NATIONAL INSTITUTE OF TECHNOLOGY

SRINAGAR

DEPARTMENT OF METALLURGICAL ENGINEERING

VIZAG STEEL PLANT TRAINING REPORT

Submitted By:-

Kalikota Prasad,

5th Metallurgy,

En Roll: 202/07,

NIT Srinagar.

Contents

1. ACKNOWLEDGEMENT

2. INTRODUCTION

3. MAJOR DEPARTMENTS IN VSP

4. METALLURICAL POINT OF View

A.R m h p (Raw material handling plant)B.Co & c c p (coke oven and coal chemical dept)C.SINTER PLANTD.Blast furnaceE. Steel melting shopF. Q a &td (QUALITY ASSURANCE AND

TECHNOLOGY DEVELOPMENT)

5. FLOW CHART

ACKNOWLEDGEMENT

With profound respect and gratitude, I take the opportunity to convey my sincere thanks to the management of VISAKHAPATNAM STEEL PLANT (VSP), VISAKHAPATNAM for giving me an opportunity to undergo industrial training in their plant.

We are grateful to Mr. J.PRABHAKARA RAO (Jr.Manager, Training and Department - VSP) for his support during the training at VSP. And also the technical staff, Sr. Superintendants, foremen, at various shops, who helped me to gain valuable practical knowledge that will help me in becoming a successful engineer in near future.

Also, I offer my sincere thanks to Prof. M. A. Baba, Head of Dept,(Training and Placement),and Prof R.Ambardar, Head of the Dept, (Metallurgy), National Institute of Technology, Srinagar, for providing me with a good reference, without which I could have never got this opportunity.

Yours Sincerely

Kalikota Prasad,

5th Metallurgy,

En Roll: 202/07,

NIT Srinagar.

INTRODUCTION

Rashtriya Ispat Nigam Limited (RINL) is the corporate entity of Visakhapatnam Steel Plant. Visakhapatnam Steel Plant (VSP), the first coastal based Steel Plant of India is located, 26 Km south west of city of destiny i.e Visakhapatnam. Bestowed with modern technologies, VSP has an installed capacity of 3Million Tonnes per annum of liquid steel and 2.656 Million Tonnes of saleable steel. At VSP there is emphases total automation, seamless integration and efficient up gradation, which result in wide range of long and structural products to meet stringent demands of discerning customers within India and abroad. VSP has become the first integrated Steel Plant in the country to be certified to all the three international standards for quality (ISO-9001), for Environment Management (ISO- 14001) & for Occupational Health & Safety (OHSAS-18001).The certificate covers quality, systems, of all, operational, maintenance, service units besides Purchase systems, Training and Marketing functions spreading over 4 regional marketing offices, 20 branch offices and 22 stock yards located all over the country.

The product profile of the plant comprises of wire rods, Rounds, reinforcement angles, channels, beams, squares, billets and blooms. The product profile also includes basic grade pig iron, granulated slag, coal chemicals and other by-products. The plant also exports power to AP Transco from its captive Thermal power plant. The steel plant has many technological features, which are unique amongst the steel plants in the country. The company is a pioneer in introducing many new technologies in the country. The production of TMT re-bars by temp core process is a shining example in this respect. Because of high level of technology existing throughout the plant, the company has a very good manufacturing capability to meet the needs of various customers.

VSP exports quality Pig iron & steel products to Sri Lanka, Myanmar, Middle East, USA, Southeast Asia (Pig iron). RINL- VSP was awarded “Star Trading House” status during 1997- 2000Having a total manpower of about 16,613 VSP has envisaged a labour productivity of 265 Tonnes per man year of Liquid Steel which is the best in the country and comparable with the international levels.VSP has achieved highest carpenter life of hearts per campaign during January 2008 and best specific energy consumption of 6.08 G cal / TLS during 2005- 06 and maximum labour productivity of 414 T/Man year during 2005-06 in pursuit of excellence.

MAJOR DEPARTMENTS IN VSP

Coke Ovens & Coal Chemical Plant

Coking coal after selective crushing and proper blending is subjected to destructive distillation (heating in the absence of air) in the Coke Ovens. After heating for nearly a period of 16- 18 hours at a temperature of about 11000 C, coke is obtained and is used as a fuel as well as reducing agent in the Blast Furnace. The Coke Ovens of VSP are engineering feats by themselves. They are the tallest ovens metre constructed in the country. The Plant has 3 batteries of 7mtr.Tall ovens with each battery consisting of 67 ovens. Another feature is the dry cooling of coke carried out by the inert gas nitrogen thus; reducing pollution considerably. Besides a Bio-chemical plant it separately undertakes the treatment of effluents. By-products like benzene, toluene, xylene, naphthalene, coal tar, creosote oil, pitch; ammonium sulphate and benzol products are also recovered from the coke ovens gas. VSP produces, among other by-products, pushkala a prime fertilizer based on ammonium sulphate.

Sinter Plant

Iron ore fines, coke breeze, limestone and dolomite along with recycled metallurgical wastes are converted into agglomerated mass at the Sinter Plant, which forms 80% of iron bearing charge in the Blast Furnace. The Sinter Plant comprises of two sinter machines each having 312 square metres of grate area with a total production capacity of 5.256 million tonnes per annum.

Blast furnace

VSP has two Blast Furnaces with an effective volume of 3200 m3. each of which are the largest in the country. Blast Furnace is charged with coke, iron ore and sinter from the top and produces about 5000 tonnes of molten iron per day. Their novel circular cast house withfour tap hole ensures continuous tapping of hot metal. The annual production capacity of these Blast Furnaces is 3.4 million tonnes of liquid iron.

Steel Melt Shop & Continuous Casting

Three Top blown converters, each of 133m 3 volume, produce a total of 2.7 million tonnes of liquid steel per annum. This liquid steel thus produced is casted in six-4 strand bloom casters. A special feature in energy conservation is the collection of Converter gas to be used as a fuel in the plant. The entire molten steel at VSP is continuously cast at the radial type continuous casting machines resulting in significant energy conservation and better quality steel. 100 percent; Continuous casting on such a large scale has been conceived for the first time in India.

Rolling Mills

The cast blooms from continuous casting department are heated and rolled in the three high speed and fully automated rolling mills namely Light & Medium Merchant Mill, Wire Rod Mill and Medium Merchant & Structural Mill, to produce various long products like Reinforcement bars, rounds, squares, flats, angles, channels, billets, wire rods etc. Technologies adopted at Rolling Mills include world-class Stelmor and Temp core processes.

