Encyclopedia of Global Resources part 17 pptx

the group. There is only one naturally occurring iso - tope, so the atomic weight of bismuth, 208.980, is known very precisely. The element is brittle and white in appearance, with a pink tinge. It occurs in a variety of crystalline structures. The metal has a high resistiv- ity and melts at 271.4° Celsius with a boiling point of 1,564° Celsius. Bismuth is unusual in that its volume expands by about3 percentwhen it solidifiesfrom the liquid. The solid has a density of 9.9 grams per cubic centimeter. Description, Distribution, and Forms With a rarity akin to that of silver, bismuth is a rela- tively minor component of the Earth’s crust. It pos- sesses some unique credentials: For example, all ele- ments with an atomic number higher than bismuth are radioactive. It is one of three elements that is less dense in the solid phase than in the liquid. It is also one of only a handful of metals that can be found in nature in their elemental, or native, form. Elemental bismuth is not particularly toxic, an unusual property in heavy metals. However, inorganic bismuth com- pounds are often extremely poisonous. The relative rarity of bismuth has minimized its environmental im- pact. History The earliest recorded use of bismuth was in the mid- 1400’s as an alloying material in casting type. German scientist Georgius Agricola stated that bismuth was a metal in the same family of metals as tin and lead. In 1753, French chemist Claude François Geoffroy iden- tified bismuth as a chemical element, confirming Agricola’s postulation. Obtaining Bismuth In addition to the native state, bismuth occurs in ores as an oxide, sulfide, and carbonate. Because of the scarcity of bismuth ores in the Earth’s crust, it is not mined directly but is typically producedcommercially by extracting and refining it from the anode sludge generated during the electrochemical production of other metals. Annual world production of bismuth is on the order of 6,000 metric tons. Uses of Bismuth Functioning as a metallurgical additive remains one of the major uses of bismuth. In particular, fusible al - loys, which have low melting points and are particu - larly useful in fire detection, often incorporate bis - muth. The other major use of bismuth is in the pharmaceutical industry, where it is used to treat indi- gestion and as an antisyphilitic agent. Craig B. Lagrone Web Sites Natural Resources Canada Canadian Minerals Yearbook, 2005: Bismuth http://www.nrcan-rncan.gc.ca/mms-smm/busi- indu/cmy-amc/content/2005/14.pdf U.S. Geological Survey Minerals Information: Bismuth Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/bismuth/ See also: Alloys; Antimony; Belgium; Canada; China; Germany; Metals and metallurgy; Mexico; Native ele- ments. Borax Category: Mineral and other nonliving resources Where Found Borax, the most widespread of the borate minerals, is found in the muds of alkaline lakes along with miner- als such as rock salt, sulfates, carbonates, and other borates. Large deposits are found in the western United States, South America, Turkey, and Tibet. Primary Uses Borax is essential to many industrial processes, nota- bly themanufacture ofglass and enamel. Other major users include the ceramics, agricultural, chemical, cleanser, and pharmaceutical industries. Technical Definition Borax (also known as sodium borate decahydrate, so- dium pyroborate, birax, sodium tetraborate decahy- drate, and sodium biborate) is an ore of boron with the chemical formula Na 2 (B 4 O 5 )(OH)4 C 8(H 2 O). Its average molecular weight is 381.4, composed of 12.06 percent sodium, 11.34 percent boron, 5.29 percent hydrogen, and 71.32 percent oxygen. Borax may be colorless, white, yellowish, or gray. Its hardness on the Mohs scale is 2 to 2.5. Borax occurs as prismatic crys - 130 • Borax Global Resources tals or as a white powder. Its specific gravity is 1.69 to 1.72. It is slightly soluble in cold water, very soluble in hot water, and insoluble in acids. It has a melting point of 75° Celsius and a boiling point of 320° Cel- sius. When heated above 740° Celsius, it fuses to form a “borax bead.” Description, Distribution, and Forms Borax isa memberof agroup ofcompounds knownas borates, minerals that contain the element boron. Bo- rax is an evaporite found in dried-up lakes and playas (desert basins). A sedimentary deposit that forms in arid regions, borax derives its name from bnraq,an Arabic word meaning “white” that was used to refer to the substance. This widespread borate mineral is found in association with other evaporites, including rock salt, sulfates, carbonates, and other borates. Bo- rax occurs as a white powder on the soil surface or in masses of short, prismatic crystals embedded in the muds of alkaline lakes. Borax is also present in many mineral waters and salt lakes. It commonly loses water to form tincalconite (Na 2 B 4 O 7 C 5H 2 O). The mostwidespread of the borate minerals, borax is notably found in arid regions near the sites of Plio- cene lakes, where hot springs and volcanic activity