FROM – 2
The Patent Act,1970
Complete Specification
(Section 10; Rule 13)
Title: - "Complete Melting Process of aluminium scrap using medium frequency induction furnace".
M/s Suneem Industries Pvt. Ltd. Plot No. C-12, Five Star MIDC Shendra, Aurangabad -431 201 Maharashtra State, INDIA
The Following specification describes the invention and the manner in which it is to be performed:

Field of the invention
The present invention relates to "A complete melting process of aluminium scrap using medium frequency induction furnace, the said method of melting various types of scrap/ Raw material/ alloying element - economically, safely as well as efficiently by employing medium frequency Induction Furnace for melting of Aluminium scrap". The raw material used for melting in the innovative method are selected from the group consisting of possible melting of homogeneous scrap to various combination of heterogeneous type of scrap. Such as
a. Thin foils scrap to bulky primary ingots.
b. Clean Tense (Casting) to 65% MS attach Tens.
c. Low Metallic containing scrap - Radiator,Turning, Borings, swarfe aluminium scrap and
thin foil chips.
d. Loose TT to Compressed Bundle of High Density (equal to aluminium).
e. Shredded TT to Shredded Tense.
f. Commercial Aluminium Scrap containing various grades, shape, e.g. Automobile Scrap,
Marine Scrap, engineering parts, electrical parts, Structural parts etc.
g. Primary pigs (25 Kg - 1200 Kg) to heavy pigs (300 Kg - 4000 Kg),
h. Loose extrusion scrap to pressed bundle scrap.
Prior Art and Back ground:-
The Coreless induction furnace is very popular for secondary route melting for various grades and / or metals, derivative of metals & grades e.g. Steel, Alloy Steel, Stainless Steel, Cast Iron, Ductile Iron, Ni Resist, Copper & Copper Base Alloy, Nickle & Nickle Base Alloy etc. There are more than 10000 foundries (few Kgs capacity to 15 MT/Heat Capacity) cattering stated and implied needs of Indian industries. For aluminium Melting there are approximately more than 2750 Units of aluminium for PDC, GDC, LPDC, Extrusion, Rod Mill, Wire Drawing, Utensil Manufacturer, Sand Casting, Billet Manufacturer, Foil Manufacturer, Sheet Manufacturer, Chequer Plate Manufacturer, Decorative Parts, Investment Casting Manufacturer etc. These units employ Rotary Furnace, Reverabaratory furnace, crucible furnace (Lift out type), stationary Pot furnaces (fuel Fired ), Tilting Pot Furnaces, Shaft Furnaces, Dip out double chamber dry hearth furnaces, Resistance Furnace etc. These melting technology often uses solid, liquid and gaseous carbonaceous/petroleum/hydrocarbons as fuel material. Only resistance furnace uses electricity yet capacity of furnace is the limitation. Presently medium

frequency induction furnace restricts aluminium melting due to limitation of various nature. Few major limitations are as follows:
> High capital cost of Induction Furnace equipments & auxiliary.
> Limitation of higher cost of Monolithic lining.
> High dross generation for meting of low aluminium content scrap.
> Unpredictable dross behavior & low lining life.
> In consistent raw material and Frequent failure of refractory lining.
> Undefined operation resulting in Frequent failure of refractory lining.
> Extraneously treacherous behavior of dross.
> Low metallic yield.
> Limitation of Scrap Selection.
> Higher percentage of Dross formation.
> High energy cost.
> High processing cost.
> Difficulty in alloy addition.
> Temp control.
> Composition control.
> Homogeneity of metal.
> Difficulty in late additions of high melting point metals and alloys for composition setting.
> Difficulty in late additions of low melting point/ volatile metals and alloys for composition setting.
> Difficulty in late additions of degassing with N2, H2, Ar, CI, He.
> Difficulty in late additions of grain refiner and degasser metal.
> Higher level of pollution during melting / finishing stage of liquid metal preparation.

For above reason, Coreless induction furnaces, are not commercially employed for economical and for secondary route Aluminium melting. Also Hetrogeneous nature/origin of scrap often results in high magnesium level (for majority automobile component, this requriment varies 0.05 to 0.4 %), Mgnasium removal by applying volatile chemicals results in generation of poisonous gasses excessive boiling of liquid metal, high dross formation, more metal loss, unpredictable process control.
In present market, aluminium scrap is melted in Rotary Furnace, Reverabaratory furnace, crucible furnace (Lift out type), stationary Pot furnaces (fuel Fired ), Tilting Pot Furnaces, Shaft Furnaces," Dip out double chamber dry hearth furnaces & resistance furnaces etc. These melting technology restricts aluminium melting due to limitation of various nature, for all type of scrap readily available in the market. Maximum difficulty for secondary melting of Aluminium by using scrap of heterogeneous origin/composition/grade results in:-
> High scrap cost
> High cost of capital equipment.
> High skilled level of person.
> Limitation of Scrap Selection.
> Higher percentage of Dross formation.
> High energy/fuel cost.
> High processing cost.
> Difficulty in alloy addition.
> Temp, control.
> Composition control.
> Homogeneity of metal.
> Higher level of pollution during melting / finishing stage of liquid metal preparation.
The present invention and a related literature are indicating "An improved process for melting of aluminium scrap - Thin foils scrap, primary ingots, Clean Tense (Casting), 3% - 65% MS attach Tense. Radiator,Turning, Borings, swarfe, thin foil chips. Loose TT, Compressed Bundle,Shredded TT, Shredded Tense, Automobile Scrap, Marine Scrap, engineering parts, electrical parts, Structural parts, Primary pigs (25 Kg - 1200 Kg) to heavy pigs (300 Kg - 4000 Kg). Loose extrusion scrap, pressed bundle scrap by medium frequency Induction furnace".

