POWER PLANT Flashcards
(167 cards)
1
Q
All the coal and partings lying between a roof and floor
A
Coalbed
2
Q
A subdivision and (or) layer of a coal bed separated from other layers by partings
of non-coal rock.
A
Bench
3
Q
A dense coal, usually black, sometimes dark brown, often with well-
defined bands of bright and dull material, used primarily as fuel in steam-electric power
generation, with substantial quantities also used for heat and power applications in
manufacturing and to make coke. Bituminous coal is the most abundant coal in active
U.S. mining regions. Its moisture content usually is less than 20 percent. The heat content
of bituminous coal ranges from 21 to 30 million Btu per ton on a moist, mineral-matter-
free basis. The heat content of bituminous coal consumed in the United States averages
24 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture
and mineral matter).
A
Bituminous Coal
4
Q
The fine screenings from crushed coke. Usually will pass through a 1/2-inch or 3/4-inch screen opening.
A
Breeze
5
Q
It is most often used as a fuel source in the process of agglomerating iron ore.
A
Breeze
6
Q
The amount of heat needed to raise the temperature of 1
pound of water by 1 degree fahrenheit. Is a convenient measure by which to compare the energy content of various fuels
A
Btu (British thermal unit)
7
Q
A compact, tough variety of coal, originating from organic spore residues,
that is noncaking, contains a high percentage of volatile matter, ignites easily, and burns
with a luminous smoky flame.
A
Cannel Coal
8
Q
Coal produced and consumed by the mine operator, a subsidiary, or parent
company (for example, steel companies and electric utilities).
A
Captive Coal
9
Q
A colorless, odorless, incombustible gas formed during
combustion in fossil-fuel electric generation plants
A
Carbon Dioxide (CO2)
10
Q
A readily combustible black or brownish-black rock whose composition, including
inherent moisture, consists of more than 50 percent by weight and more than 70 percent
by volume of carbonaceous material.
A
Coal
11
Q
It is formed from plant remains that have been
compacted, hardened, chemically altered, and metamorphosed by heat and pressure over
geologic time
A
Coal
12
Q
Natural condition of the environment at any given time.
A
Ambient
13
Q
Water-bearing stratum of permeable sand, rock, or gravel.
A
Aquifer
14
Q
Electricity-generating units that are operated to meet the constant or minimum load on the system. The cost of energy from such units is usually the lowest available to the system./
A
Baseload Plants
15
Q
A geothermal electricity generating plant employing a closed-loop heat exchange system in which the heat of the geothermal fluid (the “primary fluid”) is transferred to a lower-boiling-point fluid (the “secondary” or “working” fluid), which is thereby vaporized and used to drive a turbine/generator set.
A
Binary-Cycle Plant
16
Q
A geothermal solution containing appreciable amounts of sodium chloride or other salts.
A
Brine
17
Q
Rocks of low permeability that overlie a geothermal reservoir.
A
Cap Rocks
18
Q
A process that uses a stream of geothermal hot water or steam to perform successive tasks requiring lower and lower temperatures.
A
Cascading Heat
19
Q
Water formed by condensation of steam.
A
Condensate
20
Q
Equipment that condenses turbine exhaust steam into condensate.
A
Condenser
21
Q
A structure in which heat is removed from hot condensate.
A
Cooling Tower
22
Q
Earth’s outer layer of rock. Also called the lithosphere.
A
Crust
23
Q
A type of direct use in which a utility system supplies multiple users with hot water or steam from a central plant or well field.
A
District Heating
24
Q
Boring into the Earth to access geothermal resources, usually with oil and gas drilling equipment that has been modified to meet geothermal requirements.
A
Drilling
25
Very hot steam that doesn't occur with liquid.
Dry Steam
26
The ratio of the useful energy output of a machine or other energy-converting plant to the energy input.
Efficiency
27
Rock fracturing, water injection, and water circulation technologies to sweep heat from the unproductive areas of existing geothermal fields or new fields lacking sufficient production capacity.
Enhanced Geothermal Systems
28
A fracture or fracture zone in the Earth's crust along which slippage of adjacent Earth material has occurred at some time.
Fault
29
Steam produced when the pressure on a geothermal liquid is reduced. Also called flashing.
