Encyclopedia of Global Resources part 20 potx

U.S. Geological Survey Cadmium: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/cadmium See also: Alloys; Canada; China; Kazakhstan; Metals and metallurgy; Mexico; South Korea; Steel; United States; Zinc. Calcium compounds Category: Mineral and other nonliving resources Where Found Calcium compounds are widely distributed. Naturally occurring calcareous materials include calcite, ar- agonite, chalk, marble, shell, and coral, all of which are predominantly calcium carbonate (CaCO 3 ); other common calcium-bearing minerals include fluorite (CaF 2 ) and apatite(Ca[PO 4 ,CO 3 ] 3 [F, OH, C1]).Prin- cipal calcium ores are limestone (predominantly cal- cite), dolostone(chiefly dolomite,MgCa(CO 3 ) 2 ), and gypsum rock (mostly the mineral gypsum, or calcium sulfate, CaSO 4 ), all widespread sedimentary rocks. Calcium is present in all soil, most water, and all plant and animal life. Primary Uses Calcium compounds are used for a variety of applica- tions, includingchemical manufacture, construction, and agriculture. Uses for elemental calcium include metal refining, alloy manufacture, and uranium and plutonium processing. Technical Definition Calcium (abbreviated Ca),atomic number 20,is a me- tallic element belonging to Group IIA of the periodic table of the elements (alkaline-earth metals). It is chemically similar to strontium and barium. Its aver- age molecular weight is 40.08. Its specific gravity is 1.55 at 20° Celsius, its melting point is approximately 850° Celsius, and its boiling point is 1,480° Celsius. Description, Distribution, and Forms Calcium has a cubic crystalline structure and is silver- white in color. It is relatively soft, ductile, and mallea - ble. A chemically active element, it occurs in nature only in combination with other elements. It tarnishes readily in air, reacts with water to form a hydroxide, and combines with oxygen, carbon, hydrogen, chlo- rine, fluorine, phosphorus, sulfur, and other elements to form many compounds. Calcium is the fifth most abundant element in the Earth’s crust, of which it makes up roughly 3.6 per- cent. Calcium is not found uncombined in nature, but it is widely distributed in its many naturally occur- ring compounds. Calcium is found in all soil andmost water, as well as in all plant and animal life. Bones and teeth are composed mostly of calcium and phospho- rus, with calcium predominant. Calcium is widely distributed in its naturally occur- ring compounds, which are found in many deposits throughout the world in rocks of varying geologic age. The chief ores of calcium—limestone, dolostone, and gypsum—are sedimentary in origin and can be found in thick, extensive beds. Limestone, largely or entirely composed of calcium carbonate, is generally formed by the deposition and consolidation of the skeletons of invertebrate marine organisms, although some limestones are the result of chemical precipita- tion from solution. Dolostone, composed chiefly of the mineral dolomite, originates from the partial replacement of the calcium in limestone with magne- sium. The mineralgypsum, or calcium sulfate, precip- itates to form deposits as seawater evaporates. Cal- cium incarbonate form isfound notonly inlimestone and dolostone but also in chalk, marble, shell, and coral. Fluorite is a calcium fluoride mineral found in igneous deposits. Phosphate rock, which contains cal- cium in the form of the mineral apatite, occurs in both igneous and sedimentary deposits. Calcium is also naturally present in soil and most water. Calcium combines with other elements to form a wide varietyof naturalcompounds, includingcalcium carbonate, calcium sulfate, fluorite, and apatite. Some of these compounds may take several forms: Calcium carbonate, for instance, may exist as calcite (the pre- dominant mineral in limestone, chalk, and most mar- ble), Iceland spar, aragonite, shell, or coral, while cal- cium sulfate occurs in nature as gypsum rock, gypsite, alabaster, satin spar, and selenite. History In general, the earliest known uses of calcium com- pounds were as construction materials. From calcare- ous substances such as limestone, dolostone, marble, gypsum, andlime (calcium oxide, CaO, madeby heat - ing limestone or other calcium-rich materials), an - 160 • Calcium compounds Global Resources cient peoples and the civilizations to follow made mortar, plaster, cement, stucco, building stone, and ornamental carvings. Limestone, lime, gypsum, and other calcareous materials also have been used for centuries as soil conditioners. Beginning in the late eighteenth century, calcium compounds were increas- ingly employed in industrial processes and chemical manufacture: Limestone, for