Misplaced Pages

#628371

66-411: The metal floor is usually set up as a rectangular or oval track, and graphite is sprinkled on the floor to decrease friction . A rubber bumper surrounds each vehicle, and drivers either ram or dodge each other as they travel. The controls are usually an accelerator and a steering wheel . The cars can be made to go backwards by turning the steering wheel far enough in either direction, necessary in

132-472: A honeycomb lattice with a bond length of 0.142 nm, and the distance between planes is 0.335 nm. Bonding between layers is relatively weak van der Waals bonds , which allows the graphene-like layers to be easily separated and to glide past each other. Electrical conductivity perpendicular to the layers is consequently about 1000 times lower. There are two allotropic forms called alpha ( hexagonal ) and beta ( rhombohedral ), differing in terms of

198-462: A fluidized bed at 1000–1300 °C then it is isotropic turbostratic, and is used in blood-contacting devices like mechanical heart valves and is called pyrolytic carbon , and is not diamagnetic. Pyrolytic graphite and pyrolytic carbon are often confused but are very different materials. ) For a long time graphite has been considered to be hydrophobic. However, recent studies using highly ordered pyrolytic graphite have shown that freshly clean graphite

264-454: A gear lubricant for mining machinery, and to lubricate locks. Having low-grit graphite, or even better, no-grit graphite (ultra high purity), is highly desirable. It can be used as a dry powder, in water or oil, or as colloidal graphite (a permanent suspension in a liquid). An estimate based on USGS graphite consumption statistics indicates that 2,200 tonnes were used in this fashion in 2005. Metal can also be impregnated into graphite to create

330-523: A growth in demand for graphite in the late 1980s and early 1990s – a growth driven by portable electronics, such as portable CD players and power tools . Laptops , mobile phones , tablets , and smartphone products have increased the demand for batteries. Electric-vehicle batteries are anticipated to increase graphite demand. As an example, a lithium-ion battery in a fully electric Nissan Leaf contains nearly 40 kg of graphite. Radioactive graphite removed from nuclear reactors has been investigated as

396-431: A ladle or red-hot steel ingots and decrease heat loss, or as firestops fitted around a fire door or in sheet metal collars surrounding plastic pipe (during a fire, the graphite expands and chars to resist fire penetration and spread), or to make high-performance gasket material for high-temperature use. After being made into graphite foil, the foil is machined and assembled into the bipolar plates in fuel cells . The foil

462-663: A large scale (1.3   million metric tons per year in 2022) for uses in many critical industries including refractories (50%), lithium-ion batteries (18%), foundries (10%), lubricants (5%), among others (17%). Under extremely high pressures and extremely high temperatures it converts to diamond . Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes. Graphite occurs naturally in ores that can be classified into one of two categories either amorphous (microcrystalline) or crystalline (flake or lump/chip) which

528-646: A processing plant there, and a factory to manufacture pencils, crucibles and other products in New Jersey, described in the Engineering & Mining Journal 21 December 1878. The Dixon pencil is still in production. The beginnings of the revolutionary froth flotation process are associated with graphite mining. Included in the E&;MJ article on the Dixon Crucible Company is a sketch of

594-509: A result of the reduction of sedimentary carbon compounds during metamorphism . It also occurs in igneous rocks and in meteorites . Minerals associated with graphite include quartz , calcite , micas and tourmaline . The principal export sources of mined graphite are in order of tonnage: China , Mexico , Canada , Brazil , and Madagascar . Significant unexploited graphite resources also exists in Colombia 's Cordillera Central in

660-535: A self-lubricating alloy for application in extreme conditions, such as bearings for machines exposed to high or low temperatures. The ability to leave marks on paper and other objects gave graphite its name, given in 1789 by German mineralogist Abraham Gottlob Werner . It stems from γράφειν ("graphein") , meaning to write or draw in Ancient Greek . From the 16th century, all pencils were made with leads of English natural graphite, but modern pencil lead

726-436: A small but significant market for natural graphite. Around 7% of the 1.1 million tonnes produced in 2011 was used to make pencils. Low-quality amorphous graphite is used and sourced mainly from China. In art, graphite is typically used to create detailed and precise drawings, as it allows for a wide range of values (light to dark) to be achieved. It can also be used to create softer, more subtle lines and shading. Graphite

