| Blast furnace with the different raw materials in accordance with the needs of blast furnace production ratio,to ensure the production of blast furnace production,stability and efficiency at the same time,the maximum reduction of blast furnace iron production costs and improve economic efficiency.Shasteel 5800m3 blast furnace in the use of the blast furnace optimization system before the ore,only consider the composition and price of ore,blast furnace operation has some limitations.The system through the study of existing metallurgical properties of sand steel,to ensure that the blast furnace along the line,to find a reasonable range.Through a large number of test data,find suitable for blast furnace operation mode.Relying on the metallurgical properties of the raw materials,combined with on-site operation practice,will limit the stability of the blast furnace boundary conditions within a reasonable range,to abandon the traditional coarse ore distribution,the development of metallurgical performance and the boundary conditions of the new blast furnace optimization system,Iron production costs.Concluded as follow:(1)The low-temperature reduction pulverization rate of various ores used in Shasteel.From the index of RDI+3.15,the low-temperature reduction pulverization index of pellets is the best,and the low-temperature reduction pulverization index of sinter is the worst.However,in the comparison of the index of RDI-0.5,the value of pellets is the lowest,the index of low-temperature reduction and pulverization is the best,the value of lump ore is the highest,the index of low-temperature reduction and pulverization is the worst,and the sinter is in the middle.Therefore,different reference indicators should be selected according to the actual furnace conditions of the blast furnace.When the gas permeability is good,it should refer to RDI+3.15.When the gas permeability is poor,consider RDI-0.5 for the ingredients.(2)The reduction index of various charge materials used in Shasteel,the reduction index of sinter is better than the conventional pellets as a whole,and the reduction performance is good.Due to the different origins,the lump ore has great difference in reductibility and can be selectively used in the formulation.(3)The droplet index of various charge materials used in Shasteel,the softening start temperature of the sinter is higher than that of the pellets and lump ore,which can move the position of the reflow zone downward,which is beneficial to the improvement of the permeability of the blast furnace.The softening interval of lump ore and sinter is roughly the same,and the softening interval of the pellet is relatively low,which will make the soft-melt zone thinner,and the softening interval of the whole charge is acceptable.Due to the different origins of the lump ore,the softening start temperature is very different,and the gap between the soft melts is also large.Vanadium-titanium pellets are used less and the overall result is different from other charge.The sinter soft melt drop temperature Td is the highest,which will make the soft melt zone move down,which is beneficial to direct reduction and reduce fuel consumption.The Td of the pellets and lump ore is roughly equivalent,but the too low temperature of the droplets will cause the slag level to be too high,which is not conducive to the operation of the blast furnace.Therefore,the dosage should be controlled reasonably and effectively.(4)Under the current raw fuel condition of Shasteel,the sintering+pellet+lump mode is a reasonable charge structure;the softening start temperature of the charge structure of the sintered+lump ore is low,which easily leads to the upward movement of the soft melt zone.The gas permeability is deteriorated,which is not conducive to the blast furnace antegrade;the sintering+pellets batching mode,the temperature of the melt dripping is low,causing the slag in the blast furnace to form prematurely,and the slag level is too high,which is not conducive to the blast furnace operation.(5)For the charge structure of sinter+pellets+lump ore,sintering+low proportion pellets+high proportion of lump ore easily lead to the reflow of the soft melt zone,which is not conducive to blasting of the blast furnace;sintering+high proportion of pellets+low Proportioning block ore will cause premature formation of slag in the blast furnace,and the slag level is too high,which is not conducive to blast furnace operation.And the pressure difference is too large,there will be difficulties in falling slag.The study found that the most suitable batching structure for the current blast furnace operation of Shasteel is that the proportion is controlled within(68?72%)sinter+(10%?20%)lump ore+(10%?20)%pellets Reasonable fluctuations are most conducive to blasting the blast furnace.(6)The blast furnace ore distribution system can give the boundary conditions for stable operation of the blast furnace according to the historical operation data of different blast furnaces,which is more conducive to the operator to stabilize the blast furnace forward.(7)Based on the limiting factors of stable blast furnace operation and procurement and use conditions,the blast furnace ore distribution system gives the lowest ore cost per ton of iron,taking into account the changes in coke and coal injection cost,and gives the best cost-effective ingredient structure.(8)Under the reasonable charge structure,the optimized blast furnace batching system based on the metallurgical properties of ore and the boundary conditions of on-site production has been promoted and applied in various blast furnaces of Shasteel.For the optimized batching results of the 5800m3 blast furnace and the 2500m3 blast furnace in the ironworks,after cost accounting,the cost per ton of iron can be saved by 1 to 5 yuan/t iron. |
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