Major Sources of Raw Material

Raw Material Source

Boiler Coal Talcher, Orissa

Coking Coal Australia

Medium Coking Coal Gid/Swang/Rajarappa/Kargali

Iron Ore Lumps & Fines Bailadilla, MP

SMS Lime Stone UAE

Manganese Ore Chipurupalli, AP

SMS Dolomite Madharam, AP

Water Supply

Operational water requirement of 36mgd is being met from the Yeluru Water supply scheme of Andhra Pradesh. This water is then treated in various water treatment plants in VSP, so as to be usable for industrial purposes.

A.RMHP (RAW MATERIAL HANDLING PLANT)

The Raw Material Handling Plant (RMHP) receives the basic raw materials required for the steel making process from various sources through railway wagons and by road. These are stacked by stackers and reclaimed by reclaimers and distributed to various departments of VSP through conveyor system. The Iron Ore Fines, Iron Ore Lump, Sized Iron Ore, Limestone (BF & SMS grades), Dolomite (BF & SMS grades), Sand, Quartzite and Manganese lumps are stacked at Ore& Flux Yard. The Imported Coking Coal (ICC), Medium Coking Coal (MCC), Boiler Coal (BC) is stacked in Coal Yard. Coke is sent directly to Blast Furnace after tippling from ore and flux wagon tipplers.

These raw materials are sent to various departments as indicated below:

1. Sinter Plant: Iron Ore Fines, Lime stone (BF), Dolomite, Sand and LD slag.2. Blast Furnace: Sized Iron Ore, Limestone (BF)/ LD slag, Manganese Lump,

Quartzite and Coke.3. SMS: Dolomite (SMS), Sized Iron Ore, Dolo chips.

4. CRMP: Limestone (SMS), Dolomite (SMS), Dolo chips.5. TPP: Crushed Boiler Coal.6. COCCP: Imported coking coal (ICC), Medium coking coal (MCC).

The Raw Material Handling Plant is divided into two sections Coal Handling Plant (CHP) and Ore Handling Plant (OHP).

The facilities available in two sections are as follows:

COAL HANDLING PLANT

2 Wagon Tipplers 5 Ground & 10 Track Hoppers Stock Yards ( 10 Beds) Boiler Coal Crushing Plant Stackers, Reclaimers

And Stacker cum Reclaimer Reclaiming Conveyors Stacking Conveyors

ORE HANDLING PLANT

3 Wagon Tipplers 10 Ground and 10 Track Hoppers Stock Yard (12 Beds) Lump Ore Crushing Plant Lump Ore Screening Plant Stackers and Reclaimers Reclaiming Conveyors Stacking Conveyors

SALIENT FEATURES OF RMHP

i. Peripheral unloading system for railway wagons coming directly up to pushers.ii. Blender Reclaimers for blending of ores and flux in which the bucker wheel has a

lateral motion across the bed.iii. Wheel on Boom Reclaimers for reclaiming different materials from same bed in Ore

& Flux yard and same type coals in CHP.iv. 2 Ring Granulators for crushing of Boiler Coal.v. 3 Blender Reclaimers for blending of Iron ore fines and flux.

vi. PLC control of all systems.vii. Drier for drying SMS Sized Ore.

viii. Preparation of Sized iron Ore for use in BF to enable close size range of raw materials.

ix. Dust Extraction system is provided at various locations of RMHP to absorb the dust generated during the process.

RAW MATERIAL SPECIFICATIONS

The iron- bearing burden materials are Iron Ore fines supplied from Bailadilla mines and manganese ore from the deposit in Vizianagaram district.

The various raw materials handled in the OHP are as follows:

Sl.No Raw Materials

1.0 Iron Ore Fines.2.0 Iron Ore Lump.3.0 Sized Iron Ore.4.0 Limestone (BF grade).5.0 Limestone (SMS grade).6.0 Dolomite (BF grade).7.0 Dolomite (SMS grade).8.0 Sand.9.0 Manganese Lump.

10.0 Quartzite Lump.11.0 Sponge Iron.12.0 Pellets.13.0 LD Slag.14.0 Coke.

The various raw materials handled in the CHP are as follows:

Sl.No. Raw Materials

1.0 Imported Coking Coal.2.0 Imported Soft Coking Coal.3.0 Medium Coking Coal.4.0 Prime Coking Coal.5.0 Boiler Coal.

These Raw Materials are sent in different proportion to various customer departments as indicated below:

1. Coke Ovens : Imported Coking Coal, Medium Coking Coal, And Primary Coking Coal.

2. Thermal Power Plant: Boiler coal.3. Sinter Plant: Iron ore fines, Limestone (BF grade), Dolomite (BF grade), Sand and

LD Slag.4. Blast Furnace: Sized iron ore, Limestone (BF grade), Manganese lump,

And Quartzite lump, Coke, Sponge iron, Pellets and LD Slag.5. SMS: Sized iron ore and Dolomite (SMS grade).6. CRMP: Limestone (SMS grade) and Dolomite (SMS grade).

Stacking & Reclaiming Facilities

Facility Ore & Flux yard Coal Yard Coal Yard

a) Stackers 1400 tph (5 no’s) Twin Boom 850 tph (3 no’s) Single (Fixed Type) Boom (Swivelling Type)

b) Reclaimers 450 tph Wheel on Boom 550 tph Wheel on Boom Reclaimers (3 no’s) Reclaimers (3 no’s)

1200 / 450 tph Blender _ Reclaimers (3 no’s)c) Stacker cum _ 850 / 550 tph (1no) Reclaimer

CRUSHERS

a) Iron Ore - Cone Crusher.

b) Boiler Coal - Ring Granulator.

B.COKE OVEN AND COAL CHEMICAL DEPARTMENT

COAL PREPARATION From the storage yard, the coking coal is sent to foreign material removing

section to remove foreign matter of above 150mm size. Iron traps for ferromagnetic articles and cylindrical screens are provided for this. For averaging and proportioning of coal, 16 no’s of bins each 800 tonnes of capacity are provided along with continuous action feeders of up to 100 tonnes per hour capacity each. After blending the material is crushed to take care of petro graphic non-uniformity, high hardness and mineral content of coal. The crushing is carried out in reversible hammer crushers 2 operating and 1 standby. The crushed and blended coal (74-78% of ñ3mm size) is conveyed to two coal towers each of 4000 T capacity. Weigh bridges are provided under coal towers to weigh the coal charge. System of pneumatic blow down of blend is provided in the coal tower to take care of jamming of coal.

