HK1193848A - Method for obtaining metals and rare earth metals from scrap - Google Patents

Description

Method for obtaining metals and rare earth metals from scrap metal

The present process relates to obtaining metals, precious metals and rare earth metals from scrap metal.

Metals, noble metals and especially rare earth metals are used in a large number of key technologies.

Rare earth metals have special positions due to the limited range of naturally occurring parts, especially for highly innovative key technologies. They directly constitute the basic raw material in highly new technology-applications. Europium metal is required in cathode ray tubes for the red component of the RGB color system. The rare earth metal causes the magnet to retain its magnetic effect. These neodymium magnets are used as permanent magnets in permanently excited electric motors and are constructed in the generator of wind power installations and in the electric motor part of Kfz hybrid motors. The alloy cell also requires the element lanthanum. 13% of rare earth metal is used for the polishing agent. About 12% is used for special glasses and 8% is used for lighting devices for plasma screens and LCD screens, for energy saving lamps and radar devices. For this reason 124000 tons are consumed in 2009, whereas 189000 tons are expected to be needed in 2012. Furthermore, rare earth metals are also used in diagnostic radiology-medicine as contrast agent additives in nuclear spin analysis (magnetic tomography).

The european commission has classified rare earth metals as "key metals" in the "raw material proposal" section. According to the opinion of the committee working group, the use of rare earth metals is very important and the availability is very rare. Furthermore, the storage area of rare earth metals is very limited, and thus may play a decisive role in geopolitics in its long-lasting availability. For example, europe does not include any stockpiled countries where rare earth metals are economically available. 90% of the rare earth requirements of countries of the European Union are imported from China and satisfied. The price of various rare earth metals has increased more than ten times in the last 10 years.

The decomposition of rare earth metals is accompanied by the production of large amounts of waste in mines, which contain toxic waste. They are mostly deposited in artificial ponds enclosed by dikes. Furthermore, most rare earth metal deposition beds contain radioactive materials that carry the risk of escaping the radioactivity into air or water channels.

For the reasons mentioned above, it is becoming increasingly important to obtain recycling processes which lead the above-mentioned substances back to the economic cycle.

Of particular interest in this regard are electronic old equipment or electronic scrap metal from the disposal of electronic equipment. Significant amounts of valuable metals, precious metals and rare earth metals are contained in such waste streams. Electronic scrap metal is also largely an unutilized source of raw materials that contain very high concentrations of valuable elements. This is often the case in naturally sedimented bed minerals.

It is very difficult to separate individual metals, noble metals and rare earth metals from electronic scrap metal. This is particularly true for electronic components soldered to the circuit board, which are themselves composed of plastic and additives (Zuschlagstoffen), for example bromine-containing flame retardants. Therefore, it is very difficult to thermally recycle electronic scrap metals despite the considerable calorific value.

Thus, for example, DE102004029658 proposes a solution to this problem, which consists in first burning the contained plastic components, in order to separate the metal from the ash fouling by means of chemical and physical separation methods. However, it is disadvantageous in this respect that the flue gas produced is rich in harmful substances, such as hydrogen bromide, hydrogen chloride and hydrogen fluoride, and heavy metals. Therefore, it must be purified very expensively and laboriously. The same applies to dioxins and furans, since the usually high content of copper fractions and the catalytic effect of copper in electronic metal waste occur in large amounts in flue gases.

Other methods are also used to solve such tasks: the synthesis gas is formed by gasification to recycle the plastic component of the electronic scrap metal. Such a process is described, for example, in DE19536383A 1. However, there is a disadvantage in that hydrogen bromide and heavy metals are also obtained in the synthesis gas produced.

Therefore, separation processes are mostly established in the prior art, which process the scrap electronic metal via physical and partially chemical separation processes and separate it into separate streams of substances. Such processes are described, for example, in DE10031260B4 and DE19726105A 1. However, disadvantages of this process are the high equipment consumption and the unsatisfactory selectivity of the individual separation steps and the inadequate enrichment grade of the valuable metals. In this regard, the combination of this process with acid treatment in turn poses significant additional environmental problems.

