BE1030435A1 - Plant and a process for the heat treatment of mineral material - Google Patents

Abstract

The present invention relates to a system (10) for the heat treatment of mineral material, comprising a reactor (12) with at least one gas inlet (29) for admitting exhaust gases, the reactor (12) having an activation region (16) for activating the mineral material and an exhaust gas outlet (28) for exhausting exhaust gases (30) from the reactor (12), the exhaust gas outlet (28) being connected to the at least one gas inlet (29) in such a way that at least part of the exhaust gas (30) is supplied to the reactor (12). is supplied. The invention also relates to a method for the heat treatment of mineral material with a reactor (12), wherein the material is activated in an activation region (16) of the reactor (12) and optionally cooled in a cooling region (18) of the reactor (12), wherein the exhaust gas (30) of the reactor (12) is removed from the reactor (12), at least part of the exhaust gas (30) removed from the reactor (12) being fed back to the reactor (12).

Description

'BE2022/5267

Plant and a process for the heat treatment of mineral material

The invention relates to a system and a method for the heat treatment of mineral material with an entrained flow reactor.

It is known that in the cement and mineral industries very large amounts of heat are required for the heat treatment of the mineral material. A part of

Heat treatment often takes place in an entrained flow reactor, in which the mineral material to be treated is entrained by a hot gas stream, with heat exchange occurring between the two during the residence time in the entrained flow reactor

Gas and the mineral material comes so that the mineral material is preheated, dried, calcined and/or dehydroxilized. The required hot gas stream is provided, for example, by the exhaust gases from a furnace connected to the entrained flow reactor and/or by combustion of fuel in the entrained flow reactor. From the

DE 10 2012 022 179 A1 and DE 10 2010 008 785 B4 are also additional

Combustion chambers are known, which are connected to the entrained flow reactor and for

Combustion of mostly low-quality fuels (secondary or alternative fuels).

Encapsulated flow reactors are used, for example, to produce clinker substitutes, such as calcined clays, or to obtain metals or metal oxides

Ore-containing materials are used. When activating tones in one

The entrained flow reactor produces exhaust gases with a CO: content, which is known to be harmful to the environment.

Based on this, it is the object of the present invention to provide a system and a

Process for the heat treatment of mineral material with a

Specify an entrained flow reactor that reduces the COz content and the

Pollutants, such as nitrogen oxides, in the exhaust gas.

This object is achieved according to the invention by a device with the features of independent device claim 1 and by a method with the features of

? BE2022/5267 independent procedural claim 9 solved. Advantageous further training results from the dependent requirements.

According to a first aspect, a plant for the heat treatment of mineral material comprises a reactor with at least one gas inlet for admitting

Exhaust gases, the reactor having an activation area for activating the mineral

Material and an exhaust gas outlet for exhausting exhaust gases from the reactor. The exhaust gas outlet is connected to the at least one gas inlet such that at least part of the exhaust gas is fed to the reactor.

A return of at least part of the exhaust gas into the reactor causes a

Enrichment of the reactor exhaust gas with CO2 so that the exhaust gas has a high CO2 concentration

Content of preferably at least 75% by volume. Such a high CO2 content is advantageous for subsequent treatment of the exhaust gas, for example

Separation or storage of CO »

According to a first embodiment, the reactor is an entrained flow reactor and has a preheating area for preheating the material, an activation area

Activating the mineral material and optionally a cooling area to cool the

material. The exhaust gas outlet is preferably arranged in the preheating area, the exhaust gas outlet being connected to the activation area and/or the cooling area of the

Flystream reactor is connected in such a way that at least part of the exhaust gas

Activation area and / or a cooling area is supplied. The

Activation area, the cooling area and/or the preheating area preferably each have at least one gas inlet, which in particular is connected to the

Exhaust gas outlet is connected to conduct the exhaust gas into the gas inlet. The

Activation area, the cooling area and the preheating area are, for example, arranged at the same height level, in particular next to one another. It is also conceivable that the activation area, the cooling area and/or the preheating area are arranged at different height levels. This is preferred

Preheating area arranged above the activation area and the activation area above the cooling area. The activation region of the entrained flow reactor has, for example, at least partially a fluidized bed.

) BE2022/5267

According to a further embodiment, the activation area has at least one

Combustion chamber and/or a hot gas generator and the exhaust gas outlet is connected to the

Combustion chamber and / or the hot gas generator connected in such a way that at least one

Part of the exhaust gas is fed to the combustion chamber and/or the hot gas generator.

The activation region of the entrained flow reactor has, for example, a heating device, in particular a hot gas generator for generating a hot gas. The

Heating device is preferably in addition to the combustion chamber and/or the

Fuel inlet arranged. In particular, the heating device is such that

Riser line of the activation area connected that the hot gases generated in the heating device below the hot gases generated in the combustion chamber

Riser pipe can be initiated. The heating device preferably has a

Gas inlet for admitting recirculated exhaust gas, preferably with the

Return line is connected.

