Combined carbonaceous reducing agent for smelting metal silicon and preparation method thereof

Abstract

The invention discloses a combined carbonaceous reducing agent for smelting metal silicon and a preparation method thereof. The combined carbonaceous reducing agent comprises refined pulverized coal and petroleum coke powder, wherein the refined pulverized coal accounts for 70-80% of the total weight; the refined pulverized coal is prepared from the raw material soft coal by oil agglomeration selective flocculation de-ashing treatment; the refined pulverized coal contains 75-80% of fixed carbon, 3.5-4.5% of ash content and 16-21% of volatile content by weight; and 2-3% of binder is added into the mixture of the refined pulverized coal and the petroleum coke powder, and then a combined carbonaceous reducing agent pellet is prepared by cold press molding briquetting and drying treatment. According to the invention, the ash content and impurities in the soft coal are removed by a flotation method, the petroleum coke powder serves as supplement of the fixed carbon, and the two are combined to obtain a combined carbonaceous reducing agent with high content of fixed carbon, low ash content and low content of impurities. Through the invention, the problem that the reducing effect is unsatisfactory by using the soft coal only is solved, the smelting efficiency and the product quality are improved, and the added value of the soft coal is increased.

Description

Technical field

[0001] The invention belongs to the technical field of metal silicon smelting, and specifically relates to a combined carbonaceous reducing agent for smelting metal silicon and a preparation method thereof. Background technique

[0002] There are many types of carbonaceous reducing agents that can be used for electric furnace smelting of metallic silicon, such as charcoal, anthracite, bituminous coal, petroleum coke, etc. Although their properties are different, they can meet the requirements of high fixed carbon, low ash, high specific resistance, and reactivity Good, with certain mechanical properties, low price, easy availability and other general requirements. At present, in the electric furnace smelting metal silicon process, the most used carbonaceous reducing agent is charcoal. Charcoal has the advantages of good reactivity, high specific resistance, and is not easy to graphitize. The disadvantage is that it consumes a lot and seriously damages forest resou...

Examples

Embodiment approach

[0017] The mixture of fine coal powder and petroleum coke powder is added with 2 to 3% of binder, cold-pressed to form a pellet, and dried to prepare a combined carbonaceous reducing agent pellet.

[0018] The petroleum coke powder contains 85 to 87% by weight of fixed carbon, 0.4 to 0.6% of ash, and 10 to 12.5% ​​of volatile matter.

[0019] Such as figure 1 As shown, the preparation method of the combined carbonaceous reducing agent used for smelting metallic silicon of the present invention is to prepare fine coal powder obtained by deashing treatment of bituminous coal by oil agglomeration selective flocculation method and mixing with petroleum coke powder ,Specifically:

[0020] A. Preparation of fine coal powder: crush and finely grind bituminous coal to a particle size of -74μm~+178μm; adjust the solid weight ratio of the ore slurry to 1:3~5, add collectors, inhibitors, and foaming agents, and use a coarse The flotation method of selection and three-stage selection to obtain...

Embodiment 1

[0032] Crush and finely grind the bituminous coal to a particle size of -74μm~+178μm; adjust the slurry-to-solid weight ratio to 1:3, add diesel, water glass, and No. 2 oil, and use a flotation method of one-stage roughing and three-stage selection Refined coal powder; according to the weight ratio of refined coal powder: petroleum coke powder = 8:2, the refined coal powder and petroleum coke powder are uniformly mixed to obtain the combined carbonaceous reducing agent. The obtained refined coal powder contains 76% by weight of fixed carbon, 4% of ash, and 18% of volatile matter. The petroleum coke powder used contains 85% by weight of fixed carbon, 0.42% of ash, and 10%. The obtained combined carbonaceous reducing agent contains 77.8% by weight of fixed carbon, 3.3% of ash, and 16.4% of volatile.