The object of the invention is therefore to provide a method which makes it possible to efficiently recycle electronic scrap metal, optionally with the use of plastic-containing fractions, for an efficient conversion of energy into synthesis gas.

According to the invention, this object is achieved in that in a countercurrent gasifier having a reduction zone and an oxidation zone, which is equipped with a moving bed of bulk material, carbonaceous material is oxidized with an oxygen-containing gas in the presence of basic substances under reducing overall conditions with a total lambda of less than 1, the synthesis gas thus produced is withdrawn at the top of the countercurrent gasifier, and the metals, noble metals and rare earth metals are combined as oxides and/or in elemental form at least partially with the basic substances, wherein they are obtained from the process as enriched mixture by means of physical separation methods.

The invention offers the advantage that, on the one hand, the carbon content that is always present, for example, in electronic scrap metal can be utilized in the method, so that it ultimately also provides the required energy for obtaining the metal. Meanwhile, harmful substances such as bromine or hydrogen bromide and chlorine or hydrogen chloride are effectively combined by the alkaline substance, so that the formation of toxic dioxin and furan can be avoided. Therefore, there is no need to specially select the electronic scrap.

As described above, the carbonaceous material and the metallic waste may refer to electronic metallic waste and/or complete electronic old equipment, such as a mobile phone or a computer. The method according to the invention thus offers the advantage that the plant can be completely guided to the recycling process and does not have to be separated first, which is expensive and complicated, according to the material type.

Thereby, the carbon-containing component, such as a plastic shell or the like, serves as an energy carrier for the process, while the metal component is recovered.

Furthermore, it can be advantageous to additionally add cable residues and/or other metal-containing dusts or solid substances to the carbonaceous material and the metal waste material in order to further increase the recyclable metal content of the bulk material. It may also refer to ash from a combustion process (e.g., from a waste incineration facility), or oil shale or other naturally occurring carbonaceous material with metals, for example.

The alkaline substance used is preferably a metal oxide, a metal carbonate, a metal hydroxide or a mixture of 2 or 3 of these substances, which is metered in specifically into the gas phase above the countercurrent gasifier and/or the reduction zone and/or is mixed with the carbonaceous material before entering the vertical process chamber. These substances have proven to be particularly effective for the process according to the invention, wherein preferably alkali metal elements or alkaline earth metal elements, particularly preferably calcium, are to be contained as cations in the metal salts.

In a preferred embodiment of the process according to the invention, the alkaline substance is used at least partially in the form of fine particles having a particle size of less than 2mm as a solid and/or as a suspension in water. The formation of fines is adapted to allow the low-melting metal to adhere in liquid form to the fine-grained metal oxide below the temperature at which the oxidation zone is present and to be transported downwards in a countercurrent gasifier.

In order to improve the flow capacity of the bulk material and/or to increase its gas permeability, it is expedient to add additional coarse material to the bulk material moving bed, wherein inert minerals and/or other inorganic substances or substance mixtures with a particle size of 2mm to 300mm, as well as wood and/or other biogenic materials with a similar particle size, can be used as coarse material. In the case of wood or material of biological origin, the coarse material simultaneously serves as an energy source for the method. Naturally, the additional carbon carriers are mixed in before entering the vertical process chamber in order to increase the concentration of the recyclable carbon fraction in the bulk material moving bed and to cover the energy requirements of the process as much as possible in the oxidation zone by external addition and not by burner lances or similar devices.

The reducing overall conditions of the process are preferably an overall lambda of less than 0.7, preferably 0.5 or less, through all stages of the process chamber. The reducing conditions promote the binding of the hazardous substances in a desired manner.

Preferably, the temperature of the reduction zone is up to 1500 ℃, so that metals and rare earth metals, which are present as oxides and as elementary substances, have a standard potential of 0 volts in acid solution relative to a standard hydrogen electrode, are at least partially reduced to elementary metals via the carbon present and carbon monoxide contained in the synthesis gas. The process described offers the advantage that the elemental metal can be produced directly in the process, so that a separate physical separation process does not have to be carried out after enrichment of the extracted material.

