FORM 2
THE PATENT ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
SYSTEM, CONTINUOUS CASTING AND ROLLING MACHINE AND METHOD THEREOF.
APPLICANT
Hindalco Industries Limited, a company incorporated under the Companies Act, 1956 whose address is Birla Centurion, 7th floor, Pandurang Budhkar road, Worli, Mumbai 400030, Maharashtra, India.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes this invention and the manner in which it is to be performed.

TECHNICAL FIELD OF THE INVENTION:
[1] The present invention relates to continuous casting and rolling process of
copper rod and methods to reduce surface oxide copper.
BACKGROUND OF THE INVENTION:
[2] Among various non-ferrous metals, copper and its alloys are widely used for
manufacturing rods, wires, plates, sheets, flat bars, tubes and hollow bars. Copper products are extensively used in electrical and electronic industries because of its high electrical and thermal conductivity. It is desirous to produce continuous copper castings with no shrinkage and little segregation.
[3] It is known that copper actively reacts with oxygen to form copper oxide. The
speed of this reaction increases at higher temperature. In continuous casting and rolling process, copper metal is casted and hot rolled at around 850º C. Although, rolling process is done in a closed chamber, oxygen still exists at various stages of rolling in the multi stand rolling mill. There are open connections at the return line for soluble oil in the rolling mill from which oxygen can enter in rolling mill. Thus, it is very difficult to avoid oxidation of copper during hot rolling. A layer of copper oxide deposit on the surface of copper breaks during the multi-stand hot rolling and it is not desirous to have this oxide rolled into the bar.
[4] Conventionally, it is known to reduce oxide formation on the surface of
copper with introduction of high-pressure spray nozzles for stripping the oxide from the cast bar and with a finer control on overall oxygen input in the copper, at molten stage, in terms of parts per million. Further, it is also known to remove such oxides

by non-acidic pickling NAPS, wherein oxides are exposed to gaseous reducing
atmosphere, and by exposure to an aqueous alcohol solution. However, these known
processes/ systems could not maintain a precise control on surface oxide content in
the final product when operated at various ranges and specifically below defined
ranges of continuous casting and rolling process.
[5] Therefore, there is a need to overcome one or more of the aforementioned
problems.
SUMMARY OF THE INVENTION:
[6] Accordingly, an aspect of the present invention discloses a system of
continuous casting and rolling comprising a closed chamber for generating and regulating nitrogen gas through distributing means, connecting a tundish, an enclosed rolling mill and a finishing mill, thereto form a blanket over cast bar being rolled that prevents ingression of air through open connections of return line for said soluble oil and maintains a positive pressure in said enclosed rolling mill; and means for optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction between said cast bar and rolls in said enclosed rolling mill, wherein said nitrogen blanket formed and said optimized soluble oil inhibits formation of oxide on surface of copper cast bar and reduces dust generation during a downstream process.
[7] According to another aspect, the present invention discloses a continuous
casting and rolling machine for manufacturing reduced surface oxide copper comprising a melting shaft furnace for melting said copper; a holding furnace and a tundish proximate to said melting shaft furnace for introducing molten metal into a

casting machine at predetermined flow rate, said casting machine disposed inline to continuously cast bar from molten copper at predetermined speeds; an enclosed rolling mill for rolling copper cast bar into a continuous form of predetermined diameters and conveying said copper to a non-acidic pickling NAPS section and at least one coiler station downstream; an electronic control system in communication with said continuous casting and rolling machine for controlling and operating said machine at predetermined speeds, temperatures and pressures; and a system having a closed chamber spaced away from said machine for generating and regulating nitrogen gas through distributing means, connecting said tundish, said enclosed rolling mill and a finishing mill, thereto form a blanket over rolled in copper cast bar that prevents ingression of air through open connections of return line for soluble oil, thereby inhibiting formation of oxide on surface of copper and reducing dust generation during a downstream process.
[8] According to an embodiment, said system includes means for optimizing fat
% and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction between said cast bar and rolls in said enclosed rolling mill & further formation of oxide
[9] According to the embodiment, oxide formation on surface of copper is
dropped from 400º A to at least 250ºA, when nitrogen blanket is formed, and soluble oil is optimized.
[10] According to the embodiment, copper introduced into said melting shaft
furnace is in the form of cathodes only.

[11] According to the embodiment, said casting machine is a wheel and belt
casting machine.
[12] According to still another aspect, the present invention discloses a method for
manufacturing reduced surface oxide copper in a continuous casting and hot rolling machine as claimed in claims 2-6, comprising the steps of:
a) monitoring if pressures, temperatures and speeds of said casting machine are within predetermined range and if within predetermined range proceeding to step (b) or returning to step (a);
b) generating and regulating nitrogen gas at predetermined pressures and flow rates into said casting machine through means thereto form a blanket over rolled in copper cast bar, that prevents ingression of air through open connections of return line for soluble oil and maintains a positive pressure in enclosed rolling mill and proceeding to step (c);
c) optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction between said cast bar and rolls in said enclosed rolling mill, thereby inhibiting formation of oxide on surface of copper and reducing dust generation a during downstream process and proceeding to step (d);
d) analyzing surface oxide readings of said copper and if analyzed readings are within said predetermined range and proceeding to step (e) or returning to step (b); and
e) conveying said reduced surface oxide copper to a downstream process.

