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Steel Melting Shop Electrical Energy Reduction thro’ process innovation Presented by : Bidhan Mondal Chiranjib Das Date: 4 th March 2016

Usha Alloys & Steels Division

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Page 1: Usha Alloys & Steels Division

Steel Melting Shop

Electrical Energy Reduction thro’ process innovation

Presented by : Bidhan Mondal

Chiranjib Das Date: 4 th March 2016

Page 2: Usha Alloys & Steels Division

2

CONTENTS

a) Introduction

b) SMS : Process Flow Diagram

c) EAF features.

d) Data Sheet.

e) Need is the mother of invention.

f) Innovation.

g) Process Steps.

h) Results - Data Sheet.

i) Cost Saving & Energy Saving.

j) Horizontal Deployment.

Page 3: Usha Alloys & Steels Division

Usha Martin Ltd.

Globaly Second Largest Co. in the manufacturing of

“ Steel Wire Ropes ”

Wire Ropes For :

Shipping Mining

Cranes Bridges

Fishing Oil & Gas

Elevators Rope Ways

Tyre cord

3

Page 4: Usha Alloys & Steels Division

Usha Martin Ltd. - Key Facilities

1. Iron Making

Blast Furnace 600,000 MT (245 m3, 380 m3)

DRI Plant 500,000 MT

Sinter Plant : 800,000 MT

Coke Oven: 400,000 MT

Pellet Plant: 1,200,000 MT

2. Captive Power Plants

82.5 MW Waste Heat Recovery type

55 MW Thermal power plant

3. Oxygen plant and lime kiln plant

•70 Ton per day, 150 Ton per day, 125 Ton per day Oxygen Plants.

•2 x 50 Ton per day & 1 x 100 Ton per day Lime Kilns

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Page 5: Usha Alloys & Steels Division

Iron Making Facilities

Pellet Plant DRI Plant

Coke Oven Sinter Plant

Blast Furnace

Page 6: Usha Alloys & Steels Division

Steel Making

3 EAF

• 40 T capacity

• 40 T capacity

• 70 T capacity

5 Ladle Furnaces

3 VD units

Casters

• CCM1, CCM 2: 3 Strand; 6/11 m radius

130 mm x 130 mm

150 mm x 150 mm.

• CCM3: 2 Strand, 12/16.5/30 m radius

360 mm x 300 mm

240 mm x 200 mm

• CCM4: 4 Strand, 9/16 m radius

200 mm x 200 mm

150 mm x 150 mm

Rolling Mills

• Wire Rod Mill : 400,000 T/year.

• Blooming Mill : 300,000 T/year.

• Bar Mill : 75,000 T/year.

Size Range

Wire Rods: 5.5 – 25.40 mm

Bars/Round: 28 – 160 mm

Bars/RCS: 55 – 150 mm

Flats : Thickness (11-20 mm )

Hex : 23.5 A/F – 34.0 A/F

Rectangle : various sizes

7

Usha Martin Ltd. - Key Facilities

Page 7: Usha Alloys & Steels Division

Steel Making and Rolling Facilities

EAF Bloom Caster Reheating Furnace

Bloom Mill Bar Mill Wire Rod Mill

Page 8: Usha Alloys & Steels Division

MANAGEMENT SYSTEM CERTIFICATES

ISO / TS 16949:2009 ISO 14001:2004 EMS ISO 9001:2008 QMS

Page 9: Usha Alloys & Steels Division

MANAGEMENT SYSTEM CERTIFICATES

TPM OHSAS 18001:2007

Page 10: Usha Alloys & Steels Division

VD

EAF VD

LRF

LRF

HM LADLE

FEATURES : EAF : 1 No. • F/C CAPACITY : 40 T • TXN CAP : 20/21 MVA • TECHNOLOGY : EASTERN METEC • REGULATION : DIGITAL SIEMENS • P ON TO TAP TIME : 45 MIN • TAP TO TAP TIME : 60 MIN • OXYGEN BLOWING : 2 INJECTORS ( AIR LIQUIDE) • CHARGE MIX: * HOT METAL : 50-55% * DRI : 35-45% * SCRAP : 10-20%

• PRODUCTIVITY : 0.25 MILLION TON

LRF (2 Nos.) FEATURES : • CAPACITY : 40 T • TXN. CAPACITY : 6 MVA VD ( 01 No.) • CAPACITY : 40 T • EJECTOR : VAI SIEMENS

DRI / FLUX FEED

CCM : 02 Nos. (FLEXIBILITY OF USING BOTH CASTERS ) • TECHNOLOGY : CONCAST INDIA • RADIUS : 6/11 Mtr. • SECTION : 130 SQR. & 150 SQR. • CASTING THROUGHPUT : 1T / MIN. • AMLC / AUTO START • EMS

SMS-1 &2 : PROCESS FLOW DIAGRAM

SCRAP BKT.

