Method for obtaining non-ferrous metals, in particular black and / or raw copper, from scrap containing organic matter

Abstract

The present invention relates to a method for obtaining non-ferrous metals, in particular black and / or raw copper, from scrap containing organic matter (8), comprising the steps: i) providing a melting reactor (2), wherein the melting reactor (2) is configured such that it has at least one melting region (5), a combustion region (6) and a pyrolysis region (7), ii) supplying the melting reactor (2) with a mixture comprising the scrap containing organic matter (8) such that it first passes through the pyrolysis region (7) and the combustion region (6) before it reaches the melting region (5), and is at least partially pre-pyrolyzed and / or combusted, such that an energy-containing gas stream (9) is formed, iii) transferring the energy-containing gas stream (9) into a thermal post-combustion chamber (3), in which the energy-containing gas stream (9) is completely combusted and the thermal energy released during combustion is carried off via an energy recovery unit (11), and iv) melting the scrap containing organic matter (8) at least part of which has been pre-pyrolized and / or combusted.

Description

[0001] Process for the extraction of non-ferrous metals, in particular black and / or raw copper, from organic-containing scrap

[0002] The present invention relates to a method and a plant for the extraction of non-ferrous metals, in particular black and / or raw copper, from organic-containing scrap.

[0003] Such processes for the recovery of valuable materials are generally known from the state of the art.

[0004] European patent application EP 1 609 877 A1 discloses a process for the batch processing of metal-containing waste materials, such as electronic waste, in a rotating reactor. The feedstock, specifically the electronic waste, consists essentially of fractions of a size that allows continuous loading during operation. The material is melted in the reactor, producing a processed product that is essentially free of any organic substance because the original organic component of the feedstock is burned off during melting.

[0005] Furthermore, EP 0 070 819 B1 discloses a process for converting metal-containing waste products with a high proportion of organic substances, such as cable waste and waste from electronic equipment, into a product from which a valuable metal can be easily extracted. For this purpose, the waste products are fed into a rotating reactor vessel and then heated to expel the organic components in the form of a combustible gas, which is then incinerated outside the reactor vessel. Another process for recycling copper-containing electronic waste is disclosed in the publication by Gerardo et al., ISASMELT™ for the Recycling of E-Scrap and Copper in the US: Case Study Example of a New Compact Recycling Plant, The Minerals, Metals & Materials Society, DOI 10.1007 / s11837-014-0905-3.

[0006] Against this background, the present invention is based on the object of providing an improved method and an improved plant for the extraction of non-ferrous metals, in particular black and / or raw copper, from organic-containing scrap, compared to the prior art.

[0007] According to the invention, this object is achieved by a method having the features of patent claim 1 and by a system having the features of patent claim 10.

[0008] Further advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technologically expedient manner and can define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, where further preferred embodiments of the invention are presented.

[0009] The method according to the invention for recovering non-ferrous metals, in particular black and / or raw copper, from organic-containing scrap comprises the steps of: i) providing a melting reactor, wherein the melting reactor is configured to have at least one melting zone, one combustion zone, and one pyrolysis zone; ii) feeding the melting reactor with a mixture comprising the organic-containing scrap such that, before reaching the melting zone, the scrap first passes through the pyrolysis zone and the combustion zone and is at least partially pre-pyrolyzed and / or combusted, thereby forming an energy-containing gas stream; iii) transferring the energy-containing gas stream to a thermal post-combustion chamber, in which the energy-containing gas stream is completely combusted and the thermal energy released during combustion is removed via an energy recovery unit;and iv) melting the at least partially pre-pyrolyzed and / or incinerated organic-containing scrap.

[0010] The present invention is based on the fundamental finding that the melting of high-energy scrap, which is characterized by a high organic content, introduces a very high energy input into the melting process, which severely attacks the melting reactor or plant, leads to increased wear, and largely leaves the plant unused with the exhaust gas. The specific process approach according to the invention specifically recovers the unused energy surplus and optimizes the energy efficiency of the entire recycling process. Furthermore, wear on the melting reactor or plant is reduced.

[0011] According to the invention, the melting reactor is fed with the mixture comprising the organic-containing scrap in such a way that, before reaching the melting zone, the scrap first passes through the pyrolysis zone and the combustion zone and is at least partially pre-pyrolyzed and / or combusted. The energy-containing gas stream formed in this process is then transferred directly to a thermal post-combustion chamber and completely combusted there. This results in a lower energy input into the melt, which has a beneficial effect on the regulation of the melting process. The thermal energy released in the post-combustion is dissipated via the energy recovery unit, which preferably comprises an evaporator or a heat exchanger, and can be used, for example, to generate saturated steam or CO2-neutral electrical energy.

