Aluminium alloy melting

one What are the common aluminum alloy melting furnaces?  

Answer: Now common melting furnaces are: resistance crucible furnace, medium frequency induction furnace, oil fired reverberatory furnace, oil fired crucible furnace, coke crucible furnace. Our company uses coke crucible furnace.

two What are the characteristics of coke crucible furnace?  

Answer: (1) Low cost of boiler construction; (2) Low fuel cost; (3) High melting speed; (5) Furnace temperature is difficult to control;

(6) The life of the crucible is short; (7) The discharge of waste gas and smoke is large, and the working environment is poor.

three What are the characteristics of oil fired crucible furnace?

Answer: The oil fired furnace has the characteristics of simple structure, easy manufacturing, simple operation, convenient maintenance, furnace temperature easier to control than the coke oven, but low thermal efficiency, large fuel consumption, and high cost.

four What are the types of crucibles?

Answer: Crucibles are divided into graphite crucibles and metal crucibles, and metal crucibles are also divided into cast iron crucibles and cast steel crucibles. Our company uses graphite crucible for ground furnace and cast iron crucible for die casting melting furnace.

five Why must the new crucible be preheated and baked before use?

Answer: Because the new crucible is baked before use, the service life of the crucible can be improved. In the preheating process of the metal crucible, the inner wall of the crucible is coated with crucible coating, which forms a barrier between the metal liquid and the crucible wall to prevent the metal liquid from directly contacting the crucible wall and corroding the inner wall. (The crucible coating is generally mixed with graphite powder, water glass, zinc oxide and water in a certain proportion).

six How must aluminum spoon and slag spoon be treated before use?

Answer: Before new use, the dirt on the surface of the aluminum spoon should be removed, and the place directly in contact with the liquid metal should be preheated and coated with a layer of paint.

seven Why is it that the longer the aluminum alloy is smelted, the worse it will be used?

Answer: Because the longer the smelting time is, the higher the degree of overheating of the molten metal is, and the more serious the alloy gas absorption and oxidation are, the casting is prone to hydrogen embrittlement (hot cracking), pinholes, pores, cracks, slag inclusion and other defects during die casting production.

eight Why should the slag from aluminum alloy smelting be treated with "ash rubbing"?

Answer: Usually, the slag salvaged from the crucible contains a large number of aluminum alloy fine particles. Fluxes (such as zinc chloride) are added through "ash rubbing". The slag and flux react chemically to produce high temperature, so that aluminum alloy particles can be collected into liquid droplets after being liquid, which can be recycled to reduce the loss of aluminum alloy.