BILLET INSPECTION / RECTIFICATION &

DESPATCH

LIQUID METAL

Page 11: Usha Alloys & Steels Division

VD

EAF VD

LRF

LRF

HM LADLE

FEATURES : EAF : 1 No. • F/C CAPACITY : 70 T • TXN CAP : 60/65 MVA • TECHNOLOGY : SARRALE (SPAIN) • REGULATION : DIGITAL SIEMENS • PON TO TAP TIME : 45 MIN • TAP TO TAP TIME : 60 MIN • OXYGEN BLOWING : 2 INJECTORS ( SARRALE) • CHARGE MIX: * HOT METAL : 50-55% * DRI : 35-45% * SCRAP : 10-20% • PRODUCTIVITY : 0.5 MILLION TON

LRF (2 Nos.) FEATURES : • CAPACITY : 70 T • TXN. CAPACITY : 14 MVA VD ( 01 No.) • CAPACITY : 70 T • EJECTOR : VAI SIEMENS

DRI / FLUX FEED

CCM : 4 TECHNOLOGY : CONCAST INDIA • RADIUS :9/16 Mtr. • SECTION : 200 SQR. & 150 SQR. • CASTING THROUGHPUT : 1.7 T / MIN. • AMLC / AUTO START • EMS

SMS-3 : PROCESS FLOW DIAGRAM

SCRAP BKT.

BILLET /BLOOM INSPECTION /

RECTIFICATION & DESPATCH

LIQUID METAL

CCM : 3 TECHNOLOGY : DANIELI • RADIUS : 12/16.5/30 Mtr. • SECTION : 200x240 & 300x360. • CASTING THROUGHPUT : 0.8T / MIN. • AMLC / AUTO START • EMS

Page 12: Usha Alloys & Steels Division

Usha Martin 12

Electric arc Furnace :

EAF is basic melting unit which –

Converts solid scrap ( combination of solid scrap , DRI & hot metal

from MBF ) in to liquid .

Reduces harmful elements like “P”,“C” from the melt .

Maintains desired temp. required for further processing.

All these activities are carried out with the help of electrical

energy , Oxygen & use of different fluxes.

Electrical energy converts into heat energy , O2 gives chemical

energy which ultimately converts in to heat energy .

Page 13: Usha Alloys & Steels Division

Usha Martin 13

Electric Arc Furnace

Page 14: Usha Alloys & Steels Division

Usha Martin 14

EAF-II Features

Features:

40MT – EBT furnace

16 MVA transformer.

Oxygen lance from side panels and through slag door along with

coke injection system

Average tap to tap time = 65 - 70 mins.

Page 15: Usha Alloys & Steels Division

Usha Martin 15

EAF Working :

This EAF is working with electrical energy, oxygen blowing from

side panels & thro’ slag door along with coke injection.

Processing Steps :

Combination of Liquid PI , DRI , solid scrap is charged in to the

Furnace .

Converts completely in to liquid form – reducing P & C

Removing the slag

Raising the temp to ~ 1650 0C .

Tapping ( at 1620 – 1660 0C ) in to the ladle .

Page 16: Usha Alloys & Steels Division

Usha Martin 16

Need is the mother of invention

On 5th February 2015 , EAF transformer winding failed & resulted

in stoppage of production.

Page 17: Usha Alloys & Steels Division

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Innovation :

As transformer is failed – no electrical power.

So entire working of energy calculation is done .

Steps followed :-

1. Electrical energy required to be replaced is calculated.

2. Decided to replace this electrical energy by chemical energy.

3. Source of chemical energy - O2 , C , Si.

4. With existing mix – 54 % hot metal found that chemical

energy is not sufficiently generated .

5. Decided to increase equivalent hot metal & reduce solid

scrap like DRI & scrap .