[0012] The temperature in the pyrolysis zone is at least 180 °C, preferably at least 420 °C, more preferably at least 800 °C, and most preferably at least 900 °C. A temperature that is too low has a detrimental effect on the desired pyrolysis process, as too small a proportion of the organic component of the scrap used is pyrolyzed, and therefore too high a proportion of the organic component reaches the melt. However, the temperature must not exceed a maximum temperature, as a specific proportion of the organic component is required as fuel for the melt in order to operate the recycling process within the optimal energy-related range. Furthermore, due to the nature of the melt reactor, the temperature must not be too high, as this would lead to undesirable wear of the melt reactor.Advantageously, the maximum temperature is therefore 1500 °C, preferably 1400 °C, more preferably 1300 °C, and most preferably a maximum of 1200 °C.

[0013] Advantageously, the organic-containing scrap is fed into the melting reactor countercurrent to the energetic inert gas stream. This slows the falling velocity of the individual particles, as they are surrounded by the gas stream. Generally speaking, when considering individual particles, they should be relatively easy to heat up in order to easily release the pyrolysis gases. For example, a residence time that is too short would have a detrimental effect on the desired pyrolysis process, as too small a proportion of the organic component is pyrolyzed, resulting in too high a proportion of the organic component reaching the melt. On the other hand, the residence time should not exceed a maximum time, as a specific proportion of the organic component is required as fuel for the melt in order to operate the recycling process at its optimal energy level.In a particularly advantageous embodiment, the melt is specifically cooled by introducing an inert gas, preferably nitrogen, into the combustion and / or melting zone, forming an energetic inert gas stream. In this context, it is particularly advantageous for this energetic inert gas stream to transfer the energy-containing gas stream formed in the upper part of the melting reactor into the thermal post-combustion chamber. This ensures, on the one hand, that the melting process can be optimally adjusted and regulated. On the other hand, the thermal energy released during the melting process is almost completely recovered.

[0014] If nitrogen is used as an inert gas for targeted cooling, depending on the temperature in the melt reactor, NOX compounds may form. To reduce the formation of NOX compounds, the temperature in the melt reactor can be adjusted so that the pyrolysis zone does not exceed a maximum temperature of 1200 °C. Alternatively, the NOX compounds can be reduced in a catalytic SCR unit, which is located downstream of the afterburner chamber, for example.

[0015] The method according to the invention is intended for the pyrometallurgical processing of organic-containing scrap. Organic-containing scrap, for the purposes of the present invention, is understood to mean any scrap that contains an organic component. Preferred organic-containing scrap is selected from the group comprising electronic scrap, car shredder scrap and / or

[0016] Transformer shredder scrap, in particular shredder light fractions and / or mixtures thereof.

[0017] For the purposes of this invention, the term “electronic waste” refers to old electronic devices that are disposed of in accordance with the EU Directive

[0018] 2002 / 96 / EC. The appliance categories covered by this Directive include complete and / or (partially) disassembled large household appliances;

[0019] Small household appliances; IT and telecommunications equipment; consumer electronics equipment; lighting equipment; electrical and electronic tools (except large stationary industrial tools); electric toys and sports and leisure equipment; medical devices (except all implanted and infected devices); monitoring and control instruments; and automatic dispensing devices. For the individual products that fall into the corresponding equipment category, please refer to Annex IB of the Directive.

[0020] Such electronic waste essentially comprises hydrocarbon-containing components, such as in particular plastics, as well as metallic components, such as in particular the elements selected from the group comprising copper, nickel, lead, tin, zinc, gold, silver, antimony, palladium, indium, gallium, rhenium, titanium, aluminum and / or yttrium.

[0021] The electronic waste of the mixture is configured such that it preferably contains an aluminum content of at least 0.1 wt.%, more preferably an aluminum content of at least 0.5 wt.%, even more preferably an aluminum content of at least 1.0 wt.%, and most preferably an aluminum content of at least 3.0 wt.%. The electronic waste is limited in terms of the maximum content, since an excessively high aluminum content has a detrimental effect on the viscosity and thus the flowability of the slag phase, as well as on the separation behavior between the metallic phase and the slag phase. Therefore, the electronic waste preferably contains at most 20 wt.% aluminum, more preferably at most 15 wt.% aluminum, even more preferably at most 11 wt.% aluminum, and most preferably at most 8 wt.% aluminum.The charging and thus the energy input into the melting reactor can be uneven due to different grain sizes, in particular excessively large grain sizes, so that undesirable conditions arise during the melting process. Therefore, the electronic scrap is preferably fed in in comminuted form. Advantageously, the electronic scrap is comminuted to a grain size of less than 20.0 inches, more preferably to a grain size of less than 15.0 inches, even more preferably to a grain size of less than 12.0 inches, further preferably to a grain size of less than 10.0 inches, further preferably to a grain size of less than 5.0 inches, and most preferably to a grain size of less than 2.0 inches. However, a grain size of 0.1 inches, preferably a grain size of 0.5 inches, more preferably a grain size of 1.5 inches should not be undercut.

