Summary of the invention
For the problems referred to above that exist on existing blast furnace technology, the invention provides a kind of submerged arc plasma melting iron smelting method, object is the iron smelting method of a kind of high-level efficiency of exploitation and high energy gamma source utilization ratio.
Method of the present invention is carried out according to following steps:
Iron ore enters blast furnace, in blast furnace, melting forms molten bath, when the slag blanket of top, the molten bath formation thickness 300 ~ 500mm in blast furnace, plasma gun and coal spouting gun are inserted in slag blanket, light plasma gun and produce plasma arc, control the arc temperature of plasma arc at 1400 ~ 4000 DEG C, and interlayer by plasma gun is to the powdered iron ore of jetting in slag blanket; Simultaneously by coal spouting gun to coal injection in slag blanket, control coal dust through plasma arc Huo He center, powdered iron ore is smelted.
In aforesaid method, in the time that plasma gun is worked, controlling the outlet of plasma gun and the vertical range of slag blanket end face is 150 ~ 200mm, and the outlet of coal spouting gun exports lower than plasma gun, and both vertical range is poor is 10 ~ 20mm.
The fiery core of the plasma arc in aforesaid method is centered close to slag blanket end face below 180 ~ 220mm.
In aforesaid method, in same time, the weight ratio of the coal dust of the powdered iron ore of plasma gun winding-up and coal spouting gun winding-up is powdered iron ore: coal dust=(2.5 ~ 3.5): 1.
In aforesaid method, the carrier gas that winding-up powdered iron ore and coal dust adopt is nitrogen, and while wherein jetting powdered iron ore, the concentration of powdered iron ore in carrier gas is 20 ~ 40kg/m
3, when coal injection, the concentration of coal dust in carrier gas is 30 ~ 60kg/m
3.
Granularity≤80 order of powdered iron ore in aforesaid method, granularity≤120 order of coal dust.
The main chemical reactions equation of above-mentioned reaction comprises:
1. the decomposition step by step of iron: Fe
3o
4→ Fe+Fe
2o
3+ O
2, Fe
2o
4→ Fe+FeO+O
2;
2. the reduction reaction of iron protoxide and melting carbon: FeO
(S)+ C
(S)→ Fe+CO
2;
3. the thermolysis of coal under plasma arc: coal → C
2h
2+ C
6h
6+ CH
4+ C
(S).
Ultimate principle of the present invention is:
The powdered iron ore that sprays into molten bath is decomposed step by step rapidly under plasma arc effect, form iron protoxide and oxygen, the coal dust that sprays into molten bath is heated to molten state, decomposite carbon with oxygen combustion, the high temperature of generation makes iron, iron protoxide and carbon form molten state, and iron and carbonic acid gas are produced in reaction, and secondary response produces oxygen again, other gases after carbonic acid gas and coal dust decompose and the material intense mixing of jetting, carry out vigorous agitation to molten bath, adds the carrying out of fast response; Red-hot plasma arc makes the slag charge of slag blanket be parabolic shape upwards to splash, the combustiblematerials that the slag charge splashing carries and the oxygen of decomposition form secondary combustion, the temperature of the slag charge splashing is raise rapidly, while falling melt back pond, heat is brought back in molten bath, can make full use of the heat energy that material reaction produces; The molten iron layer of slag blanket below is relatively static, principal reaction is carried out in slag blanket, form submerged arc plasma melting, from iron ore, decomposition and iron protoxide react generation to the required oxygen of submerged arc with carbon step by step, do not need to spray into again oxygen, the volatile component that coal dust decomposites forms adiabatic combustion in slag blanket, and temperature of combustion can be reached more than 2000 DEG C, the limitation of 1300 DEG C while having broken through coal dust conventional combustion; The heat that burning produces more than 80% is stayed in slag blanket, and powdered iron ore is directly jetted in slag blanket, melts from plasma gun exit, has reduced the generation of dust.
The beneficial effect of the inventive method is to make full use of thermal source, reduces power loss, reduces production costs, and suppresses the generation of dust, stable processing technique, to enhance productivity and reduce pollute significant.
Embodiment
The power of the plasma gun adopting in the embodiment of the present invention is 80 kilowatts.
Granularity≤80 order of the powdered iron ore adopting in the embodiment of the present invention, granularity≤120 order of coal dust.
