ALUMINUM

Aluminum, the chemical element with atomic number 13 and symbol Al. It is a silvery, ductile metal. It is generally found in nature as bauxite ore and is known for its superior resistance to oxidation. The basis of this resistance is its passivation feature. It is used in the production of millions of different products in many branches of industry and has a very important place in the world economy. Structural components made of aluminum are indispensable for the aerospace industry. It finds wide usage area in transportation and construction industry, which requires lightness and high strength properties.

 

ALUMINUM FEATURES

Aluminum is a soft and light metal with a dull silvery color. This color comes from the thin oxide layer that forms on it when exposed to air. Aluminum is non-toxic and non-magnetic. It doesn’t spark. While the tensile strength of pure aluminum is about 49 megapascal (MPa), this value increases to 700 MPa when alloyed. Its density is about one third that of steel or copper. It can be easily forged, machined and cast. It has very superior corrosion properties because the oxide layer formed on it is protective. Electrical conductivity is 64.94% IACS (pure Al at 2 °C). Its melting temperature is 660 °C, and its boiling temperature is 2519 °C.

 

ALUMINUM HISTORY

The ancient Greeks and Romans used the salts of aluminum (æljʊˈmɪniəm) to fix the colors of paints and as a blood stopper. Alum is still used as a blood stopper and vasoconstrictor in today’s medicine.

Although Friedrich Wöhler is known to be the first person to decompose aluminum by mixing anhydrous aluminum chloride with potassium in 1827, the metal was produced in an impure form by a Danish physicist and chemist, Hans Christian Øersted, two years ago. Therefore, Øersted’s name is mentioned in the almanacs and in the chemistry literature as the person who discovered aluminum. French Henri Saint-Claire Deville, improved Wöhler’s method in 1846 by using sodium instead of the more expensive potassium.

In 1886, American Charles Martin Hall applied for a patent (patent number: 400655) on the production of aluminum by an electrolytic process, and in the same year, French Paul Héroult developed the same technique in Europe, being completely unaware of Hall’s invention. For this reason, the Hall-Heroult process, named after two scientists, is the basic method used all over the world in the extraction of aluminum from its ore today.

It was decided to use aluminum in the construction of the summit of the Washington monument in the USA, and the cost of approximately 30 grams of aluminum at that time was equivalent to twice the daily wage of a worker working on this project.

In the years immediately after Adolf Hitler came to power, Germany became the world leader in aluminum production. However, the commissioning of new hydroelectric power plant projects in the USA (for example, the Grand Coulee Dam) in 1942 gave the USA an advantage that Nazi Germany could not cope with. This superiority has emerged in the form of aluminum production sufficient to make 60,000 warplanes in four years.

 

The Presence of Aluminum in Nature

Although it is abundant (7.5-8.1%) in the earth’s crust, it is very rare in free form, and therefore it was once considered even more valuable than gold. The history of commercial production of aluminum is a little over 100 years old.

Aluminum was a metal that was very difficult to separate from its ore in the years it was first discovered. Aluminum is one of the most difficult metals to refine. The reason for this is that it oxidizes very quickly, this oxide layer formed is very stable, and unlike the rust in iron, it does not peel off from the surface.

Recovery of aluminum from scrap has become an important component of today’s aluminum industry. The recovery process is based on the simple remelting of the metal, which is much more economical than the production of metal from ore. Aluminum refining requires very large amounts of electrical energy, whereas the recovery process consumes 5% of the energy used in its production. The recycling process has been practiced since the early 1900s and is not new. A low profile activity until the late 1960sThe recycling phenomenon, which continues as meat, has come to the agenda more intensely with the start of making beverage cans from aluminum on this date. Other sources of recycled aluminum include auto parts, windows and doors, appliances and containers.