Flash Steam
30
A vent or hole in the Earth's surface, usually in a volcanic region, from which steam, gaseous vapors, or hot gases issue.
Fumarole
31
Of or relating to the Earth's interior heat.
Geothermal
32
The Earth's interior heat made available to man by extracting it from hot water or rocks.
Geothermal Energy
33
The rate of temperature increase in the Earth as a function of depth. Temperature increases an average of 1° Fahrenheit for every 75 feet in descent.
Geothermal Gradient
34
Devices that take advantage of the relatively constant temperature of the Earth's interior, using it as a source and sink of heat for both heating and cooling. When cooling, heat is extracted from the space and dissipated into the Earth; when heating, heat is extracted from the Earth and pumped into the space.
Geothermal Heat Pumps
35
A spring that shoots jets of hot water and steam into the air.
Geyser
36
A large geothermal steam field located north of San Francisco.
The Geysers
37
Subsurface geologic formations of abnormally high heat content that contain little or no water.
HDR (hot dry rock)
38
A device for transferring thermal energy from one fluid to another.
Heat Exchanger
39
Movement of heat from within the Earth to the surface, where it is dissipated into the atmosphere, surface water, and space by radiation.
Heat Flow
40
Underground systems of hot water and/or steam.
Hydrothermal Resource
41
The process of returning spent geothermal fluids to the subsurface. Sometimes referred to as reinjection.
Injection
42
Assessing the geologic, engineering, and physical properties and characteristics of geothermal reservoirs with instruments placed in the wellbore.
Well Logging
43
A geothermal reservoir system in which subsurface pressures are controlled by vapor rather than by liquid. Sometimes referred to as a dry-steam reservoir.
Vapor-Dominated
44
A bladed, rotating engine activated by the reaction or impulse, or both, of a directed current of fluid. In electric power applications, such as geothermal plants, the turbine is attached to and spins a generator to produce electricity.
Turbine
45
Structures and conductors that carry bulk supplies of electrical energy from power-generating units.
Transmission Line
46
The rate of increase or decrease in the Earth's temperature relative to depth.
Thermal Gradient
47
Used to describe the amount of solid materials in water.
TDS (Total dissolved solids)
48
A sinking of an area of the Earth's crust due to fluid withdrawal and pressure decline.
Subsidence
49
A measure of the quantity or concentration of dissolved salts in water.
Salinity
50
A natural underground container of liquids, such as water or steam (or, in the petroleum context, oil or gas).
Reservoir
51
The ratio of the aggregate volume of pore spaces in rock or soil to its total volume, usually stated as a percent.
Porosity
52
A theory of global-scale dynamics involving the movement of many rigid plates of the Earth's crust. Tectonic activity is evident along the margins of the plates where buckling, grinding, faulting, and vulcanism occur as the plates are propelled by the forces of deep-seated mantle convection currents. Geothermal resources are often associated with tectonic activity, since it allows groundwater to come in contact with deep subsurface heat sources.
Plate Tectonics
53
The capacity of a substance (such as rock) to transmit a fluid. The degree of _______depends on the number, size, and shape of the pores and/or fractures in the rock and their interconnections. It is measured by the time it takes a fluid of standard viscosity to move a given distance. The unit of____ is the Darcy.
Permeability
54
Electricity generating plants that are operated to meet the peak or maximum load on the system. The cost of energy from such plants is usually higher than from baseload
Peaking Plants
55
The _______ is sometimes called the ripple effect because a single expenditure in an economy can have repercussions throughout the entire economy. The _______ is a measure of how much additional economic activity is generated from an initial
Multiplier Effect
56
The Earth's inner layer of molten rock, lying beneath the Earth's crust and above the Earth's core of liquid iron and nickel.
Mantle
57
Molten rock within the Earth, from which igneous rock is formed by cooling.
Magma
58
The simultaneous demand of all customers required at any specified point in an electric power system.
Load
59
The energy represented by 1 kilowatt of power consumed for a period of 1 hour, equal to 3,413 Btus. Abbreviated kWh./ Load
Kilowatt-Hour
60
A region identified by the U.S. Geological Survey as containing geothermal resources.
