A method for preparing iron powder for reducing the content of acid-insoluble matter in iron raw materials

Abstract

The invention discloses a preparation method of iron powder for reducing an acid non-soluble substance content in an iron raw material, belongs to the technical field of powder metallurgy preparation,and solves the problem that the quality fraction of the acid non-soluble substance has poor effect in the existing process preparation process, The preparation method provided by the invention comprises the following steps of: formulating a alkali metal compound into iron ore concentrate powder; loading the prepared iron ore concentrate powder and coal powder into a reduction tank; preheating, constant temperature and cooling in a tunnel kiln; taking out a primary iron ingot from the reduction tank and cleaning the iron ingot; crushing the iron ingot; and carrying out magnetic separation to separate less coal powder and coal ash. The preparation method provided by the invention is used for preparing iron powder with the low acid non-soluble substance content.

Description

technical field

[0001] The invention relates to the field of powder metallurgy preparation, in particular to an iron powder preparation method for reducing the content of acid-insoluble matter in iron raw materials. Background technique

[0002] The powder metallurgy industry is one of the important industries in the field of new materials in my country, which needs nearly 500,000 tons of various reduced iron powders every year. Reduced iron powder is usually prepared by reducing iron oxides (iron concentrate, rolled steel scale, etc.) iron. The reduction process is divided into (solid carbon reduction) primary reduction and secondary reduction. The primary reduction is solid carbon reduction to produce primary iron powder. The main process of primary reduction is: (iron concentrate, rolled steel scale, etc.) → drying → magnetic separation →Crush→Sieve→Install reduction tank→Enter primary reduction furnace→Sponge iron→Clean brush→Crush→Magnetic separation→Primary iron powd...

Examples

Embodiment 1-8

[0049] The present invention is implemented on a tunnel kiln with an annual output of 20,000 tons of primary iron powder. Embodiments 1-8 use partial reduction tanks for testing. The iron concentrate powder used has a total iron content of 71.3% and a hydrochloric acid insoluble content of 0.25%; Coal powder adopts anthracite pulverized coal, with an average particle size of 100 mesh to 200 mesh, a fixed carbon content of 74%, a volatile matter of 8%, and ash content of 12%. head. The temperature of the constant temperature section of the tunnel kiln is 1150°C, the time of the preheating section is 24 hours, the time of the constant temperature section is 24 hours, and the time of the cooling section is 24 hours. Mix a certain proportion of alkali metal compounds into the iron concentrate powder, and the sum of the mass fractions of Na ions and K ions is 0.3% to 1%; The charging method of the kiln is added to the reduction tank; the kiln constant temperature is 1150°C, the pr...

Embodiment 9

[0057] This embodiment provides an iron powder prepared by the method of the above-mentioned embodiment 3, which is sintered into a part after secondary reduction, and the bending strength of the part is 1040 MPa.

Embodiment 10

[0059] This embodiment provides an iron powder prepared by the method of the above-mentioned embodiment 6, which is sintered into a part after secondary reduction, and the bending strength of the part is 1080 MPa.

technical field

[0001] The invention relates to the field of powder metallurgy preparation, in particular to an iron powder preparation method for reducing the content of acid-insoluble matter in iron raw materials. Background technique

[0002] The powder metallurgy industry is one of the important industries in the field of new materials in my country, which needs nearly 500,000 tons of various reduced iron powders every year. Reduced iron powder is usually prepared by reducing iron oxides (iron concentrate, rolled steel scale, etc.) iron. The reduction process is divided into (solid carbon reduction) primary reduction and secondary reduction. The primary reduction is solid carbon reduction to produce primary iron powder. The main process of primary reduction is: (iron concentrate, rolled steel scale, etc.) → drying → magnetic separation →Crush→Sieve→Install reduction tank→Enter primary reduction furnace→Sponge iron→Clean brush→Crush→Magnetic separation→Primary iron powd...

Examples

Embodiment 1-8

[0049] The present invention is implemented on a tunnel kiln with an annual output of 20,000 tons of primary iron powder. Embodiments 1-8 use partial reduction tanks for testing. The iron concentrate powder used has a total iron content of 71.3% and a hydrochloric acid insoluble content of 0.25%; Coal powder adopts anthracite pulverized coal, with an average particle size of 100 mesh to 200 mesh, a fixed carbon content of 74%, a volatile matter of 8%, and ash content of 12%. head. The temperature of the constant temperature section of the tunnel kiln is 1150°C, the time of the preheating section is 24 hours, the time of the constant temperature section is 24 hours, and the time of the cooling section is 24 hours. Mix a certain proportion of alkali metal compounds into the iron concentrate powder, and the sum of the mass fractions of Na ions and K ions is 0.3% to 1%; The charging method of the kiln is added to the reduction tank; the kiln constant temperature is 1150°C, the pr...

Embodiment 9

[0057] This embodiment provides an iron powder prepared by the method of the above-mentioned embodiment 3, which is sintered into a part after secondary reduction, and the bending strength of the part is 1040 MPa.

Embodiment 10

[0059] This embodiment provides an iron powder prepared by the method of the above-mentioned embodiment 6, which is sintered into a part after secondary reduction, and the bending strength of the part is 1080 MPa.

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