Claims
- 1. A method of manufacturing a metal alloy in an electric arc furnace having a molten metal and a slag over the upper surface of the molten metal, the method comprising:
obtaining one or more signal(s) related to variables representing the nature or quality of the slag; feeding the one or more signal(s) into a controller comprising a logic program to generate an output signal representative of the quality or nature of the slag; and adding one or more materials to the electric arc furnace through a valve that has a flow rate that can be variably adjusted to dynamically control the quality or nature of the slag by continuously adjusting the addition of the one or more material in response to the output signal generated by the controller.
- 2. The method according to claim 1, comprising adding a source of carbon into the electric arc furnace to foam the slag as the added material.
- 3. The method according to claim 1, comprising adding the source of carbon into the electric arc furnace to foam the slag by continuously injecting carbon over a flow rate of about 25 lbs/min to about 200 lbs/min.
- 4. The method according to claim 1, comprising adding the material through a rotary valve.
- 5. The method according to claim 1, comprising injecting oxygen, carbon, iron oxide, magnesium oxide, calcium oxide, lime or combinations thereof to control the quality of the slag.
- 6. The method according to claim 1, comprising supplying the electric arc furnace with scrap steel and melting the scrap steel to form a molten metal and a slag over the upper surface of the molten metal.
- 7. The method according to claim 1, comprising injecting carbon or oxygen or both to foam the slag.
- 8. A method of foaming a slag over a molten metal in an electric arc furnace, the method comprises injecting one or more materials into the electric arc furnace through a valve in fluid communication with the electric arc furnace and capable of continuously and variably adjusting the flow rate of the injected material.
- 9. The method according to claim 8, comprising injecting carbon or oxygen or both as the material.
- 10. An apparatus comprising:
an electric arc furnace capable of forming a molten metal covered, in part, by a slag; a sensor in electrical communication with the furnace and capable of sensing the nature or quality of the slag; a material handling and controlling equipment in fluid communication with the furnace for housing and adding material to the furnace to foam the slag and including a variable valve for varying the amount of material added to the furnace; and a programmable logic controller electrically coupled to the sensor and the material handling and controlling equipment for receiving and processing signals from the sensor as to the nature or quality of the slag and for regulating the amount of material added to the electric arc furnace material handling and controlling equipment through the variable valve.
- 11. The apparatus of claim 10, wherein the variable valve can be variably adjusted over a flow rate of about 25 lbs/min to about 200 lbs/min.
- 12. The apparatus of claim 10, wherein the variable valve is a rotary valve that can be variably adjusted over a flow rate of about 25 lbs/min to about 200 lbs/min.
- 13. The apparatus of claim 10, wherein the electric arc furnace comprises three electrodes for melting metal.
- 14. The apparatus of claim 10, comprising an alarm system that will alert an operator when the slag foam is below a predetermined level.
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from provisional patent application Serial No. 60/189,984, filed Mar. 17, 2000 entitled “PROCESS AND APPARATUS FOR CONTROLLING THE SLAG FOAMING WITHIN AC ARC FURNACES” the entire disclosure of which is incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60189984 |
Mar 2000 |
US |