SECTION 10

#1732779683629

792-433: A source of electricity for low-power applications. This waste is rich in carbon-14 , which emits electrons through beta decay , so it could potentially be used as the basis for a betavoltaic device . This concept is known as the diamond battery . Graphite is 'predominant anode material used today in lithium-ion batteries'. EV batteries contain four basic components: anode, cathode, electrolyte, and separator. While there

858-593: A way as to produce a mixture of crystalline and amorphous regions. In such cases, crystallinity is usually specified as a percentage of the volume of the material that is crystalline. Even within materials that are completely crystalline, however, the degree of structural perfection can vary. For instance, most metallic alloys are crystalline, but they usually comprise many independent crystalline regions (grains or crystallites ) in various orientations separated by grain boundaries ; furthermore, they contain other crystallographic defects (notably dislocations ) that reduce

924-630: Is a commercial product proposal for reducing the carbon footprint of lithium iron phosphate (LFP) batteries . It is produced from forestry waste and similar byproducts by a company in New Zealand using a novel process called thermo-catalytic graphitisation which project is supported by grants from interested parties including a forestry company in Finland and a battery maker in Hong Kong Graphite occurs in metamorphic rocks as

990-738: Is added to increase the carbon content of the steel to a specified level. An estimate based on USGS 's graphite consumption statistics indicates that steelmakers in the US used 10,500 tonnes in this fashion in 2005. Natural amorphous and fine flake graphite are used in brake linings or brake shoes for heavier (nonautomotive) vehicles, and became important with the need to substitute for asbestos . This use has been important for quite some time, but nonasbestos organic (NAO) compositions are beginning to reduce graphite's market share. A brake-lining industry shake-out with some plant closures has not been beneficial, nor has an indifferent automotive market. According to

1056-627: Is an electrical conductor , hence useful in such applications as arc lamp electrodes . It can conduct electricity due to the vast electron delocalization within the carbon layers (a phenomenon called aromaticity ). These valence electrons are free to move, so are able to conduct electricity. However, the electricity is primarily conducted within the plane of the layers. The conductive properties of powdered graphite allow its use as pressure sensor in carbon microphones . Graphite and graphite powder are valued in industrial applications for their self-lubricating and dry lubricating properties. However,

1122-439: Is determined by the ore morphology , crystallinity , and grain size . All naturally occurring graphite deposits are formed from the metamorphism of carbonaceous sedimentary rocks , and the ore type is due to its geologic setting. Coal that has been thermally metamorphosed is the typical source of amorphous graphite. Crystalline flake graphite is mined from carbonaceous metamorphic rocks , while lump or chip graphite

1188-428: Is hydrophilic ( contact angle of 70° approximately), and it becomes hydrophobic (contact angle of 95° approximately) due to airborne pollutants (hydrocarbons) present in the atmosphere. Those contaminants also alter the electric equipotential surface of graphite by creating domains with potential differences of up to 200 mV as measured with kelvin probe force microscopy . Such contaminants can be desorbed by increasing

1254-512: Is made into heat sinks for laptop computers which keeps them cool while saving weight, and is made into a foil laminate that can be used in valve packings or made into gaskets. Old-style packings are now a minor member of this grouping: fine flake graphite in oils or greases for uses requiring heat resistance. A GAN estimate of current US natural graphite consumption in this end-use is 7,500 tonnes. Graphite forms intercalation compounds with some metals and small molecules. In these compounds,

1320-556: Is made using electric arc furnaces, and the electric arc furnace itself is becoming more efficient, making more steel per tonne of electrode. An estimate based on USGS data indicates that graphite electrode consumption was 197,000 t (217,000 short tons) in 2005. Electrolytic aluminium smelting also uses graphitic carbon electrodes. On a much smaller scale, synthetic graphite electrodes are used in electrical discharge machining (EDM), commonly to make injection molds for plastics . Crystallinity Crystallinity refers to

1386-487: Is mined from veins which occur in high-grade metamorphic regions. There are serious negative environmental impacts to graphite mining. Synthetic graphite is graphite of high purity produced by thermal graphitization at temperatures in excess of 2,100 °C from hydrocarbon materials most commonly by a process known as the Acheson process . The high temperatures are maintained for weeks, and are required not only to form

SECTION 20

#1732779683629

1452-488: Is most commonly a mix of powdered graphite and clay; it was invented by Nicolas-Jacques Conté in 1795. It is chemically unrelated to the metal lead , whose ores had a similar appearance, hence the continuation of the name. Plumbago is another older term for natural graphite used for drawing , typically as a lump of the mineral without a wood casing. The term plumbago drawing is normally restricted to 17th and 18th-century works, mostly portraits. Today, pencils are still