In a further preferred embodiment of the method, it is provided that the reduced metals and rare earth metals and the metals, noble metals or rare earth metals which have been initially present in the carbonaceous material as elements at least partially reach their melting points in the reduction zone and are at least partially fixed as molten droplets on the moving bed of bulk material and are subsequently transported in the countercurrent gasifier to the oxidation zone. In this way, the concentration of the elements to be obtained begins in the bulk moving bed until the physical separation process is applicable.

A further embodiment of the process of the invention provides that the metal reduced in the reduction zone and the metal, noble metal or rare earth metal which has initially been present as elemental in the process, if having such a standard potential of less than 1 volt relative to a standard hydrogen electrode in an acid solution, are converted at least partially in the oxidation zone at temperatures of up to 1800 ℃ and with a lambda of more than 1 into oxides which are enriched with a fine-grained mineral fraction and thus produce a mixture of fine-grained basic substance constituents, the metals and rare earth metals which are present mostly in the oxidized state and the noble metal which is present in elemental form.

This embodiment can also be adapted to separate the elements to be obtained in the recycling process after concentration.

A further embodiment of the process according to the invention can provide that the mixture, which consists of fine-grained basic substances, metals and rare earth metals in oxidized form and noble metals in elemental form, is discharged partly with the bulk material moving bed at the lower end of the countercurrent gasifier and partly via synthesis gas from the top of the countercurrent gasifier.

For example, a mixture consisting of fine-grained minerals, metals and rare earth metals in oxidic form and noble metals in elemental form, which is discharged with the moving bed of bulk material at the lower end of the countercurrent gasifier, can be separated as a fine-substance mixture by screening the coarse-lumpy bulk material. In the case of a discharge via the synthesis gas, it is preferred that the mixture consists of fine-grained minerals, metals and rare earth metals in oxidized form and noble metals in elemental form, which is discharged via the synthesis gas at the top of the countercurrent gasifier, is conducted through physical solids separation together with the synthesis gas and is separated there as filter dust.

Regardless of the manner of obtaining, the fine substance mixture and/or the filter dust is preferably returned in part to the bulk material moving bed, and the partial recirculation is thereby directed to achieve a further enrichment of the metals present in oxidized form, rare earth metals and noble metals present in elemental form. As mentioned above, enrichment can subsequently improve the efficiency of metal deposition in pure form.

It is preferably also envisaged to adjust the total amount of carbonaceous material and carbon support metered in specifically to the process in the bulk material moving bed so that sufficient carbon is provided for the reduction reaction in the reduction zone and sufficient oxidizable carbon in the oxidation zone is provided for the energy input in the countercurrent gasifier.

The amount of oxygen-containing gas introduced is also preferably measured so as to provide sufficient oxygen for the complete oxidation of the residues on the pyrolysis coke, optionally residues on other carbon supports and oxidizable metals, rare earth metals and noble metals present in elemental form, present in the oxidation zone.

Particularly preferred is an embodiment of the process according to the invention in which the calcium-catalyzed reforming of the major proportion of the oil-and/or tar-containing cleavage product produced, which has a chain length of greater than C4, to carbon monoxide, carbon dioxide and hydrogen is carried out in a vertical process chamber and/or in the gas phase of the gaseous reaction product withdrawn, in the presence of steam and calcium oxide and/or calcium carbonate and/or calcium hydroxide at a temperature of greater than 400 ℃. The catalytic effect of the calcium compound thus leads to a significantly more advantageous progression of the overall process.

The water vapor is metered in a targeted manner into the gas phase in the vertical process chamber and/or above the reduction zone and/or is supplied in situ from the residual moisture of the material used.

Fig. 1 shows an embodiment of the method according to the invention. Which are intended to be illustrative of the methods of the invention and not limiting.

The carbonaceous material and the metalliferous material, preferably electronic scrap metal stream (A), is mechanically comminuted (1) to a particle size of less than 30cm and is fed from above via a vertical chute to a counter-current gasifier (2) formed as a vertical process chamber. This constitutes a moving bed of bulk material. For the subsequent constitution of the metals, noble metals and rare earth metals contained in the electronic scrap metal, an alkaline substance (3), preferably fine-grained calcium oxide, is mixed into the electronic scrap metal before entering the countercurrent gasifier (2).

