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EP-4735817-A1 - COLOR OPTIMIZATION OF ACTIVATED CLAY

EP4735817A1EP 4735817 A1EP4735817 A1EP 4735817A1EP-4735817-A1

Abstract

The invention relates to a device for activating and optimizing the color of a mineral material, wherein the device has an activation and color optimization device. The invention is characterized in that the device has a tubular reactor (30) behind the color optimization device (20) in the material flow direction, wherein the tubular reactor (30) has a solid material inlet (34), said solid material inlet (34) being connected to the color optimization device (20) in order to transfer the activated and color-optimized material, and the tubular reactor (30) has a gas inlet (36). The tubular reactor (30) has a length (32) of 5 m to 50 m, the tubular reactor (30) is connected to a deflecting device (40) at the tubular reactor end, and the deflecting device (40) has a solid material outlet (42) and a gas outlet (44).

Inventors

  • BERGER, CLAUDIA
  • Fit, Leo
  • Priesemann, Christina
  • BRINKMANN, CHRISTIAN
  • BEISHEIM, Theodor

Assignees

  • thyssenkrupp Polysius GmbH
  • thyssenkrupp AG

Dates

Publication Date
20260506
Application Date
20240619

Claims (19)

  1. 1. Device for activating and color optimizing a mineral material, the device having an activation and color optimizing device, characterized in that the device has a tubular reactor (30) downstream of the color optimizing device (20) in the material flow direction, the tubular reactor (30) having a solids inlet (34), the solids inlet (34) being connected to the color optimizing device (20) for transferring the activated and color-optimized material, the tubular reactor (30) having a gas inlet (36), the tubular reactor (30) having a length (32) of 5 m to 50 m, the tubular reactor (30) being connected at the end to a deflection device (40), the deflection device (40) having a solids outlet (42) and a gas outlet (44).
  2. 2. Device according to claim 1, characterized in that the activation and color optimization device has a separate activation device (10) and a separate color optimization device (20).
  3. 3. Device according to one of the preceding claims, characterized in that the deflection device (40) has a deflection of the gas flow of 135° to 225°, preferably of 170° to 190°.
  4. 4. Device according to one of the preceding claims, characterized in that the tubular reactor (30) is arranged such that the gas flow in the tubular reactor (30) is directed downwards.
  5. 5. Device according to claim 4, characterized in that the solids outlet (42) of the deflection device (40) is arranged at the lowest point of the deflection device (40).
  6. 6. Device according to one of the preceding claims, characterized in that a separation cyclone and/or a dust filter (60) is arranged behind the deflection device (40).
  7. 7. Device according to one of the preceding claims, characterized in that a gas conveying device (50) is arranged in front of the gas inlet (36).
  8. 8. Device according to one of the preceding claims, characterized in that the solids outlet (42) is connected to a cooling device (70).
  9. 9. Device according to one of the preceding claims, characterized in that the deflection device (40) has a first cross-sectional area at the inlet, wherein the deflection device (40) has a second cross-sectional area in the middle, wherein the second cross-sectional area is 2 to 5 times, preferably 3 to 4 times, as large as the first cross-sectional area.
  10. 10. Device according to one of the preceding claims, characterized in that the device has a gas temperature measuring device behind the deflection device (40).
  11. 11. Device according to one of the preceding claims, characterized in that the device has a first solid temperature measuring device behind the solid outlet (42).
  12. 12. Device according to one of the preceding claims, characterized in that the device has a first solid color measuring device behind the solid outlet (42).
  13. 13. Method for activating and color optimizing a mineral material, the method comprising the following steps: a) thermally activating the mineral material, b) color optimizing the activated mineral material under reducing conditions, c) cooling the color-optimized mineral material in a tubular reactor (30), d) depositing the cooled mineral material in a deflection device (40), wherein the cooling in the tubular reactor (30) takes place at a rate of 200 K/s to 650 K/s.
  14. 14. The method according to claim 13, characterized in that the gas velocity in the tubular reactor (30) is set at 15 m/s to 50 m/s.
  15. 15. Method according to one of claims 13 to 14, characterized in that the temperature of the mineral material deposited in the deflection device (40) is below 500 °C.
  16. 16. Method according to one of claims 13 to 15, characterized in that after the separation in step d), a residual separation of the cooled mineral material from the gas stream leaving the deflection device (40) takes place.
  17. 17. The method according to claim 16, characterized in that the material deposited in the residual deposition is combined with the material deposited in step d).
  18. 18. Method according to one of claims 13 to 17, characterized in that the material temperature is detected at the transition from the tubular reactor (30) to the deflection device (40) or after discharge from the deflection device (40).
  19. 19. Method according to one of claims 13 to 18, characterized in that the material color is detected after it has been discharged from the deflection device (40).