According to the inventors' knowledge, treatment of the exhaust gas for storage or further treatment of the COz proportion in the exhaust gas is possible particularly easily if the COz proportion of the exhaust gas that leaves the system, in particular the entrained flow reactor, is particularly high, in particular about 70 to 95% by volume, preferably at least 75% by volume. Such a proportion of COz in the exhaust gas enables, for example, easy liquefaction, separation or sequestration of CO. In addition, the discharged exhaust gas can be used, for example, for soda production, sugar production or for

Production of precipitated calcium carbonate can be used.

The system for heat treatment of materials optionally includes a

Crushing device, such as a mill or a crusher and/or a

Drying device for treating the material before entering the reactor.

The reactor, in particular the entrained flow reactor or the fluidized bed reactor, serves

In particular the heating, preferably the activation of the material, whereby a

Activation, for example, calcination, deacidification, dehydroxylization and / or

Decarbonization of the material includes.

* BE2022/5267

An entrained flow reactor comprises, for example, a multi-stage cyclone heat exchanger with a preheating area in the flow direction of the material

Activation area and optionally a cooling area. For example, a cooling gas flows through the cooling area and hot gases flow through the activation area and the

Preheating area of the various cyclones (based on the direction of gravity) from bottom to top, while the material to be thermally treated enters the cyclones

Countercurrent direction runs from top to bottom. The material is preferably separated from the gas stream in each of the cyclones and fed into one via an outlet

Gas flow is introduced, which is then fed to the cyclone below. In the cyclones below in the cooling area, the gas flow supplied via a compressor, for example, cools the material, with the gas being preheated.

Alternatively, the material can be cooled by at least one fan in the cyclone of the cooling area using the induced draft process. The preheated gas then flows through the riser pipe of the activation area, in which the actual thermal treatment of the material supplied from the preheating area takes place.

The gas flow in the activation area is additionally controlled via a

A hot gas is supplied to the combustion chamber or a burner in order to provide the thermal energy required for the treatment. It is also conceivable that

Riser pipe, in particular the activation area, exclusively or in addition to the

Combustion chamber or burning a fuel is supplied. The gas leaving the activation area is then used in the preheating area to preheat the

material used.

For example, the preheating area comprises a plurality of cyclones, in particular one to five cyclones, through which the material preferably flows one after the other, the material being preheated. The activation region of the entrained flow reactor adjoining the preheating region comprises, for example, one to three, preferably a cyclone and/or a riser pipe and at least one

Combustion chamber and/or a fuel inlet and/or a heater such as one

Hot gas generator.

The activation region preferably has a riser pipe which extends substantially in a vertical direction, optionally has one or more fuel inlets, and/or is connected to the combustion chamber and/or the heating device in such a way that

> BE2022/5267 hot gases generated in the combustion chamber and/or the heating device are admitted into the riser pipe. For example, the activation area has two or more

Combustion chambers and / or heating devices that are connected to the riser pipe.

In particular, the activation area has a heating device and a combustion chamber, which are connected to the riser pipe, for example, in such a way that each in the

Hot gases generated at different levels by the heating device or the combustion chamber

Positions, in particular offset in height, are introduced into the riser pipe. The

Heating device is arranged, for example, below the combustion chamber. That in that

Preheated material is preferably placed in the riser pipe of the preheating area

Activation area introduced and heated in direct current. In the direction of flow of the solid-gas mixture, at least one cyclone is connected to the riser pipe, which serves to separate solids.

The cooling area that optionally adjoins the activation area

The entrained flow reactor preferably comprises a plurality of cyclones, in particular two to four cyclones. The cooling area includes, for example, a fluidized bed cooler, a fluidized bed cooler and/or a plate cooler.

The preheating area of the entrained flow reactor preferably has a material inlet for admitting material to be treated into the entrained flow reactor. The

Preheating area preferably has an exhaust gas outlet for exhausting exhaust gas

Encapsulated flow reactor from the entrained flow reactor. The exhausted exhaust gas is converted into a

Exhaust pipe discharged. The exhaust gas is preferably exhaust gas from the preheating area, the activation area and/or the cooling area. The

The cooling area preferably has a gas inlet, for example a cooling gas inlet, which is arranged in particular at the lower end area of the cooling area, and in particular an area for the material inlet and an area for the

Material outlet.