KGRA. Known Geothermal Resource Area.
61
The amount of coal decomposed into solid coke and gaseous products by heating in a coke oven in a limited air supply or in the absence of air.
Coal Carbonized:
62
The classification of coals according to their degree of progressive alteration from lignite to anthracite. In the United States, the standard ranks of coal include lignite, subbituminous coal, bituminous coal, and anthracite and are based on fixed carbon, volatile matter, heating value, and agglomerating (or caking) properties.
Coal Rank:
63
The collection and proper storage and handling of a relatively small quantity of coal for laboratory analysis.
Coal Sampling
64
a sample taken at the exposed coal in a mine by cutting away any loose or weathered coal then collecting on a clean surface a sample of the coal seam by chopping out a channel of uniform width and depth;
Face Channel or Channel Sample
65
a channel or drill core sample taken to represent the entire geologic coalbed; it includes all partings and impurities that may exist in the coalbed.
Column Sample:
66
a face or channel sample taken of just that contiguous portion of a coalbed that is considered practical to mine, also known as a "bench;
Bench Sample:
67
a recombined coalbed sample produced by averaging together thickness-weighted coal analyses from partial samples of the coalbed, such as from one or more bench samples, from one or more mine exposures or outcrops where the entire bed could not be accessed in one sample, or from multiple drill cores that were required to retrieve all local sections of a coal seam.
Composite Sample:
68
Coal quantities that are held in storage for future use and disposition. Note: When coal data are collected for a particular reporting period (month, quarter, or year), coal stocks are commonly measured as of the last day of this period.
Coal Stocks:
69
A series of laterally extensive and (or) lenticular coal beds and associated strata that arbitrarily can be viewed as a unit. Generally, the coal beds in a coal zone are assigned to the same geologic member or formation.
Coal Zone:
70
A bed or stratum of coal. Also called a coal seam.
Coalbed:
71
A solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal from which the volatile constituents are driven off by baking in an oven at temperatures as high as 2,000 degrees Fahrenheit so that the fixed carbon and residual ash are fused together. _____ is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace. _____ from coal is grey, hard, and porous and has a heating value of 24.8 million Btu per short ton.
Coke (coal):
72
A residue high in carbon content and low in hydrogen that is the final product of thermal decomposition in the condensation process in cracking. This product is reported as marketable coke or catalyst coke. The conversion is 5 barrels (of 42 U.S. gallons each) per short ton. ________ has a heating value of 6.024 million Btu per barrel.
Coke (petroleum):
73
_______ where coal is carbonized in slot or beehive ovens for the manufacture of coke.
Coke Plants:
74
Bituminous coal suitable for making coke.
Coking Coal:
75
A form of room-and-pillar mining in which a __________machine extracts and removes coal from the working face in one operation; no blasting is required.
Continuous Mining:
76
The oldest form of room-and-pillar mining which consists of a series of operations that involve cutting the coalbed so it breaks easily when blasted with
Conventional Mining:
77
Waste from Pennsylvania anthracite preparation plants, consisting of coarse rock fragments containing as much as 30 percent small-sized coal; sometimes defined as including very fine coal particles called silt. Its heat value ranges from 8 to 17 million Btu per short ton.
Culm:
78
Resources that have been mined; include coal recovered, coal lost in mining, and coal reclassified as subeconomic because of mining.
Depleted Resources:
79
The subtraction of both the tonnage produced and the tonnage lost to mining from identified resources to determine the remaining tonnage as of a certain time.
Depletion
80
The multiplier applied to the tonnage produced to compute depletion. This multiplier takes into account both the tonnage recovered and the tonnage lost due to mining. The _________ is the reciprocal of the recovery factor in relation to a given quantity of production.
Depletion Factor:
81
A method of recovering coal from rivers or streams.
Dredge Mining:
82
An underground mine that has a horizontal or nearly horizontal entry driven along to a coalbed exposed in a hillside.
Drift Mine:
83
A form of energy generated by friction, induction, or chemical change that is caused by the presence and motion of elementary charged particles of which matter consists.
Electricity:
84
The process of producing electric energy or transforming other forms of energy into electric energy. Also the amount of electric energy produced or expressed in watthours (Wh).
