RU2375472C1 - Method and plant for complex processing of thin forms of aluminium waste - Google Patents

Abstract

FIELD: technological processes. ^ SUBSTANCE: invention is related to the field of aluminium grit production with various dispersion by means of complex mechanical-thermal processing of thin forms of aluminium waste: chips, wire, drink cans, thin sheet slug, foil wastes, in particular to method and plant for complex processing of thin forms of aluminium waste. Method includes removal of ferrous inclusions, organic admixtures and chopping, at the same time wastes are exposed to magnetic separation, crushed with production of particles of 10-26 mm size, annealing is carried out at the temperature of 600-1200C and repeatedly ground to produce particles with size of not more than 4 mm, cleaning from small aluminium particles and organic admixtures, preferably, is carried out by means of continuous aspiration of gas sent through crushing devices and annealing apparatus, crushed particles after repeated crushing is exposed to sieve classification. Plant comprises magnetic separator, two serially installed grinding devices, between which annealing apparatus is installed, gas blower and device for its classification, magnetic separator is preferably installed upstream the first crushing device, and device for classification (6) - downstream the second crushing device (3). ^ EFFECT: invention provides for increased efficiency of processing and improved quality of manufactured product. ^ 9 cl, 1 dwg, 1 tbl, 1 ex

Description

The invention relates to the field of production of aluminum grains of various dispersion by complex mechanical-thermal processing of thin forms of aluminum waste: shavings, wire, beverage cans, thin-rolled cutting, foil waste.

There is a method of processing aluminum cans for drinks, which consists in the fact that the cans are crushed and separated iron inclusions (JP 01-287231, C22B 21/06, publ. 11/17/1989).

The application of the known method does not allow to remove organic impurities from the resulting product and further processing by remelting is required.

A known method of processing aluminum cans for drinks, which consists in the fact that the cans are fired at 400-600 ° C to remove organics and crushed in a reflective grinder (Japanese application 5067687, 2807740).

The disadvantage of this method is the burning of aluminum cans entirely, which prevents the removal of organic impurities (paint coatings) and their decomposition products (soot) from the inside of the cans.

A known method of processing aluminum cans is that iron inclusions are removed from the cans, and then grinding is carried out in four stages to produce particles with decreasing particle size at each stage. The first three stages are carried out in rotary drum grinders, the fourth in the abrasive apparatus (RU 2214461, С22В 7/00, publ. 10/20/2003 - prototype).

The disadvantages of this method are:

- a large number of grinding stages, which leads to hardening of the material of the cans after each stage, thereby making it difficult to grind in the subsequent stage, which significantly increases the energy consumption and reduces the productivity of processing;

- the absence of heat treatment in the grinding process does not ensure complete removal of moisture and almost complete cleaning of organic impurities of the crushed material of the cans.

A known installation for processing scrap aluminum cans from drinks, consisting of a grinding device and a magnetic separator (JP 01-287231, C22B 21/06, publ. 11/17/1989).

A disadvantage of the known installation is the inability to obtain small flakes purified from surface contaminants (paints, organics, etc.).

A known installation for the processing of aluminum cans containing a magnetic separator, three sequentially installed rotary drum grinders, abrasion apparatus, gas blower and device for classification (RU 2214461, C22B 7/00, publ. 20.10.2003 - prototype).

A disadvantage of the known installation is the inability to obtain in the process of grinding small flakes completely purified from organic impurities (paints, organics, etc.).

An object of the invention according to the claimed method for the complex processing of thin forms of aluminum waste and installation for its implementation is to eliminate the disadvantages of the known method and installation, adopted as the closest analogue of the prototype, as well as increasing the productivity of the processing of thin forms of aluminum waste and improving the quality of the obtained powder-granule material.

The stated technical problem is solved in that in the method for the complex processing of thin forms of aluminum waste, including the removal of iron inclusions, organic impurities and grinding, according to the invention, the waste is subjected to magnetic separation, crushed to obtain particles with a particle size of 10-26 mm, fired at a temperature of 600-1200 ° C and carry out repeated grinding to obtain particles with a particle size of not more than 4 mm

In the inventive method, preferably:

- purification from small aluminum particles and organic impurities is carried out by continuous aspiration of the gas passed through the grinding device and the annealing unit;

- the crushed particles after repeated grinding are subjected to sieve classification.

The stated technical problem is solved in that the installation for the complex processing of thin forms of aluminum waste, containing a magnetic separator, grinding devices, a gas blower and a classification device, according to the invention contains two series-mounted grinding devices, between which an annealing unit is additionally placed.

In the inventive installation, preferably:

- a magnetic separator is placed in front of the first grinding device;

- the classification device is placed after the second grinding device.

The inventive installation is preferably:

- as a grinding device contains rotary drum or shock wave shredders, or hammer crushers;

- as an annealing unit contains a rotary or vibration furnace, or a furnace with a moving tray;

- as a device for classification contains a gas or vibration classifier, or sieve screen.

