DE102009056813B4 - Method and device for separating different material types of a material mixture - Google Patents

Abstract

Method for separating at least two different types of material (13, 14) of a material mixture, namely different metals of a metal mixture, preferably of aluminum and heavy metal of a metal mixture, in which one of the material types (13, 14) of a first material conveying stream (9) is determined by means of at least one X-ray detector (9) 11) and then one of the material types (13, 14) is separated on the basis of the detection result from the first material delivery stream (9), wherein the first material delivery stream (9) comprises or is formed by a first material fraction (7) which is separated by separation a starting material delivery stream (4, 15) into the first material fraction (7) and into at least one second material fraction (8) after a different movement behavior, the material fractions (7, 8) in gas flow, by wind sifting and / or zigzag sizing and / or air separation views are obtained, and wherein the radiation intensity u nd / or radiant energy of the X-ray detector (11) for detecting one of the material types (13, 14) in the first material flow (9) is adapted, and wherein a material type (13, 14) of a second material fraction (8) comprising or from this formed second material delivery stream (17) detected by at least one X-ray detector (19) and with the X-ray detector (19) downstream separating means (12, 20) on the basis of the detection result at least one of the material types (13, 14) from the second material flow (17) is separated , and wherein the radiation intensity and / or radiation energy of the X-ray detector (19) for detecting one of the material locations (13, 14) of the second material conveying stream (17) is adjusted and is different from the radiation intensity or radiation energy of the X-ray detector (11) for detection a same type of material (13, 14) in the first material flow (9).

Description

The invention relates to a method for separating at least two different material types of a material mixture, preferably different metals of a metal mixture, preferably of aluminum and heavy metal of a metal mixture, wherein one of the material types of a first material flow detected by means of at least one X-ray detector and then one of the material types (preferably the detected Material sort) is separated on the basis of the detection result from the first material flow. Alternatively, rubber, wood or plastic parts, etc. can be detected and separated from a material mixture using the X-ray detector. Furthermore, the invention relates to a separation plant for carrying out such a separation process with at least one X-ray detector for detecting one of the material types of a first material flow and downstream with the X-ray detector release means with which based on the detection result one of the material types (preferably the detected material type) from the first material flow can be separated is.

Today, metal mixtures, including light and heavy metals, by hand, separated by a sink-float system or by means of a so-called automatic sorting, in which the metal species to be separated, for example by means of an X-ray detector is detected in a material flow and separating means, such as a blowing device, be controlled on the basis of the detection result (position information) such that the metal species to be separated from the material flow, in particular by blowing, is separated. The combination of X-ray detector and release agent is also referred to in practice as X-ray sorter.

In manual sorting, humans are the determining factor in the sorting quality as well as the sorting quantity. As a rule, the sorting quality decreases with increasing throughput and vice versa. The disadvantages are the high (personnel) costs associated with hand sorting.

The separation of different material types of a material mixture by means of a floating-sink system is advantageous in terms of the achievable separation quality and the achievable high throughput. However, the high operating costs are disadvantageous because expensive ferrosilicon or magnetite is required to produce the required density of the water used. In addition, the water treatment costs for the recovery of the sealant and the maintenance and energy costs are very high. In addition, the environmental impact is significant.

The automatic sorters used today, in particular the X-ray sorters or color and metal sorters, are not yet able to achieve the required separation quality - however, they have the advantage of achieving high throughput with constant quality, and with little Operating costs and significantly lower acquisition costs.

From the DE 10 2004 041 494 A1 It is known to carry out a material-selective sorting by means of sensors and pneumatically operated discharge devices after a wind-sighting several process steps, wherein no X-ray sensors are used. The known method deals exclusively with the separation of fluff and films by means of a wind-sighting.

The DE 695 20 757 T2 describes a method for the determination of material properties by means of X-radiation. In particular, the known method of separating polymer-coated paperboard articles serves as a fraction from a waste stream of material.

For further prior art, the DE 10 2004 001 790 A1 , the DE 10 2006 034 692 A1 as well as the DE 31 46 049 A1 called.