example, found use as a key ingredient in the Leblanc and Solvay processes, two early commercial processes for manufacturing soda ash from salt. Elemental calcium was not isolated until 1808, when English chemist Sir Humphry Davy produced it as a mercury amalgam by electrolysis of calcium chloride in the presence of a mercury cath- ode. By 1904 calcium was obtained commercially by electrolysis of molten calcium chloride in the pres- ence of an iron cathode. The advent of World War II necessitated greater quantities of calcium. To meet the increased demand, an aluminothermic reduction process was developed for commercial use. Obtaining Calcium Calcium is obtained from lime through the alumi- nothermic reduction process. Limestone or a similar calcareous materialis heated to produce limeand car- bon dioxide. After lime is ground finely, it is heated with finely divided aluminum in a retort under a high vacuum to produce calcium metal. Uses of Calcium Natural and manufactured calcium compounds are used for a variety of applications. Limestone serves as a flux in iron smelting, a key component in port- land cement, a building stone, and a raw material for lime production. Lime, an essential industrial com- pound, is used in chemical manufacture, construc- tion, water softening, industrial waste treatment, and soil deacidification. Gypsum is widely used in agri- culture as a soil conditioner and in the construction industry in plaster, wallboard, cement, and tiles. Cal- cium chloride is employed as a filler in rubber, plas- tics, and ceramics. Calcium hypochlorite is a disinfec- tant used in swimming pools and in municipal and industrial bleaching and sanitation processes. Cal- cium nitrate is used as a concrete additive to reduce setting time and minimize the corrosion of steel rein- forcement bars. Calcium carbide is used in the pro- duction of acetylene gas and calcium cyanamide, a fertilizer. Arsenate and cyanide compounds of cal - cium are used as insecticides. Elemental calcium is a component of alloys used in maintenance-free batter - ies. It is used in lead refining to remove bismuth and in steel refining to remove sulfur and oxygen. Its role in uranium and plutonium processing makes calcium a strategic resource. Elemental calcium is also used in the preparation of vitamin B and chelated calcium supplements. Karen N. Kähler Further Reading Boynton, Robert S. Chemistry and Technology of Lime and Limestone. 2d ed. New York: Wiley, 1980. Greenwood, N. N.,and A.Earnshaw.“Beryllium, Mag- nesium, Calcium, Strontium, Barium, and Ra- dium.” In Chemistry of the Elements. 2d ed. Boston: Butterworth-Heinemann, 1997. Henderson, William. “The Group 2 Elements: Beryl- lium, Magnesium, Calcium, Strontium, Barium, and Radium.”In MainGroup Chemistry.Cambridge, England: Royal Society of Chemistry, 2000. Jensen, Mead L., and Alan M.Bateman. Economic Min- eral Deposits. 3d ed. New York: Wiley, 1979. 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. Myers, Richard L. The One Hundred Most Important Chemical Compounds: A Reference Guide. Westport, Conn.: Greenwood Press, 2007. Web Sites Natural Resources Canada Canadian Minerals Yearbook, Mineral and Metal Commodity Reviews http://www.nrcan-rncan.gc.ca/mms-smm/busi- indu/cmy-amc/com-eng.htm U.S. Geological Survey Fluorspar: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/fluorspar/index.html#myb U.S. Geological Survey Gypsum: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/gypsum/index.html#myb U.S. Geological Survey Lime: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/lime/index.html#myb Global Resources Calcium compounds • 161 U.S. Geological Survey Phosphate Rock: Statistics and Information http://minerals.usgs.gov/minerals/pubs/ commodity/phosphate_rock/index.html#myb See also: Cement and concrete; Feldspars; Fluorite; Gypsum; Lime; Limestone; Marble; Phosphate. Canada Categories: Countries; government and resources Canada is one of the most important countries in the world in terms of resources. Ranking third in reserves of both oil and uranium, Canada stands in a position of prime importance as a supplier of energy. Its vast hy- dropower resources add even greater importance to its role as an energy supplier. Canada’s forest resources, par- ticularly in combination with its hydropower resources, make the country a major source of clean, renewable en- ergy for the future. Canada is also a significant pro- ducer of metals, including nickel and copper, which are essential in the manufacturing of goods worldwide. The Country Canada is located in the northernmost part of the North American continent. The country is primarily bordered by water, with the north Atlantic Ocean to the east, the north