What is the difference between alloys and ores

The alloys of the other three metals were developed more recently; due to their chemical reactivity, they require electrolytic extraction processes.

The alloys of aluminium, titanium, and magnesium are valued for their high strength-to-weight ratios, and magnesium can also provide electromagnetic shielding. These materials are ideal for situations where high strength-to-weight ratio is more important than material cost, such as in aerospace and some automotive applications.

Alloys specially designed for highly demanding applications, such as jet engines, may contain more than ten elements. Metals are often extracted from the Earth by means of mining, resulting in ores that are relatively rich sources of the requisite elements. Ore is located by prospecting techniques, followed by the exploration and examination of deposits. Mineral sources are generally divided into surface mines, which are mined by excavation using heavy equipment, and subsurface mines.

Mining : Chuquicamata, Chile, is the site of the largest circumference and second deepest open pit copper mine in the world. After the ore is mined, the metals must be extracted, usually by chemical or electrolytic reduction.

Pyrometallurgy uses high temperatures to convert ore into raw metals, while hydrometallurgy employs aqueous chemistry for the same purpose. The methods used depend on the metal and their contaminants. When a metal ore is an ionic compound of that metal and a non-metal, the ore must usually be smelted or heated with a reducing agent to extract the pure metal.

Many common metals, such as iron, are smelted using carbon as a reducing agent. Some metals, such as aluminium and sodium, have no commercially practical reducing agent, and are extracted using electrolysis instead. Sulfide ores are not reduced directly to the metal, but are roasted in air to convert them to oxides. A metal can refer to an element, compound, or alloy that is a good conductor of both electricity and heat.

Example metals include gold, sodium, copper, iron, and many other elements. Metals are usually malleable, ductile, and shiny. Metals typically consist of close-packed atoms, meaning that the atoms are arranged like closely packed spheres. In a metal, atoms readily lose electrons to form positive ions cations. Those ions are surrounded by de-localized electrons, which are responsible for the conductivity.

The solid produced is held together by electrostatic interactions between the ions and the electron cloud, which are called metallic bonds.

Metals are shiny and lustrous with a high density. They have very high melting and boiling points because metallic bonding is very strong, so the atoms are reluctant to break apart into a liquid or gas. Sodium Metal : Sodium metal is soft enough to be cut with a plastic knife. Metals in general are conductive, with high electrical conductivity and high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving.

The electrical and thermal conductivities of metals originate from the fact that their outer electrons are delocalized. This means the electrons are not locked into any one atom but can move freely throughout the metal. Metals can be viewed as a collection of atoms embedded in a sea of electrons, which are highly mobile. Most of the alloys are made artificially. However, some metals like electrum alloy of gold and silver occurs naturally. Purpose of extracting ore is for profit making whereas,alloy extraction deals with quality making.

Difference between Alloy and Ore. Key Difference: An alloy is a metallic substance made by combination of metal with other types of elements. It is generally done in order to enhance properties like strength, ductility, corrosion resistance, etc. An ore is a natural source of mineral from which metals are extracted in order to gain profits. Comparison between Alloy and Ore: Alloy Ore Definition A homogeneous mixture of a metal with other types of elements An ore is a naturally occurring source of mineral from which metals are extracted economically Example Brass copper and zinc and Bronze copper and tin Galena lead ore and bauxite Aluminium Types Substitutional Alloy — some of the main metal atoms are substituted by other metal atoms of same size Interstitial Alloy — some of the holes in the closed packed metal structure are occupied by small atoms Simple Ores yielding a single metal Complex ores yielding more than one metal Naturally occurring Most of the alloys are made artificially.

Stainless Steel alloys are used in various commercial applications like cutlery, making tubes, etc. Titanium alloys are known for their toughness and therefore are made for construction of aerospace structures Ores remain of great importance as they are source of many valuable minerals Copper, gold and iron ore provides these metals which are very important in most of the industry sector Metals which are extracted from ores are used in various applications according to the characteristics possessed by them.

For example, Aluminium derived from a bauxite ore is used in the production of containers, cosmetics and medicines. Category Homogeneous mixture Usually heterogeneous. Image Courtesy: msc-ks4technology. Comments Purpose of extracting ore is for profit making whereas,alloy extraction deals with quality making.

Impurities in the iron from the Blast Furnace include carbon, sulfur, phosphorus and silicon, which have to be removed. C ast iron has already been mentioned above. This section deals with the types of iron and steel which are produced as a result of the steel-making process.

Aluminum is too high in the electrochemical series reactivity series to extract it from its ore using carbon reduction. The temperatures needed are too high to be economic. Instead, it is extracted by electrolysis. The ore is first converted into pure aluminum oxide by the Bayer Process, and this is then electrolyzed in solution in molten cryolite - another aluminum compound.

The aluminum oxide has too high a melting point to electrolyse on its own. The usual aluminum ore is bauxite. Bauxite is essentially an impure aluminum oxide. The major impurities include iron oxides, silicon dioxide and titanium dioxide. Crushed bauxite is treated with moderately concentrated sodium hydroxide solution.

The concentration, temperature and pressure used depend on the source of the bauxite and exactly what form of aluminum oxide it contains. With hot concentrated sodium hydroxide solution, aluminum oxide reacts to give a solution of sodium tetrahydroxoaluminate. The sodium tetrahydroxoaluminate solution is cooled, and "seeded" with some previously produced aluminum hydroxide. This provides something for the new aluminum hydroxide to precipitate around. The aluminum oxide is electrolyzed in solution in molten cryolite, Na 3 AlF 6.

Cryolite is another aluminum ore, but is rare and expensive, and most is now made chemically. Aluminum is usually alloyed with other elements such as silicon, copper or magnesium. Pure aluminum isn't very strong, and alloying it adds to it strength. Aluminum is especially useful because it. Anodizing essentially involves etching the aluminum with sodium hydroxide solution to remove the existing oxide layer, and then making the aluminum article the anode in an electrolysis of dilute sulfuric acid.

The oxygen given of at the anode reacts with the aluminum surface, to build up a film of oxide up to about 0. As well as increasing the corrosion resistance of the aluminum, this film is porous at this stage and will also take up dyes.

It is further treated to make it completely non-porous afterwards. That means that you can make aluminum articles with the colour built into the surface.

Aluminum is an infinitely recyclable material, and it takes up to 95 percent less energy to recycle it than to produce primary aluminum, which also limits emissions, including greenhouse gases.

Today, about 75 percent of all aluminum produced in history, nearly a billion tons, is still in use. The recycling of aluminum generally produces significant cost savings over the production of new aluminum, even when the cost of collection, separation and recycling are taken into account. The impact of steel and aluminum production on the environment can be traced back from the mining of the ores to the production of the final commercial products i.

The main sources of emissions during the different phases of manufacture include the products of combustion such as nitrous oxide, carbon dioxide, carbon monoxide, and sulfur dioxide and fugitive dust from the operation of equipment. The effect of the different emissions on air quality i. Sulfuric acid is created when water and oxygen interact with sulfur bearing minerals and chemicals in rocks. Many metals become mobile as water becomes more acidic and at high concentrations these metals become toxic to most life forms.

There is also production of enormous amounts of wastewater contaminants, hazardous wastes, and solid wastes. Learning Objectives Identify important metals and describe their extraction from their main ores. List different metals, their uses, and their alloys.