The invention has for its object to provide a method and a separation system with which a high separation quality can be ensured by means of an X-ray sorter. Preferably, the separation quality of the known swimming-sink systems should correspond.

This object is achieved in terms of the method with the features of claim 1. In this case, radiation intensity and / or radiation energy of the X-ray detector means the radiation intensity and / or the radiation energy of the emitted X-ray radiation.

With regard to the separation system, the object is achieved with the features of claim 5.

Advantageous developments of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention.

The invention has recognized that the setting of the radiation intensity and / or the radiation power of the X-ray radiation of the X-ray detector, which normally operates in the transmission method, is of crucial importance with regard to achieving a good detection quality and so that a good sorting quality. The invention has further recognized that the X-ray detectors which normally work in the transmission method have the inherent disadvantage that the material thickness of the material to be detected is included in the measurement result. However, since the material mixtures occurring in recycling are subject to extremely great fluctuations in shape, volume and strength, the known X-ray sorting systems quickly reach their performance limits. Furthermore, the invention has recognized that the radiation intensity and / or radiation energy (radiation hardness) can be adapted better to the material type to be detected in the first material flow, the tighter the classification of the first material flow, ie the more homogeneous the first material flow in the With regard to the nature of the material-type particles. It is clear that the known X-ray sorters upstream screening is not sufficient to obtain a first material flow with suitable classification. According to the invention, a good quality of detection and thus a good sorting quality can be ensured by closely classifying the first material delivery flow supplied to the X-ray sorter with respect to the projection surface / weight ratio of the particles forming the first material delivery stream. In other words, the X-ray detector for sorting the material to be separated is preceded by a sorting / classification with the aid of separation means, taking into account as a sorting criterion, if appropriate, among other criteria such as the streamlined nature of the particles, the projection surface / weight ratio of the material fractions (particles of material fractions). The different projection surface / weight ratio of the material fractions affects a different movement behavior, in particular in a different flight behavior, the material fractions. In other words, a feed stream fed to the separation means can be separated into a first material fraction and at least one second material fraction, which behave differently with regard to their movement behavior, preferably flight behavior, at (same), in particular lateral, gas flow. In particular, the material fractions having a different projection area / weight ratio differ with regard to their trajectory, in particular trajectory, or their movement distances, in particular flight distances, and / or movement heights, in particular flight heights. One of the at least two material fractions obtained by dividing the starting material conveying stream then forms the first, with regard to the Projektionsflächen- / weight ratio closely classified material flow to itself or optionally with further material, to which the radiation intensity and / or radiation energy of the X-ray detector, preferably empirically optimal is customizable, so as to ensure an optimal sorting result according to material types in the first material flow. The adaptation of the radiation intensity can be done by adjusting the anode current and / or the anode voltage (acceleration voltage). An increase in intensity (with the same hardness) can be achieved by increasing the anode voltage while keeping the anode current constant.

If necessary, this can be increased or decreased at the same time. If, on the other hand, the anode voltage is increased (at a constant anode current), this increases both the energy (hardness) and the intensity. Owing to the narrow classification, an over-blasting of comparatively small and light particles which is frequently encountered by X-ray sorters is avoided. Also, the probability of misdetection, i. H. a confusion of the material types of a material mixture by the X-ray detector minimized.

The aforementioned projection surface is understood to mean a surface which occupies a shadow of a particle when the particle is illuminated by parallel light, that is to say the surface on which a gas inflow acts. Preferably, each is the largest projection surface of the particle.

To a Ausgangsmaterialförderstrom in the at least two in terms of their flight behavior at, in particular constant, d. H. There are different possibilities or separation methods, ie, to separate the material fractions that differ from gas inflow and thus to consider the projection surface / weight ratio as a sorting criterion. For example, wind sifters, so-called zigzag sifters or air separation sifters can be used to ensure the desired narrow classification of the first material flow rate. This special narrow classification with regard to the movement behavior, in particular flight behavior, it is possible to increase the quality output of X-ray sorters (X-ray detector + release agent). In the case of air separation table classifiers, the different movement behavior must be taken into account.