Pacific Ocean to the west, and the Arctic Ocean to the north. It shares its southern bor- der with the United States and a portion of its western border with the state of Alaska. Canada primarily comprises plains but does have mountain ranges in the west and lowlands in the south. Canada’s key re- sources are oil, natural gas, potash, uranium, zinc, hydropower, and forests. Canada ranks fifteenth in purchasing powerparity and tenth in competitiveness in the global economy. The country is the fifteenth richest country in the world based on gross domestic product (GDP) per capita. Oil Oil isa form of petroleum composedof hydrogen and carbon compounds. It is a liquid form of fossilized biomass contained in underground reservoirs in sedi- mentary basins both on land areas and in seabeds. Crude oil is refined and used for fuel, lubricants, and various petrochemical feedstocks. Oil is an abundant resource in Canada. Approxi - mately 47 percent of Canada’s land is covered by sedi- mentary basins. Only a small number of these land basins are exploited. The major basin is the Western Canadian Sedimentary Basin, which has an area of 181.6 million hectares. The major oil fields of the ba- sin—including the LeDuc oil field, Norman Wells, and Redwater—are all located in the province of Al- berta. However, Canada’s greatest resources for oil production in the future are located in basins in the Beaufort Sea and in the waters off the east coast. The Hibernia oil field in theAtlantic Ocean is a majorpro- ducer of oil. The Canadian government, in coopera- tion with private companies, is developing many of these basins, including those under the Beaufort Sea. All leasesto explore andextract oil andthe manner in which it is extracted are regulated by the Canadian government. The oil sands located in the Athabasca basin in Al- berta constitute another rich source of oil for Canada. However, oil sands require unconventional means of extraction and processing that threaten the environ- ment with increased greenhouse-gas emissions. The oil in oil sands is bitumen, a heavy, viscous crude oil. It is encased in sand and water and requires consider- able processing to be converted into gasoline and jet fuel. Oil isimportant to theCanadian economyboth do- mestically and globally. Canada has ranked tenth in the world in the consumption of oil and eighth in the production of oil. In 2005, Canada was the ninth larg- est exporter of oil in theworld and ranked fourteenth in oil imports. Estimates of proven oil reserves for 2008 placed Canada third in the world. Thus, Canada is an important source for the production of oil in the global economy of the future. Natural Gas Natural gas, a highly combustible odorless and color- less liquid, is found with crude oil and in separate de- posits. Natural gas is composed of methane, butane, ethane, and propane and, like oil, is a form of petro- leum. Natural gas is extracted from wells dug deep into the Earth and also from coal-bed methane and from tight sandstone and shale. The methane ex- tracted from the last two sources is referred to as tight gas. Natural gas is found in various areas in Canada. The extraction of natural gas by drilling wells is the conventional means of retrieval but is expected to de - 162 • Canada Global Resources Global Resources Canada • 163 Canada: Resources at a Glance Official name: Canada Government: Parliamentary democracy, federation, and Commonwealth realm Capital city: Ottawa Area: 3,855,383 mi 2 ; 9,984,670 km 2 Population (2009 est.): 33,487,208 Languages: English and French Monetary unit: Canadian dollar (CAD) Economic summary: GDP composition by sector (2008 est.): agriculture, 2%; industry, 28.4%; services, 69.6% Natural resources: iron ore, nickel, zinc, copper, gold, lead, molybdenum, potash, diamonds, silver, fish, timber, wildlife, coal, petroleum, natural gas, hydropower, uranium Land use (2005): arable land, 4.57%; permanent crops, 0.65%; other, 94.78% Industries: transportation equipment, chemicals, processed and unprocessed minerals, food products, wood and paper products, fish products, petroleum and natural gas Agricultural products: wheat, barley, oilseed, tobacco, fruits, vegetables, dairy products, forest products, fish Exports (2008 est.): $459.1 billion Commodities exported: motor vehicles/parts, industrial machinery, aircraft, telecommunications equipment, chemicals, plastics, fertilizers, wood pulp, timber, petroleum, natural gas, electricity, aluminum, uranium, hydropower Imports (2008 est.): $415.2 billion Commodities imported: machinery and equipment, motor vehicles and parts, crude oil, chemicals, electricity, durable consumer goods Labor force (2008 est.): 18.22 million Labor