1518-481: Is much focus on the cathode materials – lithium, nickel, cobalt, manganese, etc. – the predominant anode material used in virtually all EV batteries is graphite. Natural graphite in steelmaking mostly goes into raising the carbon content in molten steel; it can also serve to lubricate the dies used to extrude hot steel. Carbon additives face competitive pricing from alternatives such as synthetic graphite powder, petroleum coke, and other forms of carbon. A carbon raiser

1584-448: Is now a minor part of refractories . In the mid-1980s, the carbon- magnesite brick became important, and a bit later the alumina-graphite shape. As of 2017 the order of importance is: alumina-graphite shapes, carbon-magnesite brick, Monolithics (gunning and ramming mixes), and then crucibles. Crucibles began using very large flake graphite, and carbon-magnesite bricks requiring not quite so large flake graphite; for these and others there

1650-452: Is now much more flexibility in the size of flake required, and amorphous graphite is no longer restricted to low-end refractories. Alumina-graphite shapes are used as continuous casting ware, such as nozzles and troughs, to convey the molten steel from ladle to mold, and carbon magnesite bricks line steel converters and electric-arc furnaces to withstand extreme temperatures. Graphite blocks are also used in parts of blast furnace linings where

1716-438: Is popular among artists because it is easy to control, easy to erase, and produces a clean, professional look. It is also relatively inexpensive and widely available. Many artists use graphite in conjunction with other media, such as charcoal or ink, to create a range of effects and textures in their work. Graphite of various hardness or softness results in different qualities and tones when used as an artistic medium . Graphite

1782-404: Is probably the most-used lubricant in pinewood derbies . Natural graphite has found uses in zinc-carbon batteries , electric motor brushes, and various specialized applications. Railroads would often mix powdered graphite with waste oil or linseed oil to create a heat-resistant protective coating for the exposed portions of a steam locomotive's boiler, such as the smokebox or lower part of

1848-621: Is used on Quantum -class cruise ships , where bumper cars run on electric batteries . This avoids the conductive floor/ceiling of the traditional bumper car setup, allowing the SeaPlex venue to be convertible from a bumper-car ride to a multipurpose gym (basketball court). The disadvantage is that these ships' bumper cars take several hours to recharge. Although the idea of the ride is to bump other cars, safety-conscious (or at least litigation -conscious) owners sometimes put up signs reading "This way around" and "No (head on) bumping". Depending on

1914-464: Is what makes it the dominant anode material in lithium-ion batteries. In 1893, Charles Street of Le Carbone discovered a process for making artificial graphite. In the mid-1890s, Edward Goodrich Acheson (1856–1931) accidentally invented another way to produce synthetic graphite after synthesizing carborundum (also called silicon carbide). He discovered that overheating carborundum, as opposed to pure carbon, produced almost pure graphite. While studying

1980-527: The USGS , US natural graphite consumption in brake linings was 6,510 tonnes in 2005. A foundry-facing mold wash is a water-based paint of amorphous or fine flake graphite. Painting the inside of a mold with it and letting it dry leaves a fine graphite coat that will ease the separation of the object cast after the hot metal has cooled. Graphite lubricants are specialty items for use at very high or very low temperatures, as forging die lubricant, an antiseize agent,

2046-415: The firebox . The Scope soldering iron uses a graphite tip as its heating element. Expanded graphite is made by immersing natural flake graphite in a bath of chromic acid , then concentrated sulfuric acid , which forces the crystal lattice planes apart, thus expanding the graphite. The expanded graphite can be used to make graphite foil or used directly as a "hot top" compound to insulate molten metal in

Bumper cars - Misplaced Pages Continue

2112-414: The "floating tanks" used in the age-old process of extracting graphite. Because graphite is so light, the mix of graphite and waste was sent through a final series of water tanks where a cleaner graphite "floated" off, which left waste to drop out. In an 1877 patent, the two brothers Bessel (Adolph and August) of Dresden, Germany, took this "floating" process a step further and added a small amount of oil to

2178-517: The 100th anniversary of flotation. In the United States, in 1885, Hezekiah Bradford of Philadelphia patented a similar process, but it is uncertain if his process was used successfully in the nearby graphite deposits of Chester County, Pennsylvania, a major producer by the 1890s. The Bessel process was limited in use, primarily because of the abundant cleaner deposits found around the globe, which needed not much more than hand-sorting to gather

