Method for manufacturing hot metal desulfurizing agent and apparatus for same

Abstract

The present invention provides a method of desulfurizing hot metal, which method utilizes desulfurization slag resulting from a KR hot metal desulfurizing treatment as a desulfurizing agent for hot metal again to reduce hot metal desulfurization costs and the amount of slag generated, thereby solving environmental problems.

1 . A method of manufacturing a hot metal desulfurizing agent, the method being comprising executing a treatment for creating a new surface in desulfurization slag resulting from a mechanical agitation type hot metal desulfurizing treatment.  
     
     
         2 . A method of manufacturing a hot metal desulfurizing agent for use in a mechanical agitation type hot metal desulfurizing treatment according to  claim 1 , the method being comprising executing a treatment for creating a new surface in desulfurization slag resulting from the mechanical agitation type hot metal desulfurizing treatment.  
     
     
         3 . A method according to  claim 1 , comprising a step of providing desulfurization slag resulting from the mechanical agitation type hot metal desulfurizing treatment and a step of executing the treatment for creating a new surface in the provided desulfurization slag.  
     
     
         4 . A method according to  claim 1 , wherein the step of executing the treatment for creating a new surface includes crushing a desulfurization slag grain and/or separating an aggregate of a plurality of desulfurization slag grains into desulfurization slag grains.  
     
     
         5 . A method according to  claim 1 , wherein the step of executing the treatment for creating a new surface includes crushing the desulfurization slag grain and/or separating the aggregate of a plurality of desulfurization slag grains into desulfurization slag grains by air-cooling the desulfurization slag and/or applying mechanical energy to the desulfurization slag.  
     
     
         6 . A method according to  claim 5 , wherein the desulfurization slag is cooled using one or two methods selected from the group consisting of air cooling and water cooling.  
     
     
         7 . A method according to  claim 6 , wherein the air cooling is carried out using one or two methods selected from the group consisting of natural air cooling and forced air cooling.  
     
     
         8 . A method according to  claim 6 , wherein the step of executing the treatment for creating a new surface by water cooling comprises a step of watering the desulfurization slag, and this watering step controls the amount of water provided so as to maintain the temperature of the desulfurization slag at 100° C. or higher at the end of the watering, so that only by means of cooling based on the watering, the aggregate of desulfurization slag can be separated into desulfurization slag grains and/or the desulfurization slag grains can be crushed.  
     
     
         9 . A method according to  claim 1 , wherein the step of executing the treatment for creating a new surface comprises a step of water-cooling the desulfurization slag and a step of drying a recovered desulfurizing agent resulting from the water cooling.  
     
     
         10 . A method according to  claim 1 , wherein the step of executing the treatment for creating a new surface comprises a step of cooling the desulfurization slag and a step of adjusting the grain sizes of the desulfurization slag and the recovered desulfurizing agent.  
     
     
         11 . A method according to  claim 10 , wherein the step of adjusting the grain size of the recovered desulfurizing agent using a sieve is executed at a temperature of 600° C. or higher.  
     
     
         12 . A method according to  claim 1 , wherein the step of executing the treatment for creating a new surface comprises a step of executing at least one or two treatments selected from the group consisting of a treatment for magnetically separating and removing metal from the desulfurization slag or the recovered desulfurizing agent, a treatment for removing large masses from the desulfurization slag or the recovered desulfurizing agent to set the grain size to 100 mm or smaller, and a treatment for setting the temperature of the desulfurization slag or the recovered desulfurizing agent to 200° C. or lower.  
     
     
         13 . A method according to  claim 1 , wherein the step of executing the treatment for creating a new surface comprises a step of setting the grain size of the desulfurization slag to 100 mm or smaller and the temperature thereof to 200° C. or lower.  
     
     
         14 - 32 . canceled  
     
     
         33 . The method of manufacturing low-sulfur hot metal, the method being comprising desulfurizing hot metal by adding, to the hot metal, a hot metal desulfurizing agent comprising a recovered desulfurizing agent having a new surface created therein resulting from a mechanical agitation hot metal desulfurizing treatment.  
     
     
         34 . The method of manufacturing low-sulfur hot metal, the method being comprising desulfurizing hot metal using a mechanical agitation hot metal desulfurizing treatment by adding, to the hot metal, a hot metal desulfurizing agent comprising a recovered desulfurizing agent having a new surface created therein resulting from the mechanical agitation hot metal desulfurizing treatment.  
     
     
         35 . The method of manufacturing low-sulfur hot metal according to  claim 33 , the method being comprising desulfurizing the hot metal by adding, to the hot metal, the desulfurizing agent comprising the recovered desulfurizing agent having a new surface created therein resulting from the mechanical agitation hot metal desulfurizing treatment.  
     
     
         36 . The method of manufacturing low-sulfur hot metal according to  claim 33 , the method being comprising desulfurizing the hot metal by adding, to the hot metal, the desulfurizing agent comprising the recovered desulfurizing agent having a new surface created therein which results from the mechanical agitation hot metal desulfurizing treatment and in which part or all of an aggregate of the recovered desulfurizing agent is separated into pieces.  
     
     
         37 . The method according to  claim 33 , desulfurizing the hot metal by adding, to hot metal, the recovered desulfurizing agent having a new surface created therein resulting from the mechanical agitation type hot metal desulfurizing treatment and one or more sources selected from the group consisting of a lime source and a carbon source.  
     
     
         38 . The method according to  claim 33 , desulfurizing hot metal by mixing the recovered desulfurizing agent resulting from the mechanical agitation hot metal desulfurizing treatment with one or more sources selected from the group consisting of a lime source and a carbon source, and adding this mixture to hot metal.  
     
     
         39 . The method according to  claim 33 , desulfurizing the hot metal by separately adding, to the hot metal, the recovered desulfurizing agent resulting from the mechanical agitation hot metal desulfurizing treatment and one or more sources selected from the group consisting of a lime source and a carbon source.  
     
     
         40 . The method according to  claim 37 , wherein when the lime source is added, the mixing ratio is adjusted so as to obtain a predetermined amount of pure CaO component.  
     
     
         41 . The method according to  claim 37 , comprising a step of calculating a bulk density of the recovered desulfurizing agent resulting from the mechanical agitation hot metal desulfurizing treatment, a step of calculating an amount of pure CaO component in the recovered desulfurizing agent from the calculated bulk density, and a step of adjusting an addition ratio of the crushed recovered desulfurizing agent to the lime source on the basis of the calculated amount of pure CaO component in the recovered desulfurizing agent.  
     
     
         42 . The method according to  claim 37 , comprising a step of adjusting the grain size of the carbon source to 1 mm or smaller when the carbon source is added.