force by occupation (2006): agriculture, 2%; manufacturing,13%; construction, 6%; services, 76%; other, 3% Energy resources: Electricity production (2007 est.): 612.6 billion kWh Electricity consumption (2006 est.): 530 billion kWh Electricity exports (2007 est.): 50.12 billion kWh Electricity imports (2007 est.): 19.66 billion kWh Natural gas production (2007 est.): 187 billion m 3 Natural gas consumption (2007 est.): 92.9 billion m 3 Natural gas exports (2007 est.): 107.3 billion m 3 Natural gas imports (2007 est.): 13.2 billion m 3 Natural gas proved reserves ( Jan. 2008 est.): 1.648 trillion m 3 Oil production (2007 est.): 3.425 million bbl/day Oil imports (2005): 1.229 million bbl/day Oil proved reserves ( Jan. 2008 est.): 178.6 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. Ottawa Greenland Iceland United States Canada Baffin Bay Hudson Bay Labrador Sea Arctic Ocean Pacific Ocean Atlantic Ocean cline as unconventional methods of extraction (from coal-bed methane and from shale and tight sand- stone) increase. The Western Sedimentary basin lo- cated in southwestern Canada contains the majority of theestimated Canadian natural gas reserves. There are also known reserves off the east coast near Nova Scotia and inOntario. The Arctic Ocean is believed to contain a large amount of gas hydrates, methane en- closed in frozen water on the ocean floor and under areas of permafrost. These potential reserves are not included in the estimated Canadian reserves because the technology necessary to extract them has not been developed. Natural gasplays an importantrole in the economy in both the domestic and global markets. In Canada, natural gas is an important resource because it is used by all sectors: residential, commercial, industrial, and power-generation. In 2007, Canada ranked fifth in the world in the production of natural gas and eighth in consumption. The United States, Canada’s major trading partner, plays a significant role in the Cana- dian natural gas industry. The two nations participate in an integrated marketplace that unifies the two countries’ regulation of the industry at all stages. In 2007, Canadaexported morethan one-half ofthe nat- ural gas that it produced to the United States and earned $28 billion in revenues. In global trade, Can- ada ranked third as an exporter of natural gas and fif- teenth as an importer. The country’s proved reserves of natural gas placed it twenty-first in the world. Potash Potash, the seventh most abundant element in the Earth’s crust, includes potassium compounds and any material containing potassium. The major use of potash is in the making of fertilizer. Potash was first discovered in Canada in 1943 in the province of Sas- katchewan by workers drilling oil wells. In 1951, ex- ploration for potash deposits began. The major pot- ash deposits are in the Middle Devonian Prairie Evaporite, which is located in central and south-cen- tral Saskatchewan and extends south into Manitoba and into the United States.Canada possesses approxi- mately 68 billion metric tons of potash reserves. The first company to produce potash in Canada was the Potash Company of America; the firm was founded in 1958 withunderground minesat PatienceLake. From 1960 to 1985, extensive development of potash min - ing took place in Saskatchewan and New Brunswick. In 1964, Kalium Chemical Ltd. established a potash solution mine near Regina, Saskatchewan. This was the world’s first mine of this type. The Canadian pot- ash industry is composed of nine underground mines located in Saskatchewan and three solution mines, two in Saskatchewan and one in New Brunswick. In the 1990’s, Canada became the largest exporter of potash in the world and has 43 percent of the world trade in potash. Canada exports potash to forty differ- ent countries. The United States, China, and Brazil are its greatest markets for potash. Uranium Canada is the world’s leading producer of uranium, a radioactive metal. The exploited deposits of uranium are all in Saskatchewan Province; the largest deposits of high-grade uranium are located in the Athabasca basin. The major operating uranium mines, all lo- cated in Saskatchewan, are at Rabbit Lake, McClean Lake, and McArthur Lake. The major use of uranium is in commercial nuclear power plants in the produc- tion of electricity. Canada exports 85 percent of its uranium for this purpose. The majority of the ex- ported uranium is sent to the United States, Japan, and Western Europe. The remaining 15 percent is used domestically in Canada’s CANDU reactors to produce approximately 15 percent of Canada’s elec- tricity. Canada produces almost one-third of the ura- nium produced in the world and ranks third in re- serves of