Blast-furnace operation on cokes made under differing carbonizing temperature conditions. [950 to 1050/sup 0/C coke finishing temperature]
The various factors all influenced the quality of the coke. High temperatures and carbonizing rates reduced the yield of large coke lumps (>60 mm) and increased that of intermediate lump sizes (60 to 40 and 40 to 25 mm), thereby making the coke more uniform. Low temperatures had the opposite effect. Although the coke finishing temperature had no influence on the initial properties of the reducing gas (at the tuyeres) or the material to be reduced (the iron ore burden), differences between the properties of cokes made under differing conditions led to alterations in the reduction rate within the blast furnace and the consumption of reducing agents per ton of iron made. The changes in blast-furnace performance indicate that the high-temperature coke improved the aerodynamic smelting conditions. This made it possible to increase the blast volume (driving rate) by 59 m/sup 3//min and extend the reaction periphery. The furnace conditions remained stable although the overall resistance factor was raised; the pressure drop and the dynamic gas pressure in the throat were higher. The opposite effects were obtained on using the low-temperature coke. The blast volume had to be lowered because of burden instability. Overall, the direct reduction factor fell by 3.2% with high-temperature coke and rose by 1.9% with the low-temperature grade. A cost effectiveness estimate on the blast-furnace use ofcoke made at higher flue temperatures and to higher finishing temperatures, without adjusting the carbonizing period, showed that iron smelting costs are reduced by 0.3%, because of the lower coke consumption and smelting costs.
- OSTI ID:
- 5480732
- Journal Information:
- Coke Chem., USSR (Engl. Transl.); (United States), Vol. 12; Other Information: Translated from Koks Khim.; No. 12, 15-17(1977)
- Country of Publication:
- United States
- Language:
- English
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