The hot blast is directed into the furnace through water-cooled copper nozzles called tuyeres near the base. The hot blast temperature can be from 900 °C to 1300 °C (1600 °F to 2300 °F) depending on the stove design and condition. The temperatures they deal with may be 2000 °C to 2300 °C (3600 °F to 4200 °F).
How is the blast furnace heated?
It is a type of heat exchanger, in which the heat produced by combustion of the BF gas usually mixed with natural gas (NG) or coke oven gas (COG) is stored in the checkerwork chamber, after which cold air is blown through the hot checkerwork to produce the preheated hot air blast to the furnace.
What is the output of blast furnace?
The main outputs of blast furnaces includes pig iron and slag, which is formed by combination of limestone with sulfur and other impurities. Pig iron is typically tapped every 3 to 5 hours in quantities of 300 to 600 tons .
How hot does a metal furnace get?
Hot metal (blast-furnace iron)
Tapping temperatures are in the range 1,400° to 1,500° C ( 2,550° to 2,700° F ); to save energy, the hot metal is transferred directly to the steel plant with a temperature loss of about 100° C (200° F).
Why is temperature of slag lower than 1530?
Why is the temperature of the slag coming out of the blast furnace much lower than 1530°C? Because a blast furnace does not produce steel but pig iron that melts at 1150 – 1200°C max . The exhaust gas is also rather cold because the air is blown in the bottom part of a blast furnace where it meets the coke.
What fuel is used in blast furnace?
In a blast furnace, fuel (coke) , ores, and flux (limestone) are continuously supplied through the top of the furnace, while a hot blast of air (sometimes with oxygen enrichment) is blown into the lower section of the furnace through a series of pipes called tuyeres, so that the chemical reactions take place throughout ...
What is the hottest furnace on earth?
The current official highest registered air temperature on Earth is 56.7 °C (134.1 °F), recorded on 10 July 1913 at Furnace Creek Ranch , in Death Valley in the United States.
Why is coke used in a blast furnace?
Publisher Summary. Metallurgical coke, along with iron ore and limestone, is layered into a blast furnace to convert the iron ore to metallic iron . Coke, which is mostly carbon, reacts with the blast air to produce carbon monoxide, which, in turn, reacts with the iron oxide to produce carbon dioxide and metallic iron.
Why is hot air blown into a blast furnace?
The preheated air reacts vigorously with the preheated coke, resulting in both the formation of the reducing gas (carbon monoxide) that rises through the furnace, and a very high temperature of about 1,650° C (3,000° F) that produces the liquid iron and slag.
Why coke is used in blast furnace not coal?
Coke is used as a fuel and a reducing agent in melting iron ore. It is produced by baking coal until it becomes carbon by burning off impurities without burning up the coal itself. When coke is consumed it generates intense heat but little smoke, making it ideal for smelting iron and steel.
Why it is called blast furnace?
The Blast Furnace is a large steel structure about 30 metres high. ... The furnace gets its name from the method that is used to heat it . Pre-heated air at about 1000 o C is blasted into the furnace through nozzles near its base. The largest Blast Furnaces in the UK produce around 60 000 tonnes of iron per week.
How do you make fire hot enough to melt metal?
Charcoal has twice the energy value as regular wood, so it created a fire hot enough to melt the iron out of the ore (rock). The trick to making charcoal is to heat wood to 518°F in the absence of oxygen.
How does a blast furnace make steel?
Hot air reaching 1200°C is blown in from the bottom through tuyeres and chemically reacts with the materials as they fall to the bottom of the blast furnace. This process oxidizes the coke and reduces the sintered ore, creating molten iron. The molten iron is then further processed to make steel.
Is molten metal or slag denser?
The molten iron is thicker and denser because it sinks and accumulates at the bottom of the furnace, whereas the slag is less dense because it floats on top of the molten iron.
Why is iron produced in a blast furnace converted to steel?
The combustion of iron ore with other materials in the blast furnace produces molten pig iron, which is then converted to steel. ... Blowing oxygen forces impurities (oxides, silicates, phosphates, etc.) to react with flux to form slag or escape through the top of the furnace as fumes.
How a blast furnace works Minecraft?
Blast furnaces are similar to furnaces, but can smelt only ore blocks and tools/armor made of iron, gold or chainmail. ... Once an item and a fuel are placed into the blast furnace, the block state changes to lit and the item is smelted twice as fast as a regular furnace.