Description

thyssenkrupp Polysius GmbH 1 thyssenkrupp AG Color optimization of activated tones The invention relates to a device and a method for obtaining the optimized coloration of an activated clay obtained during a reduction of an activated clay. Activated clays have become established as additives, particularly in the cement industry. The current method is to dry and calcine the clays, a thermal activation. This requires energy for heating and thermal activation, and if the temperature is too high, it can also cause further changes in the material, which may be undesirable. Due to the firing conditions during thermal activation in an oxidizing atmosphere, naturally occurring iron compounds in the clays are converted, in particular, into hematitic iron oxides. This causes a reddish coloration of the clays activated in this way, which significantly reduces the market acceptance of cements made with it. The iron content, or the content of iron in its strongly coloring trivalent oxidation state (Fe 3+ ), largely determines the color of a calcined clay. The color is an important quality parameter for the possible use of these activated clays as a component of the usually gray cement. Inferior ("lean") clays in particular can have Fe2O3 contents of an average of 2 to 9 wt.%. In the so-called "red clays", the Fe2O3 content can also be up to 15% or higher. These high iron contents can lead to a very intense and usually undesirable red discoloration of the artificial pozzolana produced in this way and the composite cements produced with it during calcination. For this reason, reducing firing conditions are set in the cooling area of plants for the production of calcined clays, for example, in order to achieve the formation of black magnetite. In order to set reducing firing conditions, fossil and CO2-intensive primary fuels such as natural gas, crude oil, lignite or hard coal that burn well are required. So-called secondary fuels in particular require continuous oxidizing firing conditions for effective firing, which in turn requires complex Post-treatment of the trivalent iron species is required to eliminate or reduce the undesirable red coloration in the thermally activated clay. From DE 10 2016 104 738 A1 a method and a device for the thermal treatment of granular solids is known. From DE 10 2008 020 600 B4 a process and a plant for the heat treatment of fine-grained mineral solids is known. A clinker substitute is known from DE 10 2011 014 498 A1. A process for producing synthetic pozzolans is known from US 2012 / 160 135 A1. From WO 2021 / 224 055 A1, a color optimization in the production of activated clays is known. The activation itself and the color optimization in a reducing atmosphere are well known to those skilled in the art and can be carried out in a variety of variations. A critical point, however, is how the hot, activated and color-optimized material is cooled in order to preserve the properties, especially the color. In addition to cooling in a reducing atmosphere or in the absence of air, rapid cooling up to 100 K/s in oxygen-containing gas, for example air, is also known. Each of these processes has advantages and disadvantages. The object of the invention is to provide a simple and extremely reliable method for cooling an activated and color-optimized clay. This object is achieved by the device having the features specified in claim 1 and by the method having the features specified in claim 13. Advantageous further developments emerge from the subclaims, the following description and the drawing. The device according to the invention serves to activate and color optimize a mineral material, in particular clays. The device has an activation and color optimization device. The activation and color optimization device can be designed in two parts or consist of a combined activation and color optimization device. In the activation and color optimization device or the activation device, a thermal treatment takes place, which leads to the clay developing the necessary properties, for example, in order to be used as a cement additive. Such activated materials are also sometimes referred to as artificial pozzolans. The activation is known from the prior art and can be carried out using any method known from the prior art. The activation device can thus be designed in any configuration known to the person skilled in the art. For example, the activation and color optimization device or the activation device can be an entrained flow calciner. The same also applies to the color optimization device. This is also known to the person skilled in the art and can be designed in any manner known to the person skilled in the art from the prior art. For example only, the color optimization device can be designed as a fluidized bed reactor. An example of a combined activation and color optimization device is an activation device according to the prior art that is operated under reducing conditions. As a further example,