Depending on the quality and physical properties of the electronic scrap metal, it can be advantageous to mix coarse material (4) with a particle size of 2mm to 300mm before entering the countercurrent gasifier (2). This is particularly relevant in the case of a moving bed of bulk material which is to be improved in terms of flow behavior or gas permeability.

Carbon carriers (5) can also be additionally mixed into the bulk material moving bed in order to increase the recyclable carbon content of the bulk material. Many different carbon carriers can be used in this connection besides wood and biogenic substances.

The mixture of electronic scrap metal, alkaline material, coarse material and optionally gaseous carbon carriers flows through the vertical process chamber (2) from top to bottom by its own weight. The counter-current gasifier has a middle zone burner lance (6) which provides for the stable formation of a substantial load of combustion and oxidation zones (7) in the vertical process chamber. The burner lances may be driven with fossil fuel (8) and oxygen-containing gas (9). Instead of fossil fuels, synthesis gas from a countercurrent gasifier (10) can also be used.

An oxygen-containing gas (11) is introduced at the lower end of the vertical process chamber. These gases are used firstly for cooling the bulk material in a cooling zone (12) before leaving the vertical process chamber. During the upward flow along the vertical process chamber, the oxygen-containing gas is thereby preheated. In accordance with the principle of countercurrent gasification, the oxygen in the oxygen-containing gas is subjected to an oxidation reaction with the carbonaceous material in the bulk material, wherein the amount of oxygen-containing gas is adjusted such that the total lambda in the vertical process chamber is preferably adjusted to less than 0.5. Whereby an oxidation zone (7) is first formed in which the residues of the carbonaceous material react with oxygen to form CO₂. In the upper part of the process chamber, the oxygen is further reduced so that finally only carbonization (Verschwelling) to form CO takes place until the still upper part of the total oxygen is finally consumed, forming a reduction zone (13) in fully reduced conditions.

When observing the flow of the mixture consisting of scrap of electronic metal, alkaline substances, coarse substances and optionally other bulk materials of carbon support from top to bottom, it can be seen that drying of the possibly moist starting material takes place first in the reduction zone (13) up to an intrinsic temperature (eignemperatur) of 100 ℃. The intrinsic temperature of the material is then raised, whereby the process of gasification of the plastic (e.g. circuit board) typically contained in the electronic metal scrap takes place, and the formation of methane, hydrogen and CO starts at intrinsic temperatures up to 500 ℃. After a large degree of degassing, the intrinsic temperature of the material is further raised by hot gases from the oxidation zone (7), whereby electrons are generatedThe scrap metal is eventually degassed completely and consists only of residual coke (Restkoks), the so-called pyrolysis coke, metals, precious metals, rare earths and ash. The pyrolysis coke and optionally other carbon carriers are transported with the bulk material further to the lower part in a vertical process chamber, where they are at a temperature above 800 ℃ in a reduction zone (13) with CO from an oxidation zone (7)₂The components are partly converted to CO by Boudouard-conversion. A portion of the pyrolyzed coke and optionally other carbon carriers reacts with water vapor also contained in the hot gases in this region according to the water gas reaction to form CO and hydrogen. Up to this process step, the metals and in particular the rare earth metals contained are present partly as oxides in the bulk moving bed.

Fig. 2 shows the different metals in column a and their standard potentials in the acid solution in volts versus a standard hydrogen electrode in column E.

The metal present as an oxide in the electronic scrap metal and having a standard potential of less than 0 volts is at least partially reduced in the reduction zone (13) by the carbon present and converted to elemental metal at temperatures of up to 1500 ℃.

Fig. 2 shows the melting points of the different metals present in elemental form in column C.

The metal initially present in the reduction zone, or present as elemental metal by reduction and having a melting point of less than 1500 ℃, is at least partially converted into molten droplets which adhere in liquid form to the fine-grained CaO and are transported further downwards in the countercurrent gasifier for the most part with a moving bed of bulk material. The same applies to metals or metal oxides present with a sufficiently large particle size, since insufficient liquefiable properties largely prevent expulsion via the gas phase.