BATTERYThe prepared coal charge in the coal tower is drawn by a charging car on the

top of the batteries and charged into the ovens as per sequence. The charged coal is gradually heated by the heating walls of the oven in the absence of air to attain a temperature of1000-10500C at the central axis of the coke mass towards the end of coking period. The coking period is generally specified between 16 hrs and 19 hrs depending on oven condition and production requirement. The volatile matter of coal liberated during carbonization is collected in gas collecting mains in the form of raw coke oven gas passing through stand pipes and direct contact cooling with ammonia liquor spray. The gas cooled from 8000 C to 800 C is drawn to coal chemical plant by Exhauster.

The residual coke is pushed out of the oven by pusher car through a guide into coke bucket. The red-hot coke is taken to coke dry cooling plant for cooling.

There are 3 batteries, each having 67 ovens. Each oven can hold 32 tons of dry coal charge. The volumetric capacity of each oven is 41.6 m3.

The heat for carbonization is supplied by under firing of coke oven gas having CV of 4200Kcal/Nm3 or mixture of BF gas & CO gas having Calorific Value 900 K cal/Nm3.

The heating system of batteries is of under jet, compound type having Twin-heating flues with re-circulation of waste gases. The dimensions of oven are as follows:

a. General Dimensions:Length 16,000 mmHeight 7,000 mmWidth on coke side 435 mmWidth on pusher side 385 mmAverage width 410 mm

b. Effective Dimensions:Length 15,160 mmHeight 6,700 mmNumber of heating flues in one heating wall 32 Nos.Distance between axes of ovens 1,400 mmNumber of charging holes 3Number of gas-off take holes 2Heating level (distance from the top ofThe hairpin of the heating flue to the 1,100 mmCarbonizing chamber roof)

Temperature in heating flues is between 13300C and 13900C and final temperature of coke mass at its central axis is between 10000C 10500C.

Following oven machinery is provided. Operating Total

Charging Cars 3 6Coke pusher 3 5Door Extractor 3 5Electric Loco 3 5Coke Car 3 7

COKE DRY COOLING PLANTThere are three coke dry cooling plants, each having four chambers. Capacity of

each chamber is 50-52 TPH. Each coke dry cooling plant consists of cooling chambers with individual lifter and lifting shaft, waste heat boiler, dust catching arrangements and smoke fan.

The cooling chamber has two technological zones. Red-hot coke is charged into the upper zone while cooling takes place in lower zone by circulating gases. Gas is forced by smoke fan into distribution channels in the lower part of the chamber and fed into the cooling zone. The gas flows upwards and gets heated. Circulating gases enter boiler, cyclones and returned to bottom part of cooling chamber by smoke fan.

The coke is cooled from 1000 – 10500C to 180-2000C while the circulating gases are heated from 160-1800C to 6000C-8000C. 20-25 Tonnes/hour of steam at 35-40 at pressure and 430-4400C is produced from one chamber. The cooled coke from the cooling chamber is discharged on to the conveyor continuously through a rotary discharging system.

COKE SORTING PLANTFrom the dry cooling plant, coke is discharged into dedusting units by conveyor.

Dedusting units are provided with equalizing bunkers and belt feeders to compensate for irregularity of coke discharge from dry cooling plant.

From the dedusting unit, coke is conveyed to crushing section. It is first separated into +70mm and -70mm fractions. The +70mm fraction is fed to two roller-toothed crusher (2nos. each of 120 TPH capacity).

The crushed product along with -70mm fraction is conveyed to screening plant where 25to 70mm and 0 to 25 mm fractions are separated using roller screens. 25 to 70mm coke is conveyed to blast furnace. Bunkers of 600 tonnes capacity are also provided for loading into wagons/trucks and dumpers for sending to yard.

0 to 25mm fraction is fed to vibrating screens provided to separate into nut coke (10 to25 mm sizes) and breeze coke (0 to 10mm). Nut coke is sent to blast furnace and breeze coke is sent by conveyor to Sinter Plant.

C.SINTER PLANT

SinteringSintering is a process of Agglomerating iron ore fines into a porous mass by incipient

fusion caused by combustion within the mass of the ore particles.

History of SinteringIron ore fines (0-10 mm) which were a result of mechanized mining could not be

charged in a Blast furnace because they reduce the permeability of burden in a blast furnace. These iron fines that were generated at mines could not ignored because of their i) Huge quantity and ii) High iron content.To use these fines effectively in a Blast furnace many processes were developed. Sintering being one of them and widely in integrated steel plants.

Raw materials used in sintering areVarious raw materials used in sintering process are

i. Iron ore fines (0-10 mm).ii. Coke - used as fuel.

iii. Limestone & Dolomite - to maintain required sinter basicity.iv. Sand - to maintain required sinter basicity.v. Metallurgical wastes - to use wastes effectively and thus reduce the cost of sintering.

vi. Lime - to enhance the process of sintering.

Sintering process1. Preparation of various raw materials.2. Mixing & Blending.3. Mixing with sinter returns in presence of water to form green balls.4. Charging on to the machine.5. Ignition and suction.

Factors affecting the sintering process

As you have discussed before sinter process consists of mixing of various raw materials, palletizing the mixture with water, charging the sinter mix on the machine, igniting the top layer and sucking atmosphere air through the ignited the bed till the entire sinter mix becomes sinter.Broadly the productivity of a sinter machine depends on the following factors.

1. Quality of input raw materials2. Permeability of sinter bed3. Vacuum under grate4. Quality of sinter

1. Quality of input Raw materialsBoth physical and chemical qualities of input raw materials affect productivity of

sinter machines. The various raw materials used in sintering are Iron ore fines, Coke breeze, Limestone, Dolomite, Sand, Metallurgical waste and Lime.

i. Physical propertiesIron ore fines used for sintering should be of the size of 0-10 mm. More of -1 mm

fraction will reduce bed permeability and will reduce the vertical speed of sintering reducing machine productivity. More of +.0 mm fraction will not participate in the process of sintering leading to poor quality of sinter and low productivity. All other raw materials should be within the size range of 0-3 mm to provide for uniform chemistry and for best ignition conditions. At VSP about 85% of iron ore fines lie between the size range of 0-10mm and 95% of other raw materials lie within the range of 0-3mm. As these size ranges are best suitable for sintering nothing more could be done in improving this factor.

ii. Chemical propertiesThe chemical composition of the input raw materials also affects sintering

productivity. Low amount Alumina in iron ore fines and low loss on ignition factor of various raw materials increases the productivity of the sinter. At VSP Alumina in iron ore fines varies from 2 to 3% and total loss on ignition of base mix varies from 18 to 20 %. As these factors are naturally linked with the various raw materials, the affect is these factors on productivity are considered as constant and no improvement activities were carried out.