uranium. The country is expected to maintain itsposition as theleader in uraniumproduc- tion. Hydropower Hydropower, a renewable resource, first became an important source of energy in Canada in the late 1800’s. Hydroelectric plants were constructed at Ni- agara Falls in Ontario and at Shawinigan Falls in Que- bec. Afterward, hydropower continued to play an im- portant rolein Canada’s economicdevelopment. The number of hydroelectric plants in Canada has grown to 475, and hydropower furnishes approximately two- thirds ofCanada’selectricity.Although thenumber of facilities using hydropower throughout Canada has increased dramatically, the country has not begun to utilize fully its resources of potential hydropower. Globally, Canada is a leader both in the production of hydropower-generated electricity and in the devel- opment of hydroelectric power-plant technology. France is the only country that exports more electric - ity than Canada. The United States, Canada’s major 164 • Canada Global Resources trading partner, imports about $2.5 billion of electric - ity from Canada every year. The majority of this elec- tricity is generated with hydropower. As global con- cerns about greenhouse-gas emissions and air pollution become ever greater, Canada’s role as a de- veloper of clean, renewable energy resources and technology continues to grow in importance. Aluminum Aluminum is not a metal native to Canada; neverthe- less, as the major refiner of aluminum, Canada plays an importent role in supplyingaluminum to theworld. The metal is shipped from all over the world to Can- ada’s refineries in Quebec, where a vast amount of hydroelectric power is available for processing. The refined aluminum is exported globally. Forests Ten percent of the world’s forests are in Canada, cov- ering 901 million hectares. Canada’s forest area also accounts for 30 percent of the boreal forest of the world. Forests play a key role in Canada’s economy. Globally, Canada isthe largestexporter offorest prod- ucts. The United States, the European Union, and China are the major markets for Canadian forest products. In 2008, the housing crisis in the United States caused a decline in both the quantity and the dollar value of soft-wood lumber exports. The popu- larity of electronic media throughout the world has brought about a decline in the amount of newsprint exported. However, the demand for pulp has be- come greater, with a significant increase in pulp ex- port to Asia. Canada exports a wide variety of forest Global Resources Canada • 165 Glacier Park in British Columbia, Canada, houses a wide array of wildlife and highlights the striking beauty of the country. (©Jay Beiler/ Dreamstime.com) products, bothwood and nontimberproducts. Christ - mas trees and maple products account for the major- ity of nontimber products. Logs, paper products, and pulp constitute the largest dollar value of timber product exports; however, Canada also exports a sub- stantial amount of wood-fabricated products such as fiberboard, both soft-and hard-wood lumber, and ply- wood. Although Canada imports some forest prod- ucts, the country is primarily an exporter of forest products, with exports far exceeding imports. The forest-products industry accounts for approxi- mately 3 percent of Canada’s GDP. Forest-based food products, such as wild mushrooms and berries, and secondary manufacturing of wood products from res- idues of timber harvesting make a significant contribu- tion to Canada’s economy. Both are also important in that theycontributeto theeconomy withoutincreasing the number of trees harvested. Canada is not only the world leader in forest products but also one of the na- tions most concerned with forestconservationand re- newal. The annual forest harvest is less than 1 percent of the total Canadian forest. Canada has a number of programs toprotect its forestlands andassure their re- generation. Approximately 40 percent of the forest is covered by various programs of land-use planning or is designated as certified forest. Legislation provides protection to approximately 8 percent of the forest. Canada is actively working to increase the economic benefits derived from its forest area and, at the same time, preserve and renew this resource. In 2008, Can- ada enacted its sixth program of strategies to manage its forests in a responsible manner. A Vision for Cana- dian Forests: 2008 and Beyond provides guidelines through 2018. One of the major components of the plan is to increase the number of forest-derived prod- ucts and of forest uses without increasing actual tree harvest. Innovations in bioenergy, bioplastics, and bio- chemicals are being developedto accomplishthis goal. Fisheries Fisheries