The combustion chamber is preferably used to generate hot gases

Combustion of oil, coal or gas or secondary fuels such as old tires or

Household waste, and preferably has a fuel inlet for admitting fuel into the combustion chamber. The heating device is preferably used to generate

Hot gases, whereby the healing gas is preferably produced electrically or by combustion of

° BE2022/5267

Oil, coal or gas is produced. The heating device can also be one

Heat exchanger act to heat a gas stream, the heat exchanger being operated electrically or by means of a combustion chamber.

At least part of the exhaust gas removed from the preheating area is sent to the

Fly stream reactor, in particular the combustion chamber, the activation area and / or the cooling area. The part of the exhaust gas that enters the combustion chamber

Activation area and / or a cooling area is also referred to as recirculated exhaust gas flow. The combustion chamber preferably has the

Activation area and/or the cooling area each have at least one gas inlet

Inlet of the recirculated exhaust gas, the gas inlet being connected via a line to the exhaust gas outlet of the preheating zone. The line for feeding the recirculated exhaust gas into the combustion chamber, the activation area and/or the

The cooling area preferably runs at least partially or completely outside the

entrained flow reactor.

Recirculating at least part of the exhaust gas into the entrained flow reactor causes the exhaust gas from the entrained flow reactor to be enriched with COz, so that the exhaust gas has a high COz content of preferably at least 75% by volume. Such a high CO2

Content is advantageous for subsequent treatment of the exhaust gas, for example

Separation or storage of CO »

According to a further embodiment, the reactor is a fluidized bed reactor and has an activation region for activating the mineral material and optionally a cooling region for cooling the material. The exhaust outlet is with the

Activation area and / or the cooling area of the fluidized bed reactor connected in such a way that at least part of the exhaust gas is supplied to the activation area and / or a cooling area. The fluidized bed reactor preferably has one

Preheating area, which is located upstream of the activation area. The preheating area of the fluidized bed reactor corresponds, for example, to that with reference to

Preheating area described in the entrained flow reactor. The exhaust gas outlet is preferably arranged in the activation area or the preheating area.

/ BE2022/5267

According to a further embodiment, the system has a gas analysis device for determining the CO2 content, the oxygen content and/or the temperature of the

Exhaust gas, the exhaust gas outlet being connected to the gas analysis device for supplying the

Exhaust gas is connected.

According to a further embodiment, the system has a gas switch which

Gas analysis device is connected downstream and designed in such a way that it divides the exhaust gas into a recirculated exhaust gas stream and a discharged exhaust gas stream, the

Proportion of the exhaust gas flows to the exhaust gas is adjustable. The gas switch is preferably in

Gas flow direction of the exhaust gas arranged behind the gas analysis device.

Preferably, the gas switch is connected to a return line which is used for

Line of the recirculated exhaust gas arranged and in particular with the combustion chamber, the activation area and / or the cooling area for supplying the recirculated

Exhaust gas flow is connected. The discharged exhaust gas stream is preferably from the

Plant left out and not returned to the reactor. In particular, the discharged gas stream is an exhaust gas treatment device, such as one

Device for the liquefaction, separation or sequestration of CO2 or another process, for example for soda production, sugar production or

Production of precipitated calcium carbonate. In particular, the proportion of

Exhaust gas flows on the exhaust gas can be adjusted continuously, preferably between 0% and 100%. A division of the exhaust gas into at least two exhaust gas streams offers this

Advantage of a targeted return of a certain proportion of the exhaust gas into the

Reactor.

According to a further embodiment, the system has a control/

Control device which is designed in such a way that it controls the proportions of the by means of the

Gas switch divided exhaust gas flows depending on the determined CO2 content,

Oxygen content and / or the determined temperature of the exhaust gas removed from the preheating area controls / regulates. The control/regulation device is, for example, mounted in the gas switch or connected to the gas switch.

The control/regulation device is preferably designed in such a way that it compares the measured values determined by means of the gas analysis device with a predetermined one

Compares limit value or range of values and if there is a deviation from the

° BE2022/5267

The measured value determined by the gas analysis device depends on the limit value or the

Value range, the proportions of the exhaust gas streams divided by the gas switch, preferably the amount of recirculated exhaust gas increases or decreases. The

The gas analysis device is preferably connected to the control/regulation device in order to transmit the measured values determined.

For example, the gas analysis device is designed to determine the CO2 concentration in the exhaust gas and is connected to the control/regulation device to transmit the determined CO2 concentration. The control/regulation device is preferably designed in such a way that it compares the CO2 concentration determined by means of the gas analysis device with a predetermined CO2 concentration limit value or CO2 concentration range and, in the event of a deviation in the CO2 concentration by means of the

CO2 concentration determined by the gas analysis device from the CO:-

Concentration limit or COz concentration range, the amount of recirculated

Exhaust gas not changed, increased or reduced.

