International aluminum scrap

Sources of aluminum scrap

Raw materials for the production of secondary aluminum – aluminum scrap – включает:

  • технологические отходы производства алюминиевой продукции;
  • отработавшие срок службы алюминиевые изделия;
  • aluminum shavings and
  • Aluminum foundry slag.

The chemical composition of aluminum scrap depends on the final chemical composition secondary aluminum alloy and, Consequently, industry sector, wherein it can be used.

Secondary aluminum alloys

Casting aluminum alloys with a high content of silicon can "absorb" is much more diverse scrap aluminum, because of their tolerance for various impurities are much wider, than wrought aluminum alloys.

Casting alloys are given less value added, than wrought alloys. Therefore, for their production does not fit all types of aluminum scrap - not only on the chemical composition, but also for reasons of economic benefits. for instance, all aluminum-silicon foundry alloys can be smelt from the extrusion scrap with addition of silicon, copper and other alloying elements. However, the lower cost of casting alloys makes it impractical.

A large share of aluminum scrap, которую переплавляют производители вторичных деформируемых алюминиевых сплавов (remelters), is domestic production of technological waste, as casting slab for rolling-pillars or ingots for extrusion, and waste production of extruded sections.

Категории алюминиевого лома: ГОСТ 1639 and ISRI

All aluminum scrap, which is collected from different sources, sorted, treated and separated into different categories to be sold to processors in the country or for export. Supplies of scrap aluminum on the world market produce according to international specifications. Эти условия курирует специальный институт (The Institute of Scrap Recycling Industries (ISRI)). These specifications include about 40 grades of aluminum scrap. Each variety has its short name, for example, «Tata». domestic Standard 1639 as amended 2009 year partly include these categories in its classification of aluminum scrap and waste.

Important factors, on which the scrap value, относятся следующие:

  1. Содержит ли лом только один алюминиевый сплав? – Это позволяет производителю вторичного алюминия точно знать, any chemical composition, he will receive, When the melt the scrap.
  2. Содержит ли лом примеси (загрязняющие вещества)? – Металлические примеси будут влиять на химический состав полученного алюминиевого расплава и могут привести к его несоответствию заданным техническим требованиям. Non-metallic impurities can lead to negative environmental consequences, as well as lower product yield.
  3. Whether the hazardous waste items, such as sealed reservoirs, которые могут привести к взрыву в печи?
  4. Готов ли лом к непосредственной загрузке в печь или его нужно подвергать какой-либо предварительной подготовке?

Process aluminum waste

scrap advantage of manufacturing technology in the waste, that they can be easily divided into individual alloys. Moreover, this scrap does not contain any so-called "pridelok", i.e, for example, steel bolts, nuts and studs, which can contribute to unwanted impurities in aluminum melt. This scrap does not require additional processing prior to loading to the melting furnace, or require it in a minimal volume. In most cases, this scrap has no paint coating and therefore provides maximum metal yield.

Possible pre-treatment may include this type of aluminum scrap can include briquetting, grinding and in a more "advanced" factories - Paint removal. This type of aluminum scrap and waste includes foundry, such as a foundry mold and casting cull.

Примерами типичных категорий ISRI являются: «Tough» и «Tata».

«Tough» ̶ Mixed technological waste aluminum alloys

It must contain pure, without cover, unpainted aluminum residues of two or more alloys, thickness of at least 0,4 mm

  • without wire bundles,
  • without wire screens,
  • no polluted and non-metallic objects.

The content of oils and lubricants should not exceed 1 %. It should not contain aluminum waste perforation size less than 1,3 mm.

«Tata» – Wastes from the production of extruded aluminum profiles

Должен содержать один сплав (обычно 6063). Может включать пресс-остатки прессового (экструзионного) производства, but should not contain any impurities. Anodised material allowed. Colored material or alloys, other than 6063, You shall be agreed between buyer and seller. Example «Tata» category briquetted aluminum scrap is shown in Figure 1.

alyuminievyy-lom-tata

Figure 1 – Отходы прессового производства («Tata»)

Scrap aluminum products after a lifetime

This category includes aluminum scrap aluminum products, которые могут иметь срок службы:

  • a few weeks, such as, in aluminum beer cans,
  • by 12 years, for example, automotive castings, or even
  • more 30 years in the case of construction products, for example, aluminum windows.

