Everything You Need to Know About Aluminum and Its Uses

Aluminum is the second most commonly used metal in the world’s industrial materials industry, and has become an indispensable core material for modern industry due to its unique combination of properties. From the aerospace equipment that flies in the sky and the automobile parts that gallop on the highway, to the curtain wall of the building that we live in everyday, the food packaging that we take with us, and even the highly sophisticated new energy equipment and medical devices, aluminum is everywhere, and its versatility has long penetrated every corner of human production and life.

This article will comprehensively cover all the core knowledge points of aluminum – from the basic definition, origin and distribution, to the types of classification, core performance, application scenarios, industry standards, and then to the sustainable development and recycling, with easy-to-understand language combined with a professional perspective, to help readers read and understand this “all-purpose metal! It helps readers to understand this “universal metal” thoroughly and clarify its application value and selection logic in various industries.

What is Aluminum?

Chemical and Physical Properties

Aluminum (chemical symbol Al, atomic number 13) is a lightweight, silvery-white metal, belonging to the 13th group of the periodic table, the third cycle of the post-transition metal, with unique physical and chemical properties. Visually, pure aluminum has a bright metallic luster and a smooth, clean surface when freshly processed. When exposed to air, it quickly forms a dense oxide film, which darkens slightly but effectively protects the metal inside.

Its core basic physical characteristics are particularly outstanding: density of only 2.7g/cm³, belonging to the typical lightweight metal; the crystal structure is face-centered cubic, which also gives aluminum good ductility and formability, laying the foundation for the subsequent processing and manufacturing.

Abundance in Nature

Aluminum is the most abundant metallic element in the earth’s crust, accounting for about 8% of the total weight of the earth’s crust, the third most abundant after oxygen and silicon. Despite this high abundance, aluminum atoms have a peripheral electron configuration of 3s²3p¹, with both a tendency to lose electrons and the possibility of gaining electrons, and exhibit acid-base amphoteric chemical properties, so they cannot exist in nature as a single substance, but only as compounds in various types of ores.

Aluminum Production Process

The industrial production of aluminum is mainly based on bauxite, and is accomplished through a two-step core process: the first step is the Bayer process, in which bauxite is refined into alumina (Al₂O₃), and the second step is the Hall-Héroult process, in which the alumina is converted into pure aluminum by electrolytic reduction.

It should be noted that the production of primary aluminum is a highly energy-intensive process, but one of the major advantages of aluminum is that it can be 100% recycled, and the energy required for recycling is only 5% of that required for primary aluminum production, which is one of the core competencies of aluminum in the field of sustainable development. Chemically, the core reaction of the Hall-Elu method can be simplified as follows: cathodic reaction 4Al³⁺ + 12e- = 4Al, anodic reaction 6O²- + 3C – 12e- = 3CO₂, total reaction 2Al₂O₃ + 3C = 4Al + 3CO₂, the actual industrial production of the reaction process is more complex, need to strictly control the process parameters.

Aluminum’s core value lies in its “lightweight and high performance coexist” characteristics: pure aluminum is soft, ductile, easy to process and molding, as well as excellent corrosion resistance, electrical conductivity and thermal conductivity, and through the alloying process, you can further enhance its strength, hardness and other mechanical properties to meet the stringent needs of different industries.

Where does Aluminum Come from?

Major Bauxite Mining Regions

The main raw material for aluminum is bauxite, an ore mostly found in tropical and subtropical regions. Currently, more than one-third of the world’s bauxite production comes from Australia, China and Guinea, which are also the core raw material suppliers for the global aluminum industry.

From the raw material conversion rate, about 4 tons of bauxite to refine 1 ton of pure aluminum, visible bauxite resources are precious. But fortunately, aluminum has the characteristics of “infinite recycling” – after the recovery of aluminum, its physical and chemical properties will not have any loss, can be repeatedly processed and used, which also greatly reduces the dependence on primary bauxite.

There is a German proverb: “Everything has an end, only the sausage has two ends” to describe the finiteness of things, but this saying does not apply to aluminum. For example, the aluminum cans we drink out of are put into recycling bins and then processed to be remade into new aluminum cans for the market in less than two months, consuming only 5% of the energy used in virgin aluminum production, and dramatically reducing greenhouse gas emissions. What’s more, the quality and performance of aluminum can remain 100% intact every time it is recycled, truly realizing a “zero-loss cycle”.

A Brief History of Aluminum

The name aluminum comes from the Latin word “alum”, which originally meant “alum”. Although aluminum is the most abundant metal element in the earth’s crust, its discovery time is much later than that of iron, copper and other metals because it exists in nature only in the form of compounds. 1827, the German chemist Friedrich Wohler made aluminum for the first time through the reaction of potassium substitution, but the yield of this method is very low, which led to the time when the aluminum is more precious than gold, and became the “rare metal” for the aristocrats. It became a “rare metal” reserved for the aristocracy.

In 1884, when the Washington Monument was completed, an aluminum pyramid about 22.6 centimeters high and weighing about 2.83 kilograms was placed on the top to protect it from lightning strikes, which was the largest aluminum product in the world at that time. An anonymous scientist later discovered through testing that this aluminum top was not pure aluminum, but was composed of 97.75% aluminum, 1.70% iron and 0.55% silicon.

In 1886, the emergence of the Hall-Elu method became a milestone in the aluminum industry; in 1888, the Bayer method was commercially applied, a low-cost refining method of high-purity alumina, which was a perfect match for the Hall-Elu method, allowing aluminum to achieve large-scale industrial production, and aluminum was gradually transformed from a “rare metal” to a “mass industrial metal”. Aluminum was gradually transformed from a “rare metal” to a “metal of mass industry”, opening up a wide range of applications in various industries.

Development and Evolution of Electrolysis Technology

The industrialized production of aluminum can not be separated from the progress of electrolysis technology, there are two main sources of development of modern aluminum electrolysis technology, while China’s aluminum electrolysis technology has also achieved a leapfrog development from the introduction to the leading.

Pioneer of Aluminum Electrolysis Technology

Founded by Charles Hall in 1888, Alcoa is one of the world’s largest aluminum producers and has always been at the forefront of aluminum smelting technology and manufacturing. Since the 1940s, Alcoa has developed a variety of prebaked aluminum electrolyzer technologies, ranging from P155 (170kA), Alcoa-697 (230kA) to Alcoa-817 (280kA), each generation of which achieves an increase in current intensity, which in turn improves production efficiency, reduces unit costs, and enhances energy utilization to meet the global market demand for aluminum demand in the global market.

However, this increase in current strength also poses a challenge: the electromagnetic and thermal effects in the electrolyzer are significantly increased, leading to increased amplitude and frequency of fluctuations at the cryolite-aluminum interface and complex fluctuation patterns, which affect the stability and efficiency of the electrolysis process. Even so, Alcoa is still a typical representative of the development of modern aluminum electrolysis technology and industrial science and technology in the world, and its technological progress has greatly promoted the development of the global aluminum industry.