Electricity Generation:
85
A station containing prime movers, electric generators, and auxiliary equipment for converting mechanical, chemical, and/or fission energy into electric energy.
Electric Power Plant:
86
The ________ (electric utilities and independent power producers) comprises electricity-only and combined-heat-and-power (CHP) plants whose primary business is to sell electricity, or electricity and heat, to the public.
Electric Power Sector:
87
The capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy).
Energy:
88
The use of energy as a source of heat or power or as an input in the manufacturing process.
Energy Consumption:
89
The nonvolatile matter in coal minus the ash.
Fixed Carbon:
90
The upper surface of the stratum underlying a coal seam. In coals that were formed in persistent swamp environments, the _______ is typically a bed of clay, known as "underclay," representing the soil in which the trees or other coal-forming swamp vegetation was rooted.
Floor:
91
Electric generation in which the prime mover is a turbine rotated by high-pressure steam produced in a boiler by heat from burning fossil fuels.
Fossil-Fuel Electric Generation:
92
Conditions in the coal deposit or in the rocks in which it occurs that may complicate or preclude mining. ________ are evaluated in the context of the current state of technology and regulations, so the impact on mining may change with time.
Geologic Considerations:
93
Energy from the internal heat of the earth, which may be residual heat, friction heat, or a result of radioactive decay. The heat is found in rocks and fluids at various depths and can be extracted by drilling and/or pumping.
Geothermal Energy:
94
An underground loading method by which coal is removed from the working face by manual labor through the use of a shovel for conveyance to the surface.
Hand Loading:
95
the unexcavated face of exposed over-burden and coal in a surface mine.
Highwall:
96
The harnessing of flowing water to produce mechanical or electrical energy.
Hydroelectric Power:
97
Undiscovered coal resources in beds that may reasonably be expected to exist in known mining districts under known geologic conditions.
Hypothetical Resources:
98
Specific bodies of coal whose location, rank, quality, and quantity are known from geologic evidence supported by engineering measurements. Included are beds of bituminous coal and anthracite 14 inches or more thick and beds of subbituminous coal and lignite 30 inches or more thick that occur at depths to 6,000 feet and whose existence and quantity have been delineated within specified degrees of geologic assurance as measured, indicated, or inferred.
Identified Resources:
99
Coal for which estimates of the rank, quality, and quantity have been computed partly from sample analyses and measurements and partly from reasonable geologic projections. Also, are computed partly from specified measurements and partly from projection of visible data for a reasonable distance on the basis of geologic evidence. The points of observation are 0.5 to 1.5 miles apart. Indicated coal is projected to extend as a 0.5-mile-wide belt that lies more than 0.25 miles from the outcrop or points of observation or measurement.
Indicated Resources:
100
Land-use restrictions that constrain, postpone, or prohibit mining in order to meet other industrial needs or goals; for example, resources not mined due to safety concerns or due to industrial or societal priorities, such as to preserve oil or gas wells that penetrate the coal reserves; to protect surface features such as pipelines, power lines, or company facilities; or to preserve public or private assets, such as highways, railroads, parks, or buildings.
Industrial Restrictions:
101
is comprised of manufacturing industries which make up the largest part of the sector, along with mining, construction, agriculture, fisheries, and forestry. Establishments in the sector range from steel mills, to small farms, to companies assembling electronic components.
Industrial Sector:
102
Coal in unexplored extensions of demonstrated resources for which estimates of the quality and size are based on geologic evidence and projection. Quantitative estimates are based largely on broad knowledge of the geologic character of the bed or region and where few measurements of bed thickness are available. The estimates are based primarily on an assumed continuation from demonstrated coal for which there is geologic evidence. The points of observation are 1.5 to 6 miles apart. Inferred coal is projected to extend as a 2.25-mile-wide belt that lies more than 0.75 miles from the outcrop or points of observation or measurement.
Inferred Resources:
103
A line on a map drawn through points of equal thickness of a designated unit (such as a coal bed).
Isopach:
104
The lowest rank of coal, often referred to as brown coal, used almost exclusively as fuel for steam-electric power generation. It is brownish-black and has a high inherent moisture content, sometimes as high as 45 percent The heat content of lignite ranges from 9 to 17 million Btu per ton on a moist, mineral-matter-free basis. The heat content of this consumed in the United States averages 13 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture and mineral matter).