are believed to be the source of the boron-rich brines that fed these lakes. Upon evaporation (hence its classifi- cation as an “evaporite”), deposits of borax and other borates formed. Buried accumulations of borax are often found in the centers of dried-up alkaline lakes, with outcrops of calcium and calcium-sodium boron minerals marking the periphery of the lake area. In the United States, there are large deposits of bo- rax in California, Nevada, and Oregon. Almost half the world’s refined borates come from Southern Cali- fornia. In California’s Mojave Desert, Searles Lake in San Bernardino County and Kramer in Kern County are two major borax deposits. AtSearles Lake,borax is the most abundant of the four borate-bearing miner- als found there. Borax is also the most abundant min- eral in the Kramer borate deposit, the largest known reserve of boron compounds in the world. Other ma- jor deposits are located in Tibet, Argentina, and Tur- key. In Argentina, for example, borax is mined at Salt Province (more than 4,000 meters above sea level) and at Tincalayu, Sijes, and the lakebeds at Salar Cauchari and Salar Diablillos. History Borax has been used commercially for thousands of years, with the earliest confirmed use in ceramic glazes traced to the tenth century c.e. The early Chi- nese, Persians, Arabs, and Babylonians knew of the mineral and its properties. It was introduced to Eu- rope by Marco Polo about 1275 c.e. Europe’s earliest source for the mineral was Tibet, where tincal (crude borax) wasused formaking glazesand solderinggold. By the 1800’s, borax had gained widespread use in glassblowing and gold refining. Italy, Tibet, and Chilewere the principal world sup - Global Resources Borax • 131 The mineral borax. (USGS) pliers of borate minerals until extensive borate depos - its were discovered in California and Nevada. An 1864 report on borax crystals found in the muds of Borax Lake in Lake County, California, was the first to pub- lish the discovery ofthe mineralin thewestern United States. In the early 1880’s, borax was also found in Death Valley. The twenty-mule teams that hauled the material mined from Death Valley across the Califor- nia desert to the railroad junction at Mojave became a widely recognized symbol for the borax industry in the United States. Obtaining Borax Borax may be obtained directly from dry lake beds on which the evaporite has formed, from open-pit borate mines, or from drilling for underground mines. At Searles Lake, borax is recovered by frac- tional crystallization from lake brine. Borax may also be made from other borate ores, including as kernite (Na 2 B 4 O 7 C 4H 2 O), colemanite (Ca 2 B 6 O 11 C 5H 2 O), and ulexite (NaCaB 5 O 9 C 8H 2 O), or by the reaction of boric acid with soda. Crystalline borax readily effloresces— that is, it loses its water of crystallization to form a white powder—particularly upon heating. Deposits of borate ores are found underground by drilling and then blasting to remove the sandstone that overlies the ore deposit. (Eventually such sites will turn into open-pit mining operations.) Huge shovels remove the rubble to get at the ore, which is then crushed and refined by mixing the crushed ore with hot water. Borates dissolve in the water, leaving the unwanted debris in solid form; the debris-free so- lution can then be pumped into tanks, which cool the solution sothat theborates cancrystallize andthen be removedfor drying, storage,and furtherprocessing. Uses of Borax The uses of borax are based on its many functional properties, which include metabolizing effects, bleaching effects, buffering effects, dispersing ef- fects, vitrifying effects, inhibiting effects, flame-proof- ing effects, and neutron-absorbing effects. Borax has been used for centuries in making glass and enamels, and it has become an essential part of many other in- dustrial processes. It is used in the manufacture of glass (notably heat-resistant and optical varieties), porcelain enamels, ceramics, shellacs, and glazes. It is a componentof agricultural chemicalssuch as fertiliz - ers and herbicides. It is used in the manufacture of chemicals, soaps, starches, adhesives, cosmetics,phar - maceuticals, insulation material, and fire retardants. In the textile industry, borax is used in fixing mor- dants on textiles, tanning leather, and spinning silk. It is effective as a mild antiseptic, a water softener, and a food preservative, although it is toxic if consumed in large doses. It is added to antifreeze to inhibit corro- sion and used as a flux for soldering and welding. Bo- rax is also a source of elemental boron, which is used as a deoxidizer and alloy in nonferrous metals, a neu- tron absorber in shields for atomic reactors, and a component of motor fuel and rocket fuel. Borax also plays an important role in chemical analysis. Borax fused by heating is used in the “bead test,” a form of chemical analysis used in the identifi- cation of certain metals. Powdered borax is heated in a platinum-wire loop over a flame until the mineral fuses to form a clear