The drawing shows a flow diagram of the integrated processing of thin forms of aluminum waste according to the claimed method and installation for its implementation.

Installation for the complex processing of thin forms of aluminum waste contains a magnetic separator 1, two sequentially installed grinding device 2, 3, annealing unit 4, gas blower 5 and a classification device 6.

The method of complex processing of thin forms of aluminum waste is implemented as follows.

The initial thin forms of aluminum waste through a magnetic separator 1, with which iron-containing inclusions (foreign metal objects) are removed, are fed to a grinding device 2, where they are ground to a particle size of 10-26 mm. Then the material is sent to the annealing unit 4, where it is thermally cleaned at a temperature of 600-1200 ° C from organic impurities and moisture. In addition, during the firing process, the strength of the metal decreases, which facilitates the second stage of grinding. After firing, the material by means of gas blower 5 and cyclone 7 is fed into the grinding device 3, in which grinding to a particle size of no more than 4 mm in size occurs. To remove dust fractions during grinding and annealing using an aspiration system consisting of a fan 9 and a cyclone 10, dust is removed from the ground material. From the grinder 3 by means of a gas blower 5 and cyclone 8, the material is fed into the device for classification 6, from which the material classified by fractions enters the container as a commercial product.

An example of the practical implementation of the method of complex processing of thin forms of aluminum waste

As thin forms of aluminum waste, aluminum beverage cans were used. After magnetic separation and removal of various iron inclusions (foreign metal objects), aluminum cans were crushed in a hammer mill to obtain particles of material with a particle size of 10-26 mm.

Primarily crushed material enters the rotary kiln, where at a temperature of 700 ° C it is fired to remove organic impurities (paint, varnishes, water). Then the material is fed for re-grinding into a hammer mill. After re-grinding, the crushed product contained less than 3% of fractions with a particle size of less than 0.2 mm. This part of the product is a dusty fraction containing less than 50% aluminum, and the rest is mechanical impurities that exfoliate from the surface of the particles (paint, varnish, soot, etc.). Using a gas blower, the material being crushed from the rotary kiln is transported to the second hammer mill for re-grinding and further transported to the classifier to separate the finished product into fractions. The removal of small aluminum particles and organic impurities is carried out by continuous aspiration of gas passing through hammer crushers and a rotary kiln.

After repeated grinding, the particles of the material had a shiny surface. Large particles after grinding contained more than 97% aluminum and as a commercial product can be used in the chemical and metallurgical industries.

The firing temperature of the initially ground material depends on the thickness of the initial aluminum waste and the type of organic compounds that must be removed.

Comparative parameters of the industrial product obtained in the inventive installation using the proposed method in comparison with the prototype are shown in the table.

Options The inventive method Prototype The number of stages of grinding 2 four The content of particles with a particle size of less than 0.2 mm in the last grinding stage less than 3% 6-12% Aluminum content in dust waste up to 50% up to 90% The aluminum content in the commercial product about 97% about 96%

The presence of distinctive features in the claimed method for the complex processing of thin forms of aluminum waste and installation for its implementation provides an increase in the productivity of the process of processing thin forms of aluminum waste and an improvement in the quality of the obtained powder-granule material in comparison with the prototype.

The use of the proposed method for the complex processing of thin forms of aluminum waste and installation for its implementation to obtain aluminum grains of various dispersion by complex mechanical-thermal processing of thin forms of aluminum waste (shavings, wire, beverage cans, thin rolled metal cutting, foil waste) provides the invention compliance with the criterion of "industrial applicability".

Claims (9)

1. The method of complex processing of thin forms of aluminum waste, including the removal of iron inclusions, organic impurities and grinding, characterized in that the waste is subjected to magnetic separation, crushed to obtain particles with a particle size of 10-26 mm, fired at a temperature of 600-1200 ° C, repeated grinding to obtain particles with a particle size of not more than 4 mm 2. The method according to claim 1, characterized in that the cleaning of small aluminum particles and organic impurities is carried out by continuous aspiration of the gas passed through the grinding device and the annealing unit. 3. The method according to claim 1, characterized in that the crushed particles after repeated grinding are subjected to sieve classification. 4. Installation for the complex processing of thin forms of aluminum waste, containing a magnetic separator, grinding devices, gas blower and classification device, characterized in that it contains two sequentially installed grinding devices, between which an annealing unit is placed. 5. Installation according to claim 4, characterized in that the magnetic separator is placed in front of the first grinding device. 6. Installation according to claim 4, characterized in that the classification device is placed after the second grinding device. 7. Installation according to claim 4, characterized in that as the grinding device contains rotary drum or shock wave shredders, or hammer crushers. 8. Installation according to claim 4, characterized in that as the annealing unit contains a rotary or vibration furnace, or a furnace with a moving tray. 9. Installation according to claim 4, characterized in that as a device for classification contains a gas or vibration classifier, or sieve screen.

Images