The above-mentioned metals, together with the residues of the pyrolysis coke and optionally other carbon carriers, are finally oxidized in an oxidation zone (7) with an oxygen-containing gas (11) flowing from below at a temperature of less than 1800 ℃ and thermally utilized. It is thereby possible that the countercurrent gasifier itself provides the energy required for gasification virtually completely. Also referred to in this respect as an autothermal gasification process.

In the case of this oxidation, the pyrolysis coke and optionally also the carbon support are virtually completely passed through to form CO₂Or CO is oxidized.

If it has a standard potential of less than 1 volt, the metal is converted to its oxide to a large extent in the oxidation zone (7); during this time noble metals, in particular gold, having a standard potential above 1 volt remain available in elemental form.

The bulk material moving bed, together with the metal present in the most oxidized form and the metal present in the elemental form, reaches a cooling zone (12).

Water (14) may also be metered into the cooling zone (12) via water jets (15) as additional refrigerant and gasifying agent.

The synthesis gas formed in the vertical process chamber is removed (16) at the top, so that a slight underpressure of 0 to-200 mbar is preferably set in the vertical process chamber from the top gas chamber (17).

During the gasification process, depending on the nature of the feedstock, a significant portion of gaseous acidic halogen-containing gases or halogens can occur. In the case of electronic metal scrap, such as bromine-containing flame retardants contained in circuit boards, can result in significant release of hydrogen bromide or elemental bromine. It is therefore advantageous to mix alkaline substances (3) between the electronic scrap metal material entering the vertical process chamber. Particularly suitable in this connection are metal oxides, metal hydroxides or metal carbonates, wherein the use of finely divided calcium oxide is particularly preferred, since it reacts spontaneously by its reactivity and large surface area with the gaseous halogen compounds or halogens formed to form solid salts, which are discharged from the vertical process chamber for the most part together with the synthesis gas taken off. In addition, other harmful substances, such as chlorine, hydrogen chloride or volatile heavy metals, can also be very effectively bound to calcium oxide and discharged from the process in the same way.

It is additionally of interest to use coarse-grained metal oxides, metal hydroxides or metal carbonates as the coarse substance (4) in order, on the one hand, to increase the proportion of bulk material in the electronic metal scrap and, on the other hand, also to provide an alkaline reaction partner for the binding of gaseous halogen compounds or halogens in the lower part of the vertical process chamber.

The withdrawn synthesis gas contains dust, which essentially consists of solid salts of halogens, fine-grained basic substances, other harmful substances and inert particles. Depending on the process and the composition of the scrap electronic metal, it is also possible for the dust to also contain small proportions of oxidized or elemental metals, rare earth metals and noble metals. This is particularly the case where very fine particles of metal are carried away from the syngas produced before the metal is reduced or converted to molten particles in the reduction zone (13).

The dust-containing synthesis gas can be treated in the gas chamber (17) of the vertical process chamber or after (16) leaving the vertical process chamber in the presence of water vapour and fine-grained calcium oxide at a temperature of more than 400 ℃. The above-mentioned temperatures can be adjusted by correspondingly adjusting the amount of oxygen-containing gas (11) in the lower end of the vertical process chamber or by the heat output of the burner lances (6) in the oxidation zone (7). However, it is particularly advantageous to use direct combustion in the synthesis gas via the burner lances (18), which are driven stoichiometrically with fuel and oxygen-containing gas or with excess oxygen-containing gas. These thermal after-treatments ensure the cracking of oils and tars still present in small quantities in the synthesis gas, in the presence of steam and calcium oxide, by the catalytic effect of calcium oxide.

Subsequently, the dust-laden syngas is dusted via hot gas filtration (19) at a temperature of more than 300 ℃. Filter dust (20) containing halogen is extracted from the process. In a preferred embodiment of the method according to the invention, it is also possible to mix the filter dust at least partially again as fine-grained alkaline substance with the bulk material in (3) and thus to drive the circulating operation of the partial filter dust.

The resulting syngas (10) is virtually halogen-free and can be used as a feedstock or fuel for a variety of different applications.

As may be required by site conditions or requirements for further use of the syngas, the syngas is cooled by a gas cooler (21) and the condensate is removed, which can then be successfully recycled. The deposited condensate (22) can be used at least partially again as a refrigerant and a gasifying agent for the vertical reaction chamber via a water lance (15).