According to the invention, at least one wind sifter and / or at least one zigzag sifter and / or one air separation table sifter are used to separate the starting material conveying stream according to the sorting criterion of the different movement behavior, in particular flight behavior. It is essential that the separation takes place according to the different movement behavior, preferably flight behavior, in particular the different flight distance and / or the different flight altitude of the material fractions (ie the material fraction particles), ie below Consideration of the sorting size of the ratio of projection surface to weight, wherein in the aforementioned separation process, the streamlining of the fractions is taken into account.

It is particularly preferred, but not mandatory, for the material forming the feedstock flow stream to be obtained by sieving from an original volume flow. In other words, the separating means for separating the starting material conveying stream into the first and the at least second material fractions comprises at least one sieve, preferably a three-dimensional sieve, i. H. an inclined at an angle of, for example, 45 ° sieve, upstream to take into account a pre-classification by particle sizes. In this preclassification, the weight of the particles plays no role as a sorting criterion. Preferably, the sieve / sieves are designed such that a particle size ratio between 1: 2 and 1: 3 is obtained, that is, a sieve cut having a ratio of 1: 2 to 1: 3, for example, 20-40 mm (1 : 2) or 40-80 mm (1: 2).

According to the invention, it is provided that not only a first, the first material fraction comprehensive or formed by this material flow is fed to an X-ray detector, but also a second, the second material fraction comprehensive or formed by this material flow. It is essential in this case that the radiation intensity and / or radiation power of the X-radiation of the X-ray detector used in each case is different for the different material delivery flows, that is adapted to the composition, which can be done empirically, for example. Once the optimum X-ray detector setting (radiation intensity and / or radiant power) has been found for a particular material fraction obtained at certain separation parameters, ie at a given gas flow rate, this X-ray detector adjustment can be reused in later separations if these separations have the same separation parameters, ie the same gas flow rate was used. Particularly preferably, a control device automatically sets the (optimum) radiation intensity and / or radiation energy as a function of the selected separation parameters, ie. H. automatically as a function of the gas flow rate and, if necessary, depending on the composition, d. H. the material types, the first material flow.

In principle, it is possible to analyze the at least two different material delivery streams successively with the same X-ray detector or, alternatively, with different X-ray detectors, either simultaneously or with a time offset.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings.

These show in:

1 in a schematic representation of the basic structure of a possible separation plant for performing a separation process, and

2 an alternative plant construction.

In the figures, like elements and elements having the same function are denoted by the same reference numerals.

In 1 is very schematic the basic structure of a plant 1 for the separation of at least two different material types of a material mixture shown. The attachment 1 comprises a sieve formed as a three-dimensional sieve 2 , for example, with a mesh size of 20 mm. This sieve 2 becomes an original volume flow 3 supplied, which is, for example, a bed of at least two types of material (preferably shredded recycling material), for example, light metal and heavy metal. This original volume flow 3 becomes, as I said, the sieve 2 supplied and divided therefrom into a (first) raw material delivery stream 4 forming material and other material 5 with a diameter> 20 mm. The (first) feedstock flow 4 will be further promoted to separating agents 6 , which are formed in the embodiment shown by a wind sifter. The disruption agents 6 are formed such that with these the starting material flow into a first material fraction 7 and a second material fraction 8th is divided, wherein the two material fractions with respect to the flight behavior (or movement behavior in an air separation table) of the material fractions forming particles differ. In the embodiment shown, the two material fractions differ 7 . 8th in terms of their flight widths with lateral air flow by means of a blower (not shown).