glassy bead. The borax bead is then dipped into a smallquantity ofthe metallicoxide to be identified. Upon reheating over the flame, the bead reacts chemically with the metallicoxide to form a metal borate, which gives the bead a characteristic color that helps identify the metal. For example, co- balt compounds yield a deep blue bead, and manga- nese compounds produce a violet one. Perhaps the most familiar use of borax is as a cleansing agent. Borax combined with hot water will create hydrogen peroxide; it lowers the acidity of water, which facilitates the bleaching action of other cleansers. Borax also acts as both a disinfectant and a pesticide byblocking the biochemistry of bothmacro- and microorganisms, such as bacteria, fungi, fleas, roaches, ants,and other pests. These sameproperties, however, mean that people must avoid overexposure to borax lest it prove toxic to the kidneys and other or- gans (a typical symptom is red and peeling skin). Finally, borates such as borax enhance the power of other cleansing chemicals by bonding with other compounds in such a way that it maintains the even dispersal of these cleansing agents in solution, thereby maximizing their surface area and hence their effectiveness. Karen N. Kähler Further Reading Chatterjee, Kaulir Kisor. “Borax and Related Min- erals.” In Uses of Industrial Minerals, Rocks, and Fresh- water. New York: Nova Science, 2009. Garrett, Donald E. “Borax.” In Borates: Handbook of Deposits, Processing, Properties, and Use. San Diego, Calif.: Academic Press, 1998. 132 • Borax Global Resources Grew, E. S., and L. M. Anovitz, eds. Boron: Mineralogy, Petrology, and Geochemistry. Washington, D.C.: Min- eralogical Society of America, 1996. Spears, John Randolph. Illustrated Sketches of Death Val- ley and Other Borax Deserts of the Pacific Coast. Edited by Douglas Steeples. Chicago: Rand McNally,1892. Reprint. Baltimore: Johns Hopkins University Press, 2001. Travis, N. J., and E. J. Cocks. The Tincal Trail: A History of Borax. London: Harrap, 1984. U.S. Borax and Chemical Corporation. The Story of Bo- rax. 2d ed. Los Angeles: Author, 1979. Web Sites U.S. Geological Survey Boron: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/boron/index.html#myb U.S. Geological Survey Death Valley Geology Field Trip: All About Death Valley Borax http://geomaps.wr.usgs.gov/parks/deva/ fthar4.html#basics U.S. Geological Survey Death Valley Geology Field Trip: Harmony Borax Works http://geomaps.wr.usgs.gov/parks/deva/ fthar1.html See also: Boron; Ceramics; Evaporites; Fertilizers; Glass; Sedimentary processes, rocks, and mineral de- posits. Boron Category: Mineral and other nonliving resources Where Found Boron is not abundant. There are about 9 parts per million of boron in the Earth’s crust, which makes bo- ron the thirty-eighth element in abundance. Com- mercially valuable deposits are rare, but the deposits in California and Turkey are very large. Primary Uses The main uses of boron are in heat-resistant glasses, glass wool, fiberglass, and porcelain enamels. It is also used in detergents, soaps,cleaners and cosmetics, and synthetic herbicides and fertilizers. Technical Definition Boron (abbreviated B), atomic number 5, belongs to Group III of the periodic table of the elements and re- sembles silicon in many of its chemical properties. It has two naturally occurring isotopes: boron 10 (19.8 percent) andboron 11(80.2 percent). Boron exists in several allotropic forms. The crystalline forms are a dark red color, and the powdered forms are black. The most stable form has a melting point of 2,180° Celsius, aboiling pointof 3,650° Celsius, and adensity of 2.35 grams per cubic centimeter. Description, Distribution, and Forms Boron is found primarily in dried lake beds in Califor- nia and Turkey. Isolated deposits also occur in China and numerous South American countries. The major deposits of borate minerals occur in areas of former volcanic activity and in association with the waters of former hot springs. Searles Lake in southeastern Cali- fornia has layers that are 1.6 percent and 2.0 percent borax. Boron is found naturally only as borate miner- als such as ulexite [B 5 O 6 (OH) 6 ] C 5H 2 O and borax Na 2 [B 4 O 5 (OH) 4 ] C 8H 2 O or as borosilicates. Boron is more concentrated in plants than in animal tissue. The use of borax laundry detergents, the burning of coal, and mining have filled the atmosphere and ir- rigation waters in some areas with boron compounds. Although there have been some reports of damage to grazing animals, boron is notconsidered a danger un- less it is in the form of a pesticide, an herbicide, or fi- berglass, which is carcinogenic. Boron is an essential element only for higher plants. The amount needed by those plants and the amount that is toxic are only a few parts per million apart, so toxicity effects can easily occur. Boron is not known to be necessary to animal life, and it is quickly excreted in urine. In high concentrations toxicity ef- fects can occur, especially in the brain, before all the boron is excreted. History