Leader of Modern Aluminum Electrolysis Technology

Pechiney is the world’s top representative of the aluminum industry and holds a leading position in the field of aluminum electrolysis technology. The company takes advantage of the abundant hydroelectric resources in the south of France to obtain low-cost electricity and maximize the efficiency of aluminum electrolysis production through technological optimization and production improvements.

From 1940 to 1978, the St. Jean de Molleine Aluminum Electrolysis Plant in France was modernized several times and the capacity of the electrolytic tanks was continuously increased, which made it the birthplace of the modern aluminum electrolysis technology AP series, and pushed forward the innovation and development of the global aluminum electrolysis technology. However, the early aluminum electrolysis process would produce exhaust gas containing fluoride, sulfur dioxide, fluorocarbons and dust, which caused serious pollution to the environment, especially fluoride, as a toxic substance, which would endanger the environment and human health.

In the 1970s, as the scale of production at the Pechine Aluminum Plant expanded, the pollution problem became more and more serious, triggering protests from local residents and environmental organizations, as well as widespread media attention. Under the joint efforts of the government and enterprises, the technology of electrolytic aluminum exhaust treatment has been gradually improved, and today most enterprises use dry purification technology to treat the exhaust gas, which can absorb 99% of hydrogen fluoride, insoluble fluoride and dust, and effectively prevent the exhaust gas from entering the living environment. What’s more, the adsorbent used in dry purification is alumina, the raw material for aluminum electrolysis. The purified fluorine-carrying alumina can be reintroduced into the electrolysis tanks as raw material, which not only compensates for the depletion of fluorine salts but also realizes the recycling of resources, which greatly improves the environment-friendliness and sustainability of the aluminum electrolysis industry. Over the past 50 years, Pechine’s achievements in improving the efficiency of the electrolyzer have made it a global leader in the development of aluminum smelting technology.

Rapid Development of Electrolytic Aluminum in China

China’s aluminum electrolysis industry started late, but has achieved leapfrog development with the support of national preferential policies and rapid economic development. in 1979, China imported the 160kA center-feeding prebaking tank from Japan (current efficiency 87.5%, production capacity 80,000 tons/year); in the mid-1980s, it independently researched and developed the 180kA aluminum electrolysis test tank (current efficiency 93.5%); and later on, on the basis of the imported technology, it developed the 180kA aluminum electrolysis test tank (current efficiency 93.5%). In the mid-1980s, China independently developed the 180kA aluminum electrolysis test tank (current efficiency of 93.5%); then, on the basis of imported technology, it designed the “Aluminum Electrolysis Tank Mathematical Model and Simulation Software System”, which provided the theoretical basis and design tools for the research and development of large-scale aluminum electrolysis tanks.

Since then, China has independently researched and developed the technology of super-large aluminum electrolysis cells of 165kA, 186kA and 280kA or above, and the success of the “National Large-scale Aluminum Electrolysis Experimental Base 280kA Test Tank” has marked China’s entry into the forefront field of modern aluminum electrolysis technology, and the establishment of its own modern aluminum electrolysis technology system. Subsequently, 320kA (current efficiency 94.43%), 400kA (current efficiency 93% or more, capacity of 340,000 tons/year), 500-600kA super-large prebaked anode aluminum electrolyzer (current efficiency 94.6%) and other technologies have been successfully developed one after another, and all the technological indexes have reached or exceeded the international advanced level.

It is thanks to the efficient development of electrolyzer technology that China’s aluminum production has achieved explosive growth. The International Aluminum Association selected “50 major events in the history of the aluminum industry”, China’s aluminum production accounted for 50% of the world ranked 10th. 2010, China’s primary aluminum production of about 16 million tons, increased to 26.5 million tons in 2013, accounting for 50% of the global total output; 2021, China’s primary aluminum production reached 39 million tons, accounting for 58 million tons of the global total output; China’s primary aluminum production reached 39 million tons, accounting for 58% of the global total output. In 2021, China’s primary aluminum production reached 39 million tons, accounting for about 58% of the global total output.

At present, the new electrolyzer production line of Shandong Weiqiao Chuangye Group has reached 600kA current strength (capacity of 1 million tons/year). The energy-saving and carbon-reducing technology of 600kA aluminum electrolyzer is a breakthrough innovation in the field of aluminum electrolysis research in the world, which is outstanding in terms of energy efficiency, carbon-reducing, longevity and environmental protection, and it promotes the advancement of the aluminum industry, and enhances the international competitiveness of China’s core aluminum electrolysis technology.

Innovation and Development of Alloy Technology

The strength of pure aluminum is low, which is difficult to meet the structural needs of the industrial field, and the emergence of alloying technology has made qualitative improvement in the performance of aluminum, and promoted the diversified development of the aluminum industry, of which duralumin and high entropy alloy are two important innovation directions.

Duralumin

In 1906, the German chemist Alfred Wilm (Alfred Wilm) found that adding a small amount of copper to aluminum can significantly improve the hardness of aluminum, which led to the birth of duralumin (Duralumin) – an alloy initially introduced into industrial production by the German Dülener Metallwerke, hence the name. The tensile strength of duralumin is usually between 300-500 MPa, with high rigidity and hardness, and is widely used in aerospace and other fields that require high material strength.

The promotion of duralumin has opened a new era of aluminum alloying – the diversification of aluminum properties can be achieved by adding other metal elements to pure aluminum through specific processing techniques. The tensile strength of aluminum alloy can reach 200-600MPa, which not only possesses good plasticity and corrosion resistance, but also can be adapted to a variety of industrial application scenarios, and has become the second largest industrial metal after steel.

The increase in strength and hardness of aluminum alloys is mainly due to the role of different alloying elements: copper, manganese, magnesium and other elements enhance the aluminum matrix through solid solution strengthening; titanium, vanadium, boron and other elements enhance the performance by refining the grains and increasing the number of nuclei; cadmium, scandium and other elements improve the performance mainly through the second-phase strengthening. The diverse combinations and arrangements of these alloying elements make aluminum alloys richer in performance and application scenarios.

High Entropy Alloys

In 1995, Prof. Junwei Yeh of Tsinghua University in Taiwan proposed a new alloy design concept – High Entropy Alloys (HEAs). Such alloys are usually composed of five or more elements in nearly equal proportions, with the concentration of each element ranging from 5% to 35%, maintaining roughly the same atomic ratio, and are characterized by the core feature that the entropy of mixing exceeds the entropy of melting, and usually form simple solid solution structures such as face-centered cubic (FCC), body-centered cubic (BCC), and densely-rowed hexagonal (HCP).

High-entropy alloys have received much attention because they contain multiple elements of different sizes and chemical properties, which can produce lattice distortion effects – such distortions not only affect the stability of the atomic spacing and lattice structure, but also dislocation motions, which can enhance the mechanical properties and thermal stability of the alloy.

In addition, the combination of multiple elements will slow down the diffusion of atoms, resulting in a “retarded diffusion effect”, so that the alloy maintains better stability at high temperatures, inhibit atomic migration and grain growth, and improve its resistance to deformation and creep resistance. At the same time, the synergistic effect of a variety of elements will also produce a “cocktail effect”, the performance of the alloy is not only affected by a single element, but also by a variety of elements of the joint action, to achieve the balance and optimization of the performance of various properties, the overall performance is greatly enhanced.