as a resource have experienced consider- able difficulties throughout the world because of cli- mate changes. Coupled with the decline in numbers in various species of fish because of climate changes, specifically warming ocean temperatures, the over- exploitation of this resource has resulted in the col- lapse of some segments of the industry. Canada’s fishing industry has not escaped this problem. While fisheries haveplayed aless important role inthe Cana - dian economy than forests, they have been a major part of the economies of the coastal provinces, espe - cially those of the Atlantic coast. The first major de- cline in Canada’s fisheries occurred in 1992 with the collapse of the Atlantic cod fisheries. This decline came about because of colder water temperatures in the LabradorSea and overfishing of the species.At- lantic cod had played a significant role in Canada’s fish exports. Canada shifted its focus to salmon, hali- but, and haddock. Shellfish—especially lobster, shrimp, and crab—account for approximately 50 per- cent of the dollar value of Canadian fish exports. Of the remaining 50 percent of export dollar value, 15 per- cent is dominated by the export of salmon. Two-thirds of the salmon exported comes from the Atlantic. However, sockeye salmon, which has a higher dollar value, is a Pacific fish and is threatened by warming in the Pacific Ocean. This is causing the salmon to move toward the Bering Sea, resulting in a reduction in the number of sockeye found in Canadian waters. Consequently, Canada’s fishing industry is shifting from reliance on a natural resource to dependency on farm-raised and ocean-cultured fish. Aquaculture, much of which is mariculture (aquaculture done in the ocean), has played an ever-greater role in the in- dustry. Both finfish and shellfish are cultured. From 1998 to 2000, aquaculture increased steadily at a rate of 14 percent per year. This change in much of the base of fisheries has created new supply sectors in Canada’s domestic economy, including the manufac- turing of cages and the production of feed supplies for the captive-raised fish and shellfish. Zinc Zinc is a bluish white metal found in the Earth’s crust. It has a large variety of uses ranging from the galvaniz- ing of steel against corrosion to the creation of alloys such as brass to use in roofing and in paint. Zinc de- posits are located in the Appalachian region of Can- ada and are mined in both open and underground mines. There are alarge numberof zincmines operat- ing in Canada, including mines in British Columbia, Manitoba, Saskatchewan, Ontario, Quebec, and the Northwest Territories. Canada is the world’s largest producer of zinc and exports about 90 percent of its zinc production. Zinc is exported both as refined metal andasconcentrate. Therefined metalthat isex- ported has been subjected to an electrolytic process and is therefore an almost pure product. Canada ex - ports zinc worldwide. The major markets for zinc as refined metal are the United States and Taiwan. For 166 • Canada Global Resources zinc concentrate, the majority of markets are in Eu - rope, especially in Belgium, Germany, Spain, and It- aly. South Korea is also an important market for zinc concentrate. Nickel Nickel is a grayish white metal and ranks twenty- fourth in abundance among metals found in the Earth’s crust. It is used primarily as an alloying agent and is found in about three thousand different alloys, including stainless steel. Nickel was first discovered in Canada near Sudbury, Ontario, where a number of companies run integrated operations in mining, mill- ing, smelting, and refining the nickel. In 1993, an- other large deposit of nickel was discovered at Voisey Bay. Canada is the second largest producer of nickel worldwide; only Russia produces more. Canada’s do- mestic market uses only 2 percent of the nickel pro- duced in the country; the remainder is exported to major markets such as the United States, Western Eu- rope, and Japan. Other Resources Canada’s other resources include salt, copper, gold, and molybdenum as well as numerous others. Salt is found in both eastern Canada,where it isabundant in the Atlantic basin, and western Canada, from Mani- toba to Alberta. Canada is the world’s fourth largest producer ofsalt. Allbut 1percent ofCanada’s tradein salt is done with its major trading partner, the United States. However, Canada imports more salt than it ex- ports. In Canada, copper, a reddish metal, is usually found in combination with sulfite minerals. The copper sul- fides often contain gold and molybdenum as well. Canada is the fifth largest mine producer of copper globally. Its two major copper-producing provinces are Ontario and British