Borax was used in ancient times to make glazes and hard glass and was traded by the Babylonians four thousand years ago. However it was not isolated in pure enough form to be characterized as an element until 1808. The isolation was achieved by Joseph- Louis Gay-Lussac and Louis-Jacques Thénard and in - Global Resources Boron • 133 dependently by Sir Humphry Davy. Boron was isolated from boric acid through a heated reaction with po- tassium. The first pure (95 to 98 per- cent) boron was isolated by Henri Moissan in 1892. Obtaining Boron The four main methods of isolating boron are reductionby metals at high temperature, electrolytic reduction of fused borates or tetrafluoro- borates, reduction by hydrogen of volatile compounds, and thermal de- composition of hydrides or halides. About 3.8 million metric tons are produced annually. Boron will form compounds with almost every ele- ment except the noble gases and a few of the heavier metals. It is said to have themost diversechemistry next to carbon and is characterized as a metalloid by someproperties and as a nonmetal by others. This rich chem- istry leads to a wide range of uses. Uses of Boron One of the most common uses of bo- ron is in the production of borosili- cate glass (Pyrex glass). Borosilicate glass does not ex- pand or contract as much as regular glass, so it does not break with temperature changes as easily as regu- lar glass. Pyrex cooking vessels and most laboratory glassware are made of borosilicate glass. Boron im- proves the tempering of steel better than other alloy- ing elements. Boron carbide is one of the hardest sub- stances known and is used in both abrasive and abrasion-resistant applications as well as in nuclear shielding. Lighter elements are better shields for neu- trons than are heavy elements such as lead. Boron-10 neutron capture therapy is one of the few ways to treat a nonoperable brain tumor. The boron-10 isotope collects in the tumor. When a neutron hits the boron, a reaction producesradiation to killthe cancercells. Borate is used in the production of glass fiber ther- mal insulation, the principal insulating material used in construction. Another glass application is as a thin, glassy coating fused onto ceramics and metals. Exam - ples include wall and floor tiles, tableware, bone china, porcelain, washing machines, pots, and architectural paneling. Boron is also used in algicides, fertilizers, herbicides, insecticides, and water treatments. Sodium polyborate can be used to control fleas, and boric acid has been used in the control of cockroaches. Fire re- tardants include zinc borate, ammonium pentaborate, and boric oxide. These are used in chipboard, cellu- lose insulation, and cotton mattresses. Boron com- pounds are also used in metallurgical processes such as fluxes and shielding slags and in electroplating baths. Borax is a water-softening agent, while boron is used as a bleaching agent. Perborates in water form hydrogen peroxide to act as a bleach. Boron is also used in cosmetics, pharmaceutical and hygienic products, pH adjusters, emulsifiers, stabilizers, and buffers. C. Alton Hassell Further Reading Adriano, Domy C. “Boron.” In Trace Elements in Terres - trial Environments: Biogeochemistry, Bioavailability, and Risks of Metals. 2ded. New York:Springer, 2001. 134 • Boron Global Resources Glass 34% Fire retardants 3% Soaps & detergents 3% Textile-grade glass fibers 13% Undistributed 34.5% Other 12.5% Source: Historical Statistics for Mineral and Material Commodities in the United States Note: U.S. Geological Survey, 2005, boron statistics, in T. D. Kelly and G. R. Matos, comps., , U.S. Geological Survey Data Series 140. Available online at http://pubs.usgs.gov/ds/2005/140/. “Undistributed” reflects trade, stocks changes, and data not reported by end use. “Other” includes agriculture, enamels, frits, glazes, metallurgy, and nuclear applications. U.S. End Uses of Boron Greenwood, N. N., and A. Earnshaw. “Boron.” In Chemistry of the Elements. 2d ed. Boston: Butter- worth-Heinemann, 1997. Grew, E. S., and L. M. Anovitz, eds. Boron: Mineralogy, Petrology, and Geochemistry. Washington, D.C.: Min- eralogical Society of America, 1996. Housecroft, Catherine E. Cluster Molecules of the P-Block Elements. New York:Oxford UniversityPress, 1994. Kogel, Jessica Elzea, et al., eds. “Boron and Borates.” In Industrial Minerals and Rocks: Commodities, Mar- kets, and Uses. 7th ed. Littleton, Colo.: Society for Mining, Metallurgy, and Exploration, 2006. Krebs, Robert E. The History and Use of Our Earth’s Chemical Elements: A Reference Guide. Illustrations by Rae Déjur. 2d ed. Westport, Conn.: Greenwood Press, 2006. Massey, A. G. “Group 13: Boron, Aluminum, Gallium, Indium, and Thallium.” In Main Group Chemistry. 