Aluminum is a reactive metal and it is very difficult to recover from its ore (aluminum oxide, Al₂O₃). Production takes place with 2 methods. The first is the Bayer method and the other is direct reduction with carbon. Since the melting temperature of aluminum oxide is about 2000 °C, it is far from being economical. Therefore, aluminum is gained by the electrolysis method. In this method, aluminum oxide is dissolved in molten cryolite and then reduced to pure metal. In this method, the working temperature of the reduction cells is around 950-980 °C. Cryolite is a natural mineral found on the island of Greenland, but it is made synthetically for aluminum production. Cryolite is a mixture of aluminum and sodium fluorides and its formula is Na₃AlF₆. Aluminum oxide (white powder) is produced by refining red bauxite because it contains approximately 30-40% iron. The name of this transaction is Bayer transaction and it has replaced the previously used Deville transaction.

In the electrolysis method, which replaces the Wöhler process, both electrodes are made of carbon. Once the ore is molten, the ions begin to circulate freely. The reaction on the negative electrode (cathode):

Take³⁺ + 3e^– → Take

indicates that the aluminum ion has been reduced by gaining electrons. The aluminum metal then sinks to the bottom of the cell in liquid form and is siphoned out from there.

On the other hand, oxygen gas is formed at the positive electrode (anode):

2O^2- → O₂ + 4e^–

The anode carbon is depleted by oxidation with this oxygen and therefore needs to be renewed at regular intervals:

O₂ + C → CO₂

Cathodes are not depleted during the electrolysis process, unlike the anodes, because there is no escape of oxygen at the cathode. The carbon of the cathode must be protected as it is covered with liquid aluminum inside the cell. On the other hand, cathodes are subject to erosion due to electrochemical processes. Depending on the current applied in the electrolysis, the cells must be completely renewed every 5-10 years.

Although aluminum electrolysis with the Hall-Héroult process consumes a lot of electrical energy, alternative methods are far from being economically and ecologically viable. Worldwide, the average specific energy consumption is about 15±0.5 kilowatt hours per kg Al (52-56 MJ/kg). In modern plants, this figure is around 12.8 kWh/kg (46.1 MJ/kg). While the electric current carried by the reduction line was 100-200 kA in old technologies, this value increased up to 350 kA in modern facilities, and it is known that trial studies have been carried out in 500 kA cells.

Electricity constitutes 20-40% of the aluminum production cost, depending on the location of the facility. For this reason, aluminum producing businesses tend to be close to areas where electrical energy is abundant and cheap, such as South Africa, New Zealand South Island, Australia, China, Middle East, Russia, Iceland, Canada Québec.

As of 2004, China is the world leader in aluminum production.

 

 

Aluminum Safety Precautions

Aluminum has not been observed to have a beneficial function on living cells. In some people, contact dermatitis (skin inflammation), which can be caused by any form of aluminum, styptic (blood-stopping) or itchy rash with the use of antiperspirant products, digestive disorders caused by eating food cooked in aluminum pots and cessation of absorption of nutrients, and Rolaids, Amphojel, and with the use of antacid (antacid) drugs such as Maalox, it can cause allergic reactions in the form of poisoning symptoms such as vomiting. Although aluminum is not as toxic to others as heavy metals, and the use of aluminum utensils (preferred because of its high corrosion resistance and good thermal conductivity) has not been proven to cause aluminum poisoning in general, high doses can show signs of poisoning. Excessive consumption of antacids containing aluminum compounds and excessive use of aluminum-containing antiperspirants can cause poisoning. Although it has been claimed that aluminum causes Alzheimer’s disease, that research has been refuted as the damage caused by Alzheimer’s disease, on the contrary, leads to aluminum accumulation in the body. In summary, if there is aluminum poisoning, it must occur by a very specific mechanism. Because throughout the life of man, the contact of the natural clay mineral in the soil with the aluminum in it is already high enough.

Aluminum’s rapid corrosionIt is necessary to avoid contact with some chemicals that cause frostbite. For example, a very small amount of mercury dropped on the surface of a piece of aluminum easily pierces the protective aluminum oxide layer, and within a few hours, even gigantic structural beams can weaken significantly. For this reason, many airlines do not allow mercury thermometers, as aluminum occupies an important place in the structural skeleton of aircraft.