2. Permeability of Sinter bedPermeability refers to the amount of space that is provided by the sinter bed to allow

atmospheric air to pass through it. A bed with higher permeability will increase the vertical speed of sintering and thus productivity will rise. A bed with low permeability will offer resistance to the flow of air and the vertical speed of sintering will reduce resulting in low productivity.

3. Vacuum under grateThe vertical speed of sintering depends on the suction that is created under the grate

more the suction higher will be the vertical speed of sintering and more the productivity. At VSP two exhausters are provided for each machine to create a suction of 1500 mm water column under the grate. Each exhauster is driven by a 5.6 MW motor capable of rotation the fan at 1000 rpm with an output of 15,000m3/min. Continuous operation of sinter machines causes wear to the suction track. Regular maintenance is carried out to reduce losses in the suction track. At sinter plant of VSP steps are taken on regular basis to maintain a minimum vacuum of 1100 mm of water column under the grate. It is observed that whenever vacuum falls below 1000 mm water column productivity comes down. So regular plugging of

leakages is taken up and once in a year capital repairs are carried out to take up large-scale repairs.

4. Quality of Sinter Sinter quality also plays an important role in the productivity of sinter machines.

Higher FeO gives strength and productivity increases but sinter with more than 11 % of FeO in undesirable in a Blast furnace. Low amount of MgO increases productivity but sinter with 2.4 % of MgO is required by Blast furnace to form a Non-viscous slag. As Quality of Sinter ì is the requirement of its customer i.e. Blast Furnace. Sinter plant has to stick to the quality requirements of Blast furnace irrespective of its own productivity.

VSP Sinter plant - An over viewSinter plant of VSP has the capacity to produce 5.256 MT of sinter per annum, which

will cater for 80 % of Iron bearing feed to Blast furnace. Two Sintering machines of Dwight Lloyd type having 312 M2 total grate area are provided for this purpose. Sinter machine is designed to operate at the rate of 1.2 T/hr/M2 for 330 days in a year.

Sinter plant consists of the following main sections

1. Flux crushing section2. Fuel storage yard3. Coke crushing & Flux screening section4. Receiving bins5. Raw material bins6. Material Mixing & Distribution Plant7. Base mix yard8. Secondary sinter mix & Palletising Plant9. Sinter machine building with Sinter cooling10. Fan building11. Slime-dewatering pump house12. Sinter Screening Plant13. Gas Cleaning Plant14. Air Cleaning Plant

Secondary Mixing and Pelletizing PlantIn this section base mix from Base Mix Yard, Lime stone & Coke fines from Raw

Material Bins sinter returns from Sinter Screening Plant, sludge from Slime Dewatering Pump House and ACP dust are fed in the required proportion to mixing drum and water is added to get required moisture content in the burden which is the final raw material for making sinter. The main equipment in this section are 2 numbers of Mixing drum (Palletizer) with capacity of640-1030 t/hr, 6 numbers of disc feeders with capacity of 210-370 m3/hr and 8 numbers of weighing devices.

Sinter Machine Building and Sinter CoolingThe already prepared sinter of 10-25mm size of received from sinter screening which

is fed as bed material to a thickness of 40 mm over the grate bars of moving pallets of the sinter machine. Burden material in the pelletizer is charged over the bed material to a thickness of 500 mm. As the raw material comes in to the ignition hearth the top layer of the charge is ignited and heated to a temperature of 10000C. The furnace is of three sectional

chamber types with a total of 10 horizontal burners that are heated with the help of mixed gas of Coke oven and Blast furnace gases. The grate is placed over vacuum chambers of 26 numbers. Air is sucked through the bed of charge and vacuum chambers by exhaust fans in the fan building.

The Sinter machine consists of endless chain of 135 pallets moving over 26 vacuum chambers. By the end of 26th vacuum chamber sintering is completed and the sinter is discharged in to single roll crusher through a hopper. The single roll crusher crushes the sinter lump in to 0 - 150 mm size, then the hot sinter passes over the hot screen, which separate ñ8mm and +8 mm screenings. The -8mm sinter screenings are cooled in a drum cooler with water to 1000C and are dispatched to secondary mixing and palletizing Plant.

The 8-150 mm size sinter is fed to St. Line cooler which is an endless chain moving on to parallel rails over 16 blowing chambers. 8 blower fans blow cold air through the chambers and cool the sinter to 1000C. The cold sinter is sent to sinter screening plant by means of conveyors for screening. The main equipment in these section two numbers of sinter machines, Single Roll Crushers, Hot screens, Drum coolers, Furnace Blower Fans, St. Line coolers, and St. line cooler blower fans.

Technical parameters of Sinter Machine

Type : Dwight LloydTotal grate area : 312 m2

Effective / Sintering area : 276 mLength between sprockets : 93.4 mWidth of the machine : 4 mNo. of pallets : 135Number of wind boxes : 26Drive arrangement : Left handWind box arrangement : Right handSpeed of machine pallets : 1.5 to 8 m/minCapacity of the machine : up to 450 TPHBed height : 500 mmHeight of bed layer : 40 mm.

Technical parameters of Straight Line Cooler

Active working area : 420 m2

Length : 118.4 mHeight of the sinter bed : 0.75 m to 1.0 mCapacity : Up to 550T/hrNumber of wind boxes : 16Number of blower fans : 8Specific flow rate : 66,000m3/ton.

D.BLAST FURNACE

BURDEN HANDLING AND FURNACE CHARGINGBurden materials are received in the stock houses, one for each furnace through a

junction house. Coke is handled by two conveyors (one stand by) o± 1600 mm width and 350 TPH capacity, sinter, lump ore by two conveyors (one stand by) of 14 00 iron width and 800 TPH capacity, Sized ore and additives will be handled by one reserve conveyor of 1500 mm width and 800 TPH.

Junction house has a cross over through rolling reversible conveyor and stationary reciprocating conveyor. For each furnace, there are 5 bins for sinter, 5 bins for coke, 3 bins for lump ore, 1 bin for nut coke, 3 bins each for limestone/LD slag and quartzite/used Silica bricks and manganese ore.

