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.

What is claimed is:  
     
         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 . A method of transporting a recovered desulfurizing agent, the method being comprising a step of loading a recovered desulfurizing agent resulting from a mechanical agitation type hot metal desulfurizing treatment onto a transport vehicle using a pair of movable basket sections that can be opened and closed and a step of using the transport vehicle to transport the recovered desulfurizing agent to a desulfurizing treatment facility.  
     
     
         15 . A method according to  claim 14 , comprising a step of screening the cooled and crushed recovered desulfurizing agent to remove large masses before or simultaneously with the step of using the transport vehicle to transport the recovered desulfurizing agent.  
     
     
         16 . A method of transporting a recovered desulfurizing agent, the method being comprising a step of loading a recovered desulfurizing agent resulting from a mechanical agitation type hot metal desulfurizing treatment onto a transport vehicle having a capability of sucking the recovered desulfurizing agent and a step of using the transport vehicle to transport the recovered desulfurizing agent to a desulfurizing treatment facility.  
     
     
         17 . A method according to  claim 14 , wherein the step of loading the recovered desulfurizing agent is executed while adjusting the height from which the recovered desulfurizing agent is dropped onto the transport vehicle, to 1.5 m or less.  
     
     
         18 . An apparatus which screens a recovered desulfurizing agent, the apparatus being comprising an apparatus main body having a sieve mesh that screens a crushed recovered desulfurizing agent and an air sucking hose attached to the apparatus main body to facilitate suction of the recovered desulfurizing agent into the apparatus main body.  
     
     
         19 . An apparatus which screens a recovered desulfurizing agent, the apparatus being comprising a member having a diagonally arranged sieve mesh, a diagonal plate diagonally arranged below the member and on which a minus sieve slides down, and a sliding way on which the minus sieve from the diagonal plate falls and then slides down, and in that the apparatus is arranged so that the spacing between the member having the sieve mesh and the diagonal plate and the vertical height of drop of a linkage between the diagonal plate and the sliding way are each 500 mm or less and the height of drop from the sliding way to the ground surface is 500 mm or less.  
     
     
         20 . A hot metal desulfurizing agent comprising a recovered desulfurizing agent resulting from a mechanical agitation type hot metal desulfurizing treatment.  
     
     
         21 . A hot metal desulfurizing agent according to  claim 20 , comprising the recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment, the hot metal desulfurizing agent being used for the mechanical agitation type hot metal desulfurizing treatment.  
     
     
         22 . A hot metal desulfurizing agent according to  claim 20 , comprising the recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment and having a new surface created therein.  
     
     
         23 . A hot metal desulfurizing agent according to  claim 20 , comprising the recovered desulfurizing agent which results from the mechanical agitation type hot metal desulfurizing treatment and in which part or all of an aggregate of recovered desulfurizing agent grains is separated into pieces.  
     
     
         24 . A hot metal desulfurizing agent according to  claim 20 , having a maximum grain size of 100 mm or smaller.  
     
     
         25 . A hot metal desulfurizing agent according to  claim 20 , comprising the recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment, the hot metal desulfurizing agent further containing one or two sources selected from the group consisting of a lime source and a carbon source.  
     
     
         26 . A hot metal desulfurizing agent according to  claim 20 , wherein the one or two sources selected from the group consisting of the lime source and the carbon source are mixed with the recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment, and this mixture is added to hot metal.  
     
     
         27 . A hot metal desulfurizing agent according to  claim 20 , wherein the one or two sources selected from the group consisting of the lime source and the carbon source are separated from the recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment, and the one or more sources and the recovered desulfurizing agent are separately added to hot metal.  
     
     
         28 . A hot metal desulfurizing agent according to  claim 20 , wherein the lime source is at least one or two sources selected from the group consisting of lime, calcium carbonate, and calcium hydroxide.  
     
     
         29 . A hot metal desulfurizing agent according to  claim 20 , wherein the total amount of calcium carbonate and calcium hydroxide, which are included in the group of lime sources, corresponds to 40 wt % or less of the whole hot metal desulfurizing agent.  
     
     
         30 . A hot metal desulfurizing agent according to  claim 20 , wherein the amount of carbon source corresponds to 30 wt % or less of the whole hot metal desulfurizing agent.  
     
     
         31 . A hot metal desulfurizing agent according to  claim 20 , wherein the carbon source is powders of grain size 1 mm or smaller.  
     
     
         32 . A hot metal desulfurizing agent according to  claim 20 , wherein the carbon source is at least one or two sources selected from the group consisting of coal, coke, and pitch.  
     
     
         33 . A 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 resulting from a mechanical agitation type hot metal desulfurizing treatment.  
     
     
         34 . A method of manufacturing low-sulfur hot metal, the method being comprising desulfurizing hot metal using a mechanical agitation type hot metal desulfurizing treatment by adding, to the hot metal, a hot metal desulfurizing agent comprising a recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment.  
     
     
         35 . A 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 resulting from the mechanical agitation type hot metal desulfurizing treatment and having a new-surface created therein.  
     
     
         36 . A 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 which results from the mechanical agitation type hot metal desulfurizing treatment and in which part or all of an aggregate of the recovered desulfurizing agent is separated into pieces.  
     
     
         37 . A method according to  claim 33 , desulfurizing the hot metal by adding, to hot metal, the recovered desulfurizing agent 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 . A method according to  claim 33 , desulfurizing hot metal by mixing the recovered desulfurizing agent resulting from the mechanical agitation type 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 . A 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 type hot metal desulfurizing treatment and one or more sources selected from the group consisting of a lime source and a carbon source.  
     
     
         40 . A 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 . A method according to  claim 37 , comprising a step of calculating the bulk density of the recovered desulfurizing agent resulting from the mechanical agitation type hot metal desulfurizing treatment, a step of calculating the amount of pure CaO component in the recovered desulfurizing agent from the calculated bulk density, and a step of adjusting the 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 . A 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.