Method and device for the heat treatment of granular solids

Patent metadata

Field	Value
Publication number	US-10569245-B2
Application number	US-201815999502-A
Country	US
Kind code	B2
Filing date	Aug 20, 2018
Priority date	Feb 23, 2016
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

A method for the heat treatment of granular solids includes initially introducing solids into a first reactor configured as a flash reactor or fluidized bed reactor where they are brought into contact with hot gases at temperatures in the range 500° C. to 1500° C. Next, the solids are passed through a residence time reactor in which they are fluidized. The residence time reactor is configured in a manner such that it has various regions which are separated from one another, from which the solid can be withdrawn in a manner such that it is provided with a variety of residence times in the residence time reactor.

First claim

The invention claimed is:

1. A method for the heat treatment of granular solids, wherein the solids are initially introduced into a first reactor configured as a flash reactor or fluidized bed reactor where they are brought into contact with hot gases at temperatures in the range of 500′C to 1500° C., and wherein the solids are then guided through a residence time reactor in which they are fluidized with a fluidizing gas, wherein the residence time reactor is configured in a manner such that it is provided with various mutually separated regions from which the solid is separately removed in a manner such that it has a residence time in the residence time reactor which is of a variable duration, wherein removal from the various regions of the residence time reactor is carried out in a manner such that not all of the regions are fluidized, wherein the fluidized regions are fluidically connected in succession, whereby specific downstream regions are no longer fluidized with a fluidizing gas and therefore actively removed and wherein each region has its own removal device.

2. The method as claimed in claim 1 , wherein solid is actively removed from at least one region.

3. The method as claimed in claim 1 , wherein the first reactor is provided with a circulating fluidized bed.

4. The method as claimed in claim 1 , wherein the air is used as the fluidizing gas in the residence time reactor.

5. The method as claimed in claim 1 , wherein the residence time in the first reactor is in the range 0.1 sec to 15 min.

6. The method as claimed in claim 1 , wherein the residence time in the residence time reactor is in the range 10 to 600 min.

7. The method as claimed in claim 1 , wherein lithium carbonate is produced and/or the temperature in both reactors is in the range 750° C. to 1500° C.

8. A device for the heat treatment of finely granulated solids, comprising a first reactor for performing a method according to claim 1 , which is configured as a flash reactor or as a fluidized bed reactor, and a second reactor, which is configured as a residence time reactor, wherein at least a portion of the residence time reactor is divided into a plurality of regions by means of partitions which are separately fluidized and which have separate outlets.

9. The device as claimed in claim 8 , wherein the individual regions are disposed with respect to each other in the manner of steps.

Assignees

• Outotec Finland Oy

Inventors

• Gasafi Edgar
• Stegemann Bertold
• Reeb Bernd

Classifications

• B01J8/26

  with two or more fluidised beds, e.g. reactor and regeneration installations · CPC title

• C22B1/10

  in fluidised form · CPC title

• B01J2208/00557

  controlling the residence time inside the reactor vessel · CPC title

• B01J8/36

  with fluidised bed through which there is an essentially horizontal flow of particles · CPC title

• B01J2208/0053

  Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling · CPC title