For example, the CO2 concentration limit is 60 to 90% by volume, in particular 70 to 80% by volume, preferably 75% by volume of CO in the exhaust gas. The control/regulation device is preferably designed in such a way that it can be used at one

If the CO2 concentration limit is not reached, the amount of recirculated exhaust gas is increased so that the recirculated exhaust gas is preferably 90 - 100% of the exhaust gas.

The control/regulation device is preferably designed in such a way that when the CO2 concentration limit value is exceeded or reached, it reduces the amount of recirculated exhaust gas, so that the recirculated exhaust gas is preferably 0 - 90% of the exhaust gas. The proportion of recirculated exhaust gas is preferably 50-70% if the CO2 concentration determined is less than 80-90% by volume, in particular 75% by volume.

According to a further embodiment, the system has a source for an oxygen-rich gas, which is connected to the activation region, the combustion chamber, and/or a cooling region of the reactor in order to supply the oxygen-rich gas. The oxygen-rich gas is preferably a gas with an oxygen content of approximately 25 to 100% by volume, in particular 60 to 80% by volume, preferably 79% by volume. The source is, for example, a memory

) BE2022/5267 and/or oxygen lines. For example, the return line has one

Inlet for oxygen-containing gas. The supply of oxygen-rich gas offers the advantage of low-pollutant combustion. For example, the proportion of CO: in the exhaust gas is increased to enable efficient enrichment.

According to a further embodiment, the control/regulating device is designed such that it controls the amount of oxygen-rich gas that is supplied to the reactor depending on the determined CO2 content, oxygen content and/or the determined temperature of the exhaust gas removed from the preheating area. regulates.

The control/regulation device is preferably designed in such a way that it compares the measured values determined by means of the gas analysis device with a predetermined one

Compares limit value or range of values and if there is a deviation from the

The measured value determined by the gas analysis device depends on the limit value or the

Value range that increases or decreases the amount of oxygen-rich gas to the reactor.

For example, the gas analysis device is used to determine the oxygen content in the

Exhaust gas is formed and connected to the control/regulation device for transmitting the determined oxygen content. The control/regulation device is preferably designed in such a way that it compares the oxygen content determined by the gas analysis device with a predetermined oxygen limit value or

Oxygen content range compares and if there is a deviation, the amount of oxygen-rich gas to the reactor increases or decreases. For example, the

Amount of oxygen to the reactor increases when the reading reaches the predetermined level

Limit value falls below.

For example, the gas analysis device is used to determine the temperature in the

Exhaust gas is formed and connected to the control/regulation device for transmitting the determined temperature. The control/regulation device is preferably designed in such a way that it compares the temperature determined by means of the gas analysis device with a predetermined temperature limit or

Temperature range compares and if there is a deviation, the amount of oxygen-rich gas to the reactor increases or decreases. For example, the

Amount of fuel to the reactor increases when the temperature reading falls below the predetermined limit.

For example, the activation area of the entrained flow reactor is at least partially as

Fluidized bed reactor formed. The activation region is preferably designed entirely as a fluidized bed reactor. In particular, the entrained flow reactor has no

Cooling area, so that the activation area has in particular a material outlet for releasing material from the entrained flow reactor. Preferably the

System has a cooler separate from the entrained flow reactor, which can be used, for example

Entrained flow cooler, fluidized bed cooler, drum cooler, plate cooler, screw cooler or a combination thereof is designed.

The invention also includes a method for the heat treatment of mineral

Material with a reactor, the material being in an activation region of the

Reactor is activated and optionally cooled in a cooling area of the reactor, the exhaust gas of the reactor being removed from it. At least part of the from the

Exhaust gas removed from the reactor is fed back into the reactor.

The advantages and configurations described with reference to the system for the heat treatment of mineral material apply to the process

Correspondence also applies to the heat treatment process.

According to one embodiment, the reactor is an entrained flow reactor and the material is preheated in a preheating area of the entrained flow reactor, in a

Activation area of the entrained flow reactor activated and optionally cooled in a cooling area of the entrained flow reactor. The exhaust gas from the entrained flow reactor comes from the

The preheating area is removed and at least part of the exhaust gas removed from the preheating area is sent to the activation area and/or the cooling area

Fly stream reactor supplied.

According to one embodiment, the activation area has at least one

Combustion chamber and / or a hot gas generator, at least part of the exhaust gas removed from the preheating area of the combustion chamber and / or the

Hot gas generator is supplied.

According to a further embodiment, the reactor is a fluidized bed reactor and that

Material is activated in an activation area of the fluidized bed reactor and optionally cooled in a cooling area of the fluidized bed reactor, the exhaust gas of

Fluidized bed reactor is removed from the fluidized bed reactor and at least part of the discharged exhaust gas is fed to the activation area and / or the cooling area of the fluidized bed reactor.

