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Mother liquid foam slag generating method for smelting stainless steel with electric furnace and dephosphorization melted iron

A technology for dephosphorizing molten iron and stainless steel, applied to electric furnaces, furnaces, furnace types, etc., can solve problems such as increased production costs, ineffective slag foaming, increased electric furnace power consumption, etc., to reduce power consumption and electrode consumption, and increase production capacity The ability to match with the process and the effect of improving the production rate

Inactive Publication Date: 2008-01-02
BAOSHAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] 2. Cr in stainless steel slag 2 o 3 High content - 8-25%;
[0005] 3. In order to avoid excessive oxidation of Cr, the amount of oxygen blowing should be strictly controlled (blowing a large amount of oxygen will cause a large amount of oxidation of chromium, reduce the recovery rate of chromium, and increase the production cost)
[0007] However, the above-mentioned prior art has the following disadvantages: 1) the slag cannot be effectively foamed, the arc light in the later stage of smelting has a large erosion on the furnace lining, and the service life of the refractory is short; ) restrictions, long power-on time, long smelting time, smelting cycle time 80-90min; 3) high power consumption, 360-400Kwh / t; 4) high environmental noise and long duration, the noise level is usually greater than 85 decibels
[0013] 1) The gas required for foaming is produced by the decomposition of calcium nitrate. After the decomposition reaction ends, the foaming of the slag ends, so its foaming is not sustainable;
[0014] 2) The decomposition reaction is an endothermic reaction. After adding calcium nitrate, the power consumption of the electric furnace will increase

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Operating points of foam slag method:

[0049] 1) The added amount of total silicon is 8.5Kg / t (total metal added amount).

[0050] 2) The basicity of slag is controlled at 1.3.

[0051] 3) The C content in the molten pool in the furnace is about 4.0%.

[0052] 4) The amount of lime added is 30kg / t; the amount of dolomite added is 20kg / t.

[0053] 5) When the power consumption is 160Kwh / t, start to inject carbon powder, the amount of injected carbon powder is 2kg / t, and at the same time, the flow rate is 2500Nm 3 / h oxygen blowing, the oxygen blowing volume is 8Nm 3 / t (calculated according to the amount added), after about 2 minutes of carbon powder injection, when the power consumption is 187Kwh / t, a large number of bubbles are generated in the slag, and foamy slag is effectively formed.

[0054] 6) When the power reaches 288Kwh / t (calculated according to the amount added), take a sample (slag sample) and start reduction.

[0055] 7) When the power is turned on t...

Embodiment 2

[0065] Operating points of foam slag method:

[0066] 1) The added amount of total silicon is 10.5Kg / t (total metal added amount).

[0067] 2) The basicity of slag is controlled at 1.8.

[0068] 3) The C content in the molten pool in the furnace is about 3.2%.

[0069] 4) The amount of lime added is 45kg / t; the amount of dolomite added is 10kg / t.

[0070] 5) When the power consumption is 165Kwh / t, start to inject carbon powder, the amount of injected carbon powder is 2.9kg / t, and at the same time, the flow rate is 3000Nm 3 / h oxygen blowing, the oxygen blowing volume is 9.16Nm 3 / t (calculated according to the amount added), after about 2 minutes of carbon powder injection, when the power consumption is 189Kwh / t, a large number of bubbles are generated in the slag, and foamy slag is effectively formed.

[0071] 6) When the power reaches 296Kwh / t (calculated according to the amount added), take a sample (slag sample) and start reduction.

[0072] 7) When the power is turne...

Embodiment 3

[0081] Operating points of foam slag method:

[0082] 1) The amount of total silicon added is 8.76Kg / t (total metal added amount);

[0083] 2) The basicity of slag is controlled at 1.65;

[0084] 3) The C content in the molten pool in the furnace is about 2.5%.

[0085] 4) The amount of lime added is 42kg / t; the amount of dolomite added is 15kg / t.

[0086] 5) When the power consumption is 183Kwh / t, the slag is thick. Spray 1.2kg / t of ferrosilicon powder to dilute the slag, and then spray 3.15kg / t of carbon powder. The carbon powder is injected for about 1 minute and 30 seconds. A large number of bubbles are generated, and when the toner injection ends, a large amount of slag overflows from the slag door;

[0087] 6) When the power reaches 326Kwh / t (calculated according to the amount added), take a sample (slag sample) and start reduction.

[0088] 7) When the power is turned on to 347.6Kwh / t (calculated according to the amount added), the temperature is measured and sample...

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PUM

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Abstract

The invention discloses a manufacturing method of stainless steel mother liquor foam slag through electric furnace dephosphorized molten iron, which comprises the following steps: 1)adding solid material with waste stainless steel, ferrochromium and silicon into electric furnace through material basket; energising to smelt; setting the quantity of siliconat at 8.5-12kg / t; 2)adding dephosphorized molten iron when the power consumption is 15-22 Mwh; controlling C content of mother liquor at 1.50-4.00%; 3)forming basic smelting pond in the furnace when the power consumption is 160-200Kwh / t; starting to blow carbon powder with content at 2-4kg / t; jetting oxygen with quantity at 2500Nm3 / h-3500Nm3 / h.

Description

technical field [0001] The invention relates to a process for smelting stainless steel by adding dephosphorized hot metal in an electric furnace, in particular to a method for generating foamy slag from mother liquor for smelting stainless steel by adding dephosphorized hot metal in an electric furnace. Background technique [0002] The technology of foaming slag is hardly used in stainless steel production at present. This is because stainless steel slags are much more difficult to foam than carbon steel slags. It is mainly caused by the following factors: [0003] 1. FeO content in stainless steel slag is low - 1-3%; [0004] 2. Cr in stainless steel slag 2 o 3 High content - 8-25%; [0005] 3. In order to avoid excessive oxidation of Cr, the amount of oxygen blowing should be strictly controlled (blowing a large amount of oxygen will cause a large amount of oxidation of chromium, reduce the recovery rate of chromium, and increase the production cost). [0006] The e...

Claims

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Application Information

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IPC IPC(8): C21C5/54
Inventor 祝方义池和冰施允
Owner BAOSHAN IRON & STEEL CO LTD
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