Lignite:
105
An automated form of underground coal mining characterized by high recovery and extraction rates, feasible only in relatively flat-lying, thick, and uniform coalbeds. A high-powered cutting machine is passed across the exposed face of coal, shearing away broken coal, which is continuously hauled away by a floor-level conveyor system.
Longwall Mining:
106
Coal for which estimates of the rank, quality, and quantity have been computed, within a high degree of geologic assurance, from sample analyses and measurements from closely spaced and geologically well known sample sites.
Measured Resources:
107
Coking coal and pulverized coal consumed in making steel.
Metallurgical Coal:
108
A unit of weight equal to 2,204.6 pounds.
Metric Ton:
109
Capable of being mined under current mining technology and environmental and legal restrictions, rules, and regulations.
Minable:
110
in coal is the parent material in coal from which ash is derived, and which comes from minerals present in the original plant materials that formed the coal, or from extraneous sources such as sediments and precipitates from mineralized water. Mineral matter in coal cannot be determined by chemical analysis and is commonly calculated using data on ash and ash-forming constituents. Coal analyses are calculated to the mineral-matter-free basis by adjusting formulas used in calculations in order to deduct the weight of mineral matter from the total coal.
Mineral-Matter-Free Basis:
111
coal contains its natural inherent or bed moisture, but does not include water adhering to the surface. Coal analyses expressed on a ______ are performed or adjusted so as to describe the data when the coal contains only that moisture which exists in the bed in its natural state of deposition, and when the coal has not lost any moisture due to drying.
Moist (Coal) Basis:
112
A mixture of hydrocarbons and small quantities of various nonhydrocarbons existing in the gaseous phase or in solution with crude oil in under-ground reservoirs.
Natural Gas
113
The marketable portion of natural gas production, which is obtained by subtracting extraction losses, including natural gas liquids removed at natural gas processing plants, from total production.
Natural Gas (Dry):
114
The price paid for a product or service at the time of the transaction. The ______, which is expressed in current dollars, is not adjusted to remove the effect of changes in the purchasing power of the dollar.
Nominal Price:
115
Electricity generated by an electric power plant whose turbines are driven by steam generated in a reactor by heat from the fissioning of nuclear fuel.
Nuclear Electric Power:
116
The __________, or mines collocated with preparation plants or tipples, located in a particular geographic area (State or region). If a mine is mining coal across two States, then it is counted as two operations. This is done so that EIA can separate production by State.
Number of Mines:
117
Coal sold in the _______, i.e., coal sold to companies other than the reporting company's parent company or an operating subsidiary of the parent company.
Open Market Coal:
118
Any material, consolidated or unconsolidated, that overlies a coal deposit.
Overburden:
119
A company which solely or jointly owns the reporting company and which is not itself a subsidiary of, or owned by, another company.
Parent Company:
120
The ratio of total production to productive capacity, times 100.
Percent Utilization:
121
Energy radiated by the sun as electromagnetic waves (electromagnetic radiation) that is converted at electric utilities into electricity by means of solar (photo-voltaic) cells or concentrating (focusing) collectors.
Photovoltiac and Solar Thermal Energy (as used at electric utilities):
122
A facility at which coal is crushed, screened, and mechanically cleaned.
Preparation Plant:
123
____________ consist of coal held in stock by producers/distributors at the end of a reporting period.
Producer and Distributor Coal Stocks:
124
The maximum amount of coal that a mining operation can produce or process during a period with the existing mining equipment and/or preparation plant in place, assuming that the labor and materials sufficient to utilize the plant and equipment are available, and that the market exists for the maximum production.
Productive Capacity:
125
1015 Btu.
Quadrillion Btu:
126
An informal classification of coal relating to its suitability for use for a particular purpose. Refers to individual measurements such as heat value, fixed carbon, moisture, ash, sulfur, major, minor, and trace elements, coking properties, petrologic properties, and particular organic constituents. The individual quality elements may be
Quality or Grade:
127
A price that has been adjusted to remove the effect of changes in the purchasing power of the dollar.________, which are expressed in constant dollars, usually reflect buying power relative to a base year.