Embodiment 2

[0034] Crush and finely grind the bituminous coal to a particle size of -74μm~+178μm; adjust the slurry-to-solid weight ratio to 1:3, add GH, water glass, and No. 2 oil, and adopt a flotation method of one-stage roughing and three-stage selection Refined coal powder; according to the weight ratio of refined coal powder: petroleum coke powder = 7.5:2.5, the refined coal powder and the petroleum coke powder are uniformly mixed to obtain the combined carbonaceous reducing agent. The obtained refined coal powder contains 75% by weight of fixed carbon, 4.5% of ash, and 20% of volatile matter. The petroleum coke powder used contains 85% by weight of fixed carbon, 0.4% of ash, and 12.5%. The obtained combined carbonaceous reducing agent contains 77.5% of fixed carbon, 3.48% of ash, and 18.13% of volatiles.

Technical field

[0001] The invention belongs to the technical field of metal silicon smelting, and specifically relates to a combined carbonaceous reducing agent for smelting metal silicon and a preparation method thereof. Background technique

[0002] There are many types of carbonaceous reducing agents that can be used for electric furnace smelting of metallic silicon, such as charcoal, anthracite, bituminous coal, petroleum coke, etc. Although their properties are different, they can meet the requirements of high fixed carbon, low ash, high specific resistance, and reactivity Good, with certain mechanical properties, low price, easy availability and other general requirements. At present, in the electric furnace smelting metal silicon process, the most used carbonaceous reducing agent is charcoal. Charcoal has the advantages of good reactivity, high specific resistance, and is not easy to graphitize. The disadvantage is that it consumes a lot and seriously damages forest resou...

Examples

Embodiment approach

[0017] The mixture of fine coal powder and petroleum coke powder is added with 2 to 3% of binder, cold-pressed to form a pellet, and dried to prepare a combined carbonaceous reducing agent pellet.

[0018] The petroleum coke powder contains 85 to 87% by weight of fixed carbon, 0.4 to 0.6% of ash, and 10 to 12.5% ​​of volatile matter.

[0019] Such as figure 1 As shown, the preparation method of the combined carbonaceous reducing agent used for smelting metallic silicon of the present invention is to prepare fine coal powder obtained by deashing treatment of bituminous coal by oil agglomeration selective flocculation method and mixing with petroleum coke powder ,Specifically:

[0020] A. Preparation of fine coal powder: crush and finely grind bituminous coal to a particle size of -74μm~+178μm; adjust the solid weight ratio of the ore slurry to 1:3~5, add collectors, inhibitors, and foaming agents, and use a coarse The flotation method of selection and three-stage selection to obtain...

Embodiment 1

[0032] Crush and finely grind the bituminous coal to a particle size of -74μm~+178μm; adjust the slurry-to-solid weight ratio to 1:3, add diesel, water glass, and No. 2 oil, and use a flotation method of one-stage roughing and three-stage selection Refined coal powder; according to the weight ratio of refined coal powder: petroleum coke powder = 8:2, the refined coal powder and petroleum coke powder are uniformly mixed to obtain the combined carbonaceous reducing agent. The obtained refined coal powder contains 76% by weight of fixed carbon, 4% of ash, and 18% of volatile matter. The petroleum coke powder used contains 85% by weight of fixed carbon, 0.42% of ash, and 10%. The obtained combined carbonaceous reducing agent contains 77.8% by weight of fixed carbon, 3.3% of ash, and 16.4% of volatile.

Embodiment 2

[0034] Crush and finely grind the bituminous coal to a particle size of -74μm~+178μm; adjust the slurry-to-solid weight ratio to 1:3, add GH, water glass, and No. 2 oil, and adopt a flotation method of one-stage roughing and three-stage selection Refined coal powder; according to the weight ratio of refined coal powder: petroleum coke powder = 7.5:2.5, the refined coal powder and the petroleum coke powder are uniformly mixed to obtain the combined carbonaceous reducing agent. The obtained refined coal powder contains 75% by weight of fixed carbon, 4.5% of ash, and 20% of volatile matter. The petroleum coke powder used contains 85% by weight of fixed carbon, 0.4% of ash, and 12.5%. The obtained combined carbonaceous reducing agent contains 77.5% of fixed carbon, 3.48% of ash, and 18.13% of volatiles.

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