Objects:-
The object of the present invention is that to facilitate for production of aluminium through various commercial scrap. Also facilitate production of various grades in accordance with the commercial standards requirements.
The important object of the present invention is being implemented in large commercial scale and established commercially for production of different grades for example: LM-2, LM-4, LM-6, LM-9, LM-21, LM-22, LM-24, LM-25, LM-27,AISi-132, ADC-10, ADC-12, AC2A, AC2B, AC3A, AC4A, AC4B,AC4C,AC4D, AC7A and other combination as per BIS, BS, JIS, DIN, ASTM, MIL Standard.
Further very important object of the present invention is that aluminum metal produced shows better recovery than other alternative conventional route of production.
Further very important object of the present invention that it gives lesser formation of slag, Burning Loss, Dross and overall non metallic disposal during the performance of alleged inventive process.
An object of the present invention is that, process method of melting different variety of homogeneous nature scrap. Raw material/ alloying element - economically, safely as well as efficiently by employing medium frequency Induction Furnace.
A most important object of the present invention is that, establishing process method of melting different variety of homogeneous nature scrap, alloying element, late additions of alloying element along with aluminium grain refinement as well as micro structure modification.
An object of the present invention is that, improved process method of aluminium melting suitable for various types of alloying addition of high temp melting point - Fe, Mn, Ti, Cu, Ni, B, V etc.
An object of the present invention is that, improved process method of aluminium melting suitable for various types of master alloy production of- Fe, Mn, Ti, Cu, Ni, B, V etc.
A further object of the present invention is that, process method which results in less thermal fluctuations for monolithic refractory lining.
A further object of the present invention is that, to address energy efficient fast melting of aluminium.
A most important object of the present invention is that, employing melting techniques which results in high metallic yield, low generation of dross and low melting loss.
A further object of the present invention is that, practicing melting techniques which results in 5
- 25% remelting of dross generated in the plant.
A further object of the present invention is that, practicing melting techniques which results in 5
- 65% melting of primary dross (purchased from primary aluminium manufacturer).

A further object of the present invention is that, preparing aluminium and aluminium alloy which provides higher mechanical properties.
A most important object of the present invention is that, developing a melting practice which permits Aluminium melting for continuous operation as well as most predictable behavior for intermittent operation.
A most important object of the present invention is that , A melting practice suitable for different alloying of high melting point.
An important object of the present invention is that, A melting practice suitable for different alloying of low melting point.
A further important object of the present invention is that , A melting practice suitable for different alloying of volatile metal addition.
A most important object of the present invention is that , A melting practice suitable for degassing with H2, N2, Ar, CI.
A further important object of the present invention is that, A melting practice suitable for developing proper grains as well as modification of grains.
A further important object of the present invention is that, A melting practice which reduces Magnesium content upto a negligible level,
An important object of the present invention is that, practicing melting techniques which results in lesser generation of final disposal as well as neutral/non-hazardous slag.

Following are few major grades/ Compositions are consistently demanding by the Automobile Manufacturer of Aluminium Component (PDC, GDC & Sand Casting)

GRADE .Fe Si Cu Mn Mg Ni Zn
LM9 0.2-0.25 12.5-13.0 0.1 Max j 0.3-0.5 l 0.4-0.6 \ 0.1 Max 0.1 Max
AC2A 0.3 Max i 4.5-5.0 3.8-4.1 0.2 Max 0.1-0.2 0.3 Max 0.2 Max 0.2 Max
HS1S 0.3-0.4 6.5-7.5 2.5-3.5 0.3 Max 0.1-0.3
0.4 Max
AC2B 0.35 Max 5.75-6.75 3.1-3.6 [ 0.5 Max 0.5 Max 0.2 Max ' 0.1 Max
LM16 0.4 Max 4.5-5.5 1.1-1.5 0.5 Max 0.4-0.6 0.1 Max 0.1 Max
AC4C 0.4 Max ,6.5-7.5 0.1 Max 0.15-0.3 0.4-0.6 0.1 Max 0.1 Max
9MNMG 0.4 Max 8.5-9.5 0.2 Max 0.4-0.6 0.3-0.4 0.2Max 0.1 Max
A413 0.4 Max 10.5-11.5 0.5 Max 0.35 Max 0.1 Max 0.3 Max 0.3 Max
LM6 0.4 Max i
11.3-12.5 0.1 Max 0.3 Max 0.1 Max 0.1 Max 0.1 Max
AC4B 0.5 Max 7.0-8.0 2.5-4.0 0.3 Max 0.4-0.55 0.2 Max 0.5 Max
ALSI10 0..6-0.8 9.0-10.0 0.1-0.25 0.3-0.4 0.25-0.5 0.1 Max 0.1 Max
ALSI132 0.7-1.0 10.5-12.5 1.5-2.5 0.55 Max 0.3 Max 0.4 Max 0.02 Max 1.4 Max 0.05 Max
ALSI132 0.30Max 11.5-12.5 1.75-2.5 0.1 Max 0.1 Max

ALSI12CU 0.8 Max 10.5-13.5 1.0 Max 0.55 Max 0.35 Max 0.3 Max 0.55 Max
ADC12 0.8 Max
10.5-12 1.5-2.5 0.5 Max 0.3 Max 0.5 Max 1.0 Max
ALSI9CU3 0.6-1.1 :
8.0-11 2.0-4.0 0.55 Max 0.55 Max ; 0.6 Max 0.9 Max
A360 1.3 Max 9.0-10.0 0.6 Max 0.35 Max 0.4-0.6 0.5Max 0.5 Max