According to one embodiment, the CO2 content, the oxygen content and/or the

Temperature of the exhaust gas removed from the preheating area is determined.

According to a further embodiment, following the determination of the CO2

Content, oxygen content and/or temperature, the exhaust gas is recirculated

Exhaust gas flow and a discharged exhaust gas flow are divided.

According to a further embodiment, the shares of the returned

Exhaust gas flow and the discharged exhaust gas flow on the exhaust gas are set depending on the determined CO2 content, oxygen content and / or the determined temperature of the exhaust gas discharged from the preheating area.

According to a further embodiment, the activation area, which has at least one combustion chamber and/or the hot gas generator and/or a cooling area of the

An oxygen-rich gas is supplied to the reactor.

According to a further embodiment, the amount of oxygen-rich gas that is supplied to the reactor is dependent on the determined CO2 content,

Oxygen content and / or the determined temperature of the exhaust gas removed from the preheating area is controlled / regulated.

Description of the drawings

The invention is explained in more detail below using several exemplary embodiments with reference to the accompanying figures.

Fig. 1 shows a schematic representation of a heat treatment system with an entrained flow reactor according to an exemplary embodiment.

Fig. 2 shows a schematic representation of a heat treatment system with an entrained flow reactor according to a further exemplary embodiment.

Fig. 1 shows a system 10 for the heat treatment of mineral material. In which

Materials include, for example, mineral materials, limestone, dolomite,

Magnesite, clays or materials containing ore. The facility and the corresponding

Heat treatment processes are preferably used to produce a

clinker substitute or the extraction of metals or metal oxides. The material to be treated is preferably comminuted, in particular by means of a

Grinding system ground.

Figures 1 and 2 show an example of an entrained flow reactor

Reactor 12. It is also conceivable to design the reactor as a fluidized bed reactor, with the following description also essentially applying to a reactor designed as a fluidized bed reactor, so that only the entrained flow reactor 12 or only the activation region 16 of the entrained flow reactor by one

Fluidized bed reactor is replaced.

The system 10 comprises an entrained flow reactor 12, which is shown schematically as a cylinder in FIG. 1, with material being introduced into the entrained flow reactor 12 at the upper end and discharged from the entrained flow reactor 12 at its lower end. The

A hot gas flows through the entrained flow reactor 12 in countercurrent to the material. In the flow direction of the material, the entrained flow reactor 12 preferably has a preheating area 14 for preheating the material and a

Activation area 16 for activating the material. Optionally has the

Flystream reactor 12 also has a cooling area 18. In the preheating area 14, the material is preferably preheated to a temperature of 300°C to 800°C. In the activation area 16, the preheated material is preferably on a

Temperature from 500 ° C to 1100 ° C, in particular decarbonization,

Dehydroxylation, calcination and/or deacidification of the material takes place. By

In the cooling area, the material is preferably cooled to a temperature of 200°C to 50°C.

For the sake of simplicity, the entrained flow reactor 12 is only shown schematically in FIG. The entrained flow reactor 12 preferably comprises a plurality of cyclones, in particular arranged vertically to one another or next to one another,

Particularly cyclone stages. The cyclones are used to separate solids from a gas stream and are connected to each other via gas lines. For example, the preheating area 14 includes a plurality of cyclones, in particular 1 to 5

Cyclones through which the material preferably flows one after the other, whereby the material is preheated. The activation region 16 of the entrained flow reactor 12 comprises, for example, 1 to 3, preferably 1 cyclone and/or a riser pipe and at least one combustion chamber 20 and/or a heating device 22, such as a hot gas generator.

The combustion chamber 20 preferably has a fuel inlet for admitting

Fuel 50 into the combustion chamber 20. The fuel 50 can be, for example, secondary fuels, such as old tires or household waste. The

Heating device 22 is, for example, a hot gas generator, the hot gas preferably being produced electrically or by burning oil, coal or gas or

Secondary fuels, such as old tires or household waste, are produced. The heating device can also be a heat exchanger for heating a gas stream, the heat exchanger being operated electrically or by means of a combustion chamber.

Preferably, up to 40 to 100%, preferably 60 to 80%, of the electricity from an electrically operated heat exchanger is obtained from renewable energy sources.

The activation area 16 preferably has a riser pipe that is located in the

Essentially extends in the vertical direction. The combustion chamber 20 and/or the

Heating device 22 is preferably connected to the riser pipe in such a way that in the

Hot gas generated by the combustion chamber 20 and/or the heating device 22 is admitted into the riser pipe. It is also conceivable that two or more combustion chambers 20 and/or

or heating devices 22 are provided, which are connected to the riser pipe.

