Investigation of the effect of silicon content in iron and its temperature on exergy indicators of the blast furnace-converter system

The aim of the work is to study the energy intensity of metal products in the "blast furnace - oxygen converter" system during the development of pulverized coal (PCF) in the blast furnace production. One of the parameters characterizing the thermodynamic indicators of blast-furnace smelting is the silicon content in liquid iron. A study was made of the effect of silicon content in iron and its temperature on the performance and thermodynamic indicators of steel production in the blast furnace – oxygen converter shop chain during the development of pulverized coal in the blast furnace. The calculated minimum and maximum values of changes in productivity and consumption of coke, and exergy indicators with a change in the silicon content in the iron. It is established that a decrease in the silicon content and the temperature of iron in a blast furnace can reduce the loss of exergy, increase the exergy efficiency, maintain a constant level or improve environmental performance. However, reducing the temperature of the iron can lead to significant disturbances in the operation of the blast furnace. It is shown that silicon content in cast iron has the greatest impact in the blast furnace-oxygen shop technological system, a decrease of which contributes to an increase in exergy efficiency, a decrease in exergy losses and an improvement in environmental indicators. The temperature of the cast iron on the exergy and environmental indicators in the "blast furnace - oxygen converter shop" system has a minor effect, however, a decrease in the temperature of the iron can lead to significant disturbances in the operation of the "blast furnace - oxygen converter" complex.

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Influence of the application of pulverized coal and natural gas in blast furnace on exergy indicators of technological system «blast furnace-oxygen converter»

Fundamental and applied problems of ferrous metallurgy ◽

10.52150/2522-9117-2018-32-107-117 ◽

2018 ◽

pp. 107-117

Author(s):

A.L. Chaika ◽

A.G. Cherniatevych ◽

A.A. Sokhatsky ◽

A.A. Moskalina ◽

T.S. Golub ◽

...

Keyword(s):

Blast Furnace ◽

Natural Gas ◽

Oxygen Converter ◽

Steel Production ◽

Environmental Indicators ◽

Pulverized Coal ◽

Technological System ◽

Economic Indicators ◽

Pig Iron ◽

Technical And Economic Indicators

The aim of the work is to study the effect of pulverized coal (PCI) on the energy indicators of the technological system of steel production «blast furnace-oxygen converter». The analysis of energy use in the technological system for the best actual periods of operation of the blast furnace (BF) using only natural gas, pulverized coal and co-injection of pulverized coal with natural gas is performed. It is shown that the technology of using PCI improves technical and economic indicators and has a positive effect on the distribution of exergic flows, exergic efficiency and environmental indicators in the system «blast furnace-oxygen converter». Comparative heat and energy and exergy analysis of actual pulverized coal consumption in the amount of 135 kg/t of pig iron compared to blowing only natural gas in the amount of 35 m3/t of pig iron showed that pulverized coal leads to a decrease in coke consumption by ~ 25% due to pulverized pulverized coal. An exergetic analysis of the predicted converter heats showed that the injection of pulverized coal to the pulpwood leads to a decrease in the total exergy supplied by ~7%, and in the case of co-application of pulverized coal with natural gas, the exergy decreases by ~ 2%. Analysis of the exergy balance of converter melting showed that a change in the consumption of pulverized coal and natural gas in the blast furnace production slightly affects the change in the exergic efficiency (up to 0.4%). In general, it is shown that the technology of using PCI improves technical and economic indicators and positively affects the distribution of exergic flows, exergic efficiency and environmental indicators in the blast furnace – oxygen converter system.

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INFLUENCE OF BLOWING PARAMETERS AND SLAG REGIME ON SILICON AND SULFUR CONTENT IN BLAST-FURNACE CAST IRON

Collection of scholarly papers of Dniprovsk State Technical University (Technical Sciences) ◽

10.31319/2519-2884.38.2021.1 ◽

2021 ◽

Vol 1 (38) ◽

pp. 7-14

Author(s):

M. Kuznetsov ◽

G. Kryachko

Keyword(s):

Blast Furnace ◽

Cast Iron ◽

Sulfur Content ◽

Silicon Content ◽

Furnace Operation ◽

Pulverized Coal ◽

Operating Conditions ◽

Noticeable Effect ◽

Silicon Oxides ◽

Coal Fuel

At two blast furnaces (BF) with a volume of 1386 and 1500 m³, the influence of the parameters of blast and slag modes on the content of silicon and sulfur in cast iron was investigated. The blast mode was evaluated by the consumption of pulverized coal fuel (PCF) and oxygen, the slag mode was evaluated by its basicity CaO / SiO₂. It was found that the injection of pulverized coal into the hearth of 1500 m³ BF in the range of flow rates from 108 to 120 g/m³·s, and in the hearth of 1386 m³ BF in the range from 90 to 110 g/m³·s was accompanied by a decrease in the silicon content in cast iron. The deterioration of the transition of silicon into cast iron with an increase in the consumption of pulverized coal is explained by the complex effect of factors that retard the reduction of its oxides. Extreme relationships were also established between the intensity of melting in terms of oxygen consumption and the silicon content in the cast iron of the furnaces under study. The extreme dependences of the studied variables are due to the dual effect of the melting intensity on the reduction of silicon oxides: a reduction in the time of contact of the metal with furnace gases reduces the possibility of transition of silicon into metal, and an increase in the volume of the silicon reduction zone improves these possibilities. When operating a 1386 m³ furnace on calcium slag in the range of CaO / SiO₂ basicity change from 0.9 to 1.3 without removing the blast furnace operation periods associated with a change in operating conditions, the absence of dependence of the silicon content in cast iron on the CaO/SiO₂ modulus was found/ In its turn this indicated the complexity of factors influencing the reduction of silicon oxides. In the same range of changes in basicity and different operating modes of the furnace, a noticeable effect of basicity on the sulfur content in cast iron was observed, which indicates the decisive role of basicity in the process of blast-furnace desulfurization.

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