BRIEF DESCRIPTION OF THE DRAWINGS:
The various aspects, features, and advantages of the embodiment of the present
invention, hereinafter more particularly described, will be more apparent from the
following description taken in conjunction with the drawings, in which:
Figure 1 shows a block diagram of a casting process performed in a continuous
casting and rolling machine, according to an aspect of the present invention;
Figure 2 shows a block diagram of a system of continuous casting and rolling
machine for introducing nitrogen into the machine, according to the aspect of the
present invention; and
Figure 3 is a logic diagram showing a sequence of method steps performed for
manufacturing reduced surface oxide copper in the continuous casting and hot rolling
machine, according to another aspect of the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE
INVENTION:
[13] In general, the present invention claims a system of continuous casting and
rolling machine for generating and regulating nitrogen gas into said machine in such a

way that said gas provides a blanket over rolled in cast bar of copper, thereto inhibit formation of oxide on surface of copper and reduce dust generation a during downstream process. According to the present invention, nitrogen is introduced into the casting process through various pipes connections for a rolling mill and one connection to the tundish for the molten metal purging. The atmosphere inside closed chamber of rolling mill is maintained neutral and nitrogen gas purging will gradually displace oxygen present and the only atmosphere remaining would be vapor created from the presence of Iso Propyl Alcohol in soluble oil and inert N2. When analyzed oxide readings on surface of copper are dropped from 400º A to at least 250ºA.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to

enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
Figures discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way that would limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged environment. The terms used to describe various embodiments are exemplary. It should be understood that these are provided to merely aid the understanding of the description, and that their use and definitions in no way limit the scope of the invention.
[14] Referring Figure 1 shows a block diagram of a casting process performed in a
continuous casting and rolling machine (100), according to an aspect of the present invention. According to the present invention, the machine (100) includes a melting shaft furnace (101) for melting said copper. A holding furnace (102) and a tundish (103) are proximate to said melting shaft furnace (101) for introducing molten metal into a casting machine (104) at predetermined flow rate. The casting machine (104) is disposed inline to continuously cast bar said molten copper at predetermined speeds. A bar preparation unit (105) having straightener rollers, a notcher assembly and trimmer tools is located next to said casting machine. A rolling mill (106) for rolling copper into a continuous form of predetermined diameters of at least 8, 11, 12.5, and

19.6 mm respectively. The enclosed rolling mill (106) is located downstream said bar preparation unit (105). The rolled copper is then conveyed to a non-acidic pickling section NAPS (107), where the surface oxide of the hot rolled copper rod is further reduced and then cooled and then transferred to at least one coiler station (108) downstream. The coiled copper is then packed and transported. An electronic control system (109) is in communication with said continuous casting and rolling machine for controlling, operating and synchronizing said machine at predetermined speeds, temperatures and pressures.
[15] According to the present invention, copper introduced into said melting shaft
furnace (101) is in the form of cathodes only.
[16] According to the present invention, casting machine (104) is a wheel & belt
casting system.
[17] Referring Figure 2 shows a block diagram of a system of continuous casting
and rolling machine for introducing nitrogen into the machine, according to the aspect of the present invention. The system (200) is spaced away from said machine (100) for introducing nitrogen gas into said machine (100) in such a way that said gas provides a blanket over rolled in copper cast bar that prevents ingression of air through open connections of return line for said soluble oil and maintains a positive pressure in said enclosed rolling mill. The system (200) is a closed chamber that generates and regulates nitrogen gas into said machine (100), through distributing means (201) connecting a tundish (103), a rolling mill (106) and a Non-Acidic Pickling system NAPS (107) of said machine (100). The system includes an isolation valve (202), a pressure regulating valve (203) and a flow meter (204) for regulating

the pressure of the nitrogen that is being introduced in the machine (100). Nitrogen gas flows from 4” header pipe line of the system which is then branched having a 2” pipe divided into at least six ½ pipe connections (201) heading towards rolling mill (106) at one end and another ½ pipe connection heading towards to the tundish (103) for the molten metal purging. The pressure in the header is 3 bar and when the pressure regulating valve (203) is added to the connection the pressure is reduced to 2 bar. Temperature is ambient throughout said machine (100). The system (200) includes means for optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction, oxide between said cast bar and rolls in said enclosed rolling mill. The nitrogen blanket formed and said optimized soluble oil inhibits formation of oxide on surface of copper and reduces dust generation during a downstream process. Oxide readings analyzed on surface of copper are dropped from 400º A to at least 260ºA and preferably 250ºA, when nitrogen blanket is formed, and soluble oil is optimized.
[18] Referring Figure 3 shows a logic diagram (300) showing a sequence of
method steps performed for manufacturing reduced surface oxide copper in the continuous casting and hot rolling machine, according to another aspect of the present invention. In step (a) (301) the electronic control system (109) monitors if pressures, temperatures and speeds of said casting machine are within predetermined range. In step (b) (302) if the monitored parameters are within a predetermined range, then nitrogen gas at predetermined pressures and flow rates is introduced into said casting machine (104) through means (111), thereto form a blanket over cast bar being rolled, that prevents ingression of air through open connections of return line for soluble oil