For example, the activation area 16 has a heating device 22 and a

Combustion chamber 20, which are connected, for example, to the riser pipe in such a way that the hot gases generated in the heating device 22 or the combustion chamber 20 are introduced into the riser pipe at different positions, in particular at different heights. The material preheated in the preheating area 14 is preferably in the

Riser pipe of the activation area 16 is inserted and heated therein in direct current. In

In the direction of flow of the solid-gas mixture, at least one cyclone is connected to the riser pipe, which serves to separate solids. The heated material is then preferably fed to the cooling area 18.

The cooling area 18 of the entrained flow reactor 12 preferably comprises a plurality of

Cyclones, in particular 1 to 4, preferably 2 to 3 cyclones. The cooling area 18 preferably has a cooling gas inlet 24, which is arranged in particular at the lower end area of the cooling area.

The preheating area 14 of the entrained flow reactor 12 preferably has one

Material inlet 26 for admitting material to be treated into the entrained flow reactor 12. Furthermore, the preheating area 14 preferably has an exhaust gas outlet 28 for exhausting exhaust gas 30 from the entrained flow reactor 12. The exhaust gas 30 is preferably exhaust gas from the preheating area 14, the

Activation area 16 and/or the cooling area 18. The system 10 includes one

Gas analysis device 32, which is preferably designed such that it

Oxygen content, the CO2 content and / or the temperature of the exhaust gas 30 is determined.

The exhaust gas outlet 28 is preferably connected to the gas analysis device 32 via lines.

In the direction of flow of the exhaust gas 30, the gas analysis device 32 is preferably followed by a gas switch 34, which is designed such that it divides the exhaust gas 30 into at least two exhaust gas streams 36, 38, with part of the exhaust gas 30 being the recirculated exhaust gas 36 and part of the Exhaust gas 30 forms the discharged exhaust gas 38.

The recirculated exhaust gas stream 36 of the exhaust gas 30 is preferably in the cooling area 18 of the entrained flow reactor 12, the combustion chamber 20, the heating device 22 and/or the

Activation area 16 of the entrained flow reactor 12 directed.

The combustion chamber 20, the heating device 22, the cooling area 18 and/or the

Activation area 16 of the entrained flow reactor 12 each has a gas inlet 29 for admitting recirculated exhaust gas 36.

The gas inlet 29 is preferably arranged in the cooling area 18 or in the lower end of the activation area 16. Optional is a gas inlet 29 in the upper one

Area of the activation area 16 arranged, for example in addition to that

Gas inlet 29 in the cooling area 18 and/or the lower area of the

Activation area 16. The exhaust gas outlet 28, in particular the gas switch 34, is connected to the respective gas inlets 29 for returning the exhaust gas 36 into the

Flystream reactor 12 connected.

The amount of recirculated exhaust gas 36 can preferably be adjusted using the gas switch 34. For example, the system 10, in particular the gas switch 34, has a

Control/regulation device, which is designed to control/regulate the amount of recirculated exhaust gas 36 depending on the at least one measured value determined by the gas analysis device 32. The gas analysis device 32 is preferably connected to the control/regulation device of the gas switch 34 in order to transmit the measured values determined. The gas switch 34, in particular the control/regulation device, is preferably designed in such a way that it combines the measured values determined by the gas analysis device 32 with a predetermined one

Compares limit value or range of values and if there is a deviation from the

Gas analysis device 32 determined measured value from the limit value or the

Value range, the amount of recirculated exhaust gas 36 increases or decreases.

For example, the gas analysis device 32 is designed to determine the CO2 concentration in the exhaust gas 30 and is connected to the gas switch 34, in particular the control/regulation device for transmitting the determined CO2 concentration.

The gas switch 34, in particular the control/regulation device, is preferably designed in such a way that it compares the CO2 concentration determined by means of the gas analysis device 32 with a predetermined CO2 concentration limit value or CO2 concentration range and, in the event of a deviation in the CO2 concentration by means of the

Gas analysis device 32 determined CO2 concentration from the CO -

Concentration limit or CO2 concentration range, the amount of recirculated

Exhaust gas 36 increased or decreased.

For example, the CO2 concentration limit is 60 - 90% by volume, in particular 70 to 80% by volume, preferably 75% by volume of CO: in the exhaust gas 30. The gas switch 34 is preferably designed in such a way that if the CO: -

Concentration limit, the amount of recirculated exhaust gas 36 increases, so that the recirculated exhaust gas 36 is preferably 60-100% of the exhaust gas 30 and in the

Cooling area 18 is introduced into the gas inlet 29. The gas switch 34 is preferably designed in such a way that when the CO »-

Concentration limit, the amount of recirculated exhaust gas 36 is reduced, so that the recirculated exhaust gas 36 is preferably 0-55% of the exhaust gas 30 and in the

Cooling area 18 is passed through the gas inlet 29 of the entrained flow reactor 12.