The bulk mixture (23) discharged at the lower end of the vertical reaction chamber contains mainly coarse-grained bulk, ash residues and fine-grained calcium oxide, wherein metal oxides and in particular rare earth metal oxides and precious metals melting at less than 1500 ℃ are enriched.

The total bulk stream can be extracted (24) from the process as a whole for recovery of metals, precious metals and rare earth metals. Particularly preferred, however, is the screening of the bulk material mixture (25), wherein the crude fraction (26) is preferably at least partially introduced into the circulation and reused as crude material additive (4) in the vertical process chamber.

The fine fraction (B) comprises ash residues and fine-grained calcium oxide, which is enriched with metal oxides and in particular rare earth metal oxides and noble metals in elemental form which melt at temperatures below 1500 ℃.

In a preferred embodiment of the process according to the invention, it is possible for the fine sieve fraction to be mixed at least partially again as fine-grained basic substance with the bulk material in (3) and thus to drive the partial circulation operation of the fine sieve fraction. It is thus possible to enrich the concentration of metal oxides and in particular rare earth metal oxides and noble metals present in elemental form which melt below 1500 ℃. This makes it possible to obtain recyclable substances particularly efficiently from the fine sieve fraction, using suitable physical and/or chemical methods.

As mentioned above, the filter dust (20) may also contain a significant proportion of metals, rare earths or precious metals. Thus, filter dust can also be used to obtain recyclable material, as appropriate, applying suitable physical and/or chemical methods.

Claims (23)

1. Method for obtaining metals, precious metals and rare earth metals from scrap metals, characterized in that scrap metals and carbonaceous materials (a) are oxidized with an oxygen-containing gas (11) in the presence of a basic substance under reducing overall conditions with a total Λ of less than 1 in a counter-current gasifier (2) provided with a bulk moving bed having a reduction zone (13) and an oxidation zone (7), the synthesis gas thus produced being withdrawn at the top (16) of the counter-current gasifier and the metals, precious metals and rare earth metals being obtained as oxides and/or in elemental form at least partially bound to the basic substance from the process by means of physical separation methods as an enriched mixture (B).

2. The method according to claim 1, characterized in that the carbonaceous material (a) and the scrap metal are scrap electronic metal and/or whole used electronic equipment.

3. Method according to one of the preceding claims, characterized in that cable residues and/or other metal-containing dust or solid substances are also metered into the carbonaceous material (a) and the metal waste to further increase the recyclable metal content of the bulk material.

4. The method of claim 3, wherein the metal-bearing dust or solid material is ash from a combustion process, or oil shale or other naturally occurring carbonaceous material having metals.

5. The method as claimed in one of the preceding claims, characterized in that metal oxides, metal carbonates, metal hydroxides or mixtures of 2 or 3 of these are used as alkaline substance, which is metered in specifically into the gas phase above the countercurrent gasifier and/or the reduction zone (13) and/or is mixed with the carbonaceous material before entering the vertical process chamber.

6. The method according to claim 3, characterized in that the metal oxides, metal carbonates and metal hydroxides comprise as cations an alkali metal element or an alkaline earth metal element, particularly preferably calcium.

7. Method according to one of the preceding claims, characterized in that the alkaline substance is used at least partially in the form of fine particles with a particle size of less than 2mm as a solid and/or as a suspension in water.

8. Method according to one of the preceding claims, characterized in that the moving bed of bulk material is formed in part by additional dosing of coarse matter (4) which is mixed with the carbonaceous material before entering the vertical process chamber in order to increase the flow capacity of the bulk material and/or its gas permeability.

9. A method according to claim 6, characterized in that as coarse material (4) mineral and/or other inorganic material or material mixture with a particle size of 2mm to 300mm is used.

10. Method according to claim 6, characterized in that as coarse matter (4) wood and/or other biogenic material is used with a grain size of 2mm to 300 mm.

11. Process according to one of the preceding claims, characterized in that the reductive overall conditions are carried out at all stages of the overall lambda through the process chamber of less than 0.7, preferably 0.5 or less.