Real Price:
128
In reference to accessible coal resources, the condition of being physically, technologically, and economically minable. Recovery rates and recovery factors may be determined or estimated for coal resources without certain knowledge of their economic minability; therefore, the availability of recovery rates or factors does not predict recoverability.
Recoverability:
129
Coal that is, or can be, extracted from a coal bed during mining.
Recoverable Coal:
130
The amount of in situ coal that can be recovered by mining existing reserves at mines reporting on Form EIA-7A.
Recoverable Reserves at Producing Mines:
131
Reserve estimates (broad meaning) based on a demonstrated reserve base adjusted for assumed accessibility factors and recovery factors. The term is used by EIA to distinguish estimated recoverable reserves, which are derived without specific economic feasibility criteria by factoring (downward) from a demonstrated reserve base for one or more study areas or regions, from recoverable reserves at active mines, which are aggregated (upward) from reserve estimates reported by currently active, economically viable mines on Form EIA-7A.
Recoverable Reserves, Estimated Recoverable Reserves:
132
An estimate of the amount of coal that can be recovered (mined) from the accessible reserves of the demonstrated reserve base.
Recoverable Reserves of Coal:
133
The percentage of total tons of coal estimated to be recoverable from a given area in relation to the total tonnage estimated to be in the demonstrated reserve base. For the purpose of calculating depletion factors only, the estimated recovery factors for the demonstrated reserve base generally are 50 percent for underground mining methods and 80 percent for surface mining methods. More precise recovery factors can be computed by determining the total coal in place and the total coal recoverable in any specific locale.
Recovery Factor:
134
The percentage of coal that can be recovered from the coal deposits at existing mines.
Recovery Percentage:
135
A repository for waste material generated by the coal cleaning process.
Refuse Bank:
136
A surface mine where coal is recovered from previously mined coal. It may also be known as a silt bank, culm bank, refuse bank, slurry dam, or dredge operation.
Refuse Mine:
137
Those products, exclusive of moisture, given off by a material as gas or vapor. In coal, volatile matter is determined by heating the coal to 950 degrees centigrade under carefully controlled conditions and measuring the weight loss, excluding weight of moisture driven off at 105 degrees centigrade.
Volatile Matter:
138
Coal that has not been accessed by mining. See accessed.
Virgin Coal:
139
Unspecified bodies of coal surmised to exist on the basis of broad geologic knowledge and theory. It include beds of bituminous coal and anthracite 14 inches or more thick and beds of subbituminous coal and lignite 30 inches or more thick that are presumed to occur in unmapped and unexplored areas to depths of 6,000 feet. The speculative and hypothetical resource categories comprise undiscovered resources.
Undiscovered Resources:
140
The extraction of coal or its products from between enclosing rock strata by underground mining methods, such as room and pillar, longwall, and shortwall, or through in-situ gasification.
Underground Mining:
141
A mine where coal is produced by tunneling into the earth to the coalbed, which is then mined with underground mining equipment such as cutting machines and continuous, longwall, and shortwall mining machines. Underground mines are classified according to the type of opening used to reach the coal, i.e., drift (level tunnel), slope (inclined tunnel), or shaft (vertical tunnel).
Underground Mine:
142
A central facility used in loading coal for transportation by rail or truck.
Tipple:
143
A coal mine that is usually within a few hundred feet of the surface. Earth and rock above or around the coal (overburden) is removed to expose the coalbed, which is then mined with surface excavation equipment such as draglines, power shovels, bulldozers, loaders, and augers. Surface mines include: area, contour, open-pit, strip, or auger mine.
Surface Mine:
144
One of the elements present in varying quantities in coal that contributes to environmental degradation when coal is burned. EIA classifies coal, in terms of pounds of sulfur per million Btu as low (less than or equal to 0.60 pounds of sulfur), medium (between 0.61 and 1.67 pounds of sulfur), and high (greater than or equal to 1.68 pounds of sulfur). When coal is sampled, sulfur content is measured as a percent by weight of coal on an “as received” or “dry” (moisture-free) basis.