6. Fixed the hot metal to 70 – 75 % .

7. Designed the O2 blowing parameters .

8. Taken the trial , fine tuned the process & freezed the process.

Page 18: Usha Alloys & Steels Division

Usha Martin 18

Data Sheet (Arcing & Oxygen Blowing)

Sl.

NoDescription Dec'14 Jan'15 Average

a) Charge Mix

DRI (%) 31.62 23 27.31

Hot Metal (%) 53.39 54 53.70

Scrap (%) 14.98 23 18.99

b) Tap to Tap Time (Mins) 68 63 65.50

c) Oxygen Nm3/Mt 47.79 57.65 52.72

d)EAF-II Power Consumption

(Kwh/Mt)209.19 194.11 201.65

e) Yield (%) 76.91 77.08 77.00

Page 19: Usha Alloys & Steels Division

Usha Martin 19

Process Steps

1. Charge Mix DRI : 20 – 22 %

Hot Metal : 70 – 75 %

Plant return : 3– 5 %

2. Oxygen Blowing Practice :

Stage Side Lance (2 Nos.) Door Lance

Initial 5 Mins 400 - 600 Nm3/hr 800 - 1000 Nm3/Hr

5 - 15 Mins 400 - 600 Nm3/hr 1000 Nm3/Hr

15 - 25 Mins 1600 - 1700 Nm3/hr 1600 - 1700 Nm3/Hr

DRI Feeding 1600 - 1700 Nm3/hr 1600 - 1700 Nm3/Hr

Slag Off

Typical Tapping Temperature 1650°C

Page 20: Usha Alloys & Steels Division

Usha Martin 20

Sl.

NoDescription Nov'15 Dec'15 Jan'16 Average

a) Charge Mix

DRI (%) 22.77 20.52 22.86 22.05

Hot Metal (%) 75.51 76.68 74.79 75.66

Scrap (%) 1.73 2.9 2.35 2.33

b) Tap to Tap Time (Mins) 68.82 73.78 66.81 69.80

c) Oxygen Nm3/Mt 79.77 78.55 68.95 75.76

d)EAF-II Power

Consumption (Kwh/Mt)0 0 0 0.00

e) Yield (%) 79.46 79.82 80.62 79.97

Data Sheet (Only Oxygen Blowing)

Page 21: Usha Alloys & Steels Division

Usha Martin 21

Result : Comparative Data

65.5052.72

201.65

2.60

77.0069.8075.76

0 0

79.97

0

20

40

60

80

100

120

140

160

180

200

220

Tap to Tap Time Oxygen (Nm3/Mt) Power (Kwh/Mt) Electrode (Kg/Mt) Yield (%)

With Arcing Without Arcing (Only on Oxygen Blowing)

Page 22: Usha Alloys & Steels Division

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Cost Saving

442

0

0

100

200

300

400

500

600

700

800

900

1000

With Arcing Without

Arcing (Only

on Oxygen

Blowing)

465

0

With Arcing Without

Arcing (Only

on Oxygen

Blowing)

907

0

With Arcing Without

Arcing (Only

on Oxygen

Blowing)

Electrical Energy Electrode Total

Rs/Mt

Page 23: Usha Alloys & Steels Division

Usha Martin 23

Cost Saving

Energy reduced to ‘Zero’

Electrode consumption reduced to ‘Zero’

Additional oxygen required 23.04 Nm3/Mt = 23.04 x 7 = 161 Rs/Mt

Cost Saving :

Energy = 201 x 2.20 = 442 Rs/Mt

Electrode = 2.6 x 179 = 465 Rs/Mt

Cost saving = 442 + 465 = 907 Rs/Mt

Net Cost saving = 907 – 161 = 746 Rs/Mt

Apart from this, reduction in flux consumption and increase in the life of EAF.

Page 24: Usha Alloys & Steels Division

Challenges & Opportunities

1. Due to increase of hot metal CO2 emission is increased by

approx. 1100 kg/heat

2. Life of oxygen lancing nozzle reduced from 600 heats to 500

heats

3. Needs to clean roof top position as it is getting jammed due to

splashing

4. Refractory consumption due to refractory delta is reduced to

zero as refractory delta is replaced by water cooled

Usha Martin 24

Page 25: Usha Alloys & Steels Division

Usha Martin 25

EAF-3 Started on oxygen blowing and with no arcing power

from 25/11/2015.

Horizontal Deployment

Page 26: Usha Alloys & Steels Division

Usha Martin 26

THANK YOU