Mining

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Entries - Entry Category: Mining

Antimony Mining

Antimony (Sb) is a hard, brittle, silver-white metal with a relatively high specific gravity (6.69) and a relatively low melting temperature. Antimony is a constituent in some alloys. The presence of this metal hardens the alloy, lowers the melting point, and decreases contraction during solidification. The metal’s main use is to impart stiffness and hardness to lead alloys. Antimony compounds are used in medicines, paint pigments, enamelware glazes, and as fireproof coatings on clothing. They are also used in the rubber and patent-leather industries. Many minerals contain antimony; however, stibnite and antimonial lead ores are the main sources of the metal. Stibnite (Sb2S3) and its alteration oxide, stibiconite (Sb3+Sb25+O6(OH)), were the only minerals mined in Arkansas for this metal. Stibnite …

Bauxite Mining

Bauxite is the principal ore of aluminum and is a mixture of aluminum oxides and hydroxides that formed from intense chemical weathering of a soil in tropical environments. Soils formed under these conditions are termed laterites. In Arkansas, the aluminum-enriched soils are the result of the decomposition and lateritic weathering of nepheline syenite, an intrusive igneous rock. During the weathering process, leaching by rain, groundwater, and salt spray decomposed the original syenite minerals (feldspar and nepheline). Weathering removed much of the silica and concentrated the newly formed aluminum oxides and hydroxides as the rock termed bauxite. Geologically, the soils formed from syenite and weathered to laterites in the Paleocene Epoch (65–55 million years ago) along the west edge of a …

Coal Mining

Coal fields in Arkansas are located in the Arkansas River Valley between the western border of the state and Russellville (Pope County) an area only about thirty-three miles wide and sixty miles long. Until about 1880, most coal mined in Arkansas was used near its original location, often to fuel the fires of blacksmiths. Between 1880 and 1920, coal was Arkansas’s first mineral/fuel output, used especially for locomotives and steam-powered machines, as well as for heating homes and businesses. After 1920, oil and oil byproducts pushed aside the popularity of coal as a fuel, and mining of coal decreased. Much of the coal mined in Franklin County and Sebastian County around the year 2000 was used in the manufacture of …

Crushed Stone Mining

Crushed stone is an angular form of construction aggregate, made by breaking quarried rock into fragments that may be sorted, sized, and recombined into a variety of products. Crushed stone is typically quarried—that is, mined using benching methods (carrying out work from a ledge in a mine or quarry) and explosives, as opposed to the mechanical digging used for extracting sand and gravel. Consolidated rock is cut into vertical ledges, so that drilling can be done from above to place explosives within the wall for proper breakage of rock during mining. Benches typically vary from twenty to sixty feet in height, depending on how competent the rock is. The quarry stone is normally run through a primary crusher and then …

Diamond Mining

Almost 100 million years ago, in what is now Pike County, nature created one of the world’s most unusual diamond-bearing formations, the big volcanic “pipe” that now serves as the centerpiece of Crater of Diamonds State Park. Famous today for recreational mining, the eroded old crater once inspired generations of diamond hunters to dream of commercial success. The history of that long quest—the expectations, the contention, and the repeated frustration—is, in itself, an invaluable legacy of the Arkansas diamond field. Unlike the typical diamond pipe, the formation in Pike County accumulated in various stages as molten rock deep within the earth’s mantle swept up through a shallower zone where diamonds had crystallized long before and then worked its way to …

Dimension Stone Mining

Dimension stone is defined as rock that is removed from its original site to be used with minor alteration (rough stone) and rock that is broken, sawn, and/or ground and polished (cut or dressed stone) for use as building and/or ornamental stone. While most of the high-quality dimension stone produced in Arkansas is used in state, some is shipped to markets worldwide. Limestone and sandstone are used as dimension stone in Arkansas. Historically, much nepheline syenite was used as hand-worked building stone in the late nineteenth and early twentieth centuries in the Little Rock (Pulaski County) area, but beginning in the middle 1940s, those labor-intensive activities gave way to the use of crushed stone for syenite. A small market exists, …

Fayetteville Shale

The natural gas field known as the Fayetteville Shale, development of which began in 2004, became recognized as one of the ten largest gas fields in the United States. The exploration of this resource was initiated by Southwestern Energy Company, which, by its high point in 2008, had booked sufficient natural gas reserves to heat every home in New York City for four years. This large find attracted other operators, creating a large, although short-lived, economic stimulus for Arkansas. The Sam M. Walton School of Business at the University of Arkansas (UA) in Fayetteville (Washington County) estimated the economic impact of the leasing programs, drilling operations, and royalty payments generated by the development in its first decade of operation at …

