmosis system for water purification.

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