Due to its unique lattice structure and excellent performance, high-entropy alloys have become one of the most promising research directions in the field of materials science in recent years, with high strength, high hardness, high wear resistance, high oxidation resistance and high corrosion resistance, etc., and have a broad application potential in the field of tools, cutting tools, molds, golf club heads, turbine blades, high temperature furnace refractory materials.

What are the Types of Aluminum?

Aluminum types are mainly classified into three categories, namely pure aluminum, deformed aluminum alloys and cast aluminum alloys, according to the manufacturing process and composition. There are significant differences in performance, processing methods and application scenarios for different types of aluminum, which need to be accurately matched with the specific needs when choosing.

Pure Aluminum

Pure aluminum has an aluminum content of 99% or more, with almost no other alloying elements added, so its performance mainly retains the inherent characteristics of pure aluminum: excellent corrosion resistance, good electrical and thermal conductivity, but lower strength and excellent ductility. Due to its limited strength, pure aluminum is not suitable for structural components, and is mainly used in scenarios that require high electrical conductivity, corrosion resistance and formability, and low load-bearing capacity.

Common grades of pure aluminum include 1050, 1060, 1100, 1350, etc. The processing methods are mainly rolling and drawing, and it is easy to be processed into the form of plates, wires and foils. Specific applications include: conductors for power transmission, chemical equipment (corrosion-resistant needs), aluminum foil for food packaging, and so on. Among them, 1100 is the most commonly used grade of pure aluminum, with the highest mechanical strength in the 1000 series and good thermal conductivity, suitable for making radiators, heat exchangers, etc.; 1350 is known for its high electrical conductivity, and is commonly used in the production of electrical products such as transformers and switchgear.

Aluminum Alloy

Aluminum alloys are made by adding one or more alloying elements (e.g. copper, magnesium, silicon, zinc, manganese, etc.) to pure aluminum. The core purpose of the alloy is to enhance the strength, hardness, heat resistance, and other properties of pure aluminum, in order to meet the needs of different industrial scenarios. According to the types and proportions of alloying elements, aluminum alloys can be divided into several series, with significant performance differences between different series and different application scenarios.

The main alloy series of aluminum alloys include: 2xxx series (aluminum-copper alloys), 3xxx series (aluminum-manganese alloys), 4xxx series (aluminum-silicon alloys), 5xxx series (aluminum-magnesium alloys), 6xxx series (aluminum-silicon-magnesium alloys), and 7xxx series (aluminum-zinc-magnesium-copper alloys). Among them, 2xxx, 6xxx, 7xxx series belong to heat-treatable reinforced alloys, through heat treatment can significantly enhance the strength; 3xxx, 4xxx, 5xxx series belong to non-heat-treatable reinforced alloys, mainly through the cold processing to achieve strength.

Here we need to clarify a core question: is aluminum alloy stronger than pure aluminum? The answer is yes. Alloying elements significantly increase the strength and hardness of aluminum through solid solution strengthening, precipitation hardening, and microstructure refinement. Heat-treatable alloys can achieve significant strength gains through controlled aging treatments, while pure aluminum is softer and more ductile, making it more suitable for molding and conductivity-based scenarios. This difference in strength determines the logic of material selection – aerospace, automotive, machinery and other areas requiring high load-bearing properties, aluminum alloys are preferred; while electrical, chemical and other areas requiring high conductivity and corrosion resistance, pure aluminum is more suitable.

Deformed Aluminum

Deformed aluminum is an aluminum alloy formed by rolling, extruding, forging and other solid-state processing methods, during which the metal remains solid and changes shape through external forces without melting. The core advantages of deformed aluminum are: high tensile strength, smooth surface, high dimensional accuracy, and stable mechanical properties, making it suitable for use in scenarios requiring high structural strength and surface quality.

Common grades of deformed aluminum include 6061 (the most versatile), 5052 (excellent corrosion resistance), 7075 (high strength), and 2024 (aerospace specific). Among them, 6061 is the most commonly used grade of deformed aluminum, with good formability, corrosion resistance and weldability, can be strengthened by heat treatment, widely used in structural components, mechanical parts, building profiles, etc.; 5052 is a non-heat-treatable strengthened alloy, excellent corrosion resistance, especially suitable for marine environments, commonly used in ships, marine equipment, etc.; 7075 is a high-strength deformed aluminum, high tensile strength, mainly used in aerospace, high-pressure vessels, etc. for the requirements for the deformation of aluminum. 7075 is a high-strength deformed aluminum with very high tensile strength, mainly used in aerospace, high-pressure containers and other scenarios with very high strength requirements; 2024 has excellent strength and fatigue properties, and is the core material for aerospace structural parts.

Deformed aluminum has a wide range of applications, including: aircraft parts in the aerospace field, profiles in the construction field, machined parts in the mechanical field, etc. It is processed in a flexible way, and can be made into plates, tubes, profiles, forgings, and other forms according to demand.

Casting Aluminum Alloy

Casting aluminum alloy is an alloy that is formed by melting aluminum alloy and pouring it into a mold. It is a near-net-shape production that does not require complex subsequent processing and is suitable for making parts with complex shapes. The alloy design of cast aluminum alloys focuses on improving melt fluidity, reducing the risk of thermal cracking, and controlling shrinkage during solidification to ensure the quality of castings.

Cast aluminum alloy common grades are A356 (aluminum – silicon – magnesium alloy) and ADC12 (aluminum – silicon – copper alloy). a356 suitable for sand casting and permanent casting, can be strengthened by heat treatment, commonly used in automotive engine block, cylinder head and other parts; ADC12 suitable for high-pressure die-casting, high molding efficiency, lower cost, commonly used in automotive brackets, pump body shell and other structural parts.

Compared with deformed aluminum, cast aluminum alloy has lower tensile strength, which is because the casting process may produce porosity, oxidation inclusions, microscopic shrinkage and other defects, affecting the material’s ductility and fatigue life, but the advantage of cast aluminum alloy is that it can be made into complex shapes, and the cost of production is relatively low, and it is suitable for mass production of parts with complex shapes.

High Entropy Alloys

As mentioned earlier, high-entropy alloys are a new type of aluminum alloy composed of five or more elements in nearly equal proportions, and characterized by high mixed entropy. Its core performance advantages are: high strength, high wear resistance, high oxidation resistance and high temperature stability, which solves the performance shortcomings of traditional aluminum alloys in high temperature and high load scenarios.

At present, high-entropy alloys are still in the research and development and promotion stage, but their application potential is huge, and in the future, they are expected to be widely used in tools, turbine blades, high-temperature furnace refractory materials and other fields with very high requirements on material performance, becoming an important direction of aluminum alloy technology innovation.

Aluminum Grades

Aluminum grades are the core identifiers for distinguishing different types of aluminum materials, developed and maintained by the Aluminum Association of America (Aluminum Association). They are classified mainly according to the main elements of the alloys and processing treatments, and are divided into the deformed aluminum series and casting aluminum series, with different naming rules and performance characteristics for different series of grades.