Gypsum Mining

Gypsum is a mineral (CaSO4·2H2O) that occurs in nature as both a mineral and, when in massive form, a rock. Massive deposits are present as sedimentary beds of varying thickness in the subsurface within the Trinity Group in southwest Arkansas. Gypsum beds dip gently to the south, being part of the Early Cretaceous Gulf Coast series of sedimentary deposits. The gypsum-bearing De Queen limestone member of the Trinity Group is exposed in a narrow belt extending from the Little Missouri River in Pike County westward through Howard and Sevier counties, and dips gently to the south. The thickest single gypsum bed (at twelve feet) is at Plaster Bluff (Pike County). A significant operation near Briar (Howard County) mines five beds …

Industrial Sand Mining

Industrial sand is a term normally applied to high-purity silica sand products with closely controlled sizing. Industrial sand is a more precisely sized and shape-graded product than common sand used as aggregates in construction materials, such as concrete and asphalt. Typically, sand is composed predominantly of quartz (SiO2), and, in the case of industrial sand, the shape, size, and composition of the grains are important to determining suitable uses for the product. Sizing of industrial sand is typically done by screening and air sorting of a dried product. The term “sand,” as used by geologists, generally refers to individual grains that range in particle size from 0.00246 to 0.0787 inch (0.0625–2.0 millimeter) in diameter. This grain size ranges from just …

Lead and Zinc Mining

The history of lead and zinc mining in Arkansas is linked because ores of these two metals often occur together. Lead and zinc in Arkansas occur principally along the upper White River and its tributaries in Baxter, Boone, Independence, Lawrence, Marion, Newton, Searcy, Sharp, and Stone counties. Other locations include the Kellogg Mine in Pulaski County and the Ouachita Mountain mineral belt. Lead (Pb) is a soft, highly dense metal recognized for its low melting point and superb resistance to corrosion. Galena (PbS), containing about eighty-six percent lead, is the only lead mineral of commercial importance in Arkansas. Silver is sometimes found as an impurity that, in larger concentrations, can be extracted as a byproduct. Lead was once used to …

Lost Louisiana Mine

The Lost Louisiana Mine is an American legend about buried Spanish treasure that has been sought since the Victorian era, primarily in Arkansas’s Ouachita and Ozark mountains regions. The legend’s core narrative is that a Spanish expedition concealed a rich gold mine in the wilderness of Spain’s Luisiana colony (hence the name), and in returning to New Orleans, all but one of the party was killed by Indians. In the early twentieth century, variants of the legend attributed the treasure to either Freemasons or Sephardic Jews exiled from Spain who brought a fortune in gold and jewels with them, or a Catholic or Aztec trove brought from Spanish Mexico. Such Spanish treasure legends were once part of a deeply anti-Spanish …

Manganese Mining

The mining of manganese ore was a very important economic activity in Arkansas between 1849 and 1959. The region around Batesville (Independence County)—including about 100 square miles located in northwestern Independence County, southeastern Izard County, and northeastern Stone County—has produced more than ninety-eight percent of the manganese ore shipped from Arkansas. A second area including portions of Polk and Montgomery counties also contains manganese ores. The first commercial exploitation of manganese was by Colonel Matthew Martin. Between 1848 and 1850, Martin purchased large tracts of land containing the ore, and, between 1850 and 1852, he shipped small quantities of manganese from Penter’s Bluff (Izard County) on the White River to Boston, New York, Philadelphia, and even Liverpool, England, where it …

Mercury Mining

Mercury, which was first mined in Arkansas in 1931, is in most rock types in trace amounts, generally occurring at higher levels in shale and clay-rich sediments and organic materials like coal than in sandstone, limestone, or dolostone. Although mercury was widely used in the past for several applications, the market for products containing mercury steadily declined in the 1980s because it was recognized to be toxic. It still has important uses, however, in the chemical and electrical industries as well as in dental applications and measuring and control devices. The mercury-bearing district in southwest Arkansas occupies an area six miles wide by thirty miles long, extending from eastern Howard County through Pike County and into western Clark County. Surface …

Mining

Mining is defined as the extraction of valuable minerals or stone (mineral resources) from the earth, usually from an ore body, vein, or bed. Materials mined in Arkansas include base metals, iron, vanadium, coal, diamonds, crushed and dimension stone, barite, tripoli, quartz crystal, gypsum, chalk, and bauxite. Mineral resources are non-renewable, unlike agricultural products or factory-produced materials. Mining in a wider sense includes extraction of any non-renewable resource, including petroleum, natural gas, bromine brine, or even water. These resources are recovered by extractive methods that differ from those of normal surface or underground “hard rock” mining methods. Early settlers in the Arkansas Territory used several local mineral commodities. These included galena (lead ore), hematite and goethite (brown iron ores), saline …