In the embodiment shown, the first material fraction forms 7 a first material flow 9 , which (via conveyor belts) to an X-ray sorter 10 is transported. The X-ray sorter 10 comprises an X-ray detector operating in the transmission method 11 and signal conducting with this connected release agent 12 based on the detection result of the X-ray detector 11 one of the material types from the first material flow 9 sort out, ie separate from this. The X-ray detector comprising an X-ray tube 11 Detects the material to be separated in the first material flow 9 and supplies, as a detection result in the exemplary embodiment shown, position data of the material fraction to be separated to a control of separating means 12 , These separate the detected type of material taking into account the speed of the first material flow 9 , for example, by blowing off. In the embodiment shown, the X-ray detector is 11 set such that its radiation intensity and / or energy is adjusted (the adjustment is done for example by adjusting the anode current and / or the anode voltage of the X-ray tube) that the first material type 13 in the first material flow 9 is recognized, whereupon this first type of material 13 from the release agents 12 is separated. At least one second type of material remains 14 , For example, the first material type 13 is aluminum and the second material type 14 is a heavy metal type.

The second material fraction obtained on the basis of air classification (alternatively zigzag sighting or air separation table sighting) 8th either at a later date the X-ray sorter shown 10 be supplied, or alternatively another, not shown X-ray sorter, or may be recycled in another way or possibly stored on stockpile.

Substantial difference in 1 shown attachment 1 to the known from the prior art system is the classification of a Ausgangsmaterialcörderstroms 4 according to the sorting criterion of the different flight behavior with gas inflow, whereby a closely classified first material flow 9 is obtained, which is relatively homogeneous in view of the aforementioned sorting criterion, so that a more accurate adjustment of the radiation intensity and / or radiation energy to the first material flow 9 is possible, as in the prior art, which leads to a significantly improved sorting result.

2 shows an alternative attachment 1 for performing a separation process for different material types of a material mixture. This in 1 The basic principle shown is again. The attachment 1 in this case comprises a sieve designed as a three-dimensional sieve 2 , which contains a volume of original volume comprising several types of material 3 divides into material for a first feedstock flow 4 and a second feedstock flow 15 , In the following, only the further processing of the first raw material conveying stream will be described 4 described. The further processing or separation of the second feedstock feed stream 15 takes place analogously with an adapted Gasanströmgeschwindigkeit of coming to use wind sifter and with an adapted radiation intensity and / or radiation energy of the X-ray sorter used.

The first feedstock flow 4 becomes a means of separation via conveyor belts 6 transported, which are formed in the embodiment shown as a wind sifter. Here, the first raw material flow becomes 4 in two material fractions 7 . 8th divided, taking into account the projection area / weight ratio. The separation takes place according to the different flight behavior of the material fractions at, here lateral, gas inflow. The first material fraction 7 forms a first material flow 9 and the second material fraction 8th a second material flow 17 , The first material flow 9 becomes a (first) X-ray sorter 10 comprising a (first) X-ray detector 11 and (first) release agents 12 , fed. The second material flow 17 becomes a (second) X-ray sorter 18 comprising a (second) X-ray detector 19 as well as signal-conducting with the (second) X-ray detector 19 Connected release agents 20 , fed. The two x-ray detectors 11 . 19 are operated with different radiation intensities and / or radiation energies, each with regard to an optimal detection of a first type of material 13 in the first or second material flow 9 . 17 is optimized. The release agents 12 divide the first material flow 9 on in the first kind of material 13 and at least the second type of material 14 , The second material flow 17 is made by the (second) release agents 20 divided into a first type of material 13 and the second kind of material 14 , The material type 13 is preferably aluminum and the material type 14 is heavy metal.

Claims (7)

