Method for producing pig iron, and blast furnace to be used therefor

Abstract

A blast furnace ( 100 ) is equipped with: a blast-furnace body ( 110 ); material-insertion means ( 111 - 113 ) for inserting a material ( 1 ) containing iron ore and coal into the interior of the blast-furnace body from the top section thereof; hot-air blowing means ( 114, 115 ) for blowing hot air ( 101 ) into the interior of the blast-furnace body through the tuyere thereof; and blast-furnace-blowing-coal supply means ( 120 - 129 ) for blowing blast-furnace-blowing coal ( 11 ) into the interior of the blast-furnace body through the tuyere thereof. Therein, the blast-furnace-blowing-coal supply means blow a blast-furnace-blowing coal having the proportion of oxygen atoms contained therein (dry base) set to 10-20 wt %, and the average pore diameter set to 10-50 nm, while the hot-air blowing means measures the melting point of the ash in the material in advance, and blows hot air which is 100-150° C. lower than the melting point of the ash.

1 . A pig iron producing method for producing pig iron from material iron ore by feeding material that includes iron ore and coal into a blast-furnace body from a top of the blast-furnace body, and blowing hot air and blast-furnace-injecting coal into the blast-furnace body from a tuyere;
 the blast-furnace-injecting coal having from 10 wt % to 20 wt % of oxygen atoms (dry base); and   an average pore diameter of from 10 nm to 50 nm;   a melting point of ash in the blast-furnace-injecting coal being measured in advance; and   a temperature of the hot air being adjusted to a temperature 100 to 150° C. lower than the melting point of the ash.   
     
     
         2 . The pig iron producing method according to  claim 1 , wherein the hot air is enriched with oxygen at the tuyere of the blast-furnace body. 
     
     
         3 . A blast furnace, comprising:
 a blast-furnace body;   material-insertion means for feeding material that includes iron ore and coal into the blast-furnace body from a top of the blast-furnace body;   hot-air blowing means for blowing hot air into an interior from a tuyere of the blast-furnace body; and   blast-furnace-injecting-coal supply means for blowing blast-furnace-injecting coal into the interior from the tuyere of the blast-furnace body;   the blast-furnace-injecting-coal supply means blowing in blast-furnace-injecting coal having an oxygen atom content (dry base) of 10 to 20 wt % and an average pore diameter of 10 to 50 nm; and   the hot-air blowing means measuring a melting point of ash in the material in advance, and blowing in hot air that is 100 to 150° C. lower than the melting point of the ash.   
     
     
         4 . The blast furnace according to  claim 3 , further comprising oxygen enrichment means for enriching oxygen of the hot air in the tuyere of the blast-furnace body. 
     
     
         5 . The blast furnace according to  claim 4 , wherein
 the oxygen enrichment means includes an injection lance to which oxygen flows, and   a tip end of the injection lance is disposed further toward an inside of the blast-furnace body than a base end side of the tuyere of the blast-furnace body.