Title of Invention	A PROCESS FOR MELTING METAL SCRAP FOR MOULDING
Abstract	This invention relates to a process for melting metal scrap for moulding comprises in the step of preheating metal scrap and an alloying wherein the proportion of metal scrap of alloying material is 0.5% to 2%, followed by adding a thermit mixture thereto and stirring to obtain the molten mixture wherein the proportion of metal scrap and alloying material melt scrap to thermit mixture is 5:1.

Full Text

FIELD OF THE INVENTION This invention relates to a process for melting metal scrap for moulding purposes. BACKGROUND OF THE INVENTION According to methods known in the art, the iron/scrap is fed into the electrical furnace and the furnace is switched on. Alloying material is then added into the furnace and the composition is checked. The composition so obtained is subjected to the step of de-slaging and refining. The ladle preheated and the molten metal is poured into the ladle. Subsequently, the molten metal is poured into the mould which is prepared separately as per the shape of the required item. The mould is then cooled and broken to get the molded item. There are certain disadvantages associated with the prior art. One of the main disadvantages is that a lot of electricity is consumed during melting operation of the furnace. Around 1200 units are consumed for the production of 1 Ton of casting. Thus for a unit of 80 Ton capacity 500 kilo watt of electric power is required per month and this requires a sepearte substation to provide continuous electricity during melting operation, and any power interruption or shut down causes huge losses. Another disadvantage is that if the electric power supply is interrupted during melting operation then the process of melting has to be restarted/recommenced and thus huge amount of electric energy is lost. Yet another disadvantage is that the electric furnace is very costly. still another disadvantage of this invention is that the system consists of sophisticated equipments and therefore high skilled and qualified peoples are needed to operate the system. A further disadvantage is that the refining of molten metal has to be carried out very carefully which is very difficult due to the individual involvement. OBJECTS OF THE INVENTION Therefore, the main object of this invention is to provide a novel process for melting metal/scrap and for moulding the same. Another object of this invention is to provide a novel process, which is very easy and can be carried out by a person of ordinary skill. Yet another object of this invention is to propose a process and wherein minimum electric energy is required to perform the process and also the capital investment is very low. Still another object of this invention is to propose a novel process wherein no electric power is required for melting the iron/scrap. These and other objects and advantages of the invention will be apparent from the ensuing description. DETAILED DESCRIPTION OF THE INVENTION According to this invention is provided a process for melting metal scrap for moulding comprises in the step of preheating metal scrap and an alloying wherein the proportion of metal scrap of alloying material is 0.5% to 2%, followed by adding a thermit mixture thereto and stirring to obtain the molten mixture wherein the proportion of metal scrap and alloying material melt scrap to thermit mixture is 5:1. in accordance with this invention the metal scrap/Iron atongwith the aitoying material is fed in a ladle and the ladle is preheated, followed by adding the thermit mixture thereto. The iadte is stirred to increase the rate of reaction and exothermic energy is produced in the ladle, which Is utilized for melting the metal scrap/Iron present in the ladle. The molten metai is then poured in the mould and the mould Is then cooled and broken to get the item. The mould is prepared by the conventional steps of sand preparation followed by moulding, mould coating and designing. Thereafter the mould Is closed and the molten metal mixture is poured into the mould. The mould is then cooled and broken to obtain the casting. The proportion of metal scrap to other alloying material is 0.5% to 2%. The proportion of metai scrap and alloying material melt Is to the thermit mixture Is 6:1. The thermit mixture used In the process according to the invention is a mixture of ferric oxide, aluminium, magnesium, Si and a salt of an alkaline earth metal, such as Calcium. The metals or compounds are taken in a proportion of about 3.6 to 4.4 parts feme oxide, preferably 4 parts feme oxide; about 0.9 to 1.1 parts aluminium, preferably 1 part aluminium; about 0.0009 to 0.0011 parts magnesium, preferably 0.001 parts magnesium; about 0.009 to 0.011 parts Silicon preferably 0.01 parts Silicon and about 0.014 to 0.017 parts, preferably 0.015 parts of an alkaline earth metal carbonate. In a preferred embodiment, the alkaline earth metal carbonate Is calcium carbonate. The alloying material comprises the usual