Columbia. Thecopper mined in Ontario is processed there, but the copper mined in BritishColumbiais exported toAsiafor processing. Shawncey Webb Further Reading Barnes, Michael. More than Free Gold: Mineral Explora- tion in Canada Since World War II. Renfrew, Ont.: General Store, 2008. Førsund, Finn R. Hydropower Economics. New York: Springer, 2007. McKay, David L. Why Mining? Victoria, B.C.: Trafford, 2002. Martin, Raymond, and William L. Leffler. Oil and Gas Production in Nontechnical Language. Tulsa, Okla.: PennWell, 2006. Wetzel, Suzanne, Luc C. Duchesne, and Michael F. Laporte. Bioproducts from Canada’s Forests: New Part- nerships inthe Bioeconomy. NewYork: Springer,2006. Zoellner, Tom. Uranium: War, Energy, and the Rock That Shaped the World. New York: Viking, 2009. See also: Aluminum; Athabasca oil sands; Canadian Environmental Protection Act; Forests; Oil and natu- ral gas distribution; Potash; Zinc. Canadian Environmental Protection Act Categories: Laws and conventions; government and resources Date: Became law June 30, 1988 The Canadian Environmental Protection Act out- lined environmental quality standards for Canada and established regulations on the manufacture, emis- sion, and discharge of toxic substances to achieve those standards. Background During the 1960’s and 1970’s the Canadian federal government and the governments of the Canadian provinces passed several laws intended to regulate pollution and clean up the environment. The Clean Water Act, passed in 1970, provided for cooperation between the federal and provincial governments on water resource management issues, particularly the cleanup of pollution in the Great Lakes. The Clean Air Act, passed in 1971, provided for similar coopera- tion to manage air quality. These acts were super- seded by the Environmental Protection Act, passed in 1988, which established broad environmental quality objectives and gave the government the authority to regulate emissions of hazardous materials. Unlike in the United States, where federal laws generally supersede localor state laws, in Canada con- stitutional jurisdictionto passlaws regulating theenvi- ronment is shared by the federal and provincial gov- ernments. As a result, the provisions of Canada’s Environmental Protection Act did not apply in any province that had enacted, and enforced, equivalent Global Resources Canadian Environmental Protection Act • 167 provincial laws. Canadian industry as well as the pro - vincial governments had lobbied for this provision so that the industries would not have to deal with two different sets of laws and both provincial and federal law enforcement authorities. Provisions The Canadian Environmental Protection Act allowed regulation ofair pollution where theemissions consti- tuted a health threat. Emissions of lead (including lead ingasoline), mercury, andother toxic substances were restricted. The act also allowed the government to control the emissions responsible for acid rain. Water quality management, provided under the act, had two objectives: to maintain the supply of safe drinking water and to minimize pollution of the fish- eries. Dumping of materials into the oceans was also controlled. The act provided for the cleanup of any unauthorized releases of toxic or hazardous materials and authorized fines or jail terms for convicted pol- luters. The actallowed the ministerof the environment or the minister of national health and welfare to issue a temporary ban on the importation or manufacture of any new substance thought to be an environmental hazard while its toxicity could be studied. In addition, the act included a list of forty-four substances already in use that were to be tested for toxicity within five years of passage of the act. Impact on Resource Use Environment Canada is the agency of the Canadian federal government responsible for overseeing the country’s environment and for the prevention of pollution of the air, land, and water across Canada. The Canadian Environmental Protection Assessment Agency, a division of Environment Canada, develops and manages the federal environmental review pro- cess and develops the national standards required to manage the toxic substances regulated by the Cana- dian Environmental Protection Act. George J. Flynn See also: Acid precipitation; Air pollution and air pollution control; Environmental law in the United States; Environmental ProtectionAgency; Greenhouse gases and global climate change; United Nations En - vironment Programme; Water pollution and water pollution control. Canning and refrigeration of food Category: Obtaining and using resources Two of the most important methods for preserving food are canning and refrigeration. Definition Canning