The discharged exhaust gas 38 is preferably discharged from the system 10. The system 10 optionally has an exhaust gas treatment device 40. At the

Exhaust gas treatment device 40 is, for example, a device for

Liquefaction, separation or sequestration of CO ». Optionally, the system 10 includes a memory 42 for storing CO split off in the exhaust gas treatment device 40. It is also conceivable to feed the discharged exhaust gas 38 and/or the exhaust gas treated in the exhaust gas treatment device 40 to a further process, for example for soda production, sugar production or for the production of precipitated calcium carbonate.

The system 10 preferably has at least one or a plurality of inlets

Letting in oxygen-rich gas 44. The oxygen-rich gas is preferably a gas with an oxygen content of 25-100% by volume.

For example, the activation area 16, the combustion chamber 20, the cooling area 18 and/or the heating device 22 each have at least one inlet for admitting oxygen-rich gas 44 into the activation area 16, the combustion chamber 20, the cooling area 18 and/or the heating device 22. The line for returning the contaminated exhaust gas 36 optionally has an inlet for admitting oxygen-rich gas 44.

The amount of oxygen-rich gas 44 that is supplied to the entrained flow reactor 12 is preferably dependent on that determined by the gas analysis device 32

Measuring values adjustable.

For example, the gas analysis device 32 is designed to determine the CO2 concentration, the temperature and/or the oxygen content in the exhaust gas 30 and is connected to the control/regulation device for transmitting the measured values determined. The control/regulation device is preferably designed in such a way that it detects the CO2 concentration determined by the gas analysis device 32,

Temperature and/or oxygen content with a predetermined limit or

Compares the limit range and, in the event of a deviation, increases or decreases the amount of oxygen-rich gas 44 that is supplied to the entrained flow reactor 12.

Optionally, the system 10 has a shredding device 46 and a

Drying device 48, which is connected upstream of the entrained flow reactor 12.

The entrained flow reactor 12 further has a material outlet 27, which is arranged, for example, at the lower end region of the cooling region 18.

The exemplary embodiment of FIG. 2 essentially corresponds to that of FIG. 1, whereby the

In contrast to FIG. 1, entrained flow reactor 12 has no cooling area. The

Plant 10 of FIG. 2 includes a separate to the entrained flow reactor 12 arranged

Cooler 52 and optionally an adjoining shredding device 54. The

Cooler 52 is arranged downstream of the material outlet 27, so that in the

Flystream reactor 12 thermally treated material is fed to the cooler 52.

The cooler 52 is preferably an entrained flow cooler,

Fluid bed cooler, drum cooler, plate cooler, screw cooler or one

Combination of this.

The lower region of the activation region 16 of the entrained flow reactor 12 of FIG. 2 is optionally designed as a fluidized bed reactor 56.

List of reference symbols 10 heat treatment system 12 entrained flow reactor 14 preheating area 16 activation area 18 cooling area 20 combustion chamber 22 heating device / hot gas generator 24 cooling gas inlet 26 material inlet 27 material outlet 28 exhaust gas outlet 29 gas inlet 30 exhaust gas 32 gas analysis device 34 gas switch 36 recirculated exhaust gas 38 discharged exhaust gas 140 Exhaust gas treatment device 42 storage 44 oxygen-rich gas 46 comminution device 48 drying facility

Fuel 52 Cooler 54 Crushing device 56 Fluidized bed reactor

Claims (18)

