不同成分的鋁合金其密度也不同，可采用重介質(zhì)分選。一般鋁鎂合 金、鋁鎂硅合金比鋁鋅合金、鋁銅合金、鋁硅合金的密度小。前蘇聯(lián)采用此方法處理廢鋁料,生產(chǎn)率可達(dá)10t/ho鋁在低溫時(shí)能保持原有的性能和塑性，而其它金屬和非金屬在低溫時(shí)呈現(xiàn)較大脆性，如低碳鋼、鋅、塑料及橡膠等。比利時(shí)有一條液氮低溫處理廢鋁生產(chǎn)線，處理能力為15000t/a，經(jīng)濟(jì)效益可觀。破碎廢鋁便于處理和運(yùn)輸，一般廢鋁料、廢鑄件、爐渣、電線及易拉罐等都要經(jīng)過破碎。破碎設(shè)備有剪切機(jī)、破碎機(jī)及火焰切割等。打包的目的在于將松散的廢鋁料壓縮成具有一定尺寸和密度的包，便于運(yùn)輸和熔煉。尤其是對邊角料、卷屑、鋁箔、切斷的廢電纜與電線、易拉罐等都要打包。

 

　　 廢鋁在熔煉之前要經(jīng)過烘干處理，以除去水分、潤滑劑、油等。一般可采用回轉(zhuǎn)烘干爐和箱式烘干爐。在現(xiàn)代烘干生產(chǎn)線上都裝有廢氣燃燒室、除塵器,對排出的廢氣、廢水進(jìn)行凈化處理。對于數(shù)量大、化學(xué)成分單一穩(wěn)定的廢鋁采用分類集中處理，可提高生產(chǎn)效率，降低成本，提高經(jīng)濟(jì)效益。如法國、日本、美國、英國、德國等都采用分類集中處理廢電纜一電線、廢易拉罐、廢鋁渣和爐渣，效果較好。

Most of the waste aluminum recovered at home and abroad is remelted and cast into recycled aluminum ingot, or a small part of the waste aluminum is directly reformed and utilized. The waste aluminum recovered from the society should be carefully pretreated according to the classification standard of recycled waste aluminum before smelting, including sorting, packing and pelleting, drying, purification and dust removal. The waste aluminum material is generally used artificial sorting in our country. When the amount of waste aluminum is large, other methods can be used, such as mechanized selection, magnetic separation, heavy medium separation and cold treatment of waste aluminum. Foreign special sorting table or sorting line for continuous processing, more selection, high efficiency. The main role of magnetic separation is to remove the ferromagnetic material in the waste aluminum, using electromagnet or permanent magnet as the magnet or magnetic wheel, the magnet is suspended above the sorting belt, the magnetic wheel is placed on the transmission roller of the sorting conveyor belt. Britain's magnetic wald test separator is when the aluminium scrap material into sorting machine, the machine on the separator one of about 800, 800 mm steel plate, the tank of cooling water in the copper pipe, copper pipe steel to produce magnetic field, after the power supply of aluminum after cutting lines produce induced current and magnetic field to produce a magnetic field, the interaction of two magnetic field would push aluminium to a certain direction, In this way, aluminum can be separated from waste nonmetals.

 

The density of aluminum alloy with different composition is also different, and can be sorted by heavy medium. General aluminum magnesium alloy, aluminum magnesium silicon alloy than aluminum zinc alloy, aluminum copper alloy, aluminum silicon alloy density is smaller. The former Soviet Union used this method to treat waste aluminum, the productivity can reach 10T/HO aluminum at low temperature can maintain the original performance and plasticity, while other metals and non-metals at low temperature show greater brittleness, such as mild steel, zinc, plastic and rubber. Belgium has a low temperature liquid nitrogen treatment waste aluminum production line, the processing capacity of 15000T /a, considerable economic benefits. Broken waste aluminum is easy to handle and transport. Generally, waste aluminum materials, waste castings, slag, wires and cans should be broken. The crushing equipment has shear machine, crusher and flame cutting, etc. The purpose of packing is to compress loose waste aluminum into a package of a certain size and density, which is easy to transport and melt. In particular, the scrap material, rolled scraps, aluminum foil, cut waste cables and wires, cans and so on must be packed.

 

Waste aluminum should be dried before melting to remove moisture, lubricant, oil and so on. Generally, rotary drying oven and box drying oven can be used. In the modern drying production line are equipped with exhaust gas combustion chamber, dust collector, exhaust gas, waste water purification treatment. Classification and centralized treatment of waste aluminum with large quantity and single and stable chemical composition can improve production efficiency, reduce costs and improve economic benefits. For example, France, Japan, the United States, the United Kingdom, Germany and other countries adopt the classification of centralized treatment of waste cables and wires, waste cans, waste aluminum slag and slag, the effect is good.