Coke, sinter and iron ore are screened in screens up to 400 m3/hr capacity to remove the fines. The screened material is fed to the inclined conveyor for burden handling to top through a horizontal conveyor. Conveyors for burden handling to top are of 2000 mm Width 2160 m3/hr capacity and are operated continuously. The materials are positioned in conveyor in separate batches at certain intervals and in a certain sequence as per preset programme. PLC system is provided for batching, weighing and feeding of the burden to the furnace top.

The Paul Wurth, bell loss top system is installed for furnace charging. The system consists of two bunkers of 47 cubic meter capacity each, charging moving hopper s rotating trough. All drives are hydraulically operated except for trough rotation and tilting which are electrically operated. Semi clean BF gas and nitrogen are used for pressure equalisation in charging bunkers. Nitrogen is used for cooling rotating trough drive and for blowing off stock bin gates and sealing valves of charging arrangement. Mechanical gauge rods are provided for measuring stock level.Exhaust station and air cleaning plant are provided for handling system. The exhaust air is directed to electrostatic precipitators (2 nos.) for cleaning. The plant capacity is 3.65x10m3/hr. The dust content of air is reduced from 2.85 gm/cum to 0.1 gm/cum, 200 tons

of dust is collected every day. The dust collected is balled in granulation plant and is automatic transported in trucks to Sinter plant.

The burden handling system premises are hydraulically flushed 600m3/hr water). Total effluents generation is 600m3/hr. After primary settling, the water is pumped to sinter plant for further use.

HOT BLAST STOVESThere are four hot blast stoves for each furnace with a total heating surface of

224,000 m2.The domes can be heated to a temperature of 14500C maximum while the waste flue temperature is up to 4000C. The stoves are capable of giving a blast temperature up to13000C. Stoves are heated by a mixture of blast furnace gas and coke oven gas having a Calorific value of 1,100 Kcal/N cum. Pressure of mixed gas before burners is 600mm W.C.

Gas mixing station is provided to mix BF gas, CO gas in required proportion and to get the necessary Calorific value. Separate stations are provided for each furnace. Mode of operation of stoves in successive (staggered parallel also can be operated).High temperature zone is lined with silica and mullite corundum refractories, medium temperature zone, with kaoline refractories and low temperature zone with fire clay refractories. The shell of dome and cylindrical part is heat insulated with a heat proof gunnite concrete in high temperature zone. Gaps between shell and walls are filled with mats from fibrous materials. Checker-work is lined with hexahedral refractories with round cells of 41mm dia. Combustion chamber is in-built construction of elliptical shape. The chimney is of 80 m high, 3.5m diameter at the mouth. It is of reinforced concrete and fire clay lined. Stack for back drought is made of metal with refractory lining. Air supply for burners is centralized. Three fans (one stand by) of 120,000m3/hr, 1080 mmwc capacity each are provided for the purposes.Water cooling arrangement has been provided for cooling of hot blast valves and burner cut-off valves.

FURNACESTwo blast furnaces of 3,200 m3 useful volume, each capable of producing 1.7 MT of

hot metal per year while operating for 350 days are installed. The basic characteristics of furnace are:

Useful height from iron notch centre line to trough bottom in verticalPosition .... 33,100 mmHeight of hearth - 4,600 mmHeight of Bosh - 3,400 mmHeight of belly - 1,900 mmHeight of shaft - 20,000 mmHeight of top - 2,300 mmHeight of dead layer - 1,203.5 mmDiameter of Hearth - 12,000 mmDiameter of belly - 13,000 mmDiameter of top - 8,900 mmBosh Angle - 79010‘37"Shaft Angle - 83043’22"Number of Tuyeres - 32Number of Tap Holes - 4 and No slag notches are provided.

The lower part of the hearth bottom is lined with graphitised carbon blocks while upper part is with high refractory mullite bricks in the centre and with carbon blocks in the periphery. Side walls of the hearth are lined with carbon blocks in lower part and

aluminosilicate bricks are used for lining of bosh, belly and shaft. Furnace top is lined with non cooled steel slabs of suspended construction, while non cooled cast iron slabs are used for furnace dome. Insulation layer was provided between slabs and shell of dome.

Lower part of the hearth bottom is air cooled. Peripheral cooling plates are used for cooling of upper part of hearth bottom, hearth, tuyere zone, bosh, belly and lower part of shaft. For middle part of the shaft, peripheral plates with independently cooled projections are used. There are 664 cooling plates. Besides, there are 32 breast coolers, 32 tuyere coolers, 32 tuyeres and 8 nozzles in furnace dome. The water requirements for cooling will be5555m3/hr (6475m3/hr max.) per furnace at 80mmwc. Clean recirculation water with suspended matter up to 50 mg/litre is used.

PIG CASTINGFour double strand pig casting machines of 1700 TPD capacity are installed to treat

off grade metal and metal diverted due to stoppages in SMS (one machine reserve). The machines can handle one furnace production. Each PCM is served by a 75 T, overhead trolley to tilt the 140 T hot metal ladles. Pig weight is about 45 Kgs. Facilities for lime washing of moulds and a re-circulating water system for cooling the pigs, including a settling tank, is provided.

The cold pig from machines are collected in wagons and sent to open gantry pig iron storage yard. The yard is of 300 x 40 m size and cold pigs are stored in separate lots according to grade. Two 150 T Rail weigh Bridges are provided to weigh outgoing loaded wagons.

HOT METAL LADLE REPAIR SHOP:The main objectives of this shop are as follows:

a. To ensure placement of hot £ clean metal ladles to each furnace in time for the castings per the casting schedule.

b. To ensure quick despatch of Hot metal loads to their planned destination and also ensure early withdrawal of empties from PCM/SMS in order to thoroughly clean inspect and clean the same before placement.

c. To effectively coordinate with Rail Traffic department/ 2BFs/ SMS/PCM to ensure achieving of above objectives.

The entire shop working rotates around the three above objectives. The main equipment/tools/devices provided in the shop to achieve those objectives are as below

a. 2 Nos. of 120/50 tons capacity E.O.T cranes (for Hot Metal ladles cleaning purposes).b. 30 Nos. of conventional open top metal ladles (capacity 140 tons each) and 7 Nos. of

Torpedo ladles (capacity 300 tons each) to hold & transfer liquid Hot Metal.c. 4 Nos. of metal ladle pits with stands to hold conventional ladles during mechanical

repair jobs/RED lining jobs.d. 1 No. 42 tons capacity punch and 2 No’s, of four beak anchor hooks to remove skull

from metal ladles and clean them.e. 2 Nos. of drying installation to dry and preheat freshly lined conventional ladles

before taking hot metal in them to avoid explosion and thermal shock.

