MODULE IV

LADLE PROCESS – AN OVERVIEW

What is Ladle ? Ladle is used to carry the molten

metal or liquid metal from one place to another place.

Upper dia. 2500mm Lower dia. 2300mm Height 3200mm

Ladle preparation It consists of two steps basically

that is lining and preheating of Ladle.

Ladle lining has two parts viz. safety lining and working lining.

Safety lining

First of all inside part of ladle is covered by 6mm thick asbestos sheet.

It consists of two types of bricks layer that is high alumina and chrome magnesite.

Just after asbestos sheet we are putting high alumina brick layer in the ladle whose size is 230x115x40mm.

After this we are doing chrome magnesite bricks lining whose size is 230x115x65mm.

Working lining

After safety lining we are doing working lining. It has four parts viz. bottom zone, metal zone,

slag zone, free zone. First of all metal zone lining is done two size

bricks are used in this lining whose size are 225/200x150x100mm. And second 240/200x150x100mm.

These are of magnesia carbon. Total 16 layers are in metal zone. Whose one layer contain 30 bricks. In this way total 480 bricks are used.

Contd. After metal zone lining of slag zone is

being done. In this case three sizes of bricks used. The sizes are 225/200x150x100mm

(15f2), 240/200x150x100mm(15f2),and 248/200x180x100mm(10f3),230/200x180x100mm(10f3).

Slag zone having 6 layers.

Contd. After slag zone, free zone lining is

being done. Free zone having two parts -.magnesia

carbon bricks layer(5layers)& high alumina bricks tiles layer(1layer).

After slag zone lining 5 layers of mag. Car. Bricks are used. Sizes are 225/200x150x100mm and 240/200x150x100mm.

HA sizes is 230x115x75x65mm.

Contd. After brick lining we are lining bottom

zone. The lining of bottom zone is done by two

ways. First fixed bottom and second floating bottom.

Here we are using floating bottom. For this purpose total 95 blocks are used. The size used is 225x200x100mm.

Chemical compositionsBottom lining Slag zone in p.sideML2 10F3MGO = 94% MGO = 96%R.C = 9% R.C = 8%Metal zone Slag zone in repairMGO = 95% MGO = 96%R.C = 9% R.C = 8%Slag zone Free zoneMGO = 97% MGO= 87%R.C = 10% R.C = 6% AL2O3 = 17%

SLIDE GATE REFRACTORY

SLIDE PLATE MGO = 85%C = 5%AL2O3= 10%COLLECTOR AND LADLE NOZZLEAL2O3 = 85%FE2O3 = 1.5%

CONTD.

SEATING AND WELL BLOCKSIO2 = 0.5%AL2O3 = 97%FE2O3 = .05%POROUS PLUGMGO = 95%

Contd. After this seating and well block is fitted

in the bottom zone. Around seating block and well block the

gap is about 50-75mm. In this gap ramming of high alumina 95-

H is being done. Small gaps remain around bottom lining

is filled by 90-S. In seating block porous plug is fitted

and in well block ladle nozzle is fitted.

Slide gate assembly Slide gate of ladle is an important part. Slide gate is fitted in bottom part of ladle. It is divided in two parts. One plate is fixed on his place which is

called fixed plate and second plate which is sliding is called sliding plate.

The dimensions of this plate is length -332mm, breadth - 172mm , thickness- 47mm (made by magnesia spinel).

Hole dia. Is 42mm.

Contd. Ladle nozzle is fitted in well block.

Before fitting it is heated in oven . Collector nozzle is last part of slide gate

assembly Which is fixed on sliding plate of slide gate system. From this the teeming of LM is done in a uniform way.

Porous plug is fitted in purging block. From this purging by argon gas is done

inside the ladle.

QUALITY OF MAGNESIAMAGNESIA HAVE MANY QUALITIES---------1. Heat conductivity of magnesite

refracories decreased with the increase in temperature .

2. These are useful for raising and and maintaining high temperature.

3. Electrical conductivity of these refractories is considerable particularly at high temperature of about 1500deg.c

CONTD.

4. Magnesia is basic in nature , resistance to the action of basic slags rich in iron oxide and lime, of magnesite refracories is very high.

5. Magnesite refractories have very low resistance to abrasion and are not capable of resisting sudden changes in temperature by disintegrate.

Properties of carbon

Carbon has many qualities------1. Chemical activity :- carbon

refracories oxidise and burn when exposed to air on heating. They are not attacked by slags as they are not generally wetted by melts. For this reason carbon use in our fce. And ladle bricks.

Contd.

2. Thermal fatigue resistance ------They have a high reistance to

fluctuation in temerature which minimise spalling of the materials.

3. Cold crushing strength --------Thermal and electrical conductivities

of carbon refractories are very high.

Castables used in liningRamming mass Mgo = 84%min.90-s Al2o3 =

90%min.95-H Al2o3 = 95%Whytheat A Al2o3 = 90%90-K Al2o3 = 90%Magnesite mortar Mgo = 85%H.A Mortar Al2o3= 70%Chm. Mag. Mortar Mgo = 40% CR2o3 = 25%

High Alumina castables

High alumina refractories have gained importance as they can give better service under severe condition than fireclay castables because of their good volume stability, high resistance to thermal shock and creep,high refracoriness, greater load bearing capacity and resistance to slag attack.

Two types of nozzlex

First -----Grind chemical Sio2 = 20-25%Zro2 = 40-45%Cr2o3 = 15-20%Particle size----- .1mm to 1mm

Second type of nozzlex

Joglekar Cr2o3 = 31.2%Zro2 = 25.6%Fe2o3= 12.2%Sio2 = 14.8%Sieve analysis 0—0.5mmService temperature – 1750deg. c

LADLE LID LININGFire crete superType 70% alumina castableNature of bond HydraulicInstallation method Vibro castingWate addition 10-11%Service temp. 1450max.Al2o3 70%Sio2 11.5%Fe2o3 5%

Lrf delta lining

Lc-70Al2o3 = 70%Sio2 = 17.5%Fe2o3 = 1.5%Cao = 2.0%

Ladle preheating After completetion of lining of

ladle,it is preheated on burners before use.

Total time of new lining preheating is 10hours.

Total time of repair lining preheating is 8 hours 30minutes.

Thank You