A continuous flux melting method and device for magnesium and magnesium alloys

Abstract

The invention relates to a continuous flux smelting method and device for magnesium and magnesium alloys, which is suitable for continuous smelting of magnesium and magnesium alloys with high-impurity and high-dust-content charge as main raw materials. In the invention, the built-in melting-promoting refining pump sucks the high-temperature melt from the upper part of the molten pool and the flux from the bottom of the crucible, and mixes with the refining gas in the pump and then sprays it out from the outlet. At the same time of compound refining, the melt in the crucible is driven to do macroscopic circulation convection, which not only promotes the melting of the furnace charge, but also realizes the uniform temperature and homogeneity of the melt in the crucible; the flux circulation purification pump is used to pump out the flux containing slag at the bottom of the crucible It is sucked to the upper surface of the molten pool, and after filtering and separating the molten slag, it flows to the surface of the crucible molten pool to provide flame retardancy, and then settles to the bottom of the crucible with the furnace charge. The above functions are carried out in parallel and uninterruptedly under the sealing of the furnace cover, which realizes the efficient, green and continuous flux melting of magnesium and magnesium alloys.

Description

technical field [0001] The invention relates to a smelting method and device, in particular to a continuous flux smelting method and device suitable for magnesium and magnesium alloys, and belongs to the field of metal smelting and processing thereof. Background technique [0002] Since the 1990s, magnesium has become another important light alloy material after aluminum. With the development of the magnesium alloy industry and the wide application of magnesium alloy products, the purity of magnesium and magnesium alloy materials (purity refers to the degree of impurity elements in the alloy, and clarity refers to the content of non-metallic impurities (including gases) in the alloy High and low) and its reproducibility have put forward higher and higher requirements, that is, higher and higher requirements have been put forward for the smelting technology of magnesium. At present, the widely used magnesium alloy smelting method is the furnace-type flux method; in order to ...

AI Technical Summary

Problems solved by technology

As mentioned above, although the method realizes continuous operation in the casting process, the process of melting and refining the charge is essentially a furnace-type production, which is completely different from the continuous operation method of the present invention.

[0007] 3. The melting process is slow: after the flux method melting crucible is filled, the melting process of the charge depends entirely on the heat transfer from the molten flux at the bottom of the crucible to the solid accumulation charge, which is limited by the low proportion of flux and the distance from the crucible wall to the central area of ​​the crucible. Limited by factors such as length and lack of convective heat transfer mechanism in the molten pool, the first half of the melting of the charge is very slow

[0009] 4. Unsatisfactory refining effect: As we all know, the refining effect of flux method smelting depends on the contact probability between flux and solid inclusions in the melt. In the current flux refining process, the contact between flux and melt inclusions depends entirely on mechanical stirring intensity and duration

Because the melting pool in the crucible is much larger than the range of action of the mechanical stirring device, it cannot provide conditions for effective contact between the flux and the inclusions in the melt during the stirring process, resulting in low purification efficiency. In order to improve the refining efficiency, the stirring and refining time has to be extended

[0010] 5. Release of corrosive gas: during flux smelting, magnesium chloride (MgCl) in the molten flux in the open crucible 2 ) and water vapor in the air (H 2 O) and oxygen (O 2 ) react and release corrosive gases HCl and Cl 2 , these gases not only deteriorate the working environment, but also lead to rapid corrosion of plant and equipment

[0011] 6. Flux emission pollution: In the smelting process of furnace-type flux method, the slag content in the flux will become higher and higher with the prolongation of use time

Engineering applications show that flux refining is still an effective medium for purifying magnesium and magnesium alloy melts, and is especially suitable for remelting and refining furnace materials with high impurities and high dust content. There are key technical problems such as unstable effects and continuous operation, but no comprehensive solution has been seen so far

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