2d ed. New York: Wiley, 2000. Smallwood, C. Boron. Geneva, Switzerland: World Health Organization, 1998. Weeks, Mary Elvira. Discovery of the Elements: Collected Reprints of a Series of Articles Published in the “Journal of Chemical Education.” Kila, Mont.: Kessinger,2003. Web Site U.S. Geological Survey Boron: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/boron/index.html#myb See also: Borax; China; Fiberglass; Glass; Herbicides; Pesticides and pest control; Turkey. Botany Category: Scientific disciplines Any topic dealing with plants, from the level of their cellular biology to the level of their economic produc- tion, is considered part of the field of botany. Definition Botany is an old branch of science that began with early humankind’s interest in the plants around them. In modern society, plant science extends beyond that interest to cutting-edge biotechnology. Overview The origins of botany, beginning around 5000 b.c.e., are rooted in human attempts to improve their lot by raising better food crops. This practical effort devel- oped into intellectual curiosity about plants in gen- eral, and the science of botany was born. Some of the earliest botanical records are included with the writ- ings of Greek philosophers, who were often physi- cians and who used plant materials as curative agents. In the second century b.c.e., Aristotle had a botanical garden and an associated library. As more details became known about plants and their function, particularly after the discovery of the microscope, the growing body of knowledge became too great for general understanding, so a number of subdisciplines arose. Plant anatomy is concerned chiefly with the internal structure of plants. Plant physiology delves into the living functions of plants. Plant taxonomy has as its interest the discovery and systematic classification of plants. Plant geography deals with the global distribution of plants. Plant ecol- ogy studies the interactions between plants and their surroundings. Plant morphology studies the form and structure of plants. Plant genetics attempts to un- derstand and work with the way that plant traits are in- herited. Plant cytology, often called cell biology, is the science of cell structure and function. Economic bot- any, which traces its interest back to the origins of bot- any, studies those plants that play important economic roles (these include major crops such as wheat, rice, corn, and cotton). Ethnobotany is a rapidly developing subarea in which scientists communicate with indige- nous peoples to explore the knowledge that exists as a part of their folk medicine. Several new drugs and the promise of others have developed from this search. At the forefront of modern botany is the field of ge- netic engineering, including the cloning of organ- isms. New or better crops have long been developed by the technique of cross-breeding, but genetic engi- neering offers a much more direct course. Using its techniques scientists can introduce a gene carrying a desirable trait directly from one organism to another. In this way scientists hope to protect crops from frost damage, to inhibit the growth of weeds, to provide in- sect repulsion as a part of the plant’s own system, and to increase the yield of food and fiber crops. The role thatplants playin the energy system ofthe Earth (and may someday play in space stations or other closed systems) is also a major area of study. Plants, through photosynthesis, convert sunlight into Global Resources Botany • 135 other useful forms of energy upon which humans have become dependent. During the same process carbon dioxide is removed from the air, and oxygen is delivered. Optimization of this process and discover- ing new applications for it are goals for botanists. Kenneth H. Brown See also: Agricultural products; Agriculture indus- try; Biotechnology;Farmland;Grasslands; GreenRev- olution; Horticulture; Plant domestication and breeding; Plants as a medical resource; Rain forests. Brass Category: Products from resources Brass, a metal alloy, has numerous practical applica- tions because of its ease of fabrication, corrosion resis- tance, and attractive appearance. It is used in hard- ware items,electrical fixtures, inexpensive jewelry,and metal decorations. Definition Brass is a copper-based alloy consisting mainly of cop- per and zinc. It can also be mixed with lead, tin, nickel, aluminum, iron, manganese, arsenic, anti- mony, and phosphorus. Overview The first brass was probably made accidentally by melting copper ore that contained a small amount of zinc. The earliest known brass object was made by the Romans about 20 b.c.e. By the eleventh century, brass was made on a large scale throughout Western Eu- rope, and brass coins, kettles, and ornaments were manufactured. In the United States, the brass indus- try developed mainly in Connecticut; at first it was de- voted primarily to making buttons. The color and composition of brass vary with the amount of copper, which ranges from 55 percent to 95 percent. When the alloy contains about 70 percent copper, it has a golden-yellow color (such brass is called yellow brass or cartridge brass). When it con- tains 80 percent or more copper, it has a reddish cop- per color (red brass). When zinc is added, brass be- comes stronger and tougher. The ductility (ability to be stretched) improves with increasing