Deformed Aluminum Series

The grade number of deformed aluminum consists of four digits, and each digit has a clear meaning: the first digit indicates the main alloying element, the second digit indicates the modified version of the alloy (0 indicates the original alloy, and non-zero indicates the modified alloy), and the third and fourth digits are the number of the specific alloy in the series (in the 1000 series, the third and fourth digits indicate the purity of the aluminum).

The following is a detailed description of each series of deformed aluminum, including composition, performance and application scenarios:

1000 series belongs to the pure aluminum series, aluminum content between 99.00%-99.99%, its tensile strength range of 82-166MPa, yield strength of 28-152MPa, this series of aluminum can not be heat treatment to strengthen, the core advantage is to have excellent corrosion resistance and electrical conductivity and heat conductivity, while the ductility is excellent, but the strength is lower, so it is mainly used in the electrical conductivity, Therefore, it is mainly used in the scenarios where the requirements for electrical conductivity, corrosion resistance and molding are high, while the requirements for load carrying capacity are low, such as electrical conductors, food packaging and various types of chemical equipment.

2000 series with copper as the main alloying element, copper content between 2.2% -6.8%, tensile strength of 110-283MPa, yield strength of 41-248MPa, can be achieved through heat treatment to enhance the strength of the core features of high-strength, but the corrosion resistance is poor, and therefore used in aerospace structures, high-pressure containers and other high strength requirements, and can be anticorrosive to its Therefore, it is mostly used for aerospace structural parts, high-pressure vessels and other scenes that require high strength and can be corrosion-resistant.

The main alloying element of the 3000 series is manganese, with a manganese content of 0.3%-1.5%, and the tensile and yield strengths are the same as those of the 2000 series, which are 110-283MPa and 41-248MPa. This series cannot be strengthened by heat treatment, and has good corrosion resistance and ductility, with a medium level of strength, which is widely used in daily necessities, radiators, and food packaging.

4000 series takes silicon as the main alloying element, the silicon content is between 3.6%-13.5%, the tensile strength is 172-414MPa, the yield strength is 45-180MPa, some grades can be strengthened by heat treatment, its core performance is characterized by a low melting point and good fluidity, so it is mainly used as a welding filler material and casting auxiliaries, which is suitable for all kinds of aluminum alloys for welding and casting processing needs.

5000 series with magnesium as the main alloying element, magnesium content between 0.05%-5.5%, tensile strength of 124-352MPa, yield strength of 41-345MPa, can not be strengthened by heat treatment, but its corrosion resistance is excellent, belongs to the marine-grade aluminum, medium strength, widely used in ships, marine equipment, and construction profiles, etc., which need to be exposed to long-term humidity or salt spray environment.

6000 series is the most versatile aluminum alloy series, the main alloying elements are silicon and magnesium, of which the silicon content is between 0.2%-1.8% and the magnesium content is between 0.35%-1.5%, the tensile strength is 124-310.3MPa, and the yield strength is 55.2-276MPa, which can be strengthened by heat treatment, taking into account the good corrosion resistance and weldability, and it is the most widely applied It is the series with the widest range of applications, which can be seen in many scenarios, such as building profiles, mechanical parts, automobile parts, and so on.

7000 series is the highest strength aluminum alloy series, the main alloying element is zinc, with magnesium and copper, the zinc content is between 0.8%-8.2%, the tensile strength is as high as 228-572MPa, the yield strength is 103-503MPa, the high strength can be realized through heat treatment, the corrosion resistance is medium, it is mainly used in aerospace, high pressure containers, high load structural components and other demanding scenarios that demand very high strength of materials. It is mainly used in aerospace, high-pressure containers, high-load structural parts and other demanding scenarios that require high material strength.

Key grades of each series

1000 series: the purest aluminum series, of which 1100 is the most commonly used grade, with an aluminum content of about 99%, with good thermal conductivity and formability, suitable for the production of radiators, aluminum foil, wires, etc.; 1350 is known for its high electrical conductivity, used in transformers, switchgear and other electrical products. The limitation of this series is that the strength is extremely low and cannot be used for structural parts.

Series 2000: With copper as the main alloying element, it has high strength and heat resistance and is suitable for high temperature and high load scenarios. Among them, 2024 is the most well-known aluminum alloy for aerospace, with excellent strength and fatigue performance, but poor corrosion resistance, which needs to be improved by cladding or anodic oxidation treatment; 2011 is a free-cutting alloy suitable for high-speed turning processing, commonly used in precision parts, but poor corrosion resistance, which needs to be coated for protection.

3000 series: manganese as the main alloying element, non-heat treatable, good corrosion resistance, good ductility, strength is about 20% higher than pure aluminum. Among them, 3003 is the most commonly used grade, widely used in refrigerators, air conditioners, building materials, etc.; 3005 has good elongation and processing performance, suitable for the production of coils, plates, parts used in wet environments.

4000 Series: Silicon as the main alloying element, low melting point, good fluidity, mainly used for welding filler materials and casting accessories. Some grades can be strengthened by adding copper and magnesium to achieve heat treatment, suitable for use with heat-treatable aluminum alloys.

5000 series: known as “marine grade aluminum”, excellent saltwater corrosion resistance, non-heat treatable, medium strength. 5052 is the highest strength grade in this series, with excellent processing performance, suitable for making ship parts and construction profiles; 5083 has added manganese and chromium for better corrosion resistance and good strength after welding, used for marine equipment and chemical equipment; 5005 is suitable for sheet metal processing, used for daily necessities and architectural decoration.

6000 Series: The most versatile aluminum alloy series, heat-treatable, taking into account strength, corrosion resistance and weldability. Among them, 6061 is the most widely used grade, which can be strengthened by T6 heat treatment, and is suitable for the production of structural parts, mechanical parts, automotive parts, etc.; 6063 is called “architectural aluminum”, with high surface finish, suitable for anodic oxidation treatment, and is widely used for doors, windows, guardrails, curtain walls and other architectural profiles; 6262 is a free cutting alloy with excellent mechanical strength and corrosion resistance, and is used for daily necessities and building decoration. 6262 is a free-cutting alloy with excellent mechanical strength and corrosion resistance, and is used for precision mechanical parts.

7000 series: the highest strength aluminum alloy series, with zinc as the main alloying element, with magnesium, copper, can achieve high strength through heat treatment. Among them, 7075 is the most well-known grade, with extremely high tensile strength, known as “aviation aluminum”, used for aircraft structural parts, high-pressure containers, etc., initially developed for battleships during the Second World War; some of the grades in this series have poor corrosion resistance and are difficult to weld, requiring special welding processes.

Casting Aluminum Series

Casting aluminum grades consist of four digits and a decimal point, with the following naming rules: the first digit indicates the main alloying element, the second and third digits are the numbers of the specific alloys in the series (in the 1XX.X series, the second and third digits indicate the purity of the aluminum), and the digits after the decimal point indicate the type of the product (.0 indicates casting, and .1 or .2 indicates ingot).

Casting aluminum series can be divided into six core series, namely 1XX.X, 2XX.X, 3XX.X, 4XX.X, 5XX.X, and 7XX.X, according to the differences in composition and performance. Different series have their own focus on compositional characteristics, mechanical properties, core advantages, and application scenarios, and are suitable for different casting needs.