BRIEF DESCRIPTION OF THE DRAWING
Figure No. 1 shows schematic diagram of crucible with description of major Component / assembly of 5.5 MT capacity induction crucible.
Description of the Invention:-
The present invention makes it possible to produce all the grades of aluminium/ aluminium alloy.Coreless induction furnace with a neutrals lining which permits Aluminium melting for continuous operation as well as most predictable behavior for intermittent operation is the need lof present industrial market. Therefore, the present invention relates to Complete Melting Process of aluminium scrap using medium frequency induction furnace , the said method makes possible to produced desired composition of various grades of aluminium scrap. Melting practice is also suitable for different alloying of high melting point added along with initial Aluminium scrap charging as well as late additions of pure Silicon (Si), Ferro-Silicon(FeSi), Copper(Cu), alloys of copper, Zinc(Zn) , alloys of Zinc, Magnesium (Mg) .alloys of Magnesium, Manganese ( Mn) ,alloys of Manganese, Titanium (Ti ),alloys of Titanium , Boron -(B) ,alloys of Boron, Vanadium (V) ,alloys of Vanadium, Nickel (Ni) ,alloys of Nickel, Chromium and Chromium alloys.
The present invention is being implemented in large commercial scale and commercially established for production of different grades of Aluminium and Aluminium Alloys as suitable for automobile industries, die caster (GDC,PDC,LPDC), sand casting permanent mould casting.
The said melting process is not limited, as well as established practice is most suitable for different alloying of low melting point added along with initial Aluminium charging (if required for specific composition)as well as late additions (if required for specific composition) of pure Tin (Sn), Phosphorous (P), alloys of copper Phosphorous, Lead (Pb) ,Strontium (Sr), alloys of Strontium, Lithium (Li ),alloys of Lithium, Zirconium (Zr) , Zirconium Alloy, Bismuth (Bi), Beryllium (Be) and Cadmium (Cd). The Same melting practice is also suitable for different Low Temperature Fluxes used for fluxing, flushing and degassing of molten aluminium as well as aluminium alloys (if required for specific composition/degassing) as well as late additions (if required for specific composition/degassing) of pure/ mixture of NaCI, KCI, NaF, HexaChloroethelene, Mag remover, N2 gas, Ar gas, He, CaO & CaCo3. The Same developed process is also suitable for Remelting low metal bearing Aluminium scrap contaminated with cutting oil , dust, dirt, grease, other oils, rubber, plastic, 30 - 90 % Aluminium containing by product of aluminium industries (Primary as well as secondary melting) The Same melting process is also suitable for production of different master alloy Silicon (Si) - 10 to 20% Si , Copper(Cu) - 5 to 15 % Cu, Magnesium (Mg) - 3 to 5% Mg, Manganese ( Mn) - 5 to 15% Mn and Titanium (Ti) - 5 to 15% Ti. Nickle(Ni) - 1 to 10% Ni, Chromium (Cr) - 0.5 to 10% Cr.

[A] Raw Material required for melting the aluminium scrap to produce
aluminium & aluminium alloy.
1.90 % Alumina Dense Castable having particle size 0-4 mm. taking a Chemical composition AI203 - 85% minimum , CaO - 6 % Max, Fe203 - 1.5% Max, Water 10 - 15 % 2. Aluminium scrap 3. Cu metal/scrap/aluminium copper master alloy 4. Manganese Metal/Ferro manganese 5.Magnesium 6. Titanium 7. TiB 8.Silicon Metal 9. Other metals as per composition 10. Rock salt 11. N2/Ar gas 12. Neutral salt 13. Dead lime powder 14. Fire clay 15. Bentonite 16. Silica ramming mass 17. Dry alumina ramming mass 18. Asbestos
[B] List of Tools Required to Perform the Invention
Cement Vibrator, Concrete Mixing Machine, Metallic Former, Mixing tray, Sets of standard shovel, Hand held magnets, Plastic Buckets, induction furnace with hydraulic tilting, carpenters set, blacksmith set, bailing press, jaw crusher, magnetic separator, screening machine, pulveriser, different size chisel, special tools for dross, shearing machine, fabricated baskets of different size & designe, different size& design of fabricated metallic spoon, different ladles gas lancing mechanism, immersion pyrometer, graphite crucible, copper mould, weighing balances, material handling equipments, spectrometer, grinder, polisher, safety hairnets, asbestos hand gloves, face mask, asbestos apron. Vibratory screen.
[C] Process of melting - Pre Operative Requirements
For induction melting to start check monolithic lining for GLD of crucible (2 mili-Amp). Also apply Wash of dead Powdered Lime/ Lime & Cement/ Talk or Mica/fire clay to inside wall of monolithic (When Crucible is Hot condition). Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before charging Start. Initial charging of 5% - 25% of clean material (furnace capacity) gives better metallic yield. After initial charging of clean as well as known composition makes further charging of contaminated nature very easy.
[D] Detailed Description of Process
Suneem Industries Pvt. Ltd. Employees two units of 5.5 MT aluminium capacity Steel shell hydraulically tilted, powered by 2000 KW supply with a provision of running either furnace as well as shearing the power from 0-100%. Induction Furnace are excellent melting units energy consumption for melting is effected by density of charge, non- metallic content in the charge , the melting practice used, MS contents in scrap, finishing temp, cleanness of operation, charging pattern, type of scrap, late addition, specific metallurgical requirement etc. Energy consumption varies from 540 Kw - 750 Kw / MT. Medium Frequency coreless induction furnaces