Facts

Date of Discovery: 1825
Discovered by Hans Christian Oersted
Name Origin: from the Latin word alumen
Uses:  airplanes, soda cans
Output: bauxite

Aluminium Chemistry

Oxidation stage

• • Aluminum When heated to 1500 °C under hydrogen atmosphere, AlH is produced.
  • Normal oxide of aluminum (Al₂O₃) 2O is produced when >silicon is heated under vacuum at 1800 °C.

Al₂S is produced by heating

• Al₂S₃ with aluminum chips at 1300 °C under vacuum. However, it quickly decomposes into starting materials. Divalent selenium is made similarly.
• Trivalent halides -AlF- -AlCl- and -AlBr- can be obtained in the gas phase when heated with aluminum.

Basic Information

Name: Aluminum
Symbol: Receive
Atomic Number: 13
Atomic Mass: 26.981539 amu
Melting Point: 660.37 °C (933.52 K, 1220.666 °F)
Boiling Point: 2467.0 °C (2740.15 K, 4472.6 °F)
Number of Protons / Electrons: 13
Number of Neutrons: 14
Classification: Other Metals
Crystal Structure: Cubic
Density @ 293 K: 2.702 g / cm ³
Color: Silver
British Spelling: Aluminum
IUPAC Spelling: Aluminum

Atomic structure

Number of Energy Levels: 3 First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 3

 

Isotopes

Isotope	Half life
Al-26	730000.0 years
Al-27	Stable
Al-28	2.3 minutes

Oxidation stage

• The presence of aluminum sub-oxide (AlO) can be demonstrated when aluminum powder is burned with oxygen.

Oxidation stage

• The

 

• • Fajans rule indicates that a simple trivalent cation (Al³⁺) cannot be found in anhydrous salts or binary compounds such as Al₂O₃. Hydroxide is a weak base and aluminum salts that are weak bases such as carbonate cannot be prepared. Strong acid salts such as nitrate are stable and soluble in water. They form hydrates with at least six molecules.
  • Aluminum hydride (AlH₃)_n can be produced using trimethyl-aluminum and excess oxygen. It burns explosively in air. It can also be produced by treating aluminum chloride with lithium hydride in ether solution. However, it cannot be separated from the solvent.
  • Aluminum carbide (Al₄C₃) can be produced by heating the mixture of elements above 1000 °C. Its light yellow crystals have a complex lattice structure and they give methane gas with water or dilute acid. Acetylide (Al₂(C₂)₃) is produced by passing acetylene over heated aluminum.
  • Aluminium nitride (AlN) can be produced from its elements at 800 °C. It hydrolyzes with water to give ammonia and aluminum hydroxide.
  • Aluminum phosphide (AlP) is made similarly and hydrolyzes to yield phosphine.

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• • Aluminum oxide (Al₂O₃) occurs in nature as corundum and is obtained by burning aluminum with oxygen or heating its hydroxide, nitrate or sulfate. As a precious stone, its hardness comes after diamond, boron nitride and carborundum. Almost insoluble in water.
  • Aluminum hydroxide can be obtained as a gelatinous precipitate by adding ammonia to an aqueous solution of an aluminum salt. It is amphoteric; It is both a very weak acid and makes aluminates with alkalis. It exists in different crystal forms.
  • Aluminum sulfide (Al₂S₃) can be produced by passing hydrogen sulfide over aluminum powder. It is polymorphic.
  • Aluminum fluoride (AlF₃) is produced from or elements by treating its hydroxide with HF. It has a giant molecular structure that passes into the gas phase without melting at 1291 °C. It is very inert. Other trivalents are dimeric and bridge-like.

There are organo-metallic compounds with

• empirical formula AlR₃ and they are at least dimeric or trimeric, if not giant molecules. They are used in the field of organic synthesis (for example, trimethyl aluminum).
• Alumino-hydrides are the most electro-positive structures known. The most useful among them is lithium aluminum hydride (Li[AlH₄]). When heated, lithium hydride decomposes into aluminum and hydrogen and hydrolyzes with water. It has many uses in organic chemistry. The alumino-halides also have a similar structure.

