Ladle Refining Furnace

DETAILS

 Description:

MOST ADVANCED TECHNOLOGIES OF LF FURNACE 
Single-electrode D.C powering LF ladle furnace
Three-electrode D.C powering LF ladle furnace
Single-electrode arm A.C powering LF ladle furnace
Tubular water-cooled roof
Microcomputer controller-hydraulic electrode regulator
VVVF-motor type electrode regulator

Main Technical Parameters: ( Technical specifications of LF,VOD,VD,type furnaces)

Rated capacity t

Ladle diameter MM

Transformer rated capacity KVA

Electrode diameter MM

Electrode pitch circle diameter MM

Heating-up rate C/min

Vacuum pumping rate Kg/h

Vacuum vessel mm

Ultimate vacuum Pa

Ladle weight t

Actual capacity t

20
15-20

2200

3150

200

500

2-3

150

2800/4100

67

18

40
30-40

2900

6300

350

850

2-3

250

4800/5000

67

25

60
50-60

3100

10000

350

650

2-3.5

360

5300/5500

67

39

70
70-80

3200

12500

400

700

2-3.5

380

5400/5600

67

43

100
90-100

3400

18000

400

700

2-3.5

400

5500/5800

67

47

150
100-150

3900

20000

450

800

2-3.5

450

6300/6600

67

52


Product Specification
Ladle Refining of liquid metal is a proven technology to produce high quality steel. LRF is used to raise the temperature and adjust the chemical composition of molten metal.


Ladle Refining Furnaces (LRFs) are used to desulphurise steel, remove other impurities and hold the molten steel for casting operations. Without LRFs, higher tap temperatures are normally required from steel making furnaces due to heat losses during refining with conventional ladles. Costs of extended furnace time, refractory wear and power/fuel consumption can all be reduced using LRFs to perform holding and refining.

Reduced scrap melting capacity in Basic Oxygen Furnaces (BOF) is another disadvantage of higher tap temperatures. The LRFs also acts as a buffer between the Steel Making Furnace (BOF) or the Electric Arc Furnace (EAF) and the continuous caster, reducing casting costs and allowing greater flexibility in steel making operations.

Process

Ladle Refining Furnaces are used for the following refining processes:

Homogenisation : Temperature and composition are equalized by stirring.

Inclusion Flotation : Non-metallic inclusions can be removed by gentle stirring of the metal. Oxygen levels of 30 parts million (ppm) have been obtained.

Desulphurisation : Synthetic slags can desulphurise from 0.025% to less than 0.015% in about forty minutes. Desulphurisation can also be accomplished by injection of CaSi or fluxes. Generally, 15 kg per ton of a CaO-Al2O3 slag is used.

Vacuum degassing: Hydrogen content can be reduced to 3 ppm.

By providing a mean to refine outside of the steel making furnace, LRFs provide many benefits including reduced alloy consumption, uniform temperature & properties and lower energy costs while increasing overall plant productivity. In addition, a vacuum environment can be attained in LRFs, which allows production of highly refined steels.

DC LRF offers following advantages over similar capacity conventional AC LRF:
1. Less specific power consumption.
2. Lower cost of operation and maintenance.
3. Reduced refractory consumption.
4. Better thermal efficiency.
5. Lesser power requirement compared to conventional LRF.
6. No line flickering.
7. It can also be operated with a weak grid.
8. Small heat size can be treated economically.

Attributes
Special attributes of Electrotherm LRF
Homogenisation: Temperature and composition are equalized by stirring.

Inclusion Flotation: Non-metallic inclusions can be removed by gentle stirring of the metal. Oxygen levels of 30 parts million (ppm) have been obtained.

Desulphurisation: Synthetic slags can desulphurise from 0.025% to less than 0.015% in about forty minutes. Desulphurisation can also be accomplished by injection of CaSi or fluxes. Generally, 15 kg per ton of a CaO-Al2O3 slag is used.

Vacuum degassing: Hydrogen content can be reduced to 3 ppm.

Grain re-structuring of Sulphides and Oxides.

Principles of D.C. Plasma LRF Operation
1. Main objectives of LRF are homogenization of chemical composition & temperature of steel, desulphurisation, removal of inclusions, lowering gas contents, adjusting temperature for tapping and to carry out trimming.
2. The DC Plasma Ladle Furnace operates in the same way as the conventional ladle furnace, but with following differences.
  Argon plasma in place of Air plasma
 
  
Operation with captive power plant
 
  
Easy operation as power supply is short circuit proof
 
  
There are only two electrodes
3. Argon injection through drilled graphite electrodes can minimizes arc flare and allows more flexibility in ladle furnace operation.
4. The argon plasma helps to maintain inert atmosphere above the melt decreasing nitrogen, oxygen and hydrogen pick-up.
5. The arc is stable and has a tendency to remain within the concavity around the electrode hole because of the high temperature, thereby reducing radiation loss to the roof and freeboard.
6. Carbon pick up from the electrode can also be decreased, since argon injection provides an extended arc due to the flow resistivity of the argon plasma and low consumption of electrodes.
7. Heating efficiency and ladle refractory life is significantly increased.
8. Use of DC Plasma decreases operational costs due to lower graphite consumption, savings in ferroalloys and power consumption


50t Ladle Refining Furnace (LF)

Refining Furnace

Email: export@cimmcarbon.com
Address: Address: 71 Renmin Road, Zhongshan District, Dalian Liaoning 116001