University of BaghdadAL-Kwarizmi collage of engineering Automated Manufacturing Engineering Dept.

Silver

Dr. Hamed S. Mahdi

Students : Ghadak M. Abbas Third Stage 2014 – 2015

- Silver was discovered 3000 BC . Found in nature in several forms, including pure metal in Norway and Canada and in the form of silver chloride as in Mexico and Canada, there is usually mixed with other metals such as gold, copper and lead.

- And are extraction and purification of silver from ores in several ways process where crushed first, and then smelted productive mixture containing the basic metal, a copper, lead and small amounts of silver in the process of copper purification separate silver from copper to be a mixture called sludge then lifted sludge treated with nitric acid to dissolve silver and then relive the way silver electrode deposition

• Chemical Name – Silver• Chemical Symbol - Ag• Atomic Number - 47• Chemical Series – Transition Metal• Group 11, Period 5, Block D• Appearance – lustrous white metal• Silver is a little harder than gold and is very ductile (can be pulled out into wires) and malleable (can be beaten into sheets), being exceeded only by gold and perhaps palladium

General Properties

Silver ColorSolid Phase

10.49  g·cm−3 Density  9.320  g·cm−3 Liquid Density  

961.78 °C Melting Point 2162 °C Boiling Point

11.28 kJ·mol-1 Heat of fusion 250.58 kJ·mol-1 Heat of vaporization

(25 °C )25.350  J·mol−1·K−1  Heat capacity

Physical Properties

- Silver Is a chemicalelement .- Crystal Structure – fcc . possesses the highest electrical conductivity of any element.- the highest thermal conductivity and reflectivity of any metal.- While silver has long been valued as a precious metal it is also used in currency coins, solar panels, water filtration, jewelry and ornaments, high-value tableware and utensils and as an investment in the forms of coins and bullion. - Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings and in catalysis of chemical reactions.

Applications

Many well-known uses of silver involves its preciousmetal properties, including currency, decorative items, and mirrors. The contrast between its bright white color and other media makes it very useful to the visual arts. By contrast, fine silver particles form the dense black in photographs and in silverpoint drawings. It has also long been used to confer high monetary value as objects (such as silver coins and investment bars) or make objects symbolic of high social or political rank. Silver salts have been used since the Middle Ages to produce a yellow or orange colors to stained glass, and more complex decorative color reactions can be produced by incorporating silver metals in blown .

Currency Silver, in the form of electrum (a gold–silver alloy), was coined to produce money around 700 BC by the Lydians. Later, silver was refined and coined in its pure form. Many nations used silver as the basic unit of monetary value. In the modern world.

Solar energy Solar modules mounted on solar trackers About 20g of silver is used in every crystalline solar photovoltaic panel made Silver is also used in plasmonic solar cells.100 million ounces of silver are projected for use by solar energy in 2015.Silver is the reflective coating of choice for concentrated solar power reflectors. In 2009, scientists at the National Renewable Energy Laboratory (NREL) and Sky Fuelteamed to develop large curved sheets of metal that have the potential to be 30% less expensive than today's best collectors of concentrated solar power by replacing glass-based models with a silver polymer sheet that has the same performance as the heavy glass mirrors, but at much lower cost and weight. It also is much easier to deploy and install. The glossy film uses several layers of polymers, with an inner layer of pure silver.

JewelryJewelry and silverware are traditionally made from sterling silver (standard silver), an alloy of 92.5% silver with 7.5% copper. In the US, only an alloy consisting of at least 90.0% fine silver can be marketed as "silver" (thus frequently stamped 900). Sterling silver (stamped 925) is harder than pure silver, and has a lower melting point (893 °C) than either pure silver or pure copper.

Water purificationSilver is used in water purifiers. It prevents bacteria and algae from building up in filters. The catalytic action of silver, in concert with oxygen, sanitizes water and eliminates the need for chlorine. Silver ions are also added to water purification systems in hospitals, community water systems, pools and spas, displacing chlorine.

DentistrySilver can be alloyed with mercury at room temperature to make amalgams that are widely used for dental fillings. To make dental amalgam, a mixture of powdered silver and other metals such as tin and gold is mixed with mercury to make a stiff paste that can be adapted to the shape of a cavity. The dental amalgam achieves initial hardness within minutes, and sets hard in a few hours.

