Mineral Commodities

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Miscellaneous Dimension Stone

Miscellaneous varieties of dimension stone (local varieties not reported to U.S. Bur. Mines according to rock type) accounted for 0.1 percent of the value and 0.5 percent of the quantity of Appalachian dimension stone production from 1945 to 1964.  Production during this period represented 2 percent of the miscellaneous dimension stone quarried in the United States.  Quantities and values of annual production in Appalachia and the United States for the 20-year period are given in table 76.  Pennsylvania was the major producing State.  Production from Appalachia, last reported in 1963, was used as rubble and flagging.

Table 76.  Production of miscellaneous varieties of dimension stone, 1945-64.  (Source: U.S. Bur. Mines)

(Please note that several sections have been skipped before the "Lime" section of the book.  If you wish to view the topics skipped, see the scanned in Table of Contents for the book.)

 

Lime

By George E. Ericksen, U.S. Geological Survey,
and Robert D. Thomson, U.S. Bureau of Mines

Lime is principally calcium oxide (CaO), or a mixture of CaO and magnesium oxide (MgO), prepared by calcining limestone or dolomite, and is a basic industrial chemical that is manufactured at several localities in Appalachia (fig. 66).  The lime-producing centers in Appalachia are:  (1) Birmingham, Ala., (2) central and western Pennsylvania, (3) Knoxville, Tenn., (4) southwestern Virginia and southeastern West Virginia, and (5) the Eastern Panhandle of West Virginia.  In 1964, 31 lime plants were operating in these areas (fig. 66).  Most of the lime is used as flux and refractory material by the steel industry, as a chemical in the manufacture of paper and for purification of water, as lime mortar by the construction industry, and as agricultural lime (aglime).

Figure 66.  Counties in the Appalachian Region in which lime is produced. 
Dots or numbers indicate lime plants in county.

Three types of lime are marketed, quicklime, hydrated lime, and dead-burned dolomite.  Quicklime is produced by calcining a high-calcium limestone at a temperature of about 2,000° F to make a product consisting almost entirely of CaO.  Hydrated lime is made by treating quicklime with a controlled amount of water to transform the CaO to Ca (OH)₂.  Dead-burned dolomite, used mainly as a refractory by the steel industry, is prepared by calcining high-purity dolomite, at high temperature (above 2,800°F).  Dead-burned dolomite is relatively inert to action of atmospheric moisture and carbon dioxide, whereas the high-calcium lime is very reactive.  The only dead-burned dolomite produced in Appalachia comes from the eastern panhandle of West Virginia.

The production of lime in Appalachia in 1964 totaled 2,273,257 short tons valued at $28,812,504 million.  To make this lime, the companies used about 4.3 million tons of limestone and dolomite.  Quicklime (including a relatively small amount of dead-burned dolomite) constituted most of the production - 2,007,213 short tons valued at $25,047,610.  Production of hydrated lime was 266.044 short tons valued at $3,764,894.  These figures indicate that in 1964 the average value of quicklime in Appalachia was $12.48 per ton and of hydrated lime $14.15 per ton.

The high-calcium limestone and high purity dolomite described in the following section on limestone and dolomite are all potential sources of lime.  High-quality aglime can be made from a magnesian limestone or calcitic dolomite as well as from pure limestone or dolomite.

Table 84 shows the geologic formations that were the sources of limestone and dolomite used for the manufacture of lime in Appalachia in 1964.  By far the greatest part of high calcium lime was produced from stone of the Vanport Limestone in western Pennsylvania, the Valentine Member (of Field, 1919) of the Curtin Formation (of Kay, 1943) in Centre County, Pa., the Mosheim Member of the Lenoir Limestone, and limestone beds in the Tomstown Dolomite in the Eastern Panhandle of West Virginia, the Holston Formation in Tennessee, and the Newala Limestone in Alabama.  Dead-burned dolomite was produced only from Tomstown Dolomite of West Virginia.

Table 84.  Limestones and dolomites used for production of lime in the Appalachian Region, 1964.

High-calcium limestone, suitable for the manufacture of high quality lime for industrial and metallurgical use, and construction is moderately abundant in many parts of Appalachia and should supply most present and future needs.  Rock suitable for making agricultural lime is abundant and widespread.

High-purity dolomite for refactory lime is less widespread in Appalachia than high-calcium limestone.  Only the Tomstown Dolomite of the Eastern Panhandle of West Virginia and the Ketona Dolomite of Alabama (now used as a fluxing stone but not used in the manufacture of lime) are major sources of high-purity dolomite.  Reserves of the Ketona Dolomite are sufficiently large to supply the needs of the present or future Birmingham steel industry.  Reserves of the high-purity Tomstown Dolomite are probably also large enough to supply the present market area in the future.  The Honaker Dolomite of eastern Tennessee contains considerable amounts of high-purity dolomite suitable for refactory lime (Robert A. Laurence, written commun., 1966), particularly in Green and Carter Counties.