2244-546: The English navy. This particular deposit of graphite was extremely pure and soft, and could easily be cut into sticks. Because of its military importance, this unique mine and its production were strictly controlled by the Crown. During the 19th century, graphite's uses greatly expanded to include stove polish, lubricants, paints, crucibles, foundry facings, and pencils , a major factor in the expansion of educational tools during

2310-531: The English term for this grey metallic-sheened mineral and even to the leadworts or plumbagos , plants with flowers that resemble this colour. The term black lead usually refers to a powdered or processed graphite, matte black in color. Abraham Gottlob Werner coined the name graphite ("writing stone") in 1789. He attempted to clear up the confusion between molybdena, plumbago and black lead after Carl Wilhelm Scheele in 1778 proved that these were at least three different minerals. Scheele's analysis showed that

2376-532: The Rue Le Dodge (renamed Rue Le Morgue during Fright Fest in the fall), it is 51 feet 9 inches (15.77 m) by 124 feet 9 inches (38.02 m) or a total of 6,455 square feet (599.7 m). A replica of the ride was built at California's Great America in Santa Clara ; in 2005, however, a concrete island was added to the middle of the floor to promote one-way traffic , reducing

2442-546: The above refractories are used to make steel and account for 75% of refractory consumption; the rest is used by a variety of industries, such as cement. According to the USGS , US natural graphite consumption in refractories comprised 12,500 tonnes in 2010. The use of graphite in batteries has increased since the 1970s. Natural and synthetic graphite are used as an anode material to construct electrodes in major battery technologies. The demand for batteries, primarily nickel–metal hydride and lithium-ion batteries , caused

2508-406: The beta form reverts to the alpha form when it is heated to 1300 °C for four hours. The equilibrium pressure and temperature conditions for a transition between graphite and diamond is well established theoretically and experimentally. The pressure changes linearly between 1.7  GPa at 0 K and 12 GPa at 5000 K (the diamond/graphite/liquid triple point ). However,

2574-434: The chemical compounds molybdenum sulfide ( molybdenite ), lead(II) sulfide ( galena ) and graphite were three different soft black minerals. Natural graphite is mostly used for refractories, batteries, steelmaking, expanded graphite, brake linings, foundry facings, and lubricants. The use of graphite as a refractory (heat-resistant) material began before 1900 with graphite crucibles used to hold molten metal; this

2640-602: The degree of structural order in a solid . In a crystal , the atoms or molecules are arranged in a regular, periodic manner. The degree of crystallinity has a large influence on hardness , density , transparency and diffusion . In an ideal gas , the relative positions of the atoms or molecules are completely random. Amorphous materials, such as liquids and glasses , represent an intermediate case, having order over short distances (a few atomic or molecular spacings) but not over longer distances. Many materials, such as glass-ceramics and some polymers , can be prepared in such

2706-462: The effects of high temperature on carborundum, he had found that silicon vaporizes at about 4,150 °C (7,500 °F), leaving the carbon behind in graphitic carbon. This graphite became valuable as a lubricant. Acheson's technique for producing silicon carbide and graphite is named the Acheson process . In 1896, Acheson received a patent for his method of synthesizing graphite, and in 1897 started commercial production. The Acheson Graphite Co.

Bumper cars - Misplaced Pages Continue

2772-480: The ejecta when supernovae exploded or low to intermediate-sized stars expelled their outer envelopes late in their lives. Graphite may be the second or third oldest mineral in the Universe. Graphite consists of sheets of trigonal planar carbon. The individual layers are called graphene . In each layer, each carbon atom is bonded to three other atoms forming a continuous layer of sp bonded carbon hexagons, like

2838-613: The equilibrium line: at 2000 K , a pressure of 35 GPa is needed. The acoustic and thermal properties of graphite are highly anisotropic , since phonons propagate quickly along the tightly bound planes, but are slower to travel from one plane to another. Graphite's high thermal stability and electrical and thermal conductivity facilitate its widespread use as electrodes and refractories in high temperature material processing applications. However, in oxygen-containing atmospheres graphite readily oxidizes to form carbon dioxide at temperatures of 700 °C and above. Graphite

2904-490: The first great rise of education for the masses. The British Empire controlled most of the world's production (especially from Ceylon), but production from Austrian, German, and American deposits expanded by mid-century. For example, the Dixon Crucible Company of Jersey City, New Jersey, founded by Joseph Dixon and partner Orestes Cleveland in 1845, opened mines in the Lake Ticonderoga district of New York, built