amounts of zinc up to about 30 percent. The best combination of strength and ductility occurs in yellow brass. Lead is added to improve machinability (ease of cutting). Tin and nickel are often added to increase the alloy’s resistance to corrosion and wear. Nickel may be added to obtain a silvery-white color that makes the alloy a more suitable base for silver plating. Aluminum is useful in improving the corrosion resis- tance of brass in turbulent or fast-moving water. The strength of brass is also improved with the addition of iron, manganese, nickel, and aluminum. The first step in making brass is to melt copper in an electric furnace. Solid pieces of zinc are then added to the melted copper, and the zinc melts rap- idly. After the copper and zinc have been melted and thoroughly mixed, the brass is ready for pouring. It is typically made into blocklike forms (ingots) or small bars (billets), making it easy to work with the brass or to store it. When it is time to make a particular piece, the bars are placed in a furnace, and after they have been reheated to the proper temperature for work- ing, the brass can be rolled and formed into the de- sired shape. A milling machine removes surface im- perfections, and the brass is then cold rolled. Brass is used in making automobile components, ship propellers, refrigeration and air-conditioning equipment (condenser tubes), decorative elements (architectural trim), plumbing hardware, camera parts, valves, screws, buttons, keys, watch and clock parts, and coins. Some brasses, mainly containing tin and manganese, are called bronzes, which are used to make statues, bells, vases, cups, and a variety of orna- ments. Alvin K. Benson See also: Alloys; Bronze; Copper; Metals and metal- lurgy; Tin; Zinc. Brazil Categories: Countries; government and resources Brazil’s metallic mineral resources, especially iron and aluminum, underpin a strong industrial sector and are high-valueexports. Brazil is the secondmost impor- tant producer of iron ore in the world after China and is a significant gold-producing nation. It ranks tenth as a diamond producer and has the second largest crude oil reserves in South America after Venezuela. 136 • Brass Global Resources Brazil’s forest industry contributes about 4 percent to the nation’s gross domestic product (GDP) and ac- counts for 7 percent of its exports, providing employ- ment for two million people. Brazil is in the top five among world nations in relation to area of land used for agriculture and ranks in the top three as an ex- porter of agricultural produce. The Country Brazil is the fifth largest country in the world, with an area of 8.5 million square kilometers. It is the largest and most geographically diverse country in South America, occupying most of the northeast of the con- tinent, and has a coastline of about 7,490 kilometers along the Atlantic Ocean. The country has a tropical or semitropical climate, with diverse natural vegeta- tion dominated by tropical rain forests, dry forests, and savannas. Brazil is generally low lying, with eleva- tions between 200 and 800 meters. Higher elevations, of about 1,200 meters, are limited to the south. Brazil has a drainage system dominated by the Amazon River, which originates in the Andes Mountains and has created an extensive lowland floodplain area in the northern part of the country. Brazil’s economy is growing rapidly. It is the largest in South America and the eighth largest in the world. Its resource base has not been fully ascertained, but key resources so far exploited include iron ore, in the states of Minas Gerais (in the south-central region) and Pará (in the north); oil, mostly in offshore fields; timber, from extensive natural forests and planta- tions; and precious stones in various locations. Agri- culture is most important in the south, where most of Brazil’s commercial crops are produced and where most cattle ranches are located. In the northeast and in the Amazon basin, agriculture tends to be subsistent and may involve shifting cultivation. Metals Brazil’s iron ore accounts for about 5 percent of its to- tal exports, with approximately half going to China, Japan, and Germany. Reserves of iron ore are esti- mated at almost 20 billion metric tons, about 7 per- cent of the world total, ranking Brazil sixth in the world. However, in terms of iron content the reserves are the best in the world. Iron ore accounts for almost 58 percent ofthe valueof Brazil’s mineral production. There are thirty-seven companies extracting iron and fifty-nine mines, allof which are open cast. The Brazil - ian mining company Vale S.A. (formerly Companhia Vale do Rio Doce) produces more than 60 percent of the iron ore in Brazil and about 15 percent of world iron ore, making it the world’s largest producer of iron ore. It is also the world’s second largest producer of nickel and is involved in the mining of bauxite, manganese, copper, kaolin, and potash. Approximately 70 percent of Brazil’s iron reserves are in the state of Minas Gerais and 25 percent are in Pará. The