Limestone and Dolomite

By George E. Ericksen and Dennis P. Cox,
U.S. Geological Survey

Introduction

Limestone and dolomite are among the most widely used mineral commodities in the United States and are essential to modern industry.  They are classified for statistical or marketing purposes as either crushed stone, regardless of final use, or dimension stone.  In this report, limestone and dolomite are discussed in geology, chemical composition, and distribution.  Other sections that describe special uses and production are those on "Cement," "Crushed Stone," "Dimension Stone," and "Lime."

Limestone and dolomite are abundant and widespread in Appalachia and constitute one of the principal mineral commodities of the region, being exceeded in total value of production only by coal and by petroleum and natural gas.  During 1964, they were exploited for crushed stone at about 300 sites, mostly open pits or quarries, but at a few places in underground mines.  Figure 67 shows the counties in Appalachia that had one or more active mines in 1964.  Table 62 shows the production of crushed limestone and dolomite in Appalachia and its value since 1945.  Table 62 shows the production of crushed limestone and dolomite in Appalachia and its value since 1945. Production in 1964 was nearly 76 million tons having a value of about $110 million (1958 constant dollars). In addition, production of crushed marble in 1964 was 1.5 million tons valued at about $13 million (table 65).

Figure 67.  Counties in the Appalachian Region with one or more
mines producing crushed limestone or dolomite in 1964. 

Limestone and dolomite are carbonate rocks and composed principally of the carbonate minerals calcite (CaCO₃) and dolomite (CaMg(CO₃)₂).  Commonly, they are referred to as limestone, but strictly speaking limestone is a rock composed chiefly of calcite, whereas dolomite consists chiefly of the mineral dolomite (containing 54.35 percent CaCO₃, and 45.65 percent MgCO₃).

For the purpose of this report, limestone and dolomite are considered to be rocks containing more than 50 percent of the carbonates calcite and dolomite.  In limestone, calcite makes up 80 percent or more of the carbonate fraction whereas in dolomite, the mineral dolomite makes up 80 percent or more of this fraction.  Rocks of more intermediate composition are called magnesian or dolomitic limestone or calcitic dolomite.  Impurities in limestone and dolomite are aluminous material such as clay and shale and siliceous material such as sand and chert.  Marble is a crystalline rock, generally formed by metamorphism of limestone or dolomite.

High-calcium limestone and high-purity (or high-magnesian) dolomite are widely used in the chemical and metallurgical industries and because they are comparatively rare, have a higher value than impure carbonate rocks.  Published specifications of chemical composition of these types vary.  In this report, high-calcium limestone is considered to consist of 95 percent or more CaCO₃ even though some authors cite a minimum of 97 percent.  High-purity dolomite has a comparable content of total carbonate of which not less than 40 percent is MgCO₃.

Uses of Crushed Limestone and Dolomite

The many uses of crushed limestone and dolomite are dependent upon either physical properties such as strength, resistance to abrasion, degree of porosity, grain size and crystallinity, and color, or upon chemical composition, wherein contained impurities are limited to specific quantities.  Although specifications differ according to use, most limestone and dolomite are suitable for general-purpose crushed stone.  Requirements for chemical and metallurgical stone vary according to use and availability of certain stone to a given industry.  Table 85 from O'Neill (1965, p. 2) shows some examples of specifications of limestone and dolomite used by industry in Pennsylvania.

Table 85.  Chemical requirements for uses of limestone and dolomite. 
(This table indicates chemical requirements as standardized
by the various consuming industries.  After O'Neill, 1965, p. 2)

The tonnage and value of crushed limestone and dolomite, by use, produced in Appalachia in 1963 and 1964 are shown in table 86.  By far the greatest use was for concrete aggregate and roadstone, but large amounts were also used in the manufacture of cement and lime and for flux and agricultural limestone.  Table 87, which shows production and value of crushed marble for the same years, indicates a principal use as roadstone but also important use as terrazzo chips.  Large amounts of pulverized marble (included in other uses in the table) are used in paint, putty, and other manufactured products.

Table 86.  Limestone and dolomite (crushed and broken stone)
sold or used by producers in the Appalachian Region.

Table 87.  Marble (crushed and broken stone)
sold or used by producers in the Appalachian Region.

The main uses or types of crushed limestone and dolomite are briefly summarized below (taken mainly from Bowles, 1956, p. 11-16).

Concrete aggregate and roadstone (also called road metal) constitute nearly two-thirds of the crushed stone produced in Appalachia; they are marketed in various sizes and used mainly by the building industry and in highway construction.  The stone must be clean, hard, strong, and free of soft or friable material; it should break into irregular, more or less equi-dimensional fragments rather than into thin platy or elongate fragments.  Roadstone also should be resistant to abrasion and have a low porosity so that it does not break up during freezing and thawing.  Concrete aggregate should be low in reactive materials such as alkalies, soluble sulfides, and certain types of silica, particularly chert, which weaken concrete or cause it to disintegrate.