Use fields

Since aluminum is a metal that cools easily and absorbs heat, it finds a wide place in the refrigeration industry. It is a metal used in many sectors because it is cheaper and more available than copper, easy to process and soft.

Aluminum is generally used in the production of coolers, spotlights, kitchen utensils, and light-weight vehicles (planes, bicycles, automobile engines, motorcycles, etc.). In addition, aluminum, which is an important material in the industry, is a metal that we always encounter in daily life.

Another usage area of ​​aluminum is asynchronous motors. Pure aluminum (~99.7% Al) is used in the rotor production of asynchronous motors by pressure casting method. Its light weight, cheapness and relatively good electrical conductivity (~59-60% IACS) compared to copper allow aluminum to take a wide place in the induction motor industry.

Aluminum Name

In English-speaking countries, it is common for the name to be spelled and pronounced as both aluminium and aluminum. aluminium is not well known in the USA, and it is mostly aluminum. In other countries outside the USA, the situation is the opposite, and the spelling of aluminium is better known. However, both spelling styles are common in Canada.

In countries other than English, the spelling of “ium” is more common. In both German and French the word is aluminium.

The “International Union of Pure and Applied Chemistry” (IUPAC) organization approved the use of aluminium as a world standard in 1990. However, three years later it endorsed the word aluminum as an acceptable term.

Quote from Mla: <http://www.chemicalelements.com/elements/al.html>.

For More Information Wikipadia

 

 

Aluminium History

 

The ancient Greeks and Romans used the salts of aluminum (æljʊˈmɪniəm) to fix the colors of paints and as a blood stopper. Alum is still used as a blood stopper and vasoconstrictor in today’s medicine.

Although it is known that Friedrich Wöhler was the first person to decompose aluminum by mixing anhydrous aluminum chloride with potassium in 1827, the metal was produced in an impure form by a Danish physicist and chemist, Hans Christian Ørsted, two years ago. Therefore, in the almanacs and chemistry literature, Øersted’s name is mentioned as the person who discovered aluminum. French Henri Saint-Claire Deville, in 1846, Wöhler’s method, developed by using sodium instead of the more expensive potassium.

In 1886, American Charles Martin Hall applied for a patent (patent number: 400655) on the production of aluminum by an electrolytic process, and in the same year, French Paul Héroult developed the same technique in Europe, being completely unaware of Hall’s invention. For this reason, the Hall-Heroult process, named after two scientists, is nowadays used to make aluminumIt is the basic method used all over the world in obtaining each of them.

It was decided to use aluminum in the construction of the summit of the Washington Monument in the USA, and the cost of approximately 30 grams of aluminum at that time was equivalent to twice the daily wage of a worker working on this project.

In the years immediately after Adolf Hitler came to power, Germany became the world leader in aluminum production. However, the commissioning of new hydroelectric power plant projects in the USA (for example, the Grand Coulee Dam) in 1942 gave the USA an advantage that Nazi Germany could not cope with. This superiority has emerged in the form of aluminum production sufficient to make 60,000 warplanes in four years.

 

Aluminum Prices

Today, Aluminum is a precious metal in many respects, and it is in the class of precious metals thanks to its features in its technically rich form and is priced instantly at London Metal Exchange. .

 

How to Calculate Aluminum Prices

The most common calculation method used worldwide to calculate aluminum prices is as follows;

LME (the value in the London Metal Exchange) x Exchange Rate + Labor + Shipping is most commonly calculated and sold.

In addition, other elements such as heat treatment (Thermic), surface polishing process, chemical coloring process and oven paint applied to increase durability according to the quality of the desired product are added to the main price of the product.

Apart from these, paint properties and other mechanical processes (Drilling, Cutting, etc.) to be preferred according to the usage area are also added to the labor cost.