Method for separating at least two different types of material ( 13 . 14 ) of a material mixture, namely different metals of a metal mixture, preferably of aluminum and heavy metal of a metal mixture, in which one of the material types ( 13 . 14 ) of a first material conveying stream ( 9 ) by means of at least one X-ray detector ( 11 ) and then one of the material types ( 13 . 14 ) based on the detection result from the first material flow ( 9 ) is separated, wherein the first material flow ( 9 ) a first material fraction ( 7 ) formed by or formed by separation of a feedstock feed stream ( 4 . 15 ) into the first material fraction ( 7 ) and in at least a second material fraction ( 8th ) after a different movement behavior, the material fractions ( 7 . 8th ) at gas inflow, through wind views and / or zigzag views and / or air separation table views and wherein the radiation intensity and / or radiation energy of the X-ray detector ( 11 ) for detecting one of the types of material ( 13 . 14 ) in the first material flow ( 9 ), and where a material variety ( 13 . 14 ) of a second material fraction ( 8th ) or formed by this second material flow ( 17 ) by means of at least one X-ray detector ( 19 ) and detected with the X-ray detector ( 19 ) downstream release agents ( 12 . 20 ) based on the detection result at least one of the material types ( 13 . 14 ) from the second material flow ( 17 ) and wherein the radiation intensity and / or radiation energy of the X-ray detector ( 19 ) for detecting one of the types of material ( 13 . 14 ) of the second material delivery stream ( 17 ) is or is and is different from the radiation intensity or radiation energy of the X-ray detector ( 11 ) for detecting a same type of material ( 13 . 14 ) in the first material flow ( 9 ). Method according to claim 1, characterized in that the separation of the starting material conveying stream ( 4 ) into the first material fraction ( 7 ) and in the at least second material fraction ( 8th ) according to different flight behavior, in particular according to different flight lengths and / or altitudes of the material fractions ( 7 . 8th ) he follows. Method according to one of claims 1 or 2, characterized in that the material ( 5 ) for the feedstock flow ( 4 ) by sieving, in particular by means of at least one three-dimensional sieve ( 2 ), from an original volume flow ( 3 ), whereby the material ( 5 ) is preferably characterized by a size ratio between about 1: 2 and about 1: 3. Method according to one of the preceding claims, characterized in that the first and the second material flow ( 9 . 17 ) successively by means of the same X-ray detector ( 11 . 19 ) or that the first and the second material flow ( 9 . 17 ), preferably simultaneously, by means of different X-ray detectors ( 11 . 19 ) to be analyzed. Separating plant for carrying out a method according to one of the preceding claims for separating at least two different types of material ( 13 . 14 ) of a material mixture, namely different metals of a metal mixture, preferably of aluminum and heavy metal of a metal mixture, with at least one X-ray detector ( 11 ) for detecting one of the types of material ( 13 . 14 ) of a first material conveying stream ( 9 ) and with the X-ray detector ( 11 ) downstream release agents ( 12 . 20 ), on the basis of the detection result one of the material types ( 13 . 14 ) from the first material flow ( 9 ) is separable, wherein separating agents ( 6 ) are provided, with which a Ausgangsmaterialförderstrom ( 4 ) into a first material fraction ( 7 ), the first material flow ( 9 ) or is contained in this and in at least a second material fraction ( 8th ) after a different movement behavior of the material fractions ( 7 . 8th ) is separable with gas flow by means of a wind sifter and / or a zigzag sifter and / or an air separation table sifter, and wherein the radiation intensity and / or radiation energy of the X-ray detector ( 11 . 19 ) to the first material flow ( 9 ) for detecting one of the types of material ( 13 . 14 ) in the first material flow ( 9 ), and where a material type ( 13 . 14 ) of a second material fraction ( 8th ) or formed by this second material flow ( 17 ) by means of at least one X-ray detector ( 19 ) is detectable and wherein with the X-ray detector ( 19 ) downstream release agents ( 20 ) based on the detection result at least one of the material types ( 13 . 14 ) from the second material flow ( 17 ) and wherein the radiation intensity and / or radiation energy of the X-ray detector ( 19 ) for detecting one of the types of material ( 13 . 14 ) of the second material delivery stream ( 17 ) is adaptable or adaptable and is different from the radiation intensity or radiation energy of the X-ray detector ( 19 ) for detecting the same type of material ( 13 . 14 ) in the first material flow ( 9 ). Separating plant according to claim 5, characterized in that at least one sieve ( 2 ), in particular a three-dimensional sieve, for screening an original volume flow ( 3 ) for obtaining the material ( 5 ) for the feedstock flow ( 4 ) is provided. Separating plant according to one of claims 5 or 6, characterized in that the first and the second material fraction ( 7 . 8th ) successively through the same X-ray detector ( 11 . 19 ), or that the first and second material fractions ( 7 . 8th ), preferably simultaneously, by different X-ray detectors ( 11 . 19 ) are eligible.

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