are most suitable for batch production of various grades without keeping any molten heal. The stirring effect of the induction power is very advantageous since the charge is mixed well.
The said method and system having equipments comprising the following steps:-
Medium frequency induction furnace charging and charge selection starts with, the Normal Metal Charge Consist of Clean Scrap and/Pure Ingot and / Alloying Metal. As a initial charging so as to avoid contamination of metal from initial charging. Further analysis Control is Obtained By Using A Charge of Known Analysis as well as a charge of carefully segregated Material. Alloying of Virgin Aluminium / Scrap is Most Favorable Under Right Charge, Calculation/ Right Analysis Control. Analysis Control is Obtained Using Additions of Pure Cu, Si, Mn, Ti & Cr With Initial Charging. Late additions of Mn, Ti, Cu, Si, Ni & Cr is Added as Pure Metal Are Best Recovered As Rich Alloys/ Hardeners. Even the late addition for pure metal of Mn, Ti, Cu, Si, Ni & Cr is added as pure metal with help of squirrel cage arrangement also.
Medium frequency induction Melting Practice Requires Furnace As Well As Metal Charge Be Clean. Apply Wash of dead Powdered Lime/ Lime & Cement/ Talk or Mica/fire clay Should be Applied - When Crucible is Hot condition. Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before charging Start. Initial charging of 5% - 25% clean & sorted scrap (of furnace capacity) gives better metallic yield. After initial charging of clean as well as known composition makes further charging of contaminated nature very easy. Also when melting has started and scrap contains dust, paper, and other carbonaceous material e.g. oil, grease, water, moisture, rubber, plastic, PVC, and other Non-metallic scrap (difficult to separate) is charged in such a way to avoid immediate contact with liquid aluminium bath. When scrap contains oil, grease, water, moisture, rubber, plastic, PVC, and other Non-metallic scrap (difficult to separate) is charge in such a way so as to remove the said impurity just after initial stage of charging (5%-25% clean & sorted scrap charging) which eliminates contaminants in form of simple burning. Avoid first sampling, removal of dross, intermittent charging till coil height of furnace. This results in high metallic yield. Crucible Must Be Cleaned After Each Heat For Adherent Dross, Entrapped Metal, Broken Pieces of Refractory other contaminants of resulting Dross which May Entrapped during Subsequent Melting. A Wash of Powdered Lime, Lime & Cement, Talk or Mica Should be Applied - When Crucible is Hot condition. Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before Next Melting Cycle Start.
Melting occurs Very Rapidly In Induction Furnace Due To Combination of Power as Well as Stirring, If this power is not controlled as per condition of scrap, variety of scrap, density of scrap, melting point of charge, other type of charge/alloying, density of charge/alloying, size of charge/alloying etc. (If not Controlled Properly) Results In Formation of High Dross.

Density of Some Dross Product In Solid State.
Si02 - 2.5 g/cm3, Aluminium- 2.7 g/cm3, AI2O3-3.80 g/cm3,Al203.XH20- 2.42 g/cm3, MgO -3.65 g/cm3, Aluminium - 2.6 g/cm3, Aluminium - 2.6 g/cm3, Cu20 -6 g/cm3, CuO - 6.40 g/cm3.
Melting occurs Very Rapidly In Induction Furnace Due To Combination of Power as Well as Stirring. When furnace is Charged Continuously so as to avoid Splashing also this results in continuous generation of smoke which prevents heated charge as well as molten heel from air contact (where oxygen present in atmosphere may react with aluminium). This process is further controlled by reducing the partial pressure of reaction/ increasing the charging rate of furnace/ avoiding carbonaceous material direct contact with liquid metal. Unprotected charging atmosphere, carbonaceous contamination, Bridging of Charge, moisture, Explosion etc. (If not Controlled Properly) Results In Formation of High Dross.
Flow diagram of Induction Furnace Aluminium Melting
Start With Clean Materials of Known Analysis - 5 - 25% of furnace capacity Charge All Calculated Cu, Si, Mn & Other High Temperature Metal. Use Clean Melting Practice as well as continuous charging.
Charge Continuously At Regular Interval.
▼
First Bath Sample To Be Drawn At Coil Height or Above ( 4 MT or above )
Add Final Stage Necessary Additions/Pure Metal (If Required in form of lighter/ thinner wall thickness
Analyse Final Sample For Chemistry & Temperature.
▼ Remove Dross From Side Wall of Crucible.
Purge Liquid Bath with N2 Gas or Ar Gas (5 Minutes To 20 Minutes).

Keep Temp of Melt Low until pouring is Ready 695 - 765°C (as per grade requirement) Other precautions:
1 Use Minimum Holding Time In The Molten Condition.
2 Avoid Water vapour or Hydrogen Contamination At Finishing Stage.
3 Do Not Agitate or Stir The Melt.
4 Use adequate Fluxing or Flushing Practice.
5 Skim off Final Dross Just Before Tapping.
6 Increase The Temperature To Required Level.
7 Cover Top Surface With Dry Lime Powder/Talc/Mica.
8 Avoid Creation of Excessive Turbulence when Pouring The Molten Metal.
9 Use Bottom Pouring of metal At Tundish.
10 For induction furnace Avoid Melting Practice, Unprotected from Combustion Products.

Annexture - "A"Coreless Induction Furnace
• Coreless Crucible Induction Furnace consist of water cooled helical coil surrounding a ramming mixture of monolithic refractory lining, forming a crucible in which the metallic mass to melted is charged.
• The coreless induction furnaces work on same principle of transformer.
• The primary is formed by helically wound, very pure low resistivity electrolytic copper tubes through which cooling water flows.
• Often to get efficient result the coil is divided into several parallel circuits.
• Water must be specially treated to prevent scale forming in the path.
• Each turns are kept properly insulated with proper spacing during monolithic refractory lining/during running of furnace.
• The coil is surrounded by a number of lamination packets constructed of laminated transformer iron steel.
• The crucible assembly consist of coil lamination packets, top and bottom sections and top as well as bottom ring are bolted together to form a "squirrel case ".
• The coil is clamped vertically by a top and bottom fabricated unit to prevent vertical de - coiling during operation .
• The coil is clamped radially by the lamination packets in combination with vertical channel , pads and jacking bolts.
• The complete coil assembly is fitted in a fabricated steel structure which is hydraulically tilied.
• Power is fed to the furnace coil through flexible water cooled cables.
• Water cooled cables, which along with rubber hoses carry cooling water to and from the coil to compensate I Rt losses resulting through coil as well as conduction losses of heat through lining to helical coil assembly.
• A limit switch is provided to switch off the power to hydraulic power pack when furnace tilts 95°.
• Due to melting operation following forces are regularly generated in monolithic lining / coil cradle assembly/crucible structure.

