Method and plant utilizing fine coal in a melter gasifier

Abstract

In a method for the production of liquid metal, in particular liquid pig iron ( 9 ) or liquid steel pre-products, from metal carriers, in particular partially reduced or reduced sponge iron ( 3 ), in a melter gasifier ( 1 ) in which with supply of a carbon-containing material at least partially formed of fine coal ( 16 ) and coal dust ( 13 ) and with supply of oxygen or oxygen-containing gas the metal carriers are melted in a bed ( 4 ) of the carbon-containing material at the simultaneous formation of a reducing gas, optionally upon previous final reduction, fine coal ( 16 ) and coal dust ( 13 ) which are being charged, are mixed with bitumen ( 20 ) in the hot state, after undergoing a drying operation, and subsequently are cold-briquetted, and the briquettes ( 25 ) thus formed are charged to the melter gasifier ( 1 ) in the cold state and in the melter gasifier ( 1 ) are subjected to shock-heating.

1. Method for the production of liquid metal from metal carriers ( 3 ) in a melter gasifier ( 1 ) in which with supply of a carbon-containing material at least partially formed of fine coal ( 16 ) and coal dust ( 13 ) and with supply of oxygen or oxygen-containing gas the metal carriers are melted in a bed ( 4 ) of the carbon-containing material with the simultaneous formation of a reducing gas, optionally upon previous final reduction, characterized in that fine coal ( 16 ) and coal dust ( 13 ) are mixed with hot bitumen ( 20 ) and subsequently are cold-briquetted, and that the briquettes ( 25 ) thus formed are charged to the melter gasifier ( 1 ) and in the melter gasifier ( 1 ) are subjected to shock-heating, and wherein the charged carbon-containing material is dried and during and/or after drying of the carbon-containing material, the fine coal ( 16 ) and coal dust ( 13 ) are separated from lumpy carbon-containing material and further treated while hot. 
     
     
       2. Method according to  claim 1 , characterized in that the liquid metal is pig iron ( 9 ) or liquid steel pre-products and the metal carrier is at least partially reduced sponge iron. 
     
     
       3. Method according to  claim 1 , characterized in that lumpy carbon-containing material ( 17 ) obtained in the separation of the fine coal ( 16 ) and of the coal dust ( 13 ) is charged to the melter gasifier ( 1 ) directly. 
     
     
       4. Method according to  claim 1 , characterized in that the separated fine coal ( 16 ) has a particle size smaller than or equal to 8 mm. 
     
     
       5. Method according to  claim 1 , characterized in that the fine coal ( 16 ) and the coal dust ( 13 ) are mixed with the bitumen ( 20 ) at a temperature below 100° C. 
     
     
       6. Method according to  claim 1 , characterized in that bitumen ( 20 ) with a softening point below 80° C. is charged. 
     
     
       7. Method according to  claim 1 , characterized in that during the mixing operation, heat is additionally supplied. 
     
     
       8. Method according to  claim 1 , characterized in that up to 30% petroleum coke is charged as carbon-containing material. 
     
     
       9. Method according to  claim 1 , characterized in that the carbon-containing material being charged is dried to a residual moisture content below 5% before being charged. 
     
     
       10. Method according to  claim 1 , characterized in that briquette chips formed during briquetting are separated from the briquettes ( 25 ) formed from the fine coal ( 16 ) and the coal dust ( 13 ) and are recycled into the briquetting process. 
     
     
       11. Method according to  claim 1 , characterized in that the briquettes ( 25 ), formed from the fine coal ( 16 ) and the coal dust ( 13 ), are cooled to a temperature below 30° C. during and/or after briquetting. 
     
     
       12. Method according to  claim 1 , characterized in that the coal ( 16 ,  13 ) charged has an ash content of 10 to 25%. 
     
     
       13. Method according to  claim 1 , characterized in that the coal ( 16 ,  13 ) charged has volatile portions of between 18 and 35%. 
     
     
       14. Method according to  claim 1 , characterized in that the fine coal ( 16 ) and the coal dust ( 13 ) at the temperature at which they exit the coal drying are mixed with bitumen ( 20 ) of roughly the same temperature. 
     
     
       15. Method according to  claim 14 , characterized in that the temperature of the fine coal, coal dust and bitumen ( 13 ,  16 ,  20 ) that are to be mixed is 70° to maximally 100° C. at the time of mixing. 
     
     
       16. Method according to  claim 15 , wherein the temperature of fine coal, coal dust and bitumen to be mixed is between 75° and 85° C. 
     
     
       17. Plant for the production of liquid metal from metal carriers comprising a melter gasifier ( 1 ), a feed duct ( 2 ) for metal carriers opening into the melter gasifier ( 1 ), feed ducts ( 5 ,  6 a,  6 b) for oxygen or an oxygen-containing gas and for a carbon-containing material formed at least partially from fine coal ( 16 ) and coal dust ( 13 ), a discharge duct ( 7 ) departing from the melter gasifier ( 1 ) for a reducing gas formed in a melter gasifier ( 1 ), and a tap ( 8 ,  8 a) for pig iron ( 9 ) and slag ( 10 ) provided on the melter gasifier ( 1 ), characterized in that a drying means ( 12 ) is provided at an upstream end of the plant for the drying of carbon-containing material ( 11 ) that is being charged, downstream of which there are connected a mixer ( 19 ), together with means ( 21 ) for providing bitumen ( 20 ) to said mixer ( 19 ), and, subsequently thereto, a cold-briquetting means ( 24 ) for briquetting fine coal ( 16 ) and coal dust ( 13 ), with the cold-briquetting means ( 24 ) being flow-connected with the gasifier ( 1 ). 
     