metais/metai oxides used In the art for aitoying such as transition metals and metal oxides. The technology used In the present Invention Is a metallothermic reaction. The Inherent heat energy In the oxides Is taken out with the help of other reducing metal like aluminium silicon etc. A metal (Me) can be reduced from Its oxide (MeO) by any material whose oxide under conditions has a low dissociating capacity than the oxide of the metal being reduced. The process is in the direction of melting steel scrap when the reaction causes a Tall in the free energy during the exothermic reduction of oxides. The oxides of the most Important metals in the manufacture of Ferro-alloys decompose is in the order of rise in dissociation capacity. MgO; ZrO2; TiO2 SiO2; V2O5;MnO;W03;MoO3. The free energy of the reactions when the preceding oxides are formed is greater than that of the following oxides. The metallothermic reduction process Is possible without heat being supplied from outside, as a result of the reaction large quantum of heat liberated. This heat energy is utilized in a controlled manner and the metal scrap arranged within the specified area gets melted. About 60 Kgs of the thermit mix according to the invention can be used to generate 1, 20,000 Kcai of heat energy which can ultimately melt about 300 Kgs of steel, hence a better thermal efficiency Is achieved and saves about 753 KW Hour electric energy in the process. A typical analysis conducted on a 300 Kgs Furnace with maximum operation power of 175 KW reveals the following (Table -1). Table -1 a Average no. of heats per day 6 b Average total weight of charge consumed per day 1754 Kgs c Average weight of charge per heat 292 Kgs d Average kWh consumed per day 1320 kWh e Average kWh consumed per heat 220 kWh f Average kWh/ton scrap charged 753 kWh/Ton g Average yield of castings 67.7% h Average Recycle (R+R) Material 30.8% The energy balance of 300 Kgs Induction Furnace is as follows (Table - 2) Table ~ 2 81. No. Item KCAL/HE % AT 1 Heat Input (Electrical energy converted to heat 1,89,200 100 energy) 2 Heat Output 76,736 40.6 A. Heat utilized In melting 300 Kgs of Metal B. Thermal Dispersion through Shell Wail 1513 0.8 C. Thermal Energy in Exhaust Gas + Unaccounted 1.10,951 58.6 losses The requirement of electrical energy for a small unit of 900 Ton per annum is reduced from 400 hp to 1 hp and capital investment reduced to Rs. 150 Lakhs to Rs. 50 lakhs. 900 Ton production wilt save 0.9 Million units of electric energy per year. Flexibility in batch melting from 10 Kegs to 500 Kgs, maintenance of costly and sophisticated equipment is eliminated and the metal gets refined automatically. Incase of temperature loss, it can be improved by adding exothermic mixture in the pouring ladle Itself. Time required for each batch melting Is 45 minutes only. The process is very simple and can be handled by semi skilled workers. Thus it is seen that the process of the present inversion Is very easy and no electric power Is required for melting the metal scrap/iron. The electric energy is required only to preheat the charge (metal/scrap) and which is negligible. WE CLAIM: 1. A process for melting metal scrap for moulding comprises in the step of preheating metal scrap and an alloying wherein the proportion of metal scrap of alloying material is 0.5% to 2%, followed by adding a thermit mixture thereto and stirring to obtain the molten mixture wherein the proportion of metal scrap and alloying material melt scrap to thermit mixture is 5:1, 2. The process as claimed in claim 1, wherein said thermit mixture comprises a mixture of ferric oxide, aluminium, magnesium, silicon and an alkaline earth metal carbonate such as for example calcium carbonate. 3. The process as claimed in claim 2, wherein Fe2O3 is present in a proportion of 3.5 to 4.4, parts by weight, preferably 4 parts by weight. 4. The process as claimed in claim 2, wherein aluminium is present in a proportion of 0.9 to 1.1 parts preferably 1 part by weight. 5. The process as claimed in claim 2, wherein magnesium is present in a proportion of 0,0009 to 0.0011 parts, preferably 0.001 parts by weight. 6. The process as claimed in claim 2, wherein silicon is present in a proportion of 0.009 to 0.011, parts by weight, preferably 0.01 parts by weight. 7. The process as claimed in claim 2, wherein the alkaline earth metal carbonate is present in a proportion of 0.014 to 0.017 parts by weight, preferably 0.015 parts by weight. 8. The process for melting steel or metal scrap for moulding substantially as herein described.

Documents:

798-mas-2002-abstract.pdf

798-mas-2002-claims filed.pdf

798-mas-2002-claims granted.pdf

798-mas-2002-correspondnece-others.pdf

798-mas-2002-correspondnece-po.pdf

798-mas-2002-description(complete)filed.pdf

798-mas-2002-description(complete)granted.pdf

798-mas-2002-description(provisional).pdf

798-mas-2002-form 1.pdf

798-mas-2002-form 26.pdf

798-mas-2002-form 3.pdf

798-mas-2002-form 4.pdf

798-mas-2002-form 5.pdf