2970-492: The floor area. Six Flags Great Adventure 's Autobahn is the largest bumper car floor, but it has not operated since 2008. Graphite Graphite ( / ˈ ɡ r æ f aɪ t / ) is a crystalline allotrope (form) of the element carbon . It consists of many stacked layers of graphene , typically in the excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under standard conditions . Synthetic and natural graphite are consumed on

3036-408: The floor separated by insulating spacers, and no ceiling grid. The strips carry the supply current, and the cars are large enough so that the vehicle covers at least two strips at all times. An array of brushes under each car makes random contact with the strips, and the voltage polarity on each contact is arranged to always provide a correct and complete circuit to operate the vehicle. A third method

3102-598: The form of graphite-bearing schists . In meteorites , graphite occurs with troilite and silicate minerals . Small graphitic crystals in meteoritic iron are called cliftonite . Some microscopic grains have distinctive isotopic compositions, indicating that they were formed before the Solar System . They are one of about 12 known types of minerals that predate the Solar System and have also been detected in molecular clouds . These minerals were formed in

3168-581: The frequent pile-ups that occur. The cars are commonly powered by one of three methods. The oldest and most common method, the Over Head System (OHS), uses a conductive floor and ceiling with opposing power polarities. Contacts under the vehicle touch the floor while a pole -mounted contact shoe touches the ceiling, forming a complete circuit . A newer method, the Floor Pick-Up (FPU) system, uses alternating strips of metal across

3234-800: The graphite from the precursor carbons but to also vaporize any impurities that may be present, including hydrogen, nitrogen, sulfur, organics, and metals. This is why synthetic graphite is highly pure in excess of 99.9% C purity, but typically has lower density, conductivity and a higher porosity than its natural equivalent. Synthetic graphite can also be formed into very large flakes (cm) while maintaining its high purity unlike almost all sources of natural graphite. Synthetic graphite has also been known to be formed by other methods including by chemical vapor deposition from hydrocarbons at temperatures above 2,500 K (2,230 °C), by decomposition of thermally unstable carbides or by crystallizing from metal melts supersaturated with carbon . Biographite

3300-460: The high thermal conductivity of the graphite is critical to ensuring adequate cooling of the bottom and hearth of the furnace. High-purity monolithics are often used as a continuous furnace lining instead of carbon-magnesite bricks. The US and European refractories industry had a crisis in 2000–2003, with an indifferent market for steel and a declining refractory consumption per tonne of steel underlying firm buyouts and many plant closures. Many of

3366-612: The host molecule or atom gets "sandwiched" between the graphite layers, resulting in a type of compound with variable stoichiometry. A prominent example of an intercalation compound is potassium graphite, denoted by the formula KC 8 . Some graphite intercalation compounds are superconductors . The highest transition temperature (by June 2009) T c = 11.5 K is achieved in CaC 6 , and it further increases under applied pressure (15.1 K at 8 GPa). Graphite's ability to intercalate lithium ions without significant damage from swelling

SECTION 50

#1732779683629

3432-568: The late 1920s to 1950s, two major US bumper cars brands were Dodgem by the Stoehrer and the Lusse Brothers' Auto-Skooter by Joseph and Robert 'Ray' Lusse. Lusse Brothers built the first fiberglass body in 1959, in part due to the survival of Chevrolet Corvette bodies over the previous six years. After getting permission from Chevrolet, then subsequently buying the actual Corvette chevrons from local Philadelphia dealers, those were attached to

3498-424: The level of enforcement by operators, these rules are often ignored by bumper car riders, especially younger children and teenagers. In the early 1920s, a patent was granted to Max Stoehrer and his son Harold for an "Amusement Apparatus" which became the basis for their Dodgem cars. They deliberately equipped their device with "novel instrumentalities to render their manipulation and control difficult and uncertain by

3564-464: The nose of their product for 1959. In the mid-1960s, Disneyland introduced hovercraft -based bumper cars called Flying Saucers , which worked on the same principle as an air hockey game; however, the ride was a mechanical failure and closed after a few years. The largest operating bumper car floor currently operating in the United States is at Six Flags Great America in Gurnee , Illinois . Called

3630-423: The occupant-operator.” They asserted that “in the hands of an unskilled operator," a "plurality of independently manipulated... cars" would “follow a promiscuous, irregular, and undefined path over the floor or other area, to not only produce various sensations during the travel of the vehicle but to collide with other cars as well as with portions of the platform provided for that purpose." During their heyday, from