Cement limestone is a limestone low in magnesium that, when mixed with the proper proportions of clay and silica, can be burned in a kiln to make portland cement.  Portland cement should contain not more than 5 percent MgO.  Cement limestone may be argillaceous and siliceous.  One which contains about the proper proportions of CaCO₃, clay, and silica required for the manufacture of cement is called a cement rock.

Lime is made by calcining and pulverizing high-calcium limestone (or dolomite) to make a product used in a wide variety of chemical and metallurgical industries as well as in construction and agriculture, as described in the preceding section on "Lime."

Fluxing stone is high-calcium limestone or high-purity dolomite used as a flux in iron and steel furnaces.  The most desirable sizes are 4-6 inches in diameter; generally material less than 2 inches in diameter is not used.

Agricultural limestone (agstone) is finely ground limestone or dolomite used as fertilizer, soil conditioner, and as a neutralizer of excess acids in the soil.  The relative amounts of calcium and magnesium are generally of no importance although the CO₂ content should be high; therefore, a relatively pure carbonate rock is best for this purpose.

Railroad ballast, used for the construction and maintenance of railroad beds, consists of crushed limestone of the size range 3/4 to 2 1/2 inches.  The specifications are similar to those for roadstone.

Riprap consists of large irregular blocks used in construction along rivers, such as shore protection, bridge piers, and docks.

Refractory stone is high-purity dolomite which is used in construction and repair of metallurgical furnaces, as bricks made of calcined dolomite, or as pulverized dolomite used in patching linings of hot furnaces.

Asphalt filler, a limestone dust of which about 80 percent will pass a 200-mesh screen, is produced as a byproduct of crushed-stone operations.  It is mixed with asphalt and tar used in road construction and in the manufacture of roofing shingles and asphalt siding.  Asphalt containing limestone filler is more durable as road-surfacing material and is more resistant to melting in hot weather than is asphalt without the filler.

Limestone sand is washed and graded material of sand size that is used as a substitute for silica sand in mortar, wall plaster, and concrete.

Coal-mine dust is pulverized, relatively high purity limestone that is spread in coal mines to check or prevent coal-dust explosions.  Such dust should contain less than 5 percent silica and should be of such a size that 100 percent will pass a 20-mesh screen and 70 percent a 200-mesh screen.

Sewage filter beds are constructed of crushed and screened limestone or dolomite that may be somewhat siliceous, but should be free of other impurities such as iron sulfide and clay.  The stone should be free of fines, should be strong and compact, and should consist of fragments having rough surfaces to provide anchorage for the bacteria and a uniform porosity when laid as a bed.

Poultry grit can be made of sized finely crushed limestone.

Crushed marble has many of the same uses as crushed limestone.  Marble chips are also used as a concrete aggregate in making terrazzo, a type of flooring that can be smoothed and polished after setting.  Pulverized marble is used in the manufacture of paint and putty and as a filler in products such as rubber, paper, and linoleum.

Occurrences in Appalachia

Limestone and dolomite are abundant and widespread in the Valley and Ridge province and along the west side of Appalachia, mainly in the Interior Low Plateaus but are relatively scarce in the Appalachian Plateaus, Piedmont, and Blue Ridge provinces (Fig 68).  Limestone and dolomite formations in the Valley and Ridge province range from Cambrian to Mississippian in age and have been so intensively folded and faulted that they commonly dip steeply and crop out in parallel belts in which the same rock sequence may be repeated several times.  Such repetition is well shown in eastern Tennessee where the many belts of dolomite shown in figure 68 belong to the Knox Group of Cambrian and Ordovician age.  In contrast, most limestone formations in the western part of Appalachia are flat-lying rocks of Mississippian age.  The flat-lying Pennsylvanian and Permian rocks underlying most of the Appalachian Plateaus (pl. 2) province have many layers of thin limestone in Ohio, Pennsylvania, and northern West Virginia.  The limestone layers decrease in number to the south.  Only the Vanport Limestone of western Pennsylvania and Ohio has been exploited on a large scale.  Scattered lenses and bands of marble, limestone, and dolomite are found in the Piedmont and Blue Ridge provinces.

Figure 68.  Principal areas of limestone and dolomite in Appalachian Region.

Limestone and dolomite formations in Appalachia that have been exploited most extensively and their distribution are listed in table 88.  All contain excellent stone for concrete aggregate and roadstone, as well as for other uses that primarily require a hard durable stone.  Most can be utilized for agricultural lime but are too impure or too variable in composition to be used as a chemical or metallurgical stone.  Several of the formations contain cement limestone, and a few contain high-calcium limestone for which they are extensively exploited.  High-purity dolomite is relatively rare in Appalachia, being found locally in only a few formations.

For convenience of discussion, the limestone and dolomite units of each of the three main structural belts or provinces of Appalachia-the metamorphic belt (Piedmont and Blue Ridge provinces), the folded belt (Valley and Ridge province), and the belt of relatively undeformed rocks (Appalachian Plateaus, Interior Low Plateaus, and Central Lowland)-are described separately.  The carbonate rocks show distinct geologic features in each of these belts that affect their availability and utilization.

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