Sulfur:
145
A coal whose properties range from those of lignite to those of bituminous coal and used primarily as fuel for steam-electric power generation. It may be dull, dark brown to black, soft and crumbly, at the lower end of the range, to bright, jet black, hard, and relatively strong, at the upper end. Subbituminous coal contains 20 to 30 percent inherent moisture by weight. The heat content of subbituminous coal ranges from 17 to 24 million Btu per ton on a moist, mineral-matter-free basis. The heat content of subbituminous coal consumed in the United States averages 17 to 18 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture and mineral matter).
Subbituminous Coal:
146
The supply of coal or coke at a mine, plant, or utility at the end of the reporting period.
Stocks:
147
All nonmetallurgical coal.
Steam Coal:
148
Undiscovered coal in beds that may occur either in known types of deposits in a favorable geologic setting where no discoveries have been made, or in deposits that remain to be recognized. Exploration that confirms their existence and better defines their quantity and quality would permit their reclassification as identified resources.
Speculative Resources:
149
The radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity.
Solar Energy:
150
A repository for the silt or culm from a preparation plant.
Slurry Dam:
151
An underground mine in which the entry is driven at an angle to reach the coal deposit.
Slope Mine:
152
Waste from Pennsylvania anthracite preparation plants, consisting of coarse rock fragments containing as much as 30 percent small-sized coal; sometimes defined as including very fine coal particles . Its heat value ranges from 8 to 17 million Btu per short ton. Synonymous with culm.
Silt:
153
A form of underground mining that involves the use of a continuous mining machine and movable roof supports to shear coal panels 150 to 200 feet wide and more than half a mile long. Although similar to longwall mining, shortwall mining is generally more flexible because of the smaller working area. Productivity is lower than with longwall mining because the coal is hauled to the mine face by shuttle cars as opposed to conveyors.
Shortwall Mining:
154
A unit of weight equal to 2,000 pounds.
Short Ton:
155
An underground mine that reaches the coalbed by means of a vertical shaft. In addition to the passages providing entry to the coalbed, a network of other passages are also dug, some to provide access to various parts of the mine and some for ventilation.
Shaft Mine:
156
A bed of coal lying between a roof and floor. Equivalent term to bed, commonly used by industry.
Seam:
157
An underground loading method by which coal is removed from the working face by a tractor unit equipped with a hydraulically operated bucket attached to the front; also called a front-end loader.
Scoop Loading:
158
A representative fraction of a coal bed collected by approved methods, guarded against contamination or adulteration, and analyzed to determine the nature; chemical, mineralogic, and (or) petrographic composition; percentage or parts-per-million content of specified constituents; heat value; and possibly the reactivity of the coal or its constituents.
Sample:
159
The reported output from Federal and/or Indian lands, the basis of royalties. It is approximately equivalent to production, which includes coal sold, and coal added to stockpiles.
Sales Volume:
160
The shippable product of a coal mine or preparation plant. Depending on customer specifications, salable coal may be run-of-mine, crushed-and-screened (sized) coal, or the clean coal yield from a preparation plant.
Salable Coal:
161
The raw coal recovered from a mine, prior to any treatment.
Run-of-mine:
162
The traditional method of underground mining in which the mine roof is supported mainly by coal pillars left at regular intervals. Rooms are places where the coal is mined; pillars are areas of coal left between the rooms. ________ is done either by conventional or continuous mining.
Room-and-Pillar Mining:
163
The rock immediately above a coal seam. The_____ is commonly a shale, often carbonaceous and softer than rocks higher up in the roof strata.
Roof:
164
Naturally occurring concentrations or deposits of coal in the Earth's crust, in such forms and amounts that economic extraction is currently or potentially feasible.
Resources:
165
Root meaning: The amount of in-situ coal in a defined area that can be recovered by mining at a sustainable profit at the time of determination. Broad meaning: That portion of the demonstrated reserve base that is estimated to be recoverable at the time of determination. Is derived by applying a recovery factor to that component of the identified resources of coal designated as the demonstrated reserve base.
Reserve(s):
166
The calendar year beginning at 12:00 a.m. January 1 and ending at 11:59 p.m. December 31.
Report Year:
167
The amount of coal in the ground after some mining, excluding coal in the ground spoiled or left in place for which later recovery is not feasible.