[0022] The mixture comprising the organic-containing scrap can have a defined organic content. However, the content of the hydrocarbon-containing components must not be too low, since otherwise a sufficient pyrolysis and / or combustion reaction will not occur. Therefore, the proportion of the hydrocarbon-containing component is preferably at least 10 wt.%, more preferably at least 15 wt.%, most preferably 20 wt.%. With regard to the maximum content, the organic-containing scrap in the mixture is limited and is therefore preferably a maximum of 98 wt.%, more preferably a maximum of 90 wt.%, even more preferably a maximum of 80 wt.%, further preferably a maximum of 70 wt.%, and most preferably a maximum of 60 wt.%.

[0023] Advantageously, step ii) of the process according to the invention is supported by selectively blowing in an oxygen-containing gas. The reaction is therefore adjusted such that complete combustion of the hydrocarbons to CO2 and H2O does not occur, but rather CO and H2 contents are also formed in the process gas. This allows the combustion of the organic components to be controlled in a targeted manner, with the thermal energy released supporting step iv) of the process. The exhaust gas stream formed in the thermal afterburning chamber is subsequently fed to a catalytic SCR unit and / or a filter device. In a further aspect, the present invention also relates to a plant for recovering non-ferrous metals, in particular black and / or raw copper, from organic-containing scrap.The plant comprises: i) a melt reactor, wherein the melt reactor is configured to have at least one melting region, one combustion region and one pyrolysis region, ii) a thermal post-combustion chamber in which an energy-containing gas stream can be completely combusted, and iii) an energy recovery unit via which thermal energy released during combustion can be dissipated.

[0024] The smelting reactor is preferably a metallurgical vessel, such as a shaft furnace, a bath smelting reactor, a Peirce-Smith converter, or a tiltable rotary converter, in particular a so-called top-blowing rotary converter (TBRC), or a tiltable vertical converter. In an advantageous embodiment, the metallurgical vessel comprises a first tap opening for tapping the metallic phase and / or a second tap opening for tapping the slag phase. The tap opening for tapping the metallic phase is advantageously arranged in the bottom and / or in the side wall of the corresponding smelting reactor, so that it can be removed via these.

[0025] To supply the oxygen-containing gas and / or the inert gas, preferably nitrogen, the melt reactor preferably comprises at least one or more injectors arranged at the level of the combustion zone and / or the melt zone. Furthermore, the system advantageously comprises a catalytic SCR unit and / or a filter device arranged downstream of the post-combustion chamber. The invention and the technical environment are explained in more detail below with reference to figures and examples. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description and / or figures.It should be noted that the figures, and in particular the proportions depicted, are only schematic. Like reference symbols denote like objects, so that explanations from other figures can be used as a supplement if necessary. They show:

[0026] Fig. 1 shows an embodiment of the system according to the invention in a highly simplified schematic representation, on the basis of which the method according to the invention is explained.

[0027] The plant 1 is designed to carry out the process according to the invention, which is intended for the extraction of black and / or raw copper from organic-containing scrap, whereby proportions of silver (Ag), gold (Au), platinum (Pt) and palladium (Pd) can also be obtained.

[0028] Plant 1 comprises a melt reactor 2, a thermal

[0029] Afterburner chamber 3 and a filter device 4. The melting reactor 2 is designed in the form of a shaft furnace and has a melting zone 5, a combustion zone 6, and a pyrolysis zone 7. In a first process step, a comminuted mixture of 100 wt. % of an organic-containing scrap 8 of a shredder light fraction (SLF) is fed into the melting reactor 2 through an opening above (not shown). The comminuted organic-containing scrap 8 has an average grain size of 1.0 to 5.0 inches, although smaller grain sizes and / or dust particles are unavoidable due to the process and may therefore be present.

[0030] The organic-containing scrap 8 fed to the melting reactor 2 first passes through the pyrolysis zone 7 and the combustion zone 6. The temperature in the pyrolysis zone 7 is in the range of 900°C to 1200°C. Of the organic-containing scrap 8 added to the melting reactor, a proportion of 10–50 wt.% of the organic component is pyrolyzed in the pyrolysis zone 7, forming an energy-containing gas stream 9. As shown in Figure 1, this is then fed to the thermal post-combustion chamber 3 and completely combusted using a burner 10, with the thermal energy released during combustion being dissipated via an energy recovery unit 11 comprising an evaporator. Hydrogen produced from renewable energy sources (so-called green hydrogen) is advantageously used as the fuel for the burner 10.

