Aluminum Ingot Melting Furnace
Parameter Settings
Operational Tasks
1. Ensure parameters are set correctly; verify them during each shift inspection.
Key Control Points
1. Aluminum melt temperature: 750 ± 10°C
Melting furnace atmosphere temperature: 850 ± 50°C; melting furnace exhaust gas temperature: 650 ± 50°C; melting furnace pressure: 40 ± 5 Pa. During non-continuous production, parameters may be adjusted to conserve energy as follows:
Aluminum melt temperature: 680–710°C; melting furnace atmosphere temperature: 800 ± 50°C; melting furnace exhaust gas temperature: 650 ± 50°C; melting furnace pressure: 40 ± 5 Pa.
Burner Ignition
Operational Steps
1. Set the "Combustion Power" knob in the second row to the "ON" position; click "Combustion Power ON" in the first row to activate the combustion system.
2. Click "Combustion Blower Operation" in the first row. Once the "Combustion Preparation" indicator stops flashing, click the corresponding burner ignition button to proceed with the burner ignition process.
Control Points
1. Ensure that the feeding process is complete before clicking "Combustion Preparation" to prevent damage to the burners. 2. The "Combustion Preparation" sequence can only be initiated if the following condition is met: the combustion blower must be running.
Loading Raw Materials
Operational Tasks
1. Load aluminum ingots and the corresponding proportion of recycled scrap (remelt material) into the transport cart.
Key Control Points
1. Ensure aluminum ingots are placed horizontally within the cart.
2. The total weight of the furnace charge per cart must not exceed 700 kg, and the material must not extend above the rim of the cart; this prevents items from falling out during the lifting process, which could lead to accidents.
Weighing
Task Description
Control Points
1. Place an empty charging cart on the floor scale to record its tare weight by pressing the "Tare Weight" button. Then, place the charging cart—loaded with aluminum ingots or recycled scrap—onto the floor scale and press the "Gross Weight" button. Determine the net weight of the aluminum ingots or recycled scrap accordingly.
1. Calibrate the floor scale once per shift and record the results in the "Floor Scale Calibration Log" (refer to the "General Floor Scale Calibration Work Instruction" for details). 2. Before each weighing operation, ensure the surface of the floor scale is free of debris and that no objects (such as steel plates) are covering the edges, as these could affect measurement accuracy. Once verified, zero out the floor scale.
Charge Composition (Furnace Charge Mix)
Operational Tasks
1. The use of recycled (revert) material must strictly adhere to the specified mix ratios.
Control Points
1. Mix Option 1: New material ≥ 60%, Grade 1 recycled material < 40%.
Mix Option 2: New material ≥ 80%, Grade 2 recycled material < 20%.
2. For each mix option, the charging sequence shall consist of two loads of new material followed by one load of recycled material; personnel must strictly follow this requirement.
Charging (Feeding)
Operational Tasks
1. Move the charging cart—loaded with the weighed materials—into the charging tower, and use the hoist to feed the aluminum ingots into the melting furnace.
Control Points
1. Before charging each furnace load, push any dross/residue from the melting chamber into the holding chamber, and clean the dross from the molten metal surface and the furnace walls within the holding chamber.
2. The amount of material charged must not exceed...
Coating Application
Task Description
1. Preheat the iron tools used during the melting and degassing processes (e.g., slag-skimming ladles, flat scrapers, etc.).
Key Control Points
1. Tool preheating temperature: 250–300°C.
2. After preheating, apply coatings No. 87 and No. 39: first, apply coating No. 87 as a base layer, followed by coating No. 39 as a top layer.
Dross Removal and Furnace Cleaning
Operational Tasks
Key Control Points
1. After cleaning, the inner walls must be free of oxide scale and accumulated dross.
1. The melting chamber and holding tools must be cleaned during every shift.
Use tools such as dross skimmers and flat scrapers to remove buildup from the furnace walls.
2. Avoid rough handling during the cleaning process to prevent damage to the furnace walls.
Aluminum Tapping
Operational Tasks
1. Before activating the aluminum tapping plug cylinder, ensure the tapping trough is clean and free of impurities. Wait until the molten aluminum in the holding furnace reaches a temperature of 750 ± 10°C.
2. Once the temperature is within the 750 ± 10°C range, open the semi-automatic tapping outlet to transfer molten aluminum into the holding furnace. When the level of the molten aluminum reaches a point more than 200 mm above the upper edge of the crucible, deactivate the cylinder and insert an asbestos plug into the conical stopper to conclude the tapping process.
Control Points
1. After tapping is complete, clean the tapping trough, ensuring no aluminum adheres to its surface; take care not to damage the inner lining during cleaning.
2. Apply a coating of "696" refractory paint to the tapping trough once per shift, ensuring an even application.
3. Verify the status of the tapping plug 1–2 minutes after the cylinder has been deactivated to ensure it is sealed tightly and no aluminum is leaking.