1) Mechanical force i.e. High compressive strength on bottom refractory crucible proportional to density of metal being melted, height of metal.
2) Mechanical force i.e. Wear due to electromagnetic stirring resulting from eddy effect and skin depth proportional to frequency of furnace , power rating , crucible size , degree of super heat above melting point, metal fluidity.
3) Mechanical force i.e. Abrasion due to electromagnetic force resulting from eddy effect and skin depth proportional to frequency of furnace , power rating , crucible size , degree of over heating above melting point, metal fluidity.
4) Mechanical force i.e. Vibration due to electromagnetic force resulting from eddy current effect and skin depth proportional to design of equipments , frequency of furnace , power rating , crucible-size , degree of under charging / over size charging, intermittent spacing between over size/ heavy charge .
5) Mechanical force i.e. Fumes and vapour penetration to the side wall of refractory due to
electromagnetic eddy current effect and skin depth proportional to design of equipments ,
frequency of furnace , power rating , crucible size , degree of under charging / over size
charging, intermittent spacing between over size/ heavy charge, bridging of charge, over
heating of liquid metal due to faulty operation volatile low temperature melting/boiling point
charge, late addition of low boiling point metal addition , gas purging / fluxing / flushing .
6) Mechanical force i.e. Chemical reaction between refractory and metal being melted resulting
due to electromagnetic force resulting from eddy current effect and skin depth proportional to
design of equipments , frequency of furnace , power rating , crucible size , degree of under
charging / over size charging bridging of charge, over heating of liquid metal due to faulty

operation, volatile low temperature melting/boiling point charge , late addition of low boiling point metal addition , gas purging / fluxing / flushing .
7) Mechanical force i.e. combination of above ail during initial charging - poking of charge/ pressing of charge ,slag removal, spooning of slag tapping of liquid metal.
8) Mechanical force i.e. thermal stresses of frequent cooling and heating.
9) Mechanical force i.e spading , cracking , chipping due to mechanical action for removal of sticky metal/ slag/ dross/burnt refractory/damage refractory.
10) Electrical & Mechanical Damages due to short circuit power failure.

Annexture "B" Detail Process of Aluminium Melting Through Induction Furnace
Medium frequency induction furnace charging and charge selection starts with, the Normal Metal Charge Consist of Clean Scrap and/Pure Ingot and / Alloying Metal. Induction furnace operation is primarily controlled by charging known composition as well as clean scrap as a initial charging so as to avoid contamination of metal from initial charging. Further analysis Control is Obtained By Using A Charge of Known Analysis as well as a charge of carefully segregated Material. Alloying of Virgin Aluminium / Scrap is Most Favorable Under Right Charge, Calculation/ Right Analysis Control. Analysis Control is Obtained Using Additions of Pure Cu, Si, Mn, Ti & Cr With Initial Charging. Late additions of Mn, Ti, Cu, Si, Ni & Cr is Added as Pure Metal Are Best Recovered As Rich Alloys/ Hardeners. Even the late addition for pure metal of Mn, Ti, Cu, Si, Ni & Cr is added as pure metal with help of squirrel cage arrangement.
Medium frequency induction Melting Practice Requires Furnace As Well As Metal Charge Be Clean. Apply Wash of dead Powdered Lime/ Lime & Cement/ Talk or Mica/fire clay Should be Applied - When Crucible is Hot condition. Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before charging Start. Initial charging of 5% - 25% of furnace capacity gives better metallic yield. After initial charging of clean as well as known composition makes further charging of contaminated nature very easy. Also when melting has started and scrap contains dust, paper, and other carbonaceous material e.g. oil, grease, water, moisture, rubber, plastic, PVC, and other Non-metallic charge difficult to separate is charged in such a way to avoid immediate contact with liquid aluminium bath. Where scrap contains oil, grease, water, moisture, rubber, plastic, PVC, and other Non-metallic charge difficult to separate is charge in such a way so as to removed the said impurity during initial stage of charging which eliminates contaminants in form of simple burning. Avoid first sampling, removal of dross, intermittent charging till coil height of furnace. This results in high metallic yield. Crucible Must Be Cleaned After Each Heat For Adherent Dross, Entrapped Metal, Broken Pieces of Refractory other contaminant Dross May Entrained In Subsequent Melt. A Wash of Powdered Lime, Lime & Cement, Talk or Mica Should be Applied - When Crucible is Hot condition. Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before Next Melting Cycle Start.
Medium Frequency coreless induction furnaces are efficient clean and rapid melting units for aluminium. Induction Furnace are excellent melting units energy consumption for melting is effected by density of charge, non- metallic content in the charge , the melting practice used, MS contents in scrap, finishing temp, cleanness of operation charging pattern, type of scrap, late addition, specific metallurgical requirement etc. The stirring effect of the induction power is very advantageous since the charge is mixed well.
The said system melts different scrap, alloying element and other metallurgical process on continuous basis for the production of different grades of aluminium. In order to improvise the metallic yield and completely avoids generation of hazardous waste.

The Normal Metal Charge Consist of Clean Scrap and/Pure Ingot and / Alloying Metal.
Analysis Control is Obtained By Using A Charge of Known Analysis.
Analysis Control is Obtained By Using A Charge of Carefully Segregated Material.
Analysis Control is Obtained By Using A Charge of Pure Primary Material, Remelt, And New Pig Material.
A loying of Virgin Aluminium / Scrap is Most Favorable Under Right Charge Calculation/ Right Analysis Control (Refer QAP For Charge Calculation)
Zn is Added as Pure Metal At End of Melting Cycle.
IV g is Added as Pure Metal At End of Melting Cycle.
Cu & Si is Added as Pure Metal Are Best Recovered As Rich Alloys/ Hardeners
l\7 n & Ti is Added as Pure Metal Are Best Recovered As Rich Alloys/ Hardeners
Ni & Cr is Added as Pure Metal Are Best Recovered As Rich Alloys/ Hardeners
Analysis Control is Obtained Using Additions of Pure Cu, Si, Mn, Ti & Cr With Initial Charging.
Scrap Heterogeneous Origin / Nature Must Be Avoided.
Avoid Turnings, Borings & Other Cutting Scrap Loaded With Cutting Oil, Grease, Water, Dust, Dirt In Final Stage of Charge Selection.
Good Melting Practice Requires Furnace As Well As Metal Charge Be Clean.

