System and method for recycling magnesium and magnesium alloy waste

Abstract

The invention discloses a system and method for recycling magnesium and magnesium alloy waste. The system comprises at least one melting furnace, wherein an air intake device is communicated to the bottom of a first crucible, inert gas is blown in from the bottom of a melt, and bubbles carry impurities in the melt to a liquid level; when a melting furnace inputs the melt into a thermal insulation casting furnace, and a first liquid outlet pipe is communicated to the part, close to the bottom, of the first crucible so as to ensure that the melt can not carry over the impurities; and a small amount of impurities are still contained in the melt after the impurities are removed, and the impurities are settled at a position, close to a feeding hole, inside the thermal insulation casting furnace, so as to ensure that the impurities settled at the bottom of a second crucible can not be carried over when the melt is transferred toward an ingot casting device, so that the impurity removing effect and efficiency are guaranteed. When the thermal insulation casting furnace transfers the melt toward the ingot casting device, at least one melting furnace completes impurity removing treatment, the melt is transferred toward the thermal insulation casting furnace, feeding to the ingot casting device is guaranteed, a continuous recycling process is realized, and the production efficiency is improved.

Description

technical field [0001] The invention relates to a recovery system and method for magnesium and magnesium alloy waste. Background technique [0002] At present, magnesium and magnesium alloy parts produced by die-casting account for more than 90% of the entire magnesium alloy parts. During the die-casting production process, the melt fills the mold cavity, resulting in a large amount of magnesium and magnesium alloy waste, and the waste rate can reach the total metal 40-60% of the input amount. However, most of the waste generated in the above-mentioned die-casting process is clean high-grade waste, and recycling this part of waste plays an extremely critical role in controlling the total cost of the product. [0003] Generally, die-casting companies deal with waste in the following ways: selling, recycling outside the factory or recycling inside the factory. The first two situations impose a great burden on the enterprise, and the external factors are too large. [0004] ...

AI Technical Summary

Problems solved by technology

The disadvantages of this technology are: the flux is mostly chloride, which is likely to cause a high content of chlorine in the product; and corrosive gases such as HCL will be produced during smelting, which will seriously corrode the equipment; the reaction between the flux and the impurity elements and oxides in the waste The product is easy to remain in the alloy, which will damage the mechanical properties and corrosion resistance of the product. It takes a long time to stand still to reduce this inclusion; the specific gravity of the flux needs to be adjusted well; the entire recovery process is intermittent or semi-continuous. Production low efficiency

However, there are still many problems in this method: the whole recycling process is intermittent or semi-continuous, and the production efficiency is not high. The existing purification and impurity removal is carried out in a melting furnace. As well as the sedimentation of impurities, the whole process of purification and removal of impurities takes a relatively long time. The melting furnace is directly connected with the ingot casting device. The time of the purification and removal process is much shorter. In this case, there will be interruptions in production, which will affect the production efficiency; At the bottom of the melt, this process can be done by resting the melt. In order to improve the discontinuity of production and shorten the time for purification and removal of impurities, the method of resting the melt can be changed to dynamic sedimentation, that is, after the removal of impurities is completed, the During the process of transferring the melt from the melting furnace to the ingot casting device, the sedimentation of impurities is accompanied, but this makes it difficult to control the effect of impurity removal, and a large amount of impurities are brought into the ingot casting device; the ability of purification and removal of impurities is limited. The inert gas bubbles bring out the inclusions in the melt. For some scraps with high inclusion content, such as thin-walled parts and scraps with high oxide content, it is difficult for the recycled alloy to meet the relevant standards, which limits the flux-free online processing. The use of recycling production lines; during the process of purification and impurity removal, when the melt is transferred out of the crucible for ingot casting, the liquid level of the melt in the crucible drops sharply, and the protective gas cannot be replenished in time, which is very easy to cause the melt in the crucible to burn. The drop of the slow melt level will bring consequences such as low production efficiency

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