X series belongs to the pure aluminum casting series, the aluminum content is maintained at 99.00%-99.99%, its tensile strength range of 131-448MPa, yield strength of 28-152MPa, the core performance is highlighted as excellent thermal conductivity, good corrosion resistance, but the strength is relatively low, and is therefore mainly used in the electrical conductivity and corrosion resistance requirements, and the structural strength of the demand is not high scene, such as various types of electrical casting. Therefore, it is mainly used in the scenarios that have requirements for electrical conductivity and corrosion resistance, but not high structural strength requirements, such as all kinds of electrical castings and parts that need to have corrosion resistance.

2XX.X series with copper as the main alloying element, copper content control in the 4.00% -6.00% between the tensile strength of 131-276MPa, yield strength of 90-345MPa, the series can be heat treatment to achieve the strength of the core advantages of high strength, but at the same time there is a poor melt mobility, low corrosion resistance short board, and therefore used in the strength of the requirements of high Therefore, it is mostly used for high-strength castings and all kinds of mechanical parts, and usually needs to be used with corresponding anti-corrosion treatment.

The main alloying elements of 3XX.X series are silicon and copper, of which the silicon content is between 5.00%-17.00%, the tensile strength and yield strength are 117-172MPa, 66-172MPa, respectively, and can be strengthened by heat treatment with good wear resistance, strong crack resistance, corrosion resistance is at a medium level, due to the performance of the engine parts to meet the use of the needs of the engine parts, therefore It is widely used in the manufacture of core components such as automobile engine block and cylinder head.

X series with silicon as the main alloying element, silicon content between 5.00%-12.00%, tensile strength and 3XX.X series are the same, are 117-172MPa, yield strength is lower, only 41-48MPa, can not be strengthened by heat treatment, but has good processability and impact resistance, low processing difficulty, good stability, suitable for the production of ordinary castings It is suitable for the production of general castings and all kinds of mechanical parts with outstanding cost performance.

X series with magnesium as the main alloying element, magnesium content of 5.00%-12.00%, tensile strength up to 131-448MPa, yield strength of 62-152MPa, can not be strengthened by heat treatment, but its corrosion resistance performance is excellent, and the appearance of the texture is good, belongs to the casting aluminum series of strong corrosion resistance, mainly used in marine castings under the marine environment and the appearance of decorative castings and corrosion resistance requirements. It is mainly used for marine castings in the marine environment and decorative castings with requirements for appearance and corrosion resistance.

X series has zinc as the main alloying element, with a zinc content of 6.20%-7.50%, a tensile strength of 207-379MPa, a yield strength of 117-310MPa, and a strength enhancement that can be realized through heat treatment, which has the core characteristics of high strength and good dimensional stability, but the casting performance is poor, and the casting process is more demanding, and therefore it is mainly used in the production of castings that have stringent requirements in terms of precision and strength. Therefore, it is mainly used for the production of high-strength precision castings with strict requirements on precision and strength.

Condition Codes

Aluminum state code is used to indicate the processing of the material, directly affecting the performance of the material, composed of a capital letter and subsequent numbers, and the brand with a hyphen connection (such as 6061-T6, 5052-H32). Common state codes and their meanings are as follows:

F (As fabricated): processing state, without any special treatment, unstable performance, only for temporary processing parts.

O (Annealed): annealed state, after complete annealing treatment, the material becomes soft, good ductility, suitable for subsequent molding process.

H (Strain-hardened): strain-hardened state (cold working), through cold working to enhance the strength of the subsequent annealing or stabilization treatment, such as H32 (cold working + stabilization treatment).

W (Solution heat-treated): solution heat-treated state, the material after high-temperature solution treatment, the need for timely aging treatment, otherwise the performance will change over time.

T (Thermally treated): heat treatment state, through the solid solution, aging and other heat treatment to enhance the strength, the subsequent number indicates the specific heat treatment, such as T6 (solid solution heat treatment + artificial aging), T4 (solid solution heat treatment + natural aging).

Examples of common states: 6061-T6 is the most widely used state, through solid solution heat treatment + artificial aging, high strength, stable performance, suitable for structural parts; 5052-H32 is cold working + stabilization treatment, medium strength, good corrosion resistance, suitable for daily necessities and construction profiles.

Properties and Advantages of Aluminium

Aluminum is widely used in various industries because of its unique physical and chemical properties, as well as its comprehensive advantages of “light weight, high efficiency, environmental protection and recyclability”, which work together to adapt to the demanding needs of different scenarios.

Physical Properties

Lightweight: with a density of only 2.7g/cm³, which is 1/3 of the density of steel (7.8g/cm³), aluminum is much lighter than steel in the same volume, which can significantly reduce the weight of products and improve efficiency (e.g., in the automotive and aerospace fields).

Excellent thermal conductivity: the thermal conductivity is about 4 times that of steel, making it an ideal thermal conductivity material, widely used in radiators, cookware, heat exchangers, etc., such as heat exchange equipment in the chemical, food, and aerospace fields.

Good conductivity: conductivity is about 62% of copper, but the density of aluminum is only 1/3 of copper, the same weight, aluminum conductivity is more efficient, so it is widely used in electric power transmission lines, bus bars, electronic radiators and so on.

High reflectivity: it can reflect 80% of light and 90% of heat, which not only has a beautiful appearance, but also can be used for heat insulation and sunscreen scenes, such as building roofs and automobile heat shields.

Good ductility and formability: soft texture, easy to roll, extrude, press, stretch, can be processed into various forms from aluminum foil (thinner than paper) to thick plates to meet the molding needs of different products.

Non-magnetic: it is a paramagnetic material, does not attract magnets, and is suitable for use in electronic shielding, medical equipment and other scenes sensitive to magnetism, such as antennas, computer disk shielding covers.

Chemical Performance

Strong corrosion resistance: when exposed to air, the surface will quickly form a dense layer of alumina oxide film, preventing further oxidation of the internal metal, with good resistance to atmospheric corrosion and fresh water corrosion; through anodic oxidation treatment, the corrosion resistance can be further enhanced.

Amphoteric properties: it can react with both strong acids and strong bases, which is the reason why it cannot exist in nature in the form of monomers, and also limits its application in strong acid and alkali environments.

Non-toxic and harmless: chemically stable and non-toxic, it is suitable for use in food packaging, cooking utensils, medical equipment and other scenarios where it comes into contact with the human body, such as food aluminum foil, surgical instruments, and prosthetics.

Core Advantages

High Strength-to-Weight Ratio: High strength and light weight, which is the most core advantage of aluminum, is especially suitable for aerospace, automotive and other weight-sensitive and high-strength areas, which can ensure structural strength while significantly reducing product weight and improving fuel efficiency, flight performance, etc.

Easy processing: It can be molded by rolling, extruding, casting, welding, machining, etc. It is fast and efficient to process, which can reduce the production cost and is suitable for mass production.