Start With Clean Materials of Known Analysis.
Use Clean Melting Practice.
Cfarge Continuously At Regular Interval.
Charge All Calculated Cu, Si, Mn & Other High Temperature Metal.
First Bath Sample to Be Drawn At Coil Height or Above.
Ac d Final Stage Necessary Additions/Pure Metal (If Required).
Analyse Final Sample For Chemistry & Temperature.
Remove Dross From Side Wall of Crucible.
Purge Liquid Bath With N2 Gas (less than 0.2 Kg/cm2 Pressure For 5 Minutes To 20 Minutes) or Ar Gas (For AC2B, AC2A, AC3A or Fe Less Than 0.3 %)
Keep Temp of Melt Low until pouring is Ready.
Use Minimum Holding Time In The Molten Condition.
Avoid Water vapour or Hydrogen Contamination At Finishing Stage.
Do Not Agitate or Stir The Melt.
Use adequate Fluxing or Flushing Practice.
SRim off Final Dross Just Before Tapping.
Increase The Temperature To Required Level.
Cover Top Surface With Dry Lime Powder/Talc/Mica/bentonite.

Avoid Creation of Excessive Turbulence when Pouring The Molten Metal.
Jse Bottom Pouring / create reservoir of metal/ Tundish mechanism to avoid dross formation during tapping.
Other precautions
Use Minimum Holding Time in The Molten Condition.
1. Avoid Water vapour or Hydrogen Contamination At Finishing Stage.
2. Do Not Agitate or Stir The Melt.
3. Use adequate Fluxing or Flushing Practice.
4. Skim off Final Dross Just Before Tapping.
5. Increase The Temperature To Required Level.
6. Cover Top Surface With Dry Lime Powder/Talc/Mica.
7. Avoid Creation of Excessive Turbulence when Pouring The Molten Metal.
8. Use Bottom Pouring of metal At Tundish.
9. For induction furnace Avoid Melting Practice, Unprotected from Combustion Products.

Annexture "C" Process for Aluminium Melting & Dross Removal
Medium frequency induction furnace charging and charge selection starts with, the Normal Metal Charge Consist of Clean Scrap and/Pure Ingot and / Alloying Metal. Induction furnace operation is primarily controlled by charging known composition as well as clean scrap as a initial charging so as to avoid contamination of metal from initial charging. Further analysis Control is Obtained By Using A Charge of Known Analysis as well as a charge of carefully segregated Material. Alloying of Virgin Aluminium / Scrap is Most Favorable Under Right Charge, Calculation/ Right Analysis Control. Analysis Control is Obtained Using Additions of Pure Cu, Si, Mn, Ti & Cr With Initial Charging. Late additions of Mn, Ti, Cu, Si, Ni & Cr is Added as Pure Metai Are Best Recovered As Rich Alloys/ Hardeners. Even the late addition for pure metal of Mn, Ti, Cu, Si, Ni & Cr is added as pure metal with help of squirrel cage arrangement.
Medium frequency induction Melting Practice Requires Furnace As Well As Metal Charge Be Clean. Apply Wash of dead Powdered Lime/ Lime & Cement/ Talk or Mica/fire clay Should be Applied - When Crucible is Hot condition. Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before charging Start. Initial charging of 5% - 25% of furnace capacity gives better metallic yield. After initial charging of clean as well as known composition makes further charging of contaminated nature very easy. Also when melting has started and scrap contains dust, paper, and other carbonaceous material e.g. oil, grease, water, moisture, rubber, plastic, PVC, and other Non-metallic charge difficult to separate is charged in such a way to avoid immediate contact with liquid aluminium bath. Where scrap contains oil, grease, water, moisture, rubber, plastic, PVC, and other Non-metallic charge difficult to separate is charge in such a way so as to removed the said impurity during initial stage of charging which eliminates contaminants in form of simple burning. Avoid first sampling, removal of dross, intermittent charging till coil height of furnace. Crucible Must Be Cleaned After Each Heat For Adherent Dross, Entrapped Metal, Broken Pieces of Refractory other contaminant Dross May Entrained In Subsequent Melt. A Wash of Powdered Lime, Lime & Cement, Talk or Mica Should be Applied - When Crucible is Hot condition. Coated

Crucible Should Be Allowed To Dry At A Red Hot Condition Before Next Melting Cycle Start.
The said system melts different scrap, alloying element and other metallurgical process on continuous basis for the production of different grades of aluminium. In order to improvise the metallic yield and completely avoids generation of hazardous waste/dross.
High dross formation results due to low metallic content of scrap.
High dross formation results due to high power and low charging rate..
High dross formation results due to bridging of charge.
High dross formation results due to carbonaceous material contaminated scrap charge at final stage.
High dross formation results due to continuous heavy charging above coil height.
High dross formation results due to intermittent irregular light weight charging below coil height.
High dross formation results due moisture contamination at final stage of melting.
High dross formation results due to excessive stirring resulting through flushing, fluxing, mechanical stirring etc.
High dross formation results due to over heating / high temp of liquid aluminium.
High dross formation results due to charging of drossy material in initial charging.
Medium Frequency coreless induction furnaces are efficient clean and rapid melting units for aluminium. Induction Furnace are excellent melting units energy consumption for melting is effected by density of charge, non- metallic content in the charge , the melting practice used, MS contents in scrap, finishing temp, cleanness of operation charging pattern, type of scrap, late addition, specific metallurgical requirement etc.