BLAST FURNACE MASSES AND COMPOUND SHOP

Refractory masses required in cast house viz., Runner mass, Mud gun mass. Tap hole frame mass are prepared in Masses Compound shop.

The raw materials required for preparing mass are received at various sizes from the different sources. These are crushed in various stages and stored in final storage bins. There are 12 final storage bins out of which 6 are used for coke, 2 for plastic fire clay, 2 for pitch and 2 for grog. The capacity of final storage bins is 30 cubic.

There are 6 operating groups for raw material handling and preparation of masses.

Group I: It is for primary handling of coke breeze and plastic fire clay. In case of coke there will not be any crushing in this stage. If coke contains moisture more than 0.51 itIs taken through rotary drier or otherwise drier is by passed and coke is taken directly to intermediate bunker o± 60 cubic meter capacity. In case of clay, the plastic clay of 250mm size is crushed in tooth roll crusher to 40mm size and if it contains Moisture. It is taken through drier or otherwise drier is by passed and the crushed clay is taken to intermediate bunker of 60 cubic meter capacity.

Group II: In this group final crushing and storage of plastic clay is carried out. Clay from intermediate bunker is taken to disintegrator through a chute feeder where it is crushed to 0.5 mm and is stored in final storage bins (2 Nos.) with the help of a belt bucket elevator and a screw feeder. The capacity of disintegrator is 5 T/Hr.

Group III: In this group crushing of coke breeze (25mm size) and storage of crushed coke in final storage bins is carried out. Coke breeze of 25 nun size from intermediate bunker is taken to four roll crusher via chute feeder where it is crushed to 1 mm and is stored in final storage bins( 6 No’s) . In four-roll crusher, the upper sets of rolls are grooved type and the bottom set or rolls are of plain type. The capacity of four-roll crusher is 6T/Hr.

Group IV: In this group pitch and grog are crushed and stored in final storage bins. The material crushed in two stages. Pitch/Grog of 250 mm size is loaded in main bunker (capacity 60 cubic meter) with the help of grab crane (capacity 10T). Then Pitch/Grog is feeded to jaw crusher through a reciprocating feeder and primary crushing takes place. After primary crushing Pitch is taken to Two-Roll crusher where it is crushed to -3 mm size and then it is stored in final storage bias (2 No’s). In case of Grog, hammer mill is used for secondary crushing. The crushed grog (1 mm size) is stored in final storage bins (2nos).

Group V & VI: In these groups mass is prepared with the raw materials stored in final storage bins. One a pan mixer is provided in each group. There are three weighing hoppers common for both the groups. Raw materials from the final storage bins in different proportions are weighed in weighing hoppers and then through conveyors they are taken to pan mixers where water/oil is mixed and mass is prepared.

NITROGEN SUPPLY AND BLOCK OF RECIPIENTSNitrogen of 97% purity is used for charging apparatus and for other equipments,

Requirements 38,370 normal cubic meter per hour. Nitrogen is supplied from Oxygen plant. To provide for emergency Nitrogen reserve, and to compensate non-uniform consumption, a block of recipients consisting of two 100 cubic meter vessels for 10 Ksca pressure and six 125qubic meter vessels for 35 to 40 Ksca pressure are provided. A Nitrogen control stationIs provided as a part of block of recipients, where pressure is reduced from 35 to 40 KscaTo 8 to10Ksca.BURDEN HANDLING SYSTEM

To control the proportioning of burden materials with due consideration for coke moisture Content & batching accuracy. This system also gives relevant data connected with the operation of the Burden handling Complex to the process personnel. This consists of the following major local systems for monitoring and control.

i. Material levels in the bins.ii. Material batch weights

iii. Coke moisture contentiv. Availability of materials and transfer of the material batches to the Blast furnace top.v. Over filling of chutes.

E. STEEL MELTING SHOP

INTRUODUCTIONIn Steel Melting Shop of Visakhapatnam Steel Plant, LD Process of steel making has

been adopted. The liquid steel obtained from LD process is cast into Blooms through Continuous Casting Machines (Bloom Casters).

For better exploitation of the available facilities and to have efficient administration in the biggest department of VSP, Steel Melting Shop is divided into two major sections.

i. Converter Shopii. Continuous Casting Shop

Each of these shops has been further divided.

CONVERTER SHOPBulk Material Handing Section (BMHS)Mixer ShopConverter BayScrap YardSlag YardLadle Preparation Bay

CONTINUOUS CASTING SHOPTundish preparation Bay (TP Bay)Argon Rinsing Station (ARS) & IRUT & LFContinuous Casting MachinesGas Cutting MachinesBloom Storage Yard.

DESCRIPTION OF FACILITIES

MIXER SHOP It is very difficult to supply the hot metal from Blast Furnace to the converter as per

its requirement, unless there is an arrangement for storing the hot metal in SMS. Mixer serves this purpose. There are two mixers in SMS. The Capacity of each mixer is 1300T Hot Metal. In mixer, temperature of hot metal is maintained by burning coke oven gas with air. The Mixer vessel is in cylindrical form with two removable spherical ends. Length of the vessel is 10.67M and diameter is 7.64M. The mixer is installed on a mixer platform and is served by mixer crane (2 no’s of capacity180T/63T/20T) The main units of the mixer are shell assembly, roller support, tilting mechanism, hand brake mechanism, charging hole cover winch, charging hole platform, spout door opening mechanism, gas & air distribution system, installation of blower, lubrication system, electrical system.

The average life of mixer is about 1.6-1.8 MT (Million Tonne), lining duration is about 30days. To reduce abnormalities in LD Steel Making, Blast Furnace is supplying Hot Metal to SMS in the following composition and temperature range.

C = 3.5 - 4.2%Si = 0.3 - 0.6%Mn = 0.25% maxP = 0.15% maxS = 0.04% max

Temperature = 1250 - 1425 Degree C.12500C – 13500C Through Mixer route13000C – 14250C Through TLC (Torpedo Ladle Car) route.

BULK MATERIAL HANDLING SECTION (BMHS)The following bulk materials are used in converter shop of SMS.Calcined Lime Dolo - used as flux in LD-Converter.

