Method and apparatus for recovering metal values from liquid slag and baghouse dust of an electric arc furnace

a technology of liquid slag and baghouse dust, which is applied in the direction of waste heat treatment, incrustation removal devices, charges, etc., can solve the problems of inevitably trapped residual amounts of valuable metal, high cost of disposal, and harm to the environment, and achieve the effect of lowering the cost of treatment and disposal

Inactive Publication Date: 2001-11-29
VALLOMY JOHN A
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

0037] The invented apparatus and process recover valuable amounts of iron and manganese from the EAF slag and recover valuable amounts and iron, lead, and zinc from the EAF baghouse dust. In addition to the value of the metal components recovered, the treated slag is non-leachable and possesses cementitious

Problems solved by technology

The modern production of steel produces a variety of waste products which are potentially harmful to the environment and the disposal of which is costly.
During deslagging, residual amounts of valuable metal are inevitably trapped within the liquid slag and subsequently decanted off along with the liquid slag.
Metals may also be accidently precluded in the liquid stage during the tapping operation.
However, slag from an electric arc furnace may not be used in the cement industry because of the less

Method used

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  • Method and apparatus for recovering metal values from liquid slag and baghouse dust of an electric arc furnace
  • Method and apparatus for recovering metal values from liquid slag and baghouse dust of an electric arc furnace
  • Method and apparatus for recovering metal values from liquid slag and baghouse dust of an electric arc furnace

Examples

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Effect test

example 1

[0041] The following example shows the amount of metallic components recoverable from EAF slag corresponding to one tonne of tapped molten steel. The silicon dioxide in this Example is input to the lower shell portion of the treatment vessel at room temperature. Component temperatures and electrical energy input is also shown.

3 Inputs 100 kg Untreated Slag (1400.degree. C.) 20.2 kg SiO.sub.2 (25.degree. C.) 11 kg dust (25.degree. C.) 6.44 kg coal (25.degree. C.) 39 kWh Outputs 107 kg Treated Slag (1400.degree. C.) CaO 38.8% SiO.sub.2 32.3% MgO 12.9% Al.sub.2O.sub.3 9.5% MnO 5.1% FeO 0.9% P.sub.2O.sub.3 0.41% S 0.032% 15.3 kg Molten Metal (1400.degree. C.) Mn 7.4% C 4.5% Si 0.29% Cu 0.15% Ni 0.014% P 39 ppm S 16 ppm 7.85 NM.sup.3 Gas (1400.degree. C.) CO 99.6% SO.sub.2 0.034% As 14 ppm 3.573 kg Vapor (1400.degree. C.) (metal in vapor phase) Zn 85.6% (3.06 kg) Pb 10.3% (0.37 kg) Na 3.9% (0.14 kg) Cd 0.3% (0.01 kg)

[0042] If room temperature slag is instead fed into the treatment vessel...

example 2

[0054] Coal-oxygen heating of slag is accomplished with an oxy-fuel burner. All figures are per tonne of tapped molten steel. The silicon dioxide in the present invention will be heated to 1200.degree. C., unlike the room temperature sand in this example.

4 Inputs 100 kg slag (1400.degree. C.) 18.4 kg SiO.sub.2 (25 .degree. C.) 11 kg dust (25.degree. C.) 42.1 kg coal (25.degree. C.) (partially for reduction; partially for heating) 25 Nm.sup.3 Outputs 108.6 kg Slag (1400.degree. C.) CaO 38.5% SiO.sub.2 32.0% MgO 12.7% Al.sub.2O.sub.3 10.3% MnO 5.1% FeO 0.9% P.sub.2O.sub.3 0.46% S 0.21% 15.3 kg Molten Metal (1400.degree. C.) Mn 7.3% C 4.5% Si 0.29% Cu 0.15% Ni 0.014% S 0.01% P 39 ppm 56.65 NM.sup.3 Gas (1400.degree. C.) CO 99.9% SO.sub.2 0.032% As 2 ppm 3.573 kg Vapor (1400.degree. C.) Zn 85.6% (3.06 kg) Pb 10.3% (0.37 kg) Cd 0.3% (0.01 kg) Na 3.9% (0.14 kg)

[0055] This shows that utilizing electric energy is better.

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Abstract

An apparatus and method for processing liquid slag and baghouse dust from a steelmaking furnace such as an EAF to recover valuable metals from the slag and dust includes a treatment vessel having a movable lower shell portion for receiving liquid slag and an upper shell portion that couples with the movable lower shell portion during heat activation of the treatment vessel. The slag is combined with silicon dioxide, a reducing agent, baghouse dust, and an inert gas before being heated to between approximately 1400° C. and 3000° C. The heat treatment results in a molten reduced iron and manganese metallic material, a treated slag layer, and an off-gas containing lead, zinc, and carbon monoxide. The off-gas is combusted, cooled, and solidified, resulting in lead oxide and zinc oxide. The slag layer is tapped, cooled, and solidified. The metallic layer is tapped for recycle in the steel making process.

Description

[0001] This application claims the benefit of U.S. Provisional Application No. 60 / 183,235 filed on Feb. 17, 2000.[0002] The present invention relates to an apparatus and method for processing the liquid slag and baghouse dust waste byproducts of an electric arc furnace to recover valuable metal components therefrom. The present invention further relates to an apparatus and method for processing the liquid slag and baghouse dust byproducts of an electric arc furnace to reduce the quantity of waste byproducts.[0003] The worldwide steel industry produces over 750 million tons of crude steel each year. The modern production of steel produces a variety of waste products which are potentially harmful to the environment and the disposal of which is costly. The most predominant of the waste products are slag and steel refining dust.[0004] For every tonne (metric ton or 1000 kilograms) of liquid steel produced by an electric arc furnace (EAF), approximately 110 kg (kilograms) of liquid slag ...

Claims

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Application Information

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IPC IPC(8): F23G7/06B09B3/00C21B3/06C21C5/52C21C5/54C21C5/56C22B5/10C22B5/16C22B7/02C22B7/04C22B19/30C22B19/34F27B3/06F27B3/08F27D3/12F27D3/15F27D3/16F27D17/00F27D99/00
CPCC21B3/06C21C5/5252C21C5/54C21C5/562C22B5/10C22B7/02C22B7/04C22B19/30C22B19/34F27B3/06F27B3/065F27B3/085F27D3/1554F27D17/008F27D2003/127F27D2003/168F27D2099/0095F27M2001/05C21B2400/02Y02P10/20Y02W30/50
Inventor VALLOMY, JOHN A.
Owner VALLOMY JOHN A
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