Bentonite-bound compacts of undersized oxidic iron carriers

Abstract

A method for producing compacts containing iron oxide from undersized oxidic iron carriers may include producing a mixture which comprises undersized oxidic iron carriers, bentonite as a binder and water, pressing the mixture and hardening the green compacts obtained by the pressing, as well as to the compacts produced by the method and to the use of the compacts as lump iron carriers. The mixture may be subjected to a kneading process lasting at least 3 minutes and up to 30 minutes, prior to the pressing. The compacts may thus be produced without a maturing process.

1 . A method for producing compacts containing iron oxide from undersized oxidic iron carriers, comprising:
 producing a mixture that comprises (a) undersized oxidic iron carriers produced by degradation of lump oxidic iron carriers, lump ore, or pellets and having a particle size of less than 10 mm, (b) bentonite as a binder, and (c) water,   kneading the mixture using a kneading process having a duration of at least 3 minutes, and   after the kneading process, pressing the mixture and hardening the green compacts obtained by the pressing.   
     
     
         2 . The method of  claim 1 , wherein the mixture comprises from 3% weight to 12% weight of bentonite, relative to the weight of undersized oxidic iron carriers in the mixture. 
     
     
         3 . The method as of  claim 1 , wherein the mixture also comprises metallurgical residual materials containing iron selected from the group consisting of:
 metalized Fe fines,   scale,   metallurgical dust,   metallurgical sludge, and   material from a steel production process.   
     
     
         4 . The method of  claim 1 , wherein the mixture also comprises at least one of finely particulate hematitic material and finely particulate limonitic material. 
     
     
         5 . The method of  claim 1 , wherein the mixture also comprises finely particulate material formed during the removal of dust from top gas, reduction gas, or generator gas of a plant for reducing oxidic iron carriers using a reduction gas. 
     
     
         6 . The method of  claim 1 , comprising heating the mixture during the kneading process. 
     
     
         7 . A compact obtained by:
 producing a mixture that, comprises (a) undersized oxidic iron carriers produced by degradation of lump oxidic iron carriers, lump ore, or pellets and having a particle size of less than 10 mm, (b) bentonite as a binder, and (c) water,   kneading the mixture using a kneading process having a duration of at least 3 minutes, and   after the kneading process, pressing the mixture and hardening the green compacts obtained by the pressing.   
     
     
         8 . A method for producing sponge iron or liquid pig iron, comprising:
 producing a compact by:
 producing a mixture that comprises (a) undersized oxidic iron carriers produced by degradation of lump oxidic iron carriers, lump ore, or pellets and having a particle size of less than 10 mm, (b) bentonite as a binder, and (c) water, 
 kneading the mixture using a kneading process having a duration of at least 3 minutes, and 
 after the kneading process, pressing the mixture and hardening the green compacts obtained, by the pressing, and 
   producing sponge iron or liquid pig iron by a process that uses the produced compact as a lump oxide.   
     
     
         9 . The method of  claim 1 , wherein the duration of the kneading process is between 5 minutes and 30 minutes. 
     
     
         10 . The method of  claim 1 , wherein the duration of the kneading process is between 5 minutes and 20 minutes. 
     
     
         11 . The method of  claim 1 , wherein the duration of the kneading process is between 5 minutes and 15 minutes. 
     
     
         12 . The method of  claim 1 , wherein the undersized oxidic iron carriers have a particle size of less than 6.3 mm. 
     
     
         13 . The method of  claim 1 , wherein the undersized oxidic iron carriers have a particle size of less than 5 mm.