Cao + Mgo = 90 - 92%LOI (Loss On ignition) = 5-7%SiO2 = 2.5% MaxSize = 10-25 mmRequirement = 6-10 T as per heat weight and hot metal composition, iron Ore Lump – Used as Coolant in steel making.

Fe = 66.9%SiO2 = 0.9%AI2O3 = 1.6%MnO2 = 0.05%Size = 15 - 60 mmRequirement = 0.5 - 3T as per blowing conditions.Raw or Calcined Dolo - Used to increase lining life of Converter.Lump Coke - Use4 to preheat the lining of newly lined converter.

One of the requirements for continuous casting process is that the liquid steel should be killed (fully deoxidised). For this and to make different grades of steel, ferro alloys (FeSi, SiMn,FeMn, etc) Coke breeze/Petroleum coke and Aluminium are added in the ladle during taping of steel from converter to ladle.

CONVERTER BAYHot metal contains different impurities (C, Si, Mn, S, and P) above safe level which

make Pig Iron brittle. But steel is nothing but refined hot metal. Refining is only possible when things are in molten phase. Refining is done by blowing oxygen in the LD converter Charged with Hot Metal, Scrap, Flux, Iron Ore, etc. In this refining process, temperature of liquid steel is kept at 17000 C (average).Different grades of steel is made by adding various ferro alloys & additives (FeSi, FeMn, Coke Breeze or Petroleum Coke, Aluminium, etc) in different quantities during taping of liquid steel from converter to steel ladle.

There are 3 LD converters in SMS. Characteristics of converter is given below

Capacity = 150 TonneEffective Volume = 133 cumConverter specific volume = 0.886 Meter Cube per TonneHeight to Diameter Ratio = 1.36

Refractory for converter lining is MgO based e.g. Sea water Magnesia, Magnesia carbon, Tar Bonded Dolomite Bricks, Pitch Bonded Dolomite Bricks etc.

Oxygen is blown in the converter through oxygen lance. It consists of three concentrically arranged steel tubes with connecting branches for Metal - Flexible - Hoses. Central pipe is for supplying oxygen, intermediate pipe is for incoming cooling water and outside pipe is for outgoing water. At lower part of lance there are 4 nos. Convergent - Divergent copper nozzles syrnmetrically arranged at 17.50 to the lance axis.

CHARACTERISTICS OF OXYGEN LANCE

Lance Travel = 16000 mmOxygen working pressure = 16 KSCGWater Working Pressure = 12 KSCGNo. of Nozzles = 5Water consumption = 130 cum/hrOxygen flow rate = 400-450 NM3/min

During blowing LD gas is generated. This is a very poisonous gas because its main Component is carbon monoxide. LD gas cooling, cleaning and collection system comprises of tube bar-tube type skirt, gas cooling hood and stack, Closed loop type gas cooling arrangement with in fan cooler, kinpactor, gas duct, ID fan, change over valve, flare-stack, gas holder, etc. When the gas composition is acceptable, it is recovered and collected in gas holder. Unacceptable LD gas is discharged through Flare Stack.

LD gas Collection system - Gas collection with suppressed Combustion.LD gas Cooling - Gas cooling with closed loop hot water pressurised

Cooling system.LD gas cleaning - Wet type cleaning system with adjustable

Throat venture.

ARGON RINSING STATION (ARS)The liquid steel which is tapped from LD converter is not homogeneous in

composition and temperature. To make the liquid steel suitable for continuous casting

purpose by making it homogenous, inert gas rinsing is done. Generally Argon gas is used for this purpose. Both bottom and top purging facilities are available. Bottom purging is superior to top purging. When both are used at a time, it is more effective.

In general, 12 minutes rinsing is done. For the entire 3 LD Converters steel transfer car track, 3 ARS are available. In case of LD-2 steel transfer car track, IRUT (Injection Refining & up Temperature) is installed. Along with steel temperature rising, Argon Rinsing is also done simultaneously. To raise the temperature at IRUT, oxygen blowing is done and simultaneously Aluminium is added.

In ARS, Aluminium is also added for complete deoxidation (to reduce oxygen potential of liquid steel below 15 PPM) and to increase Al% in liquid steel to make it suitable for continuous casting purpose.

There is one ladle furnace in ARS Bay. In Ladle Furnace, composition adjustment and liquid Steel-temperature rising can be done. Simultaneously Argon Rinsing is also done along with the above said activities. In Ladle furnace, temperature of liquid steel is raised by electric arcing. There are 3 graphite electrodes for this purpose.

When rinsing is over after achieving desired temperature and composition (varies from one steel grade to another) ladle covering compound is added at the top layer of liquid steel in the ladle. This reduces heat loss from ladle.

CONTINUOUS CASTING MACHINES (CCM)Continuous Casting may be defined as teeming of liquid metal in a mould with a false

bottom through which partially solidified ingot (same shape as mould) is continuously withdrawn at the same rate at which liquid metal is poured in the mould.

Facilities and Equipments at CCM platforms: Lift and Turn StandTo accommodate the steel ladles and place them in casting position as and when

required to facilitate sequence casting. It lifts the ladle and places the ladle at casting position by turning it and swing back the empty ladle after completion of casting.

Mould Oscillating systemTo facilitate easy with drawl of continuously cast bloom (partially solidified) from the

mould.

Oscillation frequency : 60-100 cycle/minMould Oscillation amplitude : 6 to 8 mm

Copper MouldThe foremost important factor in the continuous casting is the copper mould which

decides the efficiency of the process. The material selected for mould and the design of mould play a prominent role in obtaining the bloom of greater surface finish, better mechanical properties with minimum of casting defects. A mould with good design associated by good cooling system gives quality blooms, provided a great care, is exercised during casting.

In VSP, square (250mm x 250mm) and rectangular (320mm x 250mm) cross sectional moulds are used. These moulds are provided taper towards bottom (327 x 255 top, 324x252.5 bottom in case of 320x250 bloom) to maintain the contact between partially solidified strands and is made of copper which is necessary for achieving the necessary cooling rate. Copper is an ideal material for mould because it is having

i. Good thermal conductivity.ii. Mechanical strength must be retained at operating temperature 250 degree C.

iii. Recrystallization temperature above 300 degree C.iv. Low friction coefficient and good resistant to wear.v. Chemical immunity w.r.t. steel.

Cu-Ag 0.1 P-F 25-possess all the above properties.Length of mould at VSP is 1.0 mRadius of mould 12 m

STRAND COOLINGStrand cooling is carried in two stages: Primary and Secondary cooling.