100% recyclable: the performance of recycled aluminum is exactly the same as that of virgin aluminum, and the energy required for recycling is only 5% of the production of virgin aluminum, which can be recycled indefinitely, reducing the waste of resources and carbon emissions, and conforming to the development trend of sustainability.

Easy surface treatment: Surface treatment can be carried out through polishing, anodizing, powder coating, etc., which not only enhances the aesthetic appearance, but also strengthens the corrosion and abrasion resistance, and adapts to different scenarios in terms of appearance and performance requirements.

Excellent low-temperature performance: Unlike steel, aluminum does not become brittle in low-temperature environments, but instead becomes stronger and more corrosion-resistant, making it suitable for use in equipment and structural components in cold, icy and snowy areas.

Impermeability and Odorless: Even when processed into 0.007mm thick aluminum foil, it possesses good impermeability and is odorless and tasteless, which makes it suitable for use in food and pharmaceutical packaging, and can effectively protect the products from external contamination.

Sound absorption and shock absorption: Aluminum has certain sound absorption and shock absorption properties, especially aluminum foam, its porous structure can be used for sound absorption and shock absorption scenarios, such as architectural ceilings, automotive shock absorbers and so on.

Disadvantages and limitations of Aluminum

Despite the many advantages of aluminum, there are some drawbacks and limitations in practical applications, which need to be mitigated or circumvented through reasonable design, alloying treatment, surface treatment, and so on.

Mechanical Limitations

Softer texture: Pure aluminum and some low-strength aluminum alloys have lower hardness and are prone to dents, scratches and abrasion. Compared with steel, they have poorer abrasion resistance and are not suitable for use in high-wear scenarios.

Lower absolute strength: Although aluminum has a high strength-to-weight ratio, its absolute strength is not as good as steel, making it an unsuitable substitute for steel in some heavy-duty, high-load scenarios (e.g., large building structures, heavy machinery).

Environmental and Chemical Limitations

Prone to corrosion: Although aluminum has a certain degree of corrosion resistance, but in a strong acid and alkali environment, salt spray environment, corrosion will still occur; and dissimilar metals in contact, in the electrolyte (such as salt water, moisture), the role of galvanic corrosion will occur, aluminum as the anode will accelerate corrosion.

Poor heat resistance: the melting point of aluminum is about 660°C, much lower than steel, in high temperature environments (e.g., high temperature furnaces, high temperature areas of engines), it will lose its structural integrity and cannot be used in high temperature scenarios.

Economic limitations

Higher production costs: The production of primary aluminum is a high energy consuming process, and energy consumption is much higher than that of steel, therefore the price of primary aluminum is higher than that of steel, which will increase the production cost of the product.

Mitigation Strategies

In response to the above limitations, mitigation can be achieved through the following: enhance the strength and hardness of aluminum through alloying treatment (e.g., 7075 aluminum alloy); enhance corrosion resistance through surface treatment such as anodizing and coating; circumvent heavy load scenarios through reasonable structural design; and prevent galvanic coupling corrosion through isolation of dissimilar metals and avoidance of contact with electrolytes.

What Happens When Aluminium is in Contact with Other Metals?

When aluminum is in contact with other dissimilar metals, galvanic corrosion (Galvanic Corrosion) will occur under specific conditions, which is a key concern for aluminum in practical applications, especially in environments such as humidity and salt spray.

Galvanic Corrosion

Galvanic corrosion refers to two different metals in contact, in the same electrolyte (such as salt water, acidic solution, moisture), the formation of a primary battery, one of the metal as the anode, oxidation reaction (corrosion), the other metal as the cathode, protected from corrosion.

In the contact between aluminum and other metals, aluminum usually acts as an anode, which accelerates corrosion, while the metal with which it is in contact (e.g. copper, steel, stainless steel, etc.) acts as a cathode and is protected. This is because aluminum has a lower electrode potential, it is more likely to lose electrons and undergo oxidation reactions, resulting in accelerated corrosion of itself.

Factors Affecting the Severity of Corrosion

Type of dissimilar metals: the greater the difference between the electrode potentials of different metals, the faster the rate of galvanic coupling corrosion, the more serious the degree of corrosion. For example, when aluminum is in contact with copper, the corrosion rate is much faster than when aluminum is in contact with stainless steel.

Contact surface area: the larger the surface area of the cathode metal, the faster the corrosion rate of the anode (aluminum); conversely, the larger the anode surface area, the slower the corrosion rate.

Electrolyte type: the concentration, acidity and alkalinity of the electrolyte, temperature, etc. will affect the corrosion rate, saltwater, acidic solutions and other strong electrolytes will accelerate the galvanic coupling corrosion, and dry environment, due to the absence of electrolyte, galvanic coupling corrosion will almost not occur.

Preventive Methods

In order to prevent the occurrence of galvanic coupling corrosion when aluminum is in contact with other metals, the following measures can be taken:

Isolate dissimilar metals: Between aluminum and other metals, use insulating materials (e.g., rubber, plastic, insulating gaskets) for isolation to avoid direct contact between the two.

Conduct surface treatment: anodic oxidation, coating and other surface treatment of aluminum to form a protective film to prevent aluminum from contacting the electrolyte and reduce corrosion.

Avoid contact with electrolyte: Try to avoid aluminum parts in humid, salt spray, acidic and other environments, or take protective measures to prevent the electrolyte from touching the contact parts of aluminum and other metals.

Choose the right metal to match: Try to choose the metal with similar potential with aluminum electrode to match, reduce the potential difference and reduce the risk of galvanic coupling corrosion.

Aluminum Industry Standards

Currently, the EN standard (European Standard) is the main industry standard for aluminum, which has replaced the old BS1470 standard and has become one of the widely followed standards in the global aluminum industry, covering all aspects of aluminum inspection, mechanical properties, tolerances, alloy naming, state designation, and so on.

Overview

EN standards are a series of standards on aluminum and aluminum alloys formulated by the European Committee for Standardization (CEN), aiming to unify the quality requirements, inspection methods and naming rules of aluminum products, and to ensure the universality and safety of aluminum products. Compared with the old BS1470 standard, the EN standard is more complete, strict and covers a wider scope.

Core EN Standards and Scope of Application

The core EN industry standards for aluminum cover a number of subdivided areas, and each standard plays its own role and complements each other, jointly regulating the quality, inspection, naming and other key aspects of aluminum and aluminum alloy products, providing a unified reference basis for the global aluminum industry.

Among them, EN485-1 mainly stipulates the technical conditions for inspection and delivery of aluminum products, and specifies the inspection methods, acceptance standards and requirements in the process of delivery of aluminum products before leaving the factory to ensure that product quality is in line with the regulations; EN485-2 focuses on the mechanical properties of aluminum and aluminum alloy products, and makes specific provisions for the core mechanical property indexes of products such as tensile strength, yield strength and elongation, which is a measure of whether the mechanical properties of aluminum products are up to the required standards. It is an important basis for measuring whether the mechanical properties of aluminum products meet the standards.