This type scrap can be collected from many different sources. Before loading to the melting furnace it normally requires sorting. This scrap is inevitably contaminated with one or more kind of paint, mud, plastic, oils, greases and various metallic and non-metallic "pridelkami". For effective use of this type of aluminum scrap can require more sophisticated methods of pretreatment, including grinding and magnetic treatment, as well as various sorting methods.

For this type of aluminum scrap ISRI include categories such as, for example, taint/tabor, tense и taldon.

«Taint / tabor» - Pure mixed scrap b / a sheet of aluminum

Must keep clean, a used aluminum sheet of two or more aluminum alloys, но:

  • без масляных загрязнений;
  • без оконных жалюзей;
  • без отливок;
  • без пучков проволоки;
  • без проволочных экранов;
  • без банок от пива и напитков;
  • без радиаторных пластин;
  • без самолетных листов;
  • без бутылочных крышек;
  • без пластика;
  • без грязи;
  • no other non-metallic contaminants.

The content of oils and lubricants in general, no more than 1 %. Permission is granted to 10 % алюминиевого лома категории «Tale» (окрашенные сайдинги). On the image 2 показан пример чистого смешанного листового алюминиевого лома (Taint/tabor).

alyuminievyy-lom-taint

Figure 2 – Смешанный листовой алюминий (Taint/tabor)

«Tense» - Mixed aluminum castings

It must contain a clean aluminum castings, which may include automotive and aircraft castings, but peppers. Must not have iron, brass, dirt and non-metallic objects. The total content of oils and greases must not exceed 2 %. Mixed aluminum castings are shown in Figure 3.

alyuminievyy-lom-tense

Figure 3 – Смешанные алюминиевые отливки («Tense»)

«Taldon» – Briquetted cans of beer and beverages

Must have a density of about 225 kg / m3 for not flattened aluminum cans and 325 kg / m3 - for flattened.
Размеры: минимальный объем 0,85 m3 с размерами сторон брикета (61-100 см) х (76-132 см) х (102-213 см).
Способ увязки брикетов: от 4 by 6 стальных лент (1,6 см х 5 см) или от 6 by 10 рядов стальной проволоки (#13). Allowed to use aluminum strips and wire strength and the equivalent amount of. The use of any shims or plates of any material not allowed. Материал должен пройти магнитную обработку и не должен содержать:

  • steel,
  • lead,
  • bottle caps,
  • plastic cans and other plastic products,
  • glass,
  • wood,
  • mud,
  • grease,
  • garbage and
  • other foreign substances.

Any other aluminum items, other than cans of beer and drinks are not allowed.

Пример брикетированных алюминиевых банок («Taldon») показан на рисунке 4.

alyuminievyy-lom-taldon

Figure 4 – Брикетированные алюминиевые банки («Taldon»)

aluminum shavings

Aluminum shavings produced mainly when machining cast and rolled blanks. Normally it contains a considerable amount of oils and moisture, which must be removed before loading into the melting furnace. The advantage of aluminum scrap in the form of chips is often the, it consists of one aluminum alloy. Mixed shavings, on the other hand, is a problem, because it may comprise a number of aluminum alloys - cast and wrought - or zinc alloys.

ISRI category for mixed aluminum chips - «Telic».

aluminum dross

Aluminum dross is formed during the melting process and is composed of aluminum metal and aluminum oxide. Slag treatment by specialized companies. Slag is considered a hazardous material and, in contact with water liberates ammonia and other gases. Industry for the production of secondary aluminum processing large amounts of slag, which are formed during the production of primary aluminum. there are plants, are engaged exclusively aluminum slag from the primary isolation.

shlak-alyuminiya

Figure 5 – aluminum dross

Источник: G. Wallace, in “Fundamentals of aluminium metallurgy. Production, processing and applications” / ed. R. Lumley, 2011.