Primary Cooling The boiler feed water is used for this purpose with PH 7-9, total hardness- 0.2 DH.

This water is repeatedly pumped through the moulds in a closed cycle with re cooling blot. This water has to be treated and anticorrosive agent etc. should be added. This water is supplied at a pressure of 4-5 bars. The inlet water comes from the bottom & leaves the mould through the outlet valve which is located at the top of mould. This is indirect type of cooling.

Secondary CoolingThe water that is sprayed over the strand should cool the strand uniformly throughout

the length, to avoid under cooling of some parts of strand. The pressure will be 6 bars. The counteract flow problem due to corrosion, the pipeline will be made up of stainless steel. In secondary cooling, strand (bloom) will be completely solidified, leaving no liquid steel at all. The secondary cooling zone begins from just below the mould.

Water for secondary cooling should havePH 7-9, Total hardness 20 DHCarbonate hardness 0.7 DH

Dummy BarThe function of Dummy Bar is to seal the mould bottom, for the starting of casting

and to withdraw solidified shell until the hot strand has passed the straightening and withdrawing machines.

Backup Roller sections N1 & N2These sections are intended for supporting and directing the dummy bar and strand in

Course of casting. N1 is a four roll section installed on posts underneath the secondary cooling sections, while N2 is a six roll section installed after the 4-high stand.

Withdrawal and straightening rollersThere are four strands which are used for withdrawing and straightening the curved

bloom.These 4 stands are designated as TK1, TK2, TK3, and TK4.TK1 - 4 high strandTK2 - 2 high strandTK3 - 2 high strandTK4 - 2 high strand

Casting PowderThe main purpose of casting powder is to act as a lubricant to prevent the sticking of

steel to mould. Casting powder must be added continuously at regular intervals. The

meniscus must always be covered enough that it appears dark, but layer thickness should not exceed 30 mm.

Casting powder should meet the following requirementi. Reduce strand friction.

ii. Should protect liquid steel against reoxidation.iii. Prevent surface heat loss.iv. Promote uniform heat transfer from meniscus to mould in order to avoid longitudinal

cracks.v. Rapid and uniform spreading on the bath surface.

vi. It should also absorb some oxides in the steel without great change of its viscosity.

Technical details of CC machinesAverage Casting speed for 320x250 bloom sizes is 0.78 M/min for 250x250 bloom

size is 0.82 M/min.

Gas Cutting Machines (GCM)The strand, which continuously comes from the copper mould after getting

completely solidified, should be cut as per our requirement, to facilitate easy handling, etc. In order to cut the blooms accurately, a gas cutting machine, using acetylene and oxygen, is used. Since the bloom travels with certain speed, the machine used for cutting the bloom should travel along with the bloom. For this grippers are used, which grips the bloom and travels along with it, taking the oxy-acetylene flame with it. Each CC machine has been provided with 4 cutting machines to cut the four blooms at a time.

Details of gas cutting machinesThe pressure of the acetylene : 0.6 kg/sq.cmLength of the bloom : 5.5 to 5.8 m for 250 x250mm size

6.0 to 6.3m for 320x 250 mm sizeTime required for cutting one bloom : 1-1.5 minThe pressure of oxygen : 15 kg/cm2.

F. QUALITY ASSURANCE AND TECHNOLOGY DEVELOPMENT

ROLE & FUNCTIONS TESTING & ANALYSIS PROCESS CONTROL INSPECTION METALLOGRAPHY & NDT CERTIFICATION CALIBRATION CUSTOMER SERIVCE PRODUCT DEVELOPMENT RESEARCH & DEVELOPMENT OTHER MISC. ACTIVITIES

TESTING & ANALYSISThis entails the physical testing and chemical analysis of the

following Incoming Raw-materials.

(Coal, Iron Ore, Limestone, Dolomite, Sand, Quartzite, Manganese Ore, Ferroalloys) Coke, Coal Chemical Products, Sinter. Hot Metal, Liquid Steel, Slag (BF & SMS) Cast Steel & Finished Products. Gases, Water, Effluents, Oil, Lubricants & Refractory.

Some of the important testing facilities are Coke & coke analyser Coke reactivity apparatus Gas chromatograph Ash fusion determinator Oil testing equipment Atomic absorption spectrometer UV-VIS Spectro photometer Reducibility testing machine RUL, PCE, PLC testing equipments Conductivity meters PH meters Optical emission spectrometer Carbon & sulphur analyser Oxygen & nitrogen analyser X-ray fluorescence spectrometer Hydrogen analyser Universal testing machine Upset testing equipments Torsion testing machine Hardness testing machine Impact testing machine Optical microscopes Micro & Macro testing facilities

Magnetic particle test equipment Ultrasonic flaw detector Dye penetrate test system High speed grinder Orion Ion selective electrode meter Compression and bending testing machine Muffle furnaces, induction furnaces & drying ovens

PROCESS CONTROL Monitoring of charge coal blend composition and battery parameters at Coke Ovens. Monitoring of stacking & reclaiming sequence of all incoming raw materials at

RMHP. Charge calculations & monitoring of operating parameters at Sinter Plant. Burden calculations & monitoring of granulometry of input materials at Blast

Furnace. Monitoring of lime quality at CRMP Monitoring of blowing parameters and additions at Converter Shop. Control of casting parameters of continuous casting machines. Monitoring of cooling parameters at Stelmor and Temp core Process in WRM &

LMMM respectively.

INSPECTION 100% visual inspection of semis i.e. Blooms & Billets. On-line inspection and audit check of finished products. Inspection at intermediate stages of production. Spark testing of special grade steel. Inspection of engineering products by NDT.

METALLOGRAPHY Micro structural studies of steel products. Failure analysis of failed parts & components.

NON-DESTRUCTIVE TESTING Use of NDT for proactive, preventive and reactive maintenance of parts and

components.

CERTIFICATION By Products: Crude tar, phenol fraction, DNO, Anthracene oil, pitch, wash oil,

naphthalene, benzene, toluene, LSN, HCB, polymer, still bottom, SOL-110, ammonium sulphate.

Pig Iron Granulated BF slag Semis: Blooms and billets. Finished Products - Wire rods, re-bars, rounds, equal angles, channels, flats & beams.

CALIBRATION Vernier Callipers. Micrometers.

CUSTOMER SERVICE

Regular interaction with customers. Prompt reply on customer query and complaint. Corrective & preventive action taken/suggested based on the findings.