The powdered iron ore of selecting in the embodiment of the present invention is ground hematite, brown ocher, sparring breeze, ilmenite powder or red nickel soil breeze, and TFe is 30 ~ 65% for iron grade.
The coal dust of selecting in the embodiment of the present invention is pulverized anthracite.
Embodiment 1
The powdered iron ore adopting is ground hematite, and iron grade is 31.6%.
Iron ore melting in blast furnace is formed to molten bath, in the time that the top, molten bath in blast furnace forms the slag blanket of thickness 300mm, plasma gun and coal spouting gun are inserted in slag blanket; Controlling the outlet of plasma gun and the vertical range of slag blanket end face is 150mm; The outlet of controlling coal spouting gun exports lower than plasma gun, and both vertical ranges are poor is 10mm; Light plasma gun and produce plasma arc, the fiery core of plasma arc is centered close to slag blanket end face below 180mm, controls plasma arc arc temperature at 1400 DEG C, and interlayer by plasma gun is to the powdered iron ore of jetting in slag blanket; Simultaneously by coal spouting gun to coal injection in slag blanket, control coal dust through the core center of overdoing, the weight ratio of the coal dust that in same time, the powdered iron ore of plasma gun winding-up and coal spouting gun winding-up are jetted is powdered iron ore: coal dust=2.5:1, and powdered iron ore is smelted;
The carrier gas that above-mentioned winding-up powdered iron ore and coal dust adopt is nitrogen, and while wherein jetting powdered iron ore, the concentration of powdered iron ore in carrier gas is 20kg/m
3, when coal injection, the concentration of coal dust in carrier gas is 30kg/m
3;
The powdered iron ore that sprays into molten bath is decomposed step by step rapidly under plasma arc effect, form iron protoxide and oxygen, the coal dust that sprays into molten bath is heated to molten state, decomposite carbon with oxygen combustion, the high temperature of generation makes iron, iron protoxide and carbon form molten state, and iron and carbonic acid gas are produced in reaction, and secondary response produces oxygen again, other gases after carbonic acid gas and coal dust decompose and the material intense mixing of jetting, carry out vigorous agitation to molten bath, adds the carrying out of fast response; Red-hot plasma arc makes the slag charge of slag blanket be parabolic shape upwards to splash, the combustiblematerials that the slag charge splashing carries and the oxygen of decomposition form secondary combustion, the temperature of the slag charge splashing is raise rapidly, while falling melt back pond, heat is brought back in molten bath, principal reaction is carried out in slag blanket, form submerged arc plasma melting, from iron ore, decomposition and iron protoxide react generation to the required oxygen of submerged arc with carbon step by step, do not need to spray into again oxygen, the volatile component that coal dust decomposites forms adiabatic combustion in slag blanket, and temperature of combustion can be reached more than 2000 DEG C;
The dust that in above-mentioned steps, blast furnace produces obviously reduces, and energy consumption obviously reduces, and production process technology is stable.
Embodiment 2
The powdered iron ore adopting is brown ocher, and iron grade is 43.7%.
Iron ore melting in blast furnace is formed to molten bath, in the time that the top, molten bath in blast furnace forms the slag blanket of thickness 400mm, plasma gun and coal spouting gun are inserted in slag blanket; Controlling the outlet of plasma gun and the vertical range of slag blanket end face is 180mm; The outlet of controlling coal spouting gun exports lower than plasma gun, and both vertical ranges are poor is 15mm; Light plasma gun and produce plasma arc, the fiery core of plasma arc is centered close to slag blanket end face below 200mm, controls plasma arc arc temperature at 2000 DEG C, and interlayer by plasma gun is to the powdered iron ore of jetting in slag blanket; Simultaneously by coal spouting gun to coal injection in slag blanket, control coal dust through the core center of overdoing, the weight ratio of the coal dust that in same time, the powdered iron ore of plasma gun winding-up and coal spouting gun winding-up are jetted is powdered iron ore: coal dust=3:1, and powdered iron ore is smelted;
The carrier gas that above-mentioned winding-up powdered iron ore and coal dust adopt is nitrogen, and while wherein jetting powdered iron ore, the concentration of powdered iron ore in carrier gas is 30kg/m
3, when coal injection, the concentration of coal dust in carrier gas is 40kg/m
3;
The dust that in above-mentioned steps, blast furnace produces obviously reduces, and energy consumption obviously reduces, and production process technology is stable.
Embodiment 3
The powdered iron ore adopting is sparring breeze, and iron grade is 53.8%.