EN485-3 and EN485-4 make clear requirements for the tolerances of hot-rolled and cold-rolled aluminum materials respectively, of which EN485-3 regulates the dimensional tolerances of hot-rolled aluminum plates, profiles and other products, while EN485-4 defines the dimensional tolerances of cold-rolled aluminum plates, foils and other products to ensure the dimensional accuracy of aluminum products under different processing methods. EN515 unifies the nomenclature rules and meanings of aluminum and aluminum alloys, and clarifies the dimensional accuracy of aluminum products under different processing methods. EN515 standardizes the naming rules and meanings of aluminum and aluminum alloys, and specifies the processing methods corresponding to different state codes (e.g. F, O, H, W, T, etc.), which is convenient for the industry to unify the cognition and application.

The EN573 series revolves around the naming system and chemical composition of aluminum alloys, of which EN573-1 stipulates the numerical naming rules for deformed and cast aluminum grades, EN573-2 adopts the chemical symbol method to indicate the composition of aluminum alloys, and EN573-3 specifies the specific chemical composition requirements for each grade of aluminum and aluminum alloys. The three standards work together to clearly define the identity and composition standards of different aluminum alloys, providing clear normative guidelines for the production, inspection and application of aluminum products.

In addition to the above core standards, the EN standard system has several sub-divided standards covering the whole process of aluminum product production, processing and inspection, which further improves the standard specification of the aluminum industry. Among them, EN12020-1 and EN12020-2 are mainly for aluminum and aluminum alloy plates, strips and foils to make additional provisions on dimensional and profile tolerances, which refine the tolerance requirements for products of different thicknesses and widths to ensure the consistency and universality of product dimensions and to meet the processing needs of different industries.EN12258-1 stipulates the dimensional and profile tolerances for aluminum and aluminum alloy extruded profiles, and specifies the dimensional and profile tolerances for extruded profiles. EN12258-1 specifies the cross-section dimensions, straightness, flatness and other key indicators of extruded profiles, providing a quality basis for aluminum profiles used in construction, machinery and other fields.

In terms of inspection and testing, EN14288 specifies the chemical composition analysis methods for aluminum and aluminum alloy products, clarifies the testing principles, steps and precision requirements for different elements (such as copper, magnesium, silicon, zinc, etc.), ensures the accuracy and reliability of the results of the chemical composition test, and provides support for alloy grades determination and quality control.EN10002-1 specifies the tensile test methods for metallic materials, including specimen preparation, test equipment, test equipment and test equipment, and provides a quality basis for aluminum profiles used in construction, machinery and other fields. Including specimen preparation, test equipment, test procedures, etc., applicable to aluminum and aluminum alloy products, tensile strength, yield strength, elongation and other mechanical properties of the test, to ensure that the test results of the normative and comparable.

For casting aluminum products, EN1706 specifically for casting aluminum and aluminum alloy castings to make provisions for technical requirements, covering the casting of the chemical composition, mechanical properties, appearance quality, internal defects, etc., and clearly defined the acceptance criteria for different types of castings, applicable to sand casting, die casting, permanent casting and other casting process production of aluminum castings, casting aluminum products, to ensure the stability of the quality of casting products. In addition, the EN ISO 12944 series of standards for aluminum products, surface protective coatings to make provisions, clear performance requirements for coatings, construction methods and inspection standards, used to enhance the corrosion resistance and service life of aluminum products, suitable for use in different environments.

These EN standards are interlinked and complementary to each other, forming a complete set of aluminum and aluminum alloy product standards system, which not only regulates the production behavior of manufacturers, but also provides a clear basis for downstream users to choose products, inspection and acceptance, and promotes the standardization and normative development of the global aluminum industry. Whether it is the production enterprises, inspection organizations, or downstream applications, following the EN standard is an important prerequisite to ensure product quality and enhance market competitiveness.

Application Scenarios of Aluminum

Aluminum, with its comprehensive advantages of light weight, corrosion resistance, easy processing, recyclability, etc., has penetrated into all aspects of industrial production, daily life, and high-precision fields, and has become a core material to promote the upgrading and development of various industries. The following is a detailed introduction to the specific application scenarios of aluminum by industry, combining the performance characteristics of different aluminum materials, explaining the logic of their selection, and helping readers to accurately match their needs.

Aerospace

The aerospace industry has extremely stringent requirements for materials, requiring both high strength to ensure structural safety and lightweight characteristics to reduce flight loads. Aluminum and aluminum alloys fit this core requirement, and are the non-ferrous metal materials with the largest amount of use in the aerospace industry. Among them, 7000 series aluminum alloy (e.g. 7075) has become the preferred material for core structural parts such as aircraft fuselage, wings, landing gears, etc. by virtue of its extremely high tensile strength; 2000 series aluminum alloy (e.g. 2024), with its excellent fatigue performance, is commonly used in aircraft skins, beams, etc.; and 6061 aluminum alloy is used in aircraft internal structural parts, instrument panel brackets, etc. due to the balance of strength and weldability.

In addition, pure aluminum (1000 series) is used for aircraft electrical system wires and radiators due to its excellent thermal conductivity; cast aluminum alloys (such as A356) are used for the manufacture of complex shaped parts such as aircraft engine parts and cabin interior parts. With the upgrading of aerospace technology, new aluminum alloys, such as high-entropy alloys, are also gradually applied to high-temperature parts of spacecraft, turbine blades, etc., to further enhance the performance and service life of equipment.

Automotive Industry

Automotive lightweight is the industry development trend, aluminum as the core material of lightweight, the application is increasingly widespread. It is mainly used for engine blocks, cylinder heads, body panels, wheel hubs, chassis components, etc., which can reduce the weight of automobiles by 10%-20%, thereby reducing fuel consumption by 5%-10%. Commonly used grades include 6061, 5052, A356, etc., balancing strength and processability.

Construction

Aluminum in the construction field focuses on both decorative and structural applications, and has become one of the preferred materials for modern construction due to its durability, aesthetics and ease of processing. The main applications include window and door profiles (6063 grade is the main), building curtain walls, roofing materials, ceilings, parapets, etc., which not only meet the aesthetic needs of the building, but also resist the erosion of the wind and rain, and have a long service life.

Electrical Industry

Aluminum’s excellent conductivity and low cost make it widely used in power transmission and electrical equipment. This mainly includes high-voltage transmission lines, transformer coils, motor housings, wires and cables, etc. Grade 1350 is commonly used in transformers and switchgear due to its high conductivity.

Packaging Industry

Aluminum’s non-toxic, impermeable, odorless, and recyclable characteristics make it an ideal material for the packaging industry, especially for food, beverage, and pharmaceutical packaging. The main products include aluminum foil, aluminum cans, aluminum foil for pharmaceuticals, aluminum packaging cans, etc. Among them, beverage cans can be recycled in a closed loop, which is in line with the trend of green packaging.

Electronics Industry

In electronic equipment, aluminum is mainly used for heat dissipation and structural protection, taking advantage of its good thermal conductivity and light weight. The main applications include the shells and heat sinks of smartphones and laptops, as well as the shells of TVs and air conditioners, etc. Grades such as 6061 and 5052 are commonly used, taking into account both aesthetics and practicality.

