Which reaction increases temperature in blast furnace?

Which reaction increases temperature in blast furnace?

Of these only the reaction between oxygen and carbon is exothermic. This reaction is responsible for increasing the temperature of the blast furnace so that the other reactions between the carbon compounds and iron oxide can take place.

What exhaust gas leaves the top of a blast furnace?

(top gas), the waste gas from blast furnaces; mainly the products of the incomplete combustion of carbon. Its chemical composition during the smelting of cast iron on coal coke is 12–20 percent carbon dioxide, 20–30 percent carbon monoxide, up to 0.5 percent methane, 1–4 percent hydrogen, and 55–58 percent nitrogen.

What is high top pressure in blast furnace?

Increased top pressure helps good furnace operation and reduced fuel rate by decreasing velocity of the gases and by increasing retention time for the gas-solid reactions. In addition to reducing the fuel rate, this measure helps reduce the hot metal silicon variability and increases productivity.

How can a blast furnace increase productivity?

Increasing in the temperature of the hot air blast for every 10 deg C increases the BF productivity in the range of 800 deg C to 900 deg C by 0.5 %, in the range of 900 deg C to 1000 deg C by 0.4 %.

How steel is made in blast furnace?

To make steel, iron ore is first mined from the ground. It is then smelted in blast furnaces where the impurities are removed and carbon is added. About halfway down, limestone begins to react with impurities in the ore and the coke to form a slag. Ash from the coke is absorbed by the slag.

Which fuel is best suitable for blast furnace process?

Which fuel is best suitable for blast furnace process? Explanation: Coke is best suitable for blast furnace process as it also acts as a reducing agent in smelting iron ore.

Which fuel is used in steel industry?

The major energy source that is used as a feedstock in the steel industry is coal, and accounts for 80 percent of the total feedstock used in this industry. Coal is baked in a heated oven to produce coke and breeze.

What is the considered to be the most efficient blast pressure?

It is accepted that the “ideal” gas concentration is 9.5-10% methane, which results in the most efficient blast and highest energy. Above 13.5 to 14%, a rapid burning rather than explosion occurred with much lower pressures but with the potential for a propagating flame front.

Which gas is reduced by coke in the blast furnace?

carbon monoxide
Steel Production and Energy Other inputs include coke to produce carbon monoxide for the reduction of iron ore to iron, and other energy sources for various stages of the production process, such as preheating of air up to 1100°C for injection into blast furnaces.

What are the major limitations of blast furnace ironmaking?

Blast Furnace Disadvantages: 1. Blast furnace ironmaking is inseparable from the coke source, but the coke resources are getting less and less, but the price is getting higher and higher, the cost of iron making will be higher and higher, and it is likely that one day will meet the depletion of coke resources.

How much power can a blast furnace generate?

High concentration of CO gas in the BF gas makes the gas hazardous. The high top pressure of BF gas is utilized to operate a generator (top gas pressure recovery turbine, i.e. TRT in short). TRT can generate electrical energy (power) up to 35 kWh/ ton of hot metal without burning any fuel.

Why is BF gas used in blast furnaces?

In the past BF gas use was restricted to the heating of hot blast stoves in the blast furnaces and using it in multi fuel boilers. It was not considered to be economical for other uses because of its various characteristics. However in the recent years, several factors have contributed to its enlarged use.

What is the temperature of the bottom of a blast furnace?

“The heat evolved in this exothermic reaction raises the temperature at the bottom of the furnace to about 1900 °C …. The heat absorbed in this endothermic reaction lowers the temperature in the upper part of the furnace to about 1300 °C.” Kerrod, Robin.

What happens when you reduce the thickness of a blast furnace?

Reduction in the lining thickness results into increase in the internal volume of the blast furnace resulting into increase in the furnace production capacity. This also gives consistent furnace temperature profile throughout the furnace campaign.