Photography and electronics The use of silver in photography, in the form of silver nitrate and silver halides, has rapidly declined due to the lower demand for consumer color film from the advent of digital technology. From the peak global demand for photographic silver in 1999 (267,000,000 troy ounces or 8304.6 metric tonnes) the market had contracted almost 70% by 2013.Some electrical and electronic products use silver for its superior conductivity, even when tarnished. The primary example of this is in high quality RF connectors. The increase in conductivity is also taken advantage of in RF engineering at VHF and higher frequencies, where conductors often cannot be scaled by 6%, due to tuning requirements, e.g. cavity filters. As an additional example, printed circuits and RFID antennas can be made using silver paints,and computer keyboards use silver electrical contacts.

WindowsUsing a process called sputtering, silver, along with other optically transparent layers, is applied to glass, creating low emissivity coatings used in high-performance insulated glazing. The amount of silver used per window is small because the silver layer is only 10–15 nanometers thick. However, the amount of silver-coated glass worldwide is hundreds of millions of square meters per year, leading to silver consumption on the order of 10 cubic meters or 100 metric tons/year. Silver color seen in architectural glass and tinted windows on vehicles is produced by sputtered chrome, stainless steel or other alloys.Silver-coated polyester sheets, used to retrofit windows, are another popular method for reducing light transmission.

And it can be use also in : - Air conditioning - producing chemical elements : (Ethylene, Formaldehyde) - in engines or in machines ( reduce friction because of it`s capability to take O2 - in rewards : ( silver medal ) - in other sttuff

Colloidal Silver Dressing

Medical Uses of Silver

X – ray

Urinary catheters Endotracheal tubes

Silver Alloys

Argentium sterling silver Argentium silver is a modern sterling silver alloy which modifies the traditional alloy (92.5% silver + 7.5% copper) by replacing some of the copper with the metalloid germanium. As it contains at least 92.5% silver content of the traditional alloy . • High tarnish resistance .• Precipitation hardening and simple heat-hardening properties .• Increased ductility .• Increased thermal and electrical resistance (making alloys suitable for welding and laser forming) .• Environmental advantages (associated with not having to remove or plate over firescale) .

Billon (alloy) Billon is an alloy of a precious metal (most commonly silver, but also mercury) with a majority base metal content (such as copper). It is used chiefly for making coins, medals, and token coins. The use of billon coins dates from ancient Greece and continued through the Middle Ages. Billon coins are perhaps best known from the Roman Empire, where progressive debasements of the Roman denarius .

Britannia silver Britannia silver is an alloy of silver containing 95.83% by weight silver, the balance being usually copper. This standard was introduced in England by Act of Parliament in 1697 to replace sterling silver (92.5% silver) . Britannia standard silver was introduced as part of the great recoinage scheme of William III from 1696 . Britannia silver is considerably softer than sterling .

ElectrumElectrum is a naturally occurring alloy of gold and silver, with trace

amounts of copper and other metals. It has also been produced artificially, and is often known as green gold. The ancient Greeks

called it ` gold` or `white gold . ` Its colour rang from pale to bright

yellow. Electrum was used for the earliest metal coins, and as early as the third millennium BC in  Old Kingdom Egypt .

Goloid Goloid is an alloy of silver, gold and copper patented by Dr. William Wheeler Hubbell on May 22, 1877 . The patent specifies 1 part gold (about 3.6%) , 24 parts silver (about 87.3%) , and 2.5 parts copper (about 9.1%, all by weight) .. The alloy was used by the United States Mint to strike pattern dollars, sometimes called “ metric dollars“ . In the end, goloid was rejected as a coinage metal because it could not be distinguished from the normal U.S. 90% silver coin alloy without chemical analysis, thus inviting counterfeiters to use silver-copper alloys alone to make lower-value copies.

Shibuichi Shibuichi ( 四分一 ) is an alloy which can be patinated into a range of

subtle muted shades of blue or green, through the use of rokushō treatments. Its

name means "one-fourth" in Japanese and indicates the standard formulation of one part silver ( 5% silver)  to three parts copper (95%

copper( .

Sterling silver Sterling silver is an alloy of silver containing 92.5% by mass of silver

and 7.5% by mass of other metals, usually copper. Fine silver, for example 99.9% pure silver, is generally too soft for producing functional objects ; therefore, the silver is usually alloyed with copper to give it strength while preserving the ductility and appearance of the precious metal. These replacement metals include germanium, zinc and  platinum, as well as a variety of other additives, including silicon  and boron .

Tibetan silver Tibetan silver is used primarily in jewelry components, an

alloy of copper, and sometimes tin or nickel, with a small percentage of pure silver. Its overall appearance is of aged

silver, but it can be polished to provide highlights on complex castings.

http://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/List_of_alloys#Alloys_of_silver

Resources

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