3696-457: The phases have a wide region about this line where they can coexist. At normal temperature and pressure , 20 °C (293 K) and 1 standard atmosphere (0.10 MPa), the stable phase of carbon is graphite, but diamond is metastable and its rate of conversion to graphite is negligible. However, at temperatures above about 4500 K , diamond rapidly converts to graphite. Rapid conversion of graphite to diamond requires pressures well above

3762-408: The plant closures resulted from the acquisition of Harbison-Walker Refractories by RHI AG and some plants had their equipment auctioned off. Since much of the lost capacity was for carbon-magnesite brick, graphite consumption within the refractories area moved towards alumina-graphite shapes and Monolithics, and away from the brick. The major source of carbon-magnesite brick is now China. Almost all of

3828-575: The pure graphite. The state of the art, c.  1900 , is described in the Canadian Department of Mines report on graphite mines and mining when Canadian deposits began to become important producers of graphite. Historically, graphite was called black lead or plumbago . Plumbago was commonly used in its massive mineral form. Both of these names arise from confusion with the similar-appearing lead ores, particularly galena . The Latin word for lead, plumbum , gave its name to

3894-405: The same molecular structure as graphite. It is sometimes called white graphite , due to its similar properties. When a large number of crystallographic defects bind these planes together, graphite loses its lubrication properties and becomes what is known as pyrolytic graphite . It is also highly anisotropic, and diamagnetic , thus it will float in mid-air above a strong magnet. (If it is made in

3960-405: The stacking of the graphene layers: stacking in alpha graphite is ABA, as opposed to ABC stacking in the energetically less stable beta graphite. Rhombohedral graphite cannot occur in pure form. Natural graphite, or commercial natural graphite, contains 5 to 15% rhombohedral graphite and this may be due to intensive milling. The alpha form can be converted to the beta form through shear forces, and

4026-592: The tanks and boiled the mix – an agitation or frothing step – to collect the graphite, the first steps toward the future flotation process. Adolph Bessel received the Wohler Medal for the patented process that upgraded the recovery of graphite to 90% from the German deposit. In 1977, the German Society of Mining Engineers and Metallurgists organized a special symposium dedicated to their discovery and, thus,

SECTION 60

#1732779683629

4092-600: The temperature of graphite to approximately 50 °C or higher. Natural and crystalline graphites are not often used in pure form as structural materials, due to their shear-planes, brittleness, and inconsistent mechanical properties. In the 4th millennium BCE , during the Neolithic Age in southeastern Europe, the Marița culture used graphite in a ceramic paint for decorating pottery . Sometime before 1565 (some sources say as early as 1500), an enormous deposit of graphite

4158-632: The use of graphite is limited by its tendency to facilitate pitting corrosion in some stainless steel , and to promote galvanic corrosion between dissimilar metals (due to its electrical conductivity). It is also corrosive to aluminium in the presence of moisture. For this reason, the US Air Force banned its use as a lubricant in aluminium aircraft, and discouraged its use in aluminium-containing automatic weapons. Even graphite pencil marks on aluminium parts may facilitate corrosion. Another high-temperature lubricant, hexagonal boron nitride , has

4224-484: The vast majority of steel furnaces . They are made from petroleum coke after it is mixed with coal tar pitch . They are extruded and shaped, then baked to carbonize the binder (pitch). This is finally graphitized by heating it to temperatures approaching 3,000 °C (5,430 °F), at which the carbon atoms arrange into graphite. They can vary in size up to 3.5 m (11 ft) long and 75 cm (30 in) in diameter. An increasing proportion of global steel

4290-466: Was discovered on the approach to Grey Knotts from the hamlet of Seathwaite in Borrowdale parish , Cumbria , England , which the locals found useful for marking sheep. During the reign of Elizabeth I (1558–1603), Borrowdale graphite was used as a refractory material to line molds for cannonballs, resulting in rounder, smoother balls that could be fired farther, contributing to the strength of

4356-488: Was formed in 1899. Synthetic graphite can also be prepared from polyimide and then commercialized. Highly oriented pyrolytic graphite (HOPG) is the highest-quality synthetic form of graphite. It is used in scientific research, in particular, as a length standard for the calibration of scanning probe microscopes . Graphite electrodes carry the electricity that melts scrap iron and steel, and sometimes direct-reduced iron (DRI), in electric arc furnaces , which are

#628371