     
       18. Plant according to  claim 17 , characterized in that a separating means ( 15 ) is provided downstream of the drying means for separating fine coal ( 16 ) and coal dust ( 13 ) from the carbon-containers material being charged. 
     
     
       19. Plant according to  claim 17 , characterized in that a feed ( 6 b) is provided between the drying means ( 12 ) and the melter gasifier ( 1 ) for charging lumpy carbon-containing material ( 17 ) directly into the melter gasifier ( 1 ). 
     
     
       20. Plant according to  claim 17 , characterized in that a steam generator ( 23 ) is provided for heating the mixer ( 19 ). 
     
     
       21. Plant according to  claim 17 , characterized in that between the cold-briquetting means ( 24 ) and the melter gasifier ( 1 ) there is provided a means ( 26 ) for separating briquette chips. 
     
     
       22. Method according to  claim 5 , wherein the temperature is between 75° and 80° C. 
     
     
       23. Method according to  claim 6 , wherein the softening point is below 75° C. 
     
     
       24. A method for the production of liquid metal from metal carriers in a melter gasifier in which the metal carriers are melted in a bed of carbon- containing material in the presence of oxygen or oxygen - containing gas, and with the simultaneous formation of a reducing gas, the method comprising the steps of:      providing a supply of a carbon - containing material at least partially formed of fine coal and coal dust,        drying the fine coal and coal dust;        mixing the fine coal and coal dust with hot bitumen;        cold - briquetting the mixture of fine coal, coal dust, and hot bitumen;        forming a bed of carbon - containing material including the briquettes in the melter gasifier; and        subjecting the briquettes to shock - heating in the melter gasifier.      
     
     
       25. A method according to  claim 24 , further including the steps of:
   separating fine coal and coal dust from other components of the carbon containing material, and        providing the carbonl containing material remaining after separation of the fine coal and coal dust as part of the bed without briquetting.      
     
     
       26. A method according to  claim 25 , wherein the separated fine coal has a particle size smaller than or equal to  8  mm.  
     
     
       27. A method according to  claim 24 , wherein the fine coal and the coal dust are mixed with the bitumen at a temperature below  100 ° C. 
     
     
       28. A method according to  claim 24 , wherein the bitumen has a softening point below  80 ° C. 
     
     
       29. A method according to  claim 24 , further including the step of supplying additional heat during the mixting of the fine coal and coal dust with the hot bitumen.  
     
     
       30. A method according to  claim 24 , wherein the carbon- containing material includes up to  30   %  petroleum coke.    
     
     
       31. A method according to  claim 24 , wherein the residual moisture of the dried carbon- containing material is below  5   % .    
     
     
       32. A method according to  claim 24 , wherein chips formed during briquetting are separated from the briquettes and are recycled into the briquetting process.  
     
     
       33. A method according to  claim 24 , further including the step of cooling the briquettes during or after formation thereof to a temperature below about  30 ° C.  
     
     
       34. A method according to  claim 24 , wherein the ash content of the coal comprising the carbon- containing bed is about  10  to about  25   % .    
     
     
       35. A method according to  claim 24 , wherein the volatile content of the coal comprising the carbon- containing bed is of between about  18  and about  35   % .    
     
     
       36. A method according to  claim 24 , wherein the bitumen is at approximately the same temperature as the fine coal and coal dust after drying when the bitumen is mixed with the dried fine coal and coal dust.  
     
     
       37. A method according to  claim 36 , wherein the temperature of the fine coal, coal dust and bitumen are mixed at a temperature of between about  70 ° and about  100 ° C.  
     
     
       38. A method according to  claim 37 , wherein the temperature of the fine coal, coal dust and bitumen are mixed at a temperature of between about  75 ° and about  85 ° C.  
     
     
       39. Apparatus for production of liquid metal from metal carriers comprising:
   a melter gasifier,        first, second, third, and fourth respective sources for metal carriers, oxygen or oxygen - containing gas, and carbon - containing material including fine coal and coal dust and bitumen;        a first feed duct opening into the melter gasifier for the metal carriers;        a second feed duct opening into the melter gasifier for the oxygen or oxygen - containing gas;        a third feed duct opening into the melter gasifier for the carbon - containing material;        a discharge duct from the melter gasifier for a reducing gas formed therein;        first and second taps on the melter gasifier for pig iron and slag respectively;        a dryer located between the third source and the third feed duct for drying the carbon - containing material before delivery to the melter gassifier;        a mixer for the dried carbon - containing material and the bitumen; and        a cold briquetter located between the mixer and the third feed duct.      
     
     
       40. Apparatus according to  claim 39 , further including a separator downstream of the dryer operative to separate fine coal and coal dust from the carbon- containing material.    
     
     
       41. Apparatus according to  claim 40 , further including:
   a first feed path connected to the separator to deliver the separated fine coal and coal dust to the mixer; and        a second feed path connected to the separator to deliver residual carbon - containing material from which fine coal and coal dust has been separated directly to as fourth feed duct into the melter gasifier.      
     
     
       42. Apparatus according to  claim 39 , further including a steam generator connected to provide heat to the mixer.  
     
     
       43. Apparatus according to  claim 39 , further including:
   a separator operative to remove briquette chips from the briquettes before delivery thereof to the third feed duct; and        a feed path to deliver the briquette chips for return to the mixer.      
     
     
       44. A method according to  claim 27 , wherein the temperature is between about  75 ° and  80 ° C.  
     
     
       45. A method according to  claim 28 , wherein the softening point is below about  75 ° C.