Patent claims 1. System (10) for the heat treatment of mineral material, comprising a reactor (12) with at least one gas inlet (29) for admitting exhaust gases, the reactor (12) having an activation region (16) for activating the mineral material and an exhaust gas outlet (28 ) for exhausting exhaust gases (30) from the reactor (12), characterized in that the exhaust gas outlet (28) is connected to the at least one gas inlet (29) in such a way that at least part of the exhaust gas (30) is supplied to the reactor (12 ) is supplied. 2. Plant according to claim 1, wherein the reactor (12) is an entrained flow reactor and has a preheating area (14) for preheating the material, an activation area (16) for activating the mineral material and optionally a cooling area (18) for cooling the material and wherein the exhaust gas outlet (28) is arranged in the preheating area (14) and wherein the exhaust gas outlet (28) is connected to the activation area (16) and/or the cooling area (18) of the entrained flow reactor (12) in such a way that at least part of the Exhaust gas (30) is supplied to the activation area (16) and / or a cooling area (18). 3. System according to claim 2, wherein the activation area (16) has at least one combustion chamber (20) and / or a hot gas generator (22) and the exhaust gas outlet (28) is connected to the combustion chamber (20) and / or the hot gas generator (22) in this way is that at least part of the exhaust gas (30) is supplied to the combustion chamber (20) and / or the hot gas generator (22). 4. Plant according to claim 1, wherein the reactor (12) is a fluidized bed reactor and has an activation region (16) for activating the mineral material and optionally a cooling region (18) for cooling the material and wherein the exhaust gas outlet (28) is connected to the activation region ( 16), and/or the cooling area (18) of the fluidized bed reactor (12) is connected in such a way that at least part of the exhaust gas (30) is supplied to the activation area (16) and/or a cooling area (18). 5. System (10) according to one of the preceding claims, wherein the system (10) has a gas analysis device (32) for determining the CO2 content, the oxygen content and / or the temperature of the exhaust gas (30) and wherein the exhaust gas outlet (28) is connected to the gas analysis device (32) for supplying the exhaust gas (30). 6. System (10) according to claim 5, wherein the system (10) has a gas switch (34) which is connected downstream of the gas analysis device (32) and is designed such that it feeds the exhaust gas (30) into a recirculated exhaust gas stream (36) and divides a discharged exhaust gas stream (38), the proportion of the exhaust gas streams (36, 38) in the exhaust gas (30) being adjustable. 7. System (10) according to claim 6, wherein the system (10) has a control/regulation device which is designed such that it determines the proportions of the exhaust gas flows (36, 38) divided by means of the gas switch (34). CO2 content, oxygen content and/or the determined temperature of the exhaust gas (30) discharged from the preheating area (14). 8. System (10) according to one of the preceding claims, wherein the system (10) has a source for an oxygen-rich gas (44) and this is used to supply the oxygen-rich gas (44) to the activation region (16), the combustion chamber (20 ), the hot gas generator (22) and / or a cooling area (18) of the reactor (12) is connected. 9. Plant (10) according to claim 7, wherein the control/regulating device is designed such that it controls the amount of oxygen-rich gas (44) and/or the oxygen concentration in the oxygen-rich gas (44) which is supplied to the reactor (12). , controls/regulates depending on the determined CO2 content, oxygen content and/or the determined temperature of the exhaust gas (30) discharged from the preheating area (14). 10. Method for the heat treatment of mineral material with a reactor (12), wherein the material is activated in an activation region (16) of the reactor (12) and optionally cooled in a cooling region (18) of the reactor (12), the exhaust gas ( 30) of the reactor (12) is removed from this, characterized in that at least part of the exhaust gas (30) removed from the reactor (12) is fed back to the reactor (12). 11. The method according to claim 10, wherein the reactor (12) is an entrained flow reactor and the material is activated in a preheating area (14) of the entrained flow reactor (12) preheated in an activation area (16) of the entrained flow reactor (12) and optionally in a cooling area (18 ) of the entrained flow reactor (12) is cooled, wherein the exhaust gas (30) of the entrained flow reactor (12) is removed from the preheating area (14) and at least part of the exhaust gas (30) removed from the preheating area (14) is sent to the activation area (16) and/or is supplied to the cooling area (18) of the entrained flow reactor (12). 12. The method according to claim 11, wherein the activation region (16) has at least one combustion chamber (20) or a hot gas generator (22) and at least part of the exhaust gas (30) removed from the preheating region (14) of the combustion chamber (20) and / or is fed to the hot gas generator (22). 13. The method according to claim 10, wherein the reactor (12) is a fluidized bed reactor and the material is activated in an activation region (16) of the fluidized bed reactor and optionally cooled in a cooling region (18) of the fluidized bed reactor, wherein the exhaust gas (30) of the fluidized bed reactor is discharged from the fluidized bed reactor and at least part of the discharged exhaust gas (30) is fed to the activation region (16) and/or the cooling region (18) of the fluidized bed reactor. 14. The method according to any one of claims 10 to 13, wherein the CO2 content, the oxygen content and / or the temperature of the exhaust gas (30) discharged from the reactor (12) is determined. 15. The method according to any one of claims 10 to 14, wherein following the determination of the CO2 content, oxygen content and / or the temperature, the exhaust gas (30) is divided into a recirculated exhaust gas stream (36) and a discharged exhaust gas stream (38). 16. The method according to claim 15, wherein the proportions of the divided exhaust gas streams (36, 38) in the exhaust gas (30) depend on the determined CO2 content, oxygen content and / or the determined temperature of the exhaust gas (30) discharged from the reactor (12). ) is set. 17. The method according to any one of claims 10 to 16, wherein the activation region (16), the at least one combustion chamber (20), the hot gas generator (22) and / or a cooling region (18) of the entrained flow reactor or the fluidized bed reactor is supplied with an oxygen-rich gas (44). is supplied. 18. The method according to claim 17, wherein the amount of oxygen-rich gas (44) that is supplied to the reactor (12) depends on the determined CO2 content, oxygen content and / or the determined temperature of the exhaust gas discharged from the reactor (12). (30) is controlled/regulated.