[0031] The at least partially pre-pyrolyzed and / or combusted organic-containing scrap 8 is then melted in the melting reactor 2. The combustion reaction can be specifically controlled by the addition of oxygen, which is supplied to the melting reactor 2 via an oxygen injector 12. The volume flow of the oxygen is adjusted such that a reducing atmosphere always prevails on the surface of the melt and complete combustion of the organic component to CO2 and FI2O does not occur, but rather specific contents of CO and H2 are present in the process gas, which are also fed to the thermal afterburning chamber 3 and combusted. Furthermore, an inert gas, such as nitrogen, can be specifically introduced into the combustion and / or melting zone 5, 6 via the injector 12. This cools the melt and forms an energetic inert gas stream 14.As shown in the schematic representation, the energy-charged inert gas stream 14 transfers the energy-containing gas stream 9 formed in the upper part of the melt reactor 2 into the thermal afterburning chamber 3. The exhaust gas stream 15 formed in the thermal afterburning chamber 3 is then fed to the filter device 4.

[0032] List of reference symbols

[0033] 1 Plant 2 Melt reactor

[0034] 3 thermal afterburner chamber

[0035] 4 Filter device

[0036] 5 Melting range

[0037] 6 Combustion area 7 Pyrolysis area

[0038] 8 Electronic waste

[0039] 9 Energy-containing gas stream

[0040] 10 Burner 11 Heat exchanger 12 Injector

[0041] 13 inert gas stream

[0042] 14 Exhaust

[0043] 15 Exhaust gas flow

Claims

Patent claims:

1. A process for recovering non-ferrous metals, in particular black and / or crude copper, from organic-containing scrap (8), comprising the steps of: i) providing a melting reactor (2), wherein the melting reactor (2) is configured to have at least one melting zone (5), one combustion zone (6), and one pyrolysis zone (7); ii) feeding the melting reactor (2) with a mixture comprising the organic-containing scrap (8), such that, before reaching the melting zone (5), the scrap first passes through the pyrolysis zone (7) and the combustion zone (6) and is at least partially pre-pyrolyzed and / or combusted, forming an energy-containing gas stream (9); iii) transferring the energy-containing gas stream (9) into a thermal afterburner (3).in which the energy-containing gas stream (9) is completely combusted and the heat energy released during combustion is dissipated via an energy recovery unit (11), and iv) melting of the organic-containing scrap (8) that has been at least partially pre-pyrolyzed and / or combusted.

2. Method according to claim 1, wherein the melt is cooled by supplying an inert gas to the combustion and / or melting area (5, 6) and an energy-charged inert gas stream (14) is formed.

3. Method according to claim 2, wherein the energy-containing gas stream (9) is transferred into the thermal afterburner chamber (3) by means of the energy-charged inert gas stream (14).

4. Method according to one of the preceding claims, wherein the organic-containing scrap (8) is fed to the melting reactor (2) in countercurrent flow to the energy-charged inert gas stream (14).

5. Method according to any of the preceding claims, wherein the pyrolysis zone (7) has a temperature of at least 180 °C, preferably a temperature of at least 420 °C, more preferably a temperature of at least 800 °C, and most preferably a temperature of at least 900 °C.

6. Method according to one of the preceding claims, wherein the organic scrap (8) is supplied in crushed form according to step ii).

7. Method according to any of the preceding claims, wherein the mixture comprising the organic-containing scrap (8) has an organic content of at least 10 wt.%.

8. Method according to one of the preceding claims, wherein the exhaust gas flow (15) formed in the thermal afterburning chamber (3) is fed to a filter device (4).

9. Method according to one of the preceding claims, wherein step ii) is supported by selective injection of an oxygen-containing gas.

10. Plant (1) for the recovery of non-ferrous metals, in particular black and / or raw copper, from organic-containing scrap (8), comprising: i) a melting reactor (2), wherein the melting reactor (2) is configured to have at least one melting zone (5), one combustion zone (6), and one pyrolysis zone (7); ii) a thermal afterburner (3) in which an energy-containing gas stream (9) is fully combustible; and iii) an energy recovery unit (11) through which heat energy released during combustion can be dissipated.

11. Plant (1) according to claim 10, further comprising at least one Injector (12, 13) for supplying an oxygen-containing gas and / or an inert gas.

12. System (1) according to claim 10 or 11, further comprising a filter device (4).