12. Method according to one of the preceding claims, characterized in that the carbon-rich material (a) is mixed with additional carbon carriers (5) before entering the vertical process chamber (2) in order to increase the concentration of the carbon-recyclable fraction in the moving bed of bulk material.

13. The method according to one of the preceding claims, characterized in that the temperature of the reduction zone (13) is up to 1500 ℃, so that said metals and rare earth metals, which are present as oxides and as elementary substances and have a standard potential of 0 volts in acid solution relative to a standard hydrogen electrode, are at least partially reduced to elementary metals via the carbon present and the carbon monoxide contained in the synthesis gas.

14. The method according to one of the preceding claims, characterized in that the reduced metals and rare earth metals and the metals, noble metals or rare earth metals which have been initially present in the carbonaceous material as elements at least partially reach their melting points in the reduction zone (13) and are at least partially fixed as molten droplets on the moving bed of bulk material and are subsequently transported in a countercurrent gasifier to the oxidation zone (7).

15. The method as claimed in one of the preceding claims, characterized in that the metal reduced in the reduction zone (13) and the metal, noble metal or rare earth metal which has initially been present as an element in the process, if having such a standard potential of less than 1 volt relative to a standard hydrogen electrode in an acid solution, are converted at least partially into oxides at temperatures of up to 1800 ℃ and with Λ of more than 1 in the oxidation zone (7), which are enriched with a fine-grained mineral fraction and thus produce a mixture from fine-grained basic substances, the metals and rare earth metals which are present mostly in the oxidized state and the noble metal which is present in the elemental form.

16. The method as claimed in one of the preceding claims, characterized in that the mixture, which consists of fine-grained alkaline substances, metals and rare earth metals in oxidic form and noble metals in elemental form, is discharged partly with the moving bed of bulk material at the lower end (23) of the countercurrent gasifier and partly via synthesis gas from the top end (16) of the countercurrent gasifier.

17. The method as claimed in claim 14, characterized in that the mixture consisting of fine-grained minerals, metals and rare earth metals in oxidic form and noble metals in elemental form, which is discharged at the lower end (23) of the countercurrent gasifier together with the moving bed of bulk material, is separated as a fine-grained mixture by screening (25) the coarse bulk material.

18. The method according to claim 14, characterized in that the mixture, which consists of fine-grained minerals, metals and rare earth metals in oxidized form and precious metals in elemental form, is discharged via the synthesis gas at the top end (16) of the countercurrent gasifier, is conducted together with the synthesis gas through a physical solids separation (19) and is separated there as filter dust (20).

19. The method according to claim 15 or 16, characterized in that the fine-material mixture (B) and/or the filter dust (20) is partly returned at (3) into the bulk-material moving bed, and whereby the partial recirculation leads to a further enrichment of metals present in oxidized form, rare earth metals and precious metals present in elemental form.

20. The method as claimed in one of the preceding claims, characterized in that the total amount of carbonaceous material and the specifically metered carbon carrier (5) introduced into the process in total in the bulk material moving bed is adjusted such that sufficient carbon is provided for the reduction reaction in the reduction zone (13) and sufficient oxidizable carbon in the oxidation zone (7) is provided for the energy input in the countercurrent gasifier.

21. The process as claimed in one of the preceding claims, characterized in that the total amount of oxygen-containing gas introduced into the process in total is adjusted such that sufficient oxygen is provided for the complete oxidation of the residues on the pyrolysis coke present in the oxidation zone (7), optionally residues on other carbon supports and oxidizable metals, rare earth metals and noble metals present in elemental form.

22. The method according to one of the preceding claims, characterized in that the calcium catalytic reforming of the major fraction of the produced oil-and/or tar-containing cleavage products is carried out in a vertical process chamber (2) and/or in the gas phase (17) of the withdrawn gaseous reaction products in the presence of water vapor and calcium oxide and/or calcium carbonate and/or calcium hydroxide at a temperature of more than 400 ℃, converting said cleavage products having a chain length of more than C4 into carbon monoxide, carbon dioxide and hydrogen.

23. The method as claimed in claim 5, characterized in that the water vapor is metered in a targeted manner into the gas phase in the vertical process chamber (2) and/or above the reduction zone (13) and/or is supplied in situ from the residual moisture of the material used.