Marine Industry

Aluminum’s seawater corrosion resistance (especially 5000 series aluminum alloy) makes it suitable for marine environment applications, mainly including ship hulls, offshore platforms, marine equipment components, etc., which can effectively resist seawater erosion and prolong service life.

High-End and Emerging Applications

With the development of technology, the application of aluminum continues to extend to the high-end field, mainly including:

New energy field: solar panel frames (high strength, corrosion resistance), wind turbine blades and nacelles (lightweight, anti-fatigue), aluminum-based batteries (energy storage solutions, huge potential).

Medical field: surgical instruments, medical device housings, prosthetics (lightweight, biocompatible).

High-end manufacturing: high-entropy alloys for cutting tools, molds, turbine blades to enhance equipment durability.

Aluminum Recycling

Aluminum’s recyclability is one of its core advantages over other industrial metals such as steel and copper, and it is also an important contributor to the global practice of “dual-carbon” goals and the promotion of green and low-carbon development.

Compared with the complete production process of primary aluminum from bauxite mining, refining to smelting, recycled aluminum does not need to go through the complex ore mining, alumina refining and other links, which not only can significantly save the earth’s limited mineral resources, but also significantly reduce energy consumption and greenhouse gas emissions, is a very representative of the environmental protection of materials under the model of the circular economy, and is the core competitiveness of the aluminum industry to achieve sustainable development.

Why Recycled Aluminum?

The value of recycling aluminum is reflected in energy saving, cost control, environmental protection and emission reduction, and resource recycling and other dimensions, whether from the perspective of industrial development or ecological protection, has an irreplaceable significance:

Saving energy and reducing pressure on energy consumption: the primary production of aluminum is a high energy-consuming industry, especially the electrolysis link needs to consume a lot of electricity, while the energy consumption of recycled aluminum is only about 5% of that of primary aluminum. Specifically, recycling 1 ton of scrap aluminum only needs to consume about 500 kWh of electricity, while the production of 1 ton of primary aluminum needs to consume about 10,000 kWh of electricity. Recycling 1 ton of aluminum can directly save about 95% of electricity and fossil fuels, which can effectively alleviate the pressure of global energy tension.

Reduce production costs and avoid market risks: primary aluminum production needs to go through bauxite mining, long-distance transportation, alumina refining and other links, not only the process is complex, but also by the fluctuation of international bauxite prices, transportation costs, and other factors, the production cost is not stable. The raw materials of recycled aluminum mainly come from the trimmings and scraps of industrial production, as well as the discarded aluminum products in daily life, without the need to invest a large amount of money in ore mining and long-distance transportation, which can significantly reduce the operating costs of the production enterprises, and can also effectively avoid the business risks brought about by fluctuations in the international bauxite market.

Environmental protection and emission reduction, guarding the ecological environment: The primary aluminum production process generates a large amount of greenhouse gases and pollutants such as carbon dioxide, fluoride, etc. At the same time, bauxite mining destroys the surface vegetation, leads to soil erosion, causes soil erosion and other ecological problems. In contrast, carbon emissions can be reduced by more than 90% during the production of recycled aluminum, and there is no need to mine bauxite, which effectively reduces the damage to forests, land and other ecological resources, reduces pollutant emissions, and contributes to global ecological and environmental governance.

Resource recycling, sustainable use: Aluminum has unique physical and chemical properties, and can be recycled repeatedly without losing its own performance. Whether it is discarded aluminum foil, cans, end-of-life cars, or aluminum components in the building, it can be re-processed into new aluminum products after standardized recycling treatment, realizing the closed-loop cycle of “resources-products-discarded-recycled-products”. The closed-loop cycle of “resources – products – waste – recycling – reproducts” is achieved, allowing limited aluminum resources to play an unlimited value, and truly realizing the sustainable use of “inexhaustible, inexhaustible”.

Aluminum Recycling Process

After years of development, the global aluminum recycling industry has formed a mature, standardized industrial chain, from the collection of scrap aluminum to reprocessing into qualified products, the entire process is standardized and orderly, efficient and environmentally friendly, mainly divided into four core steps, each step has a strict operating standards to ensure that the quality of the recycled aluminum in line with the subsequent production requirements:

Collection and sorting: Aluminum scrap is recycled from a wide range of sources, mainly including industrial production waste (such as the edges and corners of aluminum processing, cutting debris, scrapped aluminum billets, etc.), daily life consumption waste (such as beverage cans, food packaging aluminum foil, discarded aluminum kitchen utensils, etc.), as well as end-of-life products in the aluminum components (such as end-of-life automobile aluminum body, engine parts, building demolition of the aluminum curtain wall, windows and doors, etc.). profiles, etc.). After collection, the staff will sort different grades and types of aluminum scrap through density separation, manual sorting and other methods to avoid mixing different materials and grades of aluminum together, which will affect the quality and efficiency of the subsequent recycling and processing.

Pre-treatment: The sorted aluminum scrap needs to be pre-treated to remove surface impurities and pollutants, in order to prepare for the subsequent melting and refining. The pretreatment process mainly includes two parts: one is to crush and pulverize the scrap aluminum, processing it into uniform granular form, which is convenient for subsequent melting; the second is to remove the impurities such as paint, plastic, oil and so on attached to the surface of the scrap aluminum by heating and burning, and at the same time, dry the granular scrap aluminum, completely remove the surface moisture and pollutants, so as to ensure the purity of the recycled aluminum.

Melting and refining: The pre-treated scrap aluminum particles will be sent to a professional furnace for heating and melting. After the scrap aluminum is completely melted into a molten state, the staff will remove impurities and air bubbles in the molten aluminum through mechanical stirring and filtration to ensure the purity of the molten aluminum. Subsequently, according to the subsequent production of product demand, add the appropriate amount of alloying elements (such as copper, magnesium, zinc, etc.), adjust the chemical composition of the molten aluminum, so that it meets the appropriate product standards, for the subsequent casting process ready.

Casting: After refining the molten aluminum, will be poured into the pre-designed mold for casting, according to the product demand, can be cast into ingots, plates, wires, profiles and other different forms of semi-finished products, these semi-finished products after further processing, can be reintroduced into industrial production and daily life, to achieve the recycling of aluminum resources.

At present, the global aluminum recycling industry is developing well, in which the recycling rate of beverage cans is at a high level, and about 70% of the materials in newly produced beverage cans come from recycled aluminum, realizing an efficient closed-loop cycle. Meanwhile, with the continuous upgrading of recycling technology and improvement of the recycling system, the aluminum recycling rate in construction, automotive and other fields is also continuing to improve, injecting a strong impetus for the green and sustainable development of the aluminum industry.

Summary

As the most abundant metal element in the earth’s crust, aluminum has evolved from a once-rare precious metal to a core material for modern industry by virtue of its excellent characteristics, such as lightness, corrosion resistance, easy processing and recyclability.

Whether for industrial production, commercial projects, or everyday life, aluminum is a cost-effective, environmentally sustainable material. It is recommended to give priority to aluminum and aluminum alloys when selecting materials, and to choose appropriate grades and states according to specific needs; at the same time, actively participate in the recycling of aluminum, practice a green lifestyle, and jointly promote the sustainable development of the aluminum industry.