and maintains a positive pressure in enclosed rolling mill and then the method proceeds to step (c) (303). If the obtained parameters are not within predetermined range, then return to step (301). Step (303) includes optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction between said cast bar and rolls in said enclosed rolling mill, thereby inhibiting formation of oxide on surface of copper and reducing dust generation a during downstream process and proceeding to step (d) (304). Step (304) includes analyzing surface oxide readings of said copper and if analyzed readings are within said predetermined range and the method proceeds to step (305) or returns to step (302). Step (d) (305) the reduced surface oxide copper is conveyed to a further downstream process of non-acidic pickling NAPS section and coiling.
ADVANTAGES:
1. With introduction of nitrogen in copper metal, the end product has good mechanical properties.
2. Prevention of re-oxidation of copper at high temperature and further reducing the surface oxide of copper, thereby reducing dust generation of the end product.
3. Less dust generation in the downstream processing will improve the quality of final products like magnet wires, transformers strips & less wire breaks in the cables
[19] The present invention has been described in the context of a system for
introducing nitrogen gas into a continuous casting and rolling machine for manufacturing reduced surface oxide copper rod. The invention discloses specific

types of arrangements, specific type of casting machines, pipe connections operating
a specified pressures and temperatures. However, there can be different arrangements,
not limited to specific pipe connections of any numbers, diameter, pressures,
temperatures and material may be used. Suitable modifications may be done when
using other arrangements, which are generally known to the persons in the art.
[20] In the foregoing detailed description of aspects embodiments of the invention,
various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description of aspects, embodiments of the invention, with each claim standing on its own as a separate embodiment.
[21] It is understood that the above description is intended to be illustrative, and
not restrictive. It is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” is used as the plain-English equivalent of the respective term “comprising” respectively.

WE CLAIM:
1. A system of continuous casting and rolling machine comprising:
a closed chamber for generating and regulating nitrogen gas through distributing means, connecting a tundish, an enclosed rolling mill and a finishing mill, thereto form a blanket over rolled in copper cast bar that prevents ingression of air through open connections of return line for said soluble oil and maintains a positive pressure in said enclosed rolling mill; and
means for optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction between said cast bar and rolls in said enclosed rolling mill, wherein
said nitrogen blanket formed and said optimized soluble oil inhibits formation of oxide on surface of copper and reduces dust generation during a downstream process.
2. A continuous casting and rolling machine for manufacturing reduced surface
oxide copper comprising:
a melting shaft furnace for melting said copper;
a holding furnace and a tundish proximate to said melting shaft furnace for introducing molten metal into a casting machine at predetermined flow rate, said casting machine disposed inline to continuously cast bar from said molten copper at predetermined speeds;
an enclosed rolling mill for rolling copper into a continuous form of predetermined diameters and conveying said copper to a non-acidic pickling section and at least one coiler station downstream;

an electronic control system in communication with said continuous casting and rolling machine for controlling and operating said machine at predetermined speeds, temperatures and pressures; and
a system having a closed chamber spaced away from said machine for generating and regulating nitrogen gas through distributing means, connecting said tundish, said enclosed rolling mill and a finishing mill, thereto form a blanket over rolled in copper cast bar that prevents ingression of air through open connections of return line for soluble oil, thereby inhibiting formation of oxide on surface of copper and reducing dust generation during a downstream process.
3. The machine as claimed in claim 2, wherein said system includes means for optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction between said cast bar and rolls in said enclosed rolling mill.
4. The machine as claimed in claims 2-3, wherein oxide formation on surface of copper is dropped from 400º A to at least 250ºA, when nitrogen blanket is formed, and soluble oil is optimized.
5. The machine as claimed in claims 2-4, wherein copper introduced into said melting shaft furnace is in the form of cathodes only.
6. The machine as claimed in claims 2-5, wherein said casting machine is a wheel and belt casting machine.
7. A method for manufacturing reduced surface oxide copper in a continuous casting and hot rolling machine as claimed in claims 2-6, comprising the steps of:

a) monitoring if pressures, temperatures and speeds of said casting machine are within predetermined range and if within predetermined range proceeding to step (b) or returning to step (a);
b) generating and regulating nitrogen gas at predetermined pressures and flow rates into said casting machine through means thereto form a blanket over rolled in copper cast bar, that prevents ingression of air through open connections of return line for soluble oil and maintains a positive pressure in enclosed rolling mill and proceeding to step (c);
c) optimizing fat % and % of Iso Propyl Alcohol concentration in said soluble oil thereto reduce friction & oxide between said cast bar and rolls in said enclosed rolling mill, thereby inhibiting formation of oxide on surface of copper and reducing dust generation a during downstream process and proceeding to step (d);
d) analyzing surface oxide readings of said copper and if analyzed readings are within said predetermined range and proceeding to step (e) or returning to step (b); and
e) conveying said reduced surface oxide copper to a downstream process.