Production line for producing national-standard magnesium alloy ingots on the basis of magnesium alloy waste material

Abstract

A production line comprises: a pretreatment system, a melting and refining system, and a casting system; magnesium alloy waste material passes in sequence through the pretreatment system, the melting and refining system, and the casting system, resulting in magnesium alloy ingots that conform to national standards. The production line for producing national-standard magnesium alloy ingots on the basis of magnesium alloy waste material processes magnesium alloy waste material, passing same through a pretreatment system, a preheating system a melting and refining system, a thermal insulation system, a casting system, and a post-treatment system; coatings and impurities on the surface of the magnesium alloy waste material are removed, and the material is processed into magnesium alloy ingots conforming to national standards; the pieces of equipment of each system are well-connected, the degree of automation is high, operation is simple, and production is highly efficient.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of PCT / CN2015 / 073191 filed Feb. 16, 2015, which is incorporated herein by reference.BACKGROUND OF THE INVENTION1. Technical Field[0002]The present invention relates to production lines for recycling metals, and more particularly to a production line for producing GB-standard magnesium alloy ingots from magnesium alloy waste material.2. Description of Related Art[0003]GB standards (hereafter also mentioned as national standard) refer to the Chinese national standards issued by the Standardization Administration of China (SAC), the Chinese National Committee of the ISO and IEC. Magnesium is one of the abundant light metal elements on the earth. Magnesium has a specific weight of 1.74 g / cm3, equal to only two-thirds of that of aluminum, two-fifths of that of titanium, or one-fourth of steel. Magnesium alloys are alloys made of magnesium as the base and other elements. Magnesium alloys are small in density a...

AI Technical Summary

Benefits of technology

The invention provides a production line for making standard magnesium alloy ingots from waste materials. The line removes surface impurities from the waste materials to ensure consistent washing, increases efficiency, and minimizes material loss. This allows the waste materials to be directly used in producing the ingots, conserving resources and protecting the environment.

Problems solved by technology

However, rapid growth of output of magnesium alloy necessarily brings about sharp increase of magnesium alloy waste material.

Besides, magnesium alloy products in use can accumulate mass greasiness, dirt and oxide layers.

All these make the inactive or discarded magnesium alloy products when becoming Grade 8 waste more difficult to process and recycle.

While both of the methods reuse magnesium alloy waste material, the first one leads to either degraded use or consumptive use of magnesium alloy waste material, where the resulting products are usually disposable and unrecyclable and thus seriously squander the resources.

However, in the prior art, there is no way to use magnesium alloy waste material directly as the material for producing GB-standard magnesium alloy ingots, because of the difficulties in processing of recycled magnesium alloy waste material.

Existing production lines for processing recycled magnesium alloy waste material have various problems.

First, magnesium alloy waste material cannot directly produce GB-standard magnesium alloy ingots via general production process, and various solvents and impurity-removing agents have to be added in the process to reduce impurities in the resulting magnesium alloy ingots to meet the requirements of GB-standard magnesium alloy ingots.

Second, it is difficult to clean coating and impurities attached to magnesium alloy waste material, and material loss is considerable, making utilization of magnesium alloy waste material relatively low.

CN 101947705A discloses methods for producing magnesium alloy welding wires by adopting magnesium alloy foundry scraps, wherein pickling is performed by means of soaking, leading to poor pickling effectiveness and consistency plus low efficiency.

This existing method fails to achieve uniform agitation, which may lead to problems such as unevenly pickling, the agitator getting jammed by waste, long pickling time, and huge loss of material in the pickling process.

This may bring about gas inclusion in the subsequent processes, which makes reprocessing of magnesium alloy waste material dangerous and lowers utilization.

Fourth, in smelting and casting processes, the liquid magnesium alloy (the melt) is not protected from air, and this can cause secondary oxidization, making the casted magnesium alloy ingots contain too many impurities to meet the requirement of the national standards for magnesium alloy ingots.

In addition, the prior art fails to handle the waste residue, waste water, and waste gas generated in magnesium alloy waste material's recycling process in a proper and sustainable manner, and this causes environmental pollution and resource wasting.

However, the waste residue and waste water are reused without having the magnesium ions therein extracted, and this may lead to excessive magnesium in the waste residue and waste water and subjects their reuse to secondary contamination, thus being less environmentally friendly.

None of the known production lines can provide high-effectiveness and high-value recycling and reuse of magnesium alloy waste material, especially magnesium alloy scrap.

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