The formed dross is removed by rabbling side walls and thoroughly mixing the dross at the top side of the induction furnace here tools are designed such as considering furnace dia, furnace height, volume of dross, type of dross & time required for removal of dross.
> Crucible Must Be Cleaned After Each Heat For Adherent Dross & Entrapped Metal.
> A Wash of Powdered Lime, Lime & Cement, Talk or Mica Should be Applied When Crucible is Hot condition.
> Coated Crucible Should Be Allowed To Dry At A Red Hot Condition Before Next Melting Cycle Start.
Density of Some Dross Product In Solid State.
SI02 - 2.5 g/cm3, Aluminium -2.7 g/cm3, AI203 -3.80 g/cm3, Al203,XH20-2.42 g/cm3; MgO -3.65 g/cm3, Cu20- 6 g/cm3, CuO - 6.40 g/cm3.
> Melting occurs Very Rapidly in Induction Furnace Due To Combination of Power as Well as Stirring, If Not Control Properly Results In Formation of High Dross.
> Avoid Melting Practice, Un Protected from Combustion Products.
> Charge Continuously To Avoid Splashing, Un Protected Atmosphere, Contamination, Bridging of Charge, Explosion etc.
> Separation of dross and Metal is Difficult Due To Low Differences/ High Density of Dross

Annexure "D" Process for Aluminium Melting (Induction Furnace) - Fluxing or Flushing
Melting occurs Very Rapidly In Induction Furnace Due To Combination of Power as Well as Stirring, once molten metal is ready as per commercial requirement the liquid metal at low temp (670 - 750 .c) is flush by passing inert gas which facilitates Effective Separation of Molten Metal, Dross And Siag This also facilitates to remove dissolved Hydrogen & Entrapped Dross, Refractory etc.
Fluxing Time:-
0.6 - 1.3 Fe And 8.5 - 14 % Si - 5 To 10 Minutes , 0.6 - 0.8 Fe And 8.5 - 14 % Si - 7 To 10 Minutes , 0.6 - 1.0 Fe And 8.5 - 14 % Si - 5 To 10 Minutes , 0.3 - 0.6 Fe And 5.5 - 14 % Si - 10 To 15 Minutes , 0.3 - 0.6 Fe And 5.5 - 14 % Si (With Cu) - 10 To 15 Minutes, 0.1 - 0.35 Fe And 4.5 - 18 % Si - 15 To 25 Minutes
To Provide More Effective Separation of Molten Metal, Dross And Slag.
To Remove Dissolved Hydrogen & Entrapped Dross, Refractory etc.
Purge Dry N2 Gas - Commercial Grade (7.5 - 12 cubic ft./Minute) or Purge Dry Ar Gas - Commercial Grade (7.5 - 12 cubic ft./Minute) or Purge Dry He Gas -Commercial Grade (7.5 - 12 cubic ft./Minute) or Purge Dry CI With Ca -Commercial Grade (7.5 - 12 cubic ft./Minute) Or Purge Hexachloro Ethelene Tablets. The above Gases Are Bubbled Slowly Through The Melt For Hydrogen And Lighter Dross Removal. After Flushing Raise The Temperature Quickly For Required Level (725 - 850.c)

Annexure "E" Some Important Grade Produced By Induction Melting - Temperature & Composition (for Example 5- 7Kg Ingot)

GRADE Fe Si Cu Mn Mg Ni Zn Temperature
A360 1.3 Max 9.0-10.0 0.6 Max 0.35 Max 0.4-0.6 0.5 Max 0.5 Max 700-790
A413 0.4 Max 10.5-11.5 0.5 Max 0.35 Max 0.1 Max 0.3 Max 0.3 Max 730-820
AC2A 0.3 Max 4.5-5.0 3.8-4.1 0.2 Max 0.1-0.2 0.3 Max 0.2 Max 740 - 820
AC2B 0.35 Max 5.75-6.75 3.1-3.6 0.5 Max 0.5 Max 0.2 Max 0.1 Max 740-820
AC4B 0.5 Max 7.0-8.0 2.5-4.0 0.3 Max 0.4-0.55 0.2 Max 0.5 Max 740-820
AC4C 0.4 Max 6.5-7.5 0.1 Max 0.15-0.3 0.4-0.6 0.1 Max 0.1 Max 740 -820
ADC12 0.8 Max 10.5-12 1.5-2.5 0.5 Max 0.3 Max 1.5 Max 1.0 Max 700 - 790
ALSUO 0.6-0.8 9.0-10.0 0.1-0.25 0.3-0.4 0.25-0.5 0.1 Max 0.1 Max 700-790
ALSI12CU 0.8 Max 10.5-13.5 1.0 Max 0.55 Max 0.35 Max 0.3 Max 0.55 Max 700-790
ALS1132 0.7-1.0 10.5-12.5 1.5-2.5 0.55 Max 0.3 Max 0.4 Max 1.4 Max 700- 780
ALSI132 0.30 Max 11.5-12.5 1.75-2.5 0.1 Max 0.1 Max 0.02 Max 0.05 Max 740-820
ALSI9CU3 0.6-1.1 8.0-11 2.0-4.0 0.55 Max 0.55 Max 0.6 Max 0.9 Max 700-790
HS1S 0.3-0.4 6.5-7.5 2.5-3.5 0.3 Max 0.1-0.3 0.2 Max 0.4 Max 740-820
LM16 0.4 Max 4.5-5.5 1.1-1.5 0.5 Max 0.4-0.6 0.1 Max 0.1 Max 740-820
LM6 0.4 Max 11.3-12.5 0.1 Max 0.3 Max 0.1 Max 0.1 Max 0.1 Max 740 -820
LM9 0.2-0.25 12.5-13.0 0.1 Max 0.3-0.5 0.4-0.6 0.1 Max 0.1 Max 740-820
9MNMG 0.4 Max 8.5-9.5 0.2 Max 0.4-0.6 0.3-0.4 0.2 Max 0.1 Max 740 -820

Annexure "F" Processing of Aluminium Scrap Suitable for Induction Furnace Melting
> Draw Pro rata Sample of Unloaded Scrap 100 Kgs - 3000 Kgs /25 MT Scrap.
> Carefully Segregate For Aluminium Scrap, MS Attached Aluminium scrap, Zn Attached Aluminium scrap, Cu Attached Aluminium scrap, Brass Attached Aluminium scrap, Mg Attached Aluminium scrap, Cu scrap, Zn scrap, Brass scrap, Mg scrap, Mild steel scrap, Stainless steel scrap, nickel scrap, Plastic & Rubber, Dust etc (As Applicable).
> Weight The Above For Percentile Recovery.
> Draw Samples and Prepare Button Sample for chemical analysis.
> Analysis of Button Sample.
> Prepare identifiable lots suitable for induction furnace charging.

