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Method for producing hot sponge iron by directly reducing iron based on ammonia gas

A technology of reduced iron and sponge iron, which is applied to furnace types, furnaces, shaft furnaces, etc., can solve the problem of complex greenhouse gas emissions from iron ore easily reduced, pulverized, bonded, and cooled equipment, and is easy to store for a long time. The effect of long-distance transportation, cost reduction, good reduction characteristics

Active Publication Date: 2021-06-08
UNIV OF SCI & TECH LIAONING +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The tempered gas contains CO, CO 2 and CH 4 , can not solve the problem of CO reduction, the existence of reducing gaseous carbon, the easy reduction of iron ore, pulverization and bonding, complex cooling equipment and CO 2 issues such as greenhouse gas emissions

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] In this embodiment, the process of producing hot sponge iron by directly reducing iron ore with ammonia gas is as follows:

[0056] 1) Heat the reduction section of the shaft furnace to 900°C±1°C, put 3g±0.01g of iron oxide powder (purity: 99.95%) into the reduction section of the shaft furnace with a diameter of 20mm; feed nitrogen into the reduction section Purge for 10 minutes to discharge other gases in the reduction section; feed nitrogen into the reduction section at a flow rate of 100ml / min, and at the same time raise the temperature at a rate of 10K / min, and keep the temperature for 30 minutes after the temperature reaches 900°C;

[0057] 2) Feed the mixed gas of ammonia and nitrogen into the reducing section, wherein ammonia accounts for 40% by volume of the mixed gas; the mixed gas is preheated to 900°C;

[0058] 3) Ammonia is partially decomposed into hydrogen and nitrogen under the catalysis of iron oxide, and the decomposed hydrogen and undecomposed ammonia...

Embodiment 2

[0062] In this embodiment, the process of producing hot sponge iron by directly reducing iron ore with ammonia gas is as follows:

[0063] 1) Heat the reduction section of the shaft furnace to 900°C±1°C, put 8g±0.01g of natural lump ore (iron content 56.62%-65.69%) with a particle size of 10-12mm into the shaft furnace with a diameter of 20mm In the reduction section of the furnace; feed nitrogen into the reduction section to purge for 12 minutes, and discharge other gases in the reduction section; feed nitrogen into the reduction section at a flow rate of 90ml / min, and simultaneously raise the temperature at a heating rate of 12K / min. After the temperature reaches 905°C, keep the temperature constant for 30 minutes;

[0064] 2) Feed the mixed gas of ammonia and nitrogen into the reducing section, wherein ammonia accounts for 50% by volume of the mixed gas; the mixed gas is preheated to 920°C;

[0065] 3) Ammonia is partially decomposed into hydrogen and nitrogen under the ca...

Embodiment 3

[0069] In this embodiment, the process of producing hot sponge iron by directly reducing iron ore with ammonia gas is as follows:

[0070] 1) Heat the reduction section of the shaft furnace to 900°C±1°C, put 8g±0.01g of pellets with a particle size of 10-12mm (iron content is 64.87%-66.59%) into the shaft furnace with a diameter of 20mm In the reducing section of the furnace; feed nitrogen into the reducing section to purge for 8 minutes, and discharge other gases in the reducing section; feed nitrogen into the reducing section at a flow rate of 120ml / min, and raise the temperature at a heating rate of 8K / min at the same time. After the temperature reaches 910°C, keep the temperature constant for 30 minutes;

[0071] 2) Feed the mixed gas of ammonia and nitrogen into the reducing section, wherein ammonia accounts for 60% by volume of the mixed gas; the mixed gas is preheated to 880°C;

[0072] 3) Ammonia is partially decomposed into hydrogen and nitrogen under the catalysis o...

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Abstract

The invention relates to a method for producing hot sponge iron by directly reducing iron based on ammonia gas. The method comprises the following steps of introducing ammonia gas into a reaction device filled with an iron-containing raw material, catalyzing and decomposing the ammonia gas by iron oxide in the iron-containing raw material to generate nitrogen and hydrogen, and simultaneously directly participating in the reduction reaction of the iron oxide to reduce the iron oxide into metal iron. According to the method, ammonia gas is adopted as a hydrogen carrier and a direct reducing agent, the reduction reaction of iron is rapidly carried out by guaranteeing the reaction temperature and the ammonia gas concentration, and the purpose of direct reduction ironmaking is achieved.

Description

technical field [0001] The invention relates to the technical field of direct reduction ironmaking, in particular to a method for producing hot sponge iron based on direct reduction of iron with ammonia gas. Background technique [0002] Direct reduction ironmaking is a method of reducing iron ore into metallic iron in a reaction device with a gas or solid reducing agent below the softening temperature of the ore. The product is called direct reduced iron (DRI). The appearance before oxygen, due to the loss of oxygen, a large number of micropores are formed, and it looks like a sponge structure under the microscope, so it is also called sponge iron. [0003] Gas-based shaft furnace direct reduction ironmaking has become the mainstream sponge iron production method in the world today due to its advantages of easy operation, low energy consumption, and high efficiency. At present, gas-based direct reduction ironmaking generally uses CO and H 2 As a gas reducing agent to prod...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21B13/02
CPCC21B13/0073C21B13/02
Inventor 李先春王绍艳张东柯孙菀岑王焕然
Owner UNIV OF SCI & TECH LIAONING