Method for directly producing ferrochromium from chrome ore powder and coal

A ferrochrome alloy and production method technology, which is applied in the field of direct production of ferrochrome alloy by using chrome ore powder and coal, can solve the problems of large consumption of ferrosilicon reduction, large consumption of argon gas, and short service life of furnace lining, so as to reduce dependence and improve Effects of reduction rate of metal and acceleration of reaction speed

Inactive Publication Date: 2008-03-19
BAOSHAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

But its disadvantages are: the service life of the furnace lining is short; the consumption of reduced ferrosilicon is large; at present, ultra-low C, ultra-low nitrogen, and stainless steel cannot be produced, and the gas content in the steel is high; the consumption of argon is large
[0017] The above studies have increased the use of fine ore to a certain extent and reduced production costs, but they have not fundamentally changed the problems of high-quality lump ore and high power consumption for smelting ferrochrome in submerged arc furnaces.

Method used

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  • Method for directly producing ferrochromium from chrome ore powder and coal
  • Method for directly producing ferrochromium from chrome ore powder and coal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0074] (1) Ingredients

[0075] According to the chemical composition range of each component in the pellets and the principle of ingredients, three batches of pellet reduction tests were carried out. Table 1 is the main chemical composition of each raw material.

[0076] Table 1 The main chemical composition of each raw material (%)

[0077]

[0078] (2) Mixing

[0079] Using the raw materials in Table 1, according to the principle of the present invention, take Cr / (Fe+Cr)=30% in the pellets, and Al in the slag phase 2 O 3 = 15%, alkalinity R = 1.6, fully mix and make it uniform in the mixer, spray 7-10% of water in the late stage of mixing to fully wet it.

[0080] (3) Pellet suppression

[0081] The above-mentioned mixed raw materials are pressed in a ball press into oblate pellets with a length of about 3 cm and a width of about 3 cm and a thickness of about 2 cm (or slightly larger or smaller). The composition is shown in Table 2.

[0082] Table 2 Ingredients composition of...

Embodiment 2

[0092] Except for the following steps, the others were the same as in Example 1, and the ferrochrome alloy was prepared.

[0093] (3) Pellet suppression

[0094] The mixed raw materials obtained in the step (2) of Example 1 are pressed in a ball press into oblate pellets with a length of about 3 cm and a width of about 3 cm and a thickness of about 2 cm (or slightly larger or smaller). See Table 4.

[0095] Table 4 Ingredients composition of pellets (%)

[0096] Raw materials

[0097] (4) Pellet aging

[0098] The above pellets were reduced in a rotary hearth furnace, the temperature was controlled at 1450°C, and the reduction time was 20 minutes. The pellets after being baked are cooled and aged. The pellets are pulverized after aging for one day.

[0099] (5) Screening and separation

[0100] The above-mentioned pellets were pulverized and sieved to obtain ferrochromium alloy. The composition and yield of chromium and iron are shown in Table 5.

[0101] Table 5 Compositi...

Embodiment 3

[0105] Except for the following steps, the others were the same as in Example 1, and the ferrochrome alloy was prepared.

[0106] (3) Pellet suppression

[0107] The raw materials mixed in the step (2) of Example 1 are pressed in a ball press into oblate pellets with a length of about 3 cm and a width of about 3 cm and a thickness of about 2 cm (or slightly larger or smaller). The composition is shown in the table 6.

[0108] Table 6 Ingredients composition of pellets (%)

[0109] Raw materials

[0110] (4) Pellet aging

[0111] The above three kinds of pellets were reduced in a rotary hearth furnace, the temperature was controlled at 1450°C, and the reduction time was 20 minutes. The pellets after being baked are cooled and aged. The pellets are pulverized after aging for one day.

[0112] (5) Screening and separation

[0113] The above-mentioned pellets were pulverized and sieved to obtain ferrochromium alloy. The composition and yield of chromium and iron are shown in...

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Abstract

The present invention relates to a method for directly producing ferro chromium with chrome powder and coal. The chrome powder and the coal powder, etc are produced into carbon-bearing pellets, and the reaction temperature is controlled below the pellet soft melting temperature. The slag phase alkalinity is enhanced, to increase the reaction temperature as far as possible, thereby speeding up the reaction speed and improving the metal percent reduction. During the cooling process, the high alkalinity metallised pellet is naturally pulverized because of the existence of thermal stress and excessive carbon powder, and the ferro chromium can be obtained by sieving. Harmful elements of P, S, etc in the raw material are mainly reserved in the slag phase, and thereby the ferro chromium with low P and S content can be obtained. The method of the present invention replaces the traditional electric arc furnace smelting method, provides the ferro chromium with low cost for the smelting and the production of stainless steel, and reduces the dependence of the production of the ferro chromium on a large amount of electric power and lump ore. The ferro chromium is ferro chromium with low P and S content.

Description

Technical field [0001] The present invention relates to a direct reduction production method of ferrochrome. Specifically, the present invention relates to a method for directly producing ferrochrome using chrome ore powder and coal. The production method provides low-cost ferrochrome for the production of stainless steel. The ferrochrome alloy is a ferrochrome alloy with low P and S content. Background technique [0002] The methods of smelting stainless steel are: one-step method, two-step method and three-step method. One-step method, that is, the electric furnace smelts stainless steel in one step. Since this method is a stainless steel production method with high cost and low productivity, it is rarely used at present. [0003] Many years ago, someone combined any of the VOD (vacuum oxygen blowing decarburization) and AOD (decarburization with argon and oxygen) refining devices with electric furnaces to form a two-step stainless steel production process, using electric furna...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21B13/08C22B1/24C22B5/10
CPCY02P10/20
Inventor 张友平周渝生
Owner BAOSHAN IRON & STEEL CO LTD
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