Iron ore melting in blast furnace is formed to molten bath, in the time that the top, molten bath in blast furnace forms the slag blanket of thickness 500mm, plasma gun and coal spouting gun are inserted in slag blanket; Controlling the outlet of plasma gun and the vertical range of slag blanket end face is 200mm; The outlet of controlling coal spouting gun exports lower than plasma gun, and both vertical ranges are poor is 20mm; Light plasma gun and produce plasma arc, the fiery core of plasma arc is centered close to slag blanket end face below 220mm, controls plasma arc arc temperature at 3000 DEG C, and interlayer by plasma gun is to the powdered iron ore of jetting in slag blanket; Simultaneously by coal spouting gun to coal injection in slag blanket, control coal dust through the core center of overdoing, the weight ratio of the coal dust that in same time, the powdered iron ore of plasma gun winding-up and coal spouting gun winding-up are jetted is powdered iron ore: coal dust=3.5:1, and powdered iron ore is smelted;
The carrier gas that above-mentioned winding-up powdered iron ore and coal dust adopt is nitrogen, and while wherein jetting powdered iron ore, the concentration of powdered iron ore in carrier gas is 40kg/m
3, when coal injection, the concentration of coal dust in carrier gas is 50kg/m
3;
The dust that in above-mentioned steps, blast furnace produces obviously reduces, and energy consumption obviously reduces, and production process technology is stable.
Embodiment 4
The powdered iron ore adopting is ilmenite powder, and iron grade is 62.5%.
Iron ore melting in blast furnace is formed to molten bath, in the time that the top, molten bath in blast furnace forms the slag blanket of thickness 500mm, plasma gun and coal spouting gun are inserted in slag blanket; Controlling the outlet of plasma gun and the vertical range of slag blanket end face is 200mm; The outlet of controlling coal spouting gun exports lower than plasma gun, and both vertical ranges are poor is 20mm; Light plasma gun and produce plasma arc, the fiery core of plasma arc is centered close to slag blanket end face below 220mm, controls plasma arc arc temperature at 4000 DEG C, and interlayer by plasma gun is to the powdered iron ore of jetting in slag blanket; Simultaneously by coal spouting gun to coal injection in slag blanket, control coal dust through the core center of overdoing, the weight ratio of the coal dust that in same time, the powdered iron ore of plasma gun winding-up and coal spouting gun winding-up are jetted is powdered iron ore: coal dust=3:1, and powdered iron ore is smelted;
The carrier gas that above-mentioned winding-up powdered iron ore and coal dust adopt is nitrogen, and while wherein jetting powdered iron ore, the concentration of powdered iron ore in carrier gas is 40kg/m
3, when coal injection, the concentration of coal dust in carrier gas is 60kg/m
3;
The dust that in above-mentioned steps, blast furnace produces obviously reduces, and energy consumption obviously reduces, and production process technology is stable.
Embodiment 5
The powdered iron ore adopting is red nickel soil breeze, and iron grade is 38.9%.
Iron ore melting in blast furnace is formed to molten bath, in the time that the top, molten bath in blast furnace forms the slag blanket of thickness 500mm, plasma gun and coal spouting gun are inserted in slag blanket; Controlling the outlet of plasma gun and the vertical range of slag blanket end face is 180mm; The outlet of controlling coal spouting gun exports lower than plasma gun, and both vertical ranges are poor is 15mm; Light plasma gun and produce plasma arc, the fiery core of plasma arc is centered close to slag blanket end face below 210mm, controls plasma arc arc temperature at 2500 DEG C, and interlayer by plasma gun is to the powdered iron ore of jetting in slag blanket; Simultaneously by coal spouting gun to coal injection in slag blanket, control coal dust through the core center of overdoing, the weight ratio of the coal dust that in same time, the powdered iron ore of plasma gun winding-up and coal spouting gun winding-up are jetted is powdered iron ore: coal dust=3:1, and powdered iron ore is smelted;
The carrier gas that above-mentioned winding-up powdered iron ore and coal dust adopt is nitrogen, and while wherein jetting powdered iron ore, the concentration of powdered iron ore in carrier gas is 40kg/m
3, when coal injection, the concentration of coal dust in carrier gas is 50kg/m
3;
The dust that in above-mentioned steps, blast furnace produces obviously reduces, and energy consumption obviously reduces, and production process technology is stable.