ores occur as hematite (ferric oxide), and, in 2007, more than 300 million metric tons were pro- duced. The Carajás Mine in Pará is the world’s largest iron-ore mine. Owned by Vale S.A., it is an open-cast mine with reserves of 1.4 billion metric tons, plus de- posits of manganese, copper, tin, cobalt, and alumi- num. In general, the Carajás District is exceptionally rich in minerals and has iron-ore reserves estimatedat 16 billion metric tons. Other base metals produced in substantial quantities include manganese and alumi- num, of whichBrazil accounts for 25 percent and 12.4 percent, respectively, of world production. Gold, tantalum, and niobium are also produced in Brazil. The late 1980’s were the period of peak gold production for Brazil. Reserves comprise almost 2 percent of the world total and are found mainly in Minas Gerais and Pará. In 2006, Brazil produced 40 metric tons;the chief mining company wasAnglogold Ashanti Mineração Ltda., which contributed about 7.7 metric tons. Most was used by the jewelry industry. About 32 metric tons were exported; Japan was the major recipient. Tantalum and niobium are relatively rare metals, but Brazil is a major source of both. Tantalum is extracted from tantalite and colombite mined from one site, Pitinga/Mineração Taboca, in the state of Amazonas. It is used for the manufacture of electro- lytic capacitors. Brazil provides roughly 20 percent of the world total, making it the second largest producer behind Australia. This mine also produces tin, ura- nium, and niobium. The latter is used in forensic sci- ence and to make alloys with iron to improve the strength of piping, among other uses. It is found in four states, of which Minas Gerais contains 73 percent of the reserves, and isextracted from pyrochlore (nio- bium oxide). Brazil produces most of the world’s nio- bium, which amounted to about 57,000 metric tons in 2008. Fossil Fuels Brazil has substantial reserves of coal, oil, and natural gas. Brazil’s energy production is as follows: 38 per - Global Resources Brazil • 137 138 • Brazil Global Resources Brazil: Resources at a Glance Official name: Federative Republic of Brazil Government: Federal republic Capital city: Brasília Area: 3,287,851 mi 2 ; 8,514,877 km 2 Population (2009 est.): 198,739,269 Language: Portuguese Monetary unit: real (BRL) Economic summary: GDP composition by sector (2008 est.): agriculture, 6.7%; industry, 28%; services, 65.3% Natural resources: bauxite, gold, iron ore, manganese, nickel, niobium, phosphates, platinum, tin, tantalum, uranium, petroleum, hydropower, timber, precious and semiprecious stones, graphite Land use (2005): arable land, 6.93%; permanent crops, 0.89%; other, 92.18% Industries: textiles, shoes, chemicals, cement, lumber, iron ore, tin, steel, aircraft, motor vehicles and parts, other machinery and equipment Agricultural products: coffee, soybeans, wheat, rice, corn, sugarcane, cocoa, citrus, beef Exports (2008 est.): $197.9 billion Commodities exported: transport equipment, iron ore, soybeans, footwear, coffee, automobiles Imports (2008 est.): $173.1 billion Commodities imported: machinery, electrical and transport equipment, chemical products, oil, automotive parts, electronics Labor force (2008 est.): 93.65 million Labor force by occupation (2003 est.): agriculture, 20%; industry, 14%; services, 66% Energy resources: Electricity production (2007 est.): 437.3 billion kWh Electricity consumption (2007 est.): 402.2 billion kWh Electricity exports (2007 est.): 2.034 billion kWh Electricity imports (2007 est.): 40.47 billion kWh (supplied by Paraguay) Natural gas production (2007 est.): 9.8 billion m 3 Natural gas consumption (2007 est.): 19.8 billion m 3 Natural gas exports (2007 est.): 0 m 3 Natural gas imports (2007 est.): 10 billion m 3 Natural gas proved reserves ( Jan. 2008 est.): 347.7 billion m 3 Oil production (2007 est.): 2.277 million bbl/day Oil imports (2005): 648,800 bbl/day Oil proved reserves ( Jan. 2008 est.): 12.35 billion bbl Source: Data from The World Factbook 2009. Washington, D.C.: Central Intelligence Agency, 2009. Notes: Data are the most recent tracked by the CIA. Values are given in U.S. dollars. Abbreviations: bbl/day = barrels per day; GDP = gross domestic product; km 2 = square kilometers; kWh = kilowatt-hours; m 3 = cubic meters; mi 2 = square miles. Brasília Brazil Colombia Argentina Bolivia Peru Paraguay Uruguay Venezuela Atlantic Ocean Pacific Ocean cent from oil, 9.6 percent from natural gas, 6 per - cent from coal, and the remainder comprising hydro- electric power, ethanol from sugarcane, and nuclear power. Globally, its coal reserves are not extensive (930 million metric tons compared to 271,000 million met- ric tons produced by the United States). More than 50 percent of Brazil’s coal comes from the state of Rio Grande do Sul, while 46 percent comes from Santa Catarina and 1.3 percent comes from Paraná, Brazil’s southernmost states. This coal is used within Brazil. In relation to global oil reserves and production, Brazil is ranked sixteenth and