Annexure "G" Charge Preparation/Charge Grain refinement
> Ti acts as grain refiner (0.02 - 0.15 %)
> B with Ti Improves performance of grain refiner.
> Higher Si Level Requires Higher Addition of grain refiner.
> Add TiB or Ti Metal as per Customer Specification.
> If master Alloy is used than apply along with N2 Purging.

Annexure "H" Induction Furnace - Preparation of Refractory Lining (Alumina Castable)
> For Lining Check GLD of crucible Before Crucible is subject to refractory lining (2 mili-Amp)
> Prepare a 15 - 25 mm layer of coil coat.
> Prepare for Bottom Refractory by placing non magnetic SS Antena.
> Prepare side lining by employing Re-usable metallic former.
> Allow natural cureing for 72 Hrs (Max).
> Allow water curing for 72 Hrs(Min).
> Allow natural drying for 96 Hrs (Min).
> Pre Heat Monolithic Lining.
> Connect GLD.
> Apply Holding Power of 500Kw-750Kw for 4-12 Hrs.
> Crucible is ready for operation.
> Ensure low power melting of first heat (1200 Kw max)

^ Hold the metal dross and mixture of rock salt (35 - 50 Kg) at 750 - 850 .c for 1 Hour (Min)
Annexure "I" Induction furnace - Preparation of Refractory Patching/ Repairing
^ Inspect Inner Surface of Monolithic Lining For Cracks, Dross,
Slag, Metal Penetration. ^ Scrub & Remove all foreign material ^ Remove Sticky Aluminium. ^ Chip off all damage portions. ^ Clean with compressed air. ^ Rectify the damaged portion. ^ Cure for 12 - 72 Hrs as per lining practice. ^ Check for GLD. ^ Pre Heat The Lining.
^ Apply Holding Power of 500Kw-750Kw for 4-12 Mrs. ^ Crucible is ready for operation. ^ Ensure low power melting of first heat (1200 Kw mx)

Annexure "J" Aluminium Modification (Sr) of structure
> The ability of Sr to Modify Structuer of AISi Alloy (LPDC,LP,GDC,Sand Cast) for Longer Period of Metal Holding)
> Add Sr as master alloy (10% Sr)
> If master Alloy is used than apply along with N2 Purging.
> Solubility of Sr is complete within 3-7 min.

Sr No. %Si %Sr Required Per MT Addition
01 4-7 0.01-0.02 l-2Kg
02 8-10 0.03-0.04 3-4Kg
03 11-13 0.04-0.06 4-6 Kg

We Claim,
1) A Complete Melting Process of aluminium scrap using medium frequency induction
furnace in a large commercial scale production of different grades of Aluminium and Aluminium
Alloys as suitable for automobile industries, die caster (GDC,PDC,LPDC), sand casting
permanent mould casting etc, comprising the following steps,
Cleaning and charging, clean scrap and/ or Pure Ingot and / Alloying Metal, Virgin Aluminium / Scrap in which added a Pure Cu, Si, Mn, Ti & Cr With Initial Charging, Late additions of Mn, TI, Cu, Si, Ni & Cr is Added as Pure Metal with help of squirrel cage arrangement,
The said Initial charging of 5% - 25% of furnace capacity gives better metallic yield. After initial charging of clean as well as known composition makes further charging of contaminated nature which is required to be removed during initial stage of charging by cleaning Crucible after Each Heat,
B) Controlling the process by reducing the partial pressure of reaction/ increasing the
charging rate of furnace/ avoiding carbonaceous material direct contact with liquid metal such as to avoid High Dross,
2) A method as claimed in claim 1, wherein the contaminants such as adherent Dross,
Entrapped Metal, Broken Pieces of Refractory other contaminant Dross May Entrapped In
Subsequent Melt, is being removed by rabbling of side wall of monolithic lining, applying a
washing by usage of Powdered Lime, Lime & Cement, Talk or Mica - When Crucible is Hot
condition.
3) A method as claimed in above claims which further starts with in a sequential manner such as Start with Clean Materials of Known Analysis - 5% - 25% of furnace capacity,
Charge All Calculated Cu, Si, Mn & Other High Temperature Metal. Use Clean Melting Practice as well as continuous charging. Charge Continuously At Regular Interval.

First Bath Sample To Be Drawn At Coil Height or Above ( 4 MT or above )

Add Final Stage Necessary Additions/Pure Metal (If Required in form of lighter/ thinner wall thickness
Analyse Final Sample For Chemistry & Temperature.

Remove Dross From Side Wall of Crucible.

Purge Liquid Bath with N2 Gas or Ar Gas (5 Minutes To 20 Minutes).
Keep Temp of Melt Low until pouring is Ready 695 - 765°C
4) A method as claimed in above claims that it gives lesser formation of slag, Burning Loss, Dross and overall non metallic disposal.
5) A method as claimed in above claims establishing process method of melting different variety of homogeneous nature scrap, alloying element, late additions of alloying element along with aluminium grain refinement as well as micro structure modification.
6) A method as claimed in above claims establishing process of aluminium melting suitable for various types of alloying addition of high temp melting point - Fe, Mn, Ti, Cu, Ni, B, V etc., along with master alloy production of - Fe, Mn, Ti, Cu, Ni, B, V etc.
7) A method as claimed in above claims establishing process which results in less thermal fluctuations for monolithic refractory lining as well as addressing energy efficient fast melting of aluminium along with high metallic yield, low generation of dross and low melting loss. Melting practice which permits Aluminium melting for continuous operation as well as most predictable behavior for intermittent operation.
8) A method as claimed in above claims establishing melting techniques which results in 5% - 25% re-melting of dross generated in the plant as well as 5% - 65% melting of primary dross (purchased from primary aluminium manufacturer).
9) A method as claimed in above claims establishing a melting practice suitable for different alloying of low melting point, different alloying of volatile metal addition, degassing (with H2, N2, Ar, CI), reduction of Magnesium, grain refining & modification of grains.
10) A method as claimed in above claims establishing a melting techniques which results in lesser generation of final disposal as well as neutral/non-hazardous slag.