Quartz Mining

Arkansas is one of a small number of places in the world with enough quartz crystals to justify commercial mining. Though the amount of unmined quartz in the state is not yet known, Arkansas does have, in terms of both size and quality, some world-class deposits of quartz. Quartz is a common mineral that becomes crystallized under extreme geologic pressure. These crystals have been used to make oscillators for radios, computer chips, and clocks. Quartz crystals are also valued for their beauty as mineral specimens and gemstones. In 1967, the General Assembly adopted the quartz crystal as the Arkansas State Mineral. History of Quartz in ArkansasA quartz arrowhead that is estimated to be over 11,000 years old was discovered at …

Saltpeter Mining

Potassium nitrate, or saltpeter, is a naturally occurring mineral that is vital to the production of gunpowder. Found in limestone caves in the Arkansas Ozarks, it became one of the state’s most important chemical industries during the Civil War due to the Confederacy’s demand for arms. Although this resource was a definite advantage for the Confederacy, problems with labor, security, and transportation made Arkansas’s saltpeter mines an ultimate failure. Saltpeter deposits were known by early Arkansas settlers long before the Civil War in Madison, Searcy, Independence, Marion, and Newton counties. A geographical survey was conducted by Dale David Owens from 1857 to 1860. His findings were published in 1860, and, by 1862, the Confederacy, looking to arm itself for the …

Sand and Gravel Mining

aka: Gravel and Sand Mining
Sand is usually defined as an accumulation of mineral grains in sizes ranging from one-sixteenth to two millimeters. Sand normally consists predominantly of quartz grains of variable degrees of roundness. Other mineral grains within the sand size range are also present and typically consist of feldspar, chert, ilmenite, and other less abundant resistant minerals. Gravel is considered to be an unconsolidated mixture of rock fragments, pebbles, cobbles, and boulders of indefinite size, but always larger than sand-sized materials. Gravel normally consists of a mixture of rock types, depending upon the original source, and may consist of various quartz rock varieties, such as chert, sandstone, novaculite, agate, and milky vein quartz, as well as limestone, dolostone, and other resistant rock types. …

Silver Mining

The silver in Arkansas is mixed sulfide ores of lead, zinc, copper, and antimony in small, scattered deposits in parts of the southern and eastern Ouachita Mountains. Most of the known mining activity involving silver took place between 1840 and 1927 and rarely resulted in profit to owners and operators. Sale of claims or mines to unsuspecting investors was usually the only route to profit. The mines opened in the 1800s were shallow, reaching maximum depths of less than 200 feet. Most of the deposits where mining was undertaken are clustered in three groups. One is along Kellogg Creek in Pulaski County, north of the Arkansas River. Deposits in another group were clustered along tributaries near the confluence of the north …

Tripoli Mining

Tripoli is a microcrystalline form of quartz (SiO2) that is derived by the alteration of chert, chalcedony, or novaculite, or leaching of highly siliceous limestones. The removal of carbonate is essential to the formation of Arkansas tripoli. Tripoli is present in three general areas of Arkansas: northwestern Arkansas near Rogers (Benton County), in the Ouachita Mountains near Hot Springs (Garland County), and near Athens (Howard County). Tripoli has varied uses. Due to its inert nature and its fine-grained texture, tripoli has numerous applications, mainly as an abrasive in polishing, buffing, and burnishing compounds; in scouring soaps and powders; a filler or extender in plastics, rubber, and sealants like caulks and epoxy resins; and a pigment in paints. It also improves …

United Mine Workers of America (UMWA)

The United Mine Workers of America (UMWA) was at one time the most powerful union in the United States. The union, which remains active in the twenty-first century, encouraged the development of the Arkansas State Federation of Labor. The UMWA was formed in 1890 in Columbus, Ohio, when Knights of Labor Trade Assembly No. 135 merged with the National Progressive Union of Miners and Mine Laborers. This combined union banned discrimination against any members based on race, national origin, or religion. By 1898, the UMWA had achieved improvements in wages and hours per week with mine operators in Pennsylvania, Ohio, Indiana, and Illinois. In 1898, the UMWA began organizing miners in western Arkansas. Arkansas became a part of District 21, and …

Vanadium Mining

Major deposits of vanadium were discovered in central Arkansas by Union Carbide’s Western Exploration Group in the 1960s. Vanadium orebodies are found in two isolated igneous intrusive complexes in the Ouachita Mountains of Arkansas: the Potash Sulphur Springs (now Wilson Springs) complex located in Garland County and the Magnet Cove complex in Hot Spring County. The Wilson Springs vanadium deposits were the first to be mined solely for vanadium in the United States. The major use of vanadium is as an alloying metal in iron and steel (ferroalloy). Small amounts of vanadium added to iron and steel significantly increase its strength, improve toughness and ductility, and reduce weight, making it suitable for structural and pipeline steel. Vanadium also increases high-temperature …