fourteenth, respec- tively, and has about 1 percent of estimated global re- serves. In 2006, production was about 90 million met- ric tons, an annual increase of more than 5 percent that was mainly due to raised output from offshore oil fields, notably the Campos and Santos basins lo- cated off the southeast coast of the state of Rio de Ja- neiro. Thesefields contain thevast majority ofBrazil’s proven reserves. Such increases have made Brazil al- most selfsufficient inoil, though light crude isstill im- ported because of refinery capacity. The state-owned company Petrobras controls about 95 percent of crude oil production, which amounts to about 2.277 million barrels per day. Brazil ranks fortieth for natural gas re- serves and thirty-third for production. It produced about 9.8 billion cubic meters in 2007, mostly from offshore fields,all ofwhich is consumedwithin Brazil. Other Energy Resources Most of Brazil’s remaining energy needs are met by hydroelectric power and ethanol, a biofuel made from sugarcane. Brazil is the third largest producer of hydropower in the world. Approximately 27 percent of its potential could be exploited economically. Al- though just less than half has been realized, it pro- vides about 84 percent of Brazil’s electricity. Much of this has been made possible by the vast Itaipu Dam constructed in the late 1980’s, which Brazil shares with neighboring Paraguay. Other large-scale schemes include the Tucurui Dam on the Tocantins River in Pará and Boa Esperança on the Parnaíba River near the city of Guadalupe. Another dam, the Belo Monte, is proposed on the Xingu River, also in the state of Pará. However, this project is controversial because of the adverse environmental and social impacts associ- ated with such large-scale projects. Many small-scale dams also contributeto Brazil’shydropower capacity. Although Brazil is not the only nation to develop biofuels, it is unique insofar as ethanol became avail - able as a fuel in the 1920’s. Ethanol rose to promi - nence in the mid-1970’s, when world oil crises prompted the Brazilian government to decree that all automobiles had to operate on a fuel that contained at least 10 percent ethanol. Brazil is a leading pro- ducer of ethanol and user of ethanol as a fuel; it has been described as having the world’s first sustainable biofuel economy. In 2006, Brazil was responsible for 33 percent of the global production of ethanol and for 42 percent of the ethanol used as fuel. Ethanol is produced by the fermentation of sugarcane, one of Brazil’smajor crops, whichwas introduced byEurope- ans in the sixteenth century. In 2007, Brazil produced 514 million metric tons of sugarcane from 6.7 million hectares, mostly in the central/southern region. Be- tween 40 and 50 percent is used for ethanol fuel and the rest forsugar, which is amajor export. The sucrose content is the raw material for ethanol, which is pro- duced at more than 370 processing plants, mostly in Brazil’s southern and coastal states. Brazil has auto- mobiles that can run on any combination of petro- leum/ethanol-based fuels, though environmental im- plications remain because sugarcane plantations rely on irrigation, mechanization, and other techniques that affect the environment. Agricultural Resources Brazil is a world leader in the export of agricultural products, and the agricultural sector contributes more than 5 percent to the nation’s gross domestic product (GDP). Of Brazil’s total land area (almost 8.5 million square kilometers), about 2.6 million square kilome- ters are used for crop production. Apart from sugar- cane, soybeans, maize, rice, coffee, wheat, and cotton are significant economic crops. Beef production is also importantin Brazil; the country has extensive cat- tle ranches in the hinterland of São Paulo. According to statistics compiled by the Food and Agriculture Or- ganization, soybeans and maize are grown on 20.6 and 13.8 million hectares, respectively, crops that pro- duce about 58 and 50 million metric tons, respec- tively. Soybean cultivation has increased significantly but is no longer dominant in São Paulo’s hinterland, having expanded into central western and northeast- ern regions (where its and sugarcane’s spread occurs at theexpense ofsavanna andforest ecosystems).This expansion is partly associated with increased demand for biofuels. Brazil is the world’s biggest exporter of soybeans, sending 25 million metric tons to markets in Asia and Europe. Global Resources Brazil • 139 . reserves of coal, oil, and natural gas. Brazil’s energy production is as follows: 38 per - Global Resources Brazil • 137 138 • Brazil Global Resources Brazil: Resources at a Glance Official name:. plants, from the level of their cellular biology to the level of their economic produc- tion, is considered part of the field of botany. Definition Botany is an old branch of science that began. production of other metals. Annual world production of bismuth is on the order of 6,000 metric tons. Uses of Bismuth Functioning as a metallurgical additive remains one of the major uses of bismuth.