is the technique of preserving food in air- tight containers through the use of heat, while refrig- eration is the process of preservation through the use of low temperatures. Canning inactivates enzymes and kills microorganisms that would cause food to spoil during storage, while refrigeration stops the growth and activity of most microorganisms that cause food spoilage. Overview Canning and refrigeration are processes that pre- serve food by slowing down its normal decay. Without these food storage processes, most people would have to grow their own food, and large cities could not ex- ist. Food could not be transported from rural areas to urban areas without being spoiled or destroyed by pests. Famines would be more frequent and wide- spread, since surpluses of food could not be stored to guard against emergencies. Canning is themost common method of food pres- ervation in developed countries,and it is thebasis of a large segment of the commercial food industry. In this process, fruits, vegetables, fish, meat, poultry, soups, and other foods are sealed in airtight contain- ers and then heated to destroy microorganisms that may cause spoilage. The airtight packaging protects the food from contamination and permits storage at room temperatures for many months. One disadvan- tage of canning is that the heat required for steriliza- tion changes the food’s texture, color, and flavor. The canning process was developed by a French chef, Nicolas Appert, in the early 1800’s. He worked out a process of packing food in glass jars, which were then tightly corked and heated in boiling water. Glass or tin-coated sheet steel containers are used in the commercial canning ofmany foods, and beginningin the early 1960’s aluminum cans were used for canned liquids. Virtually alltypes of foodare cannedcommer- cially, and the products are available in cans of all sizes. Refrigeration, or cold storage, keeps food fresh at 168 • Canning and refrigeration of food Global Resources temperatures somewhat above 0° Celsius. Refrigera- tion takes place when heat flows to a receiver colder than itssurroundings. Lowtemperatures do not steril- ize food,but they doslow downthe growthof microor- ganisms and decrease enzymes that cause food to de- teriorate. Refrigeration produces few changes in food, and theoriginal color, flavor, texture, andnutrients of the food are retained. Cold storage has been used for hundreds—or thousands—of years to preserve foods, dating back to when people stored food inside cool caves. Ice was a valuable cargo fornineteenth century ships,but it was expensive and difficult to transport. In 1851, the first commercial machine for making ice was patented by John Gorrie, an American physician. This develop- ment led to the large-scale use of refrigeration for shipping and storing foods. After World War I, the do- mestic refrigerator began to displace the icebox, and with the widespread dissemination of mechanical re- frigeration in homes, the development of a frozen- food industry became possible. Soon a large fleet of refrigerated trucks was transporting the products. Alvin K. Benson See also: Agricultural products; Aluminum; Food chain; Food shortages; Freeze-drying of food; Popula- tion growth; Tin. Capitalism and resource exploitation Category: Social, economic, and political issues Originating in Western Europe in the sixteenth cen- tury, capitalism is a socioeconomic system that chan- nels individual efforts toward increasing economic growth. Historically, economic growth is associated with an increasing human population and the in- creasing exploitation of natural resources. Background Capitalism has a number of characteristics that differ- entiate it from traditional economies and command economies. First, as Karl Polanyi observes in The Great Transformation (1964), capitalism ischaracterized by a market economy. A market economy means subject - ing human beings, means of production, and nature Global Resources Capitalism and resource exploitation • 169 Workers at a factory in the Philippines stuff sardines into cans. (AFP/Getty Images) . extraction of natural gas by drilling wells is the conventional means of retrieval but is expected to de - 162 • Canada Global Resources Global Resources Canada • 163 Canada: Resources at a Glance Official. government and resources Canada is one of the most important countries in the world in terms of resources. Ranking third in reserves of both oil and uranium, Canada stands in a position of prime importance. major 164 • Canada Global Resources trading partner, imports about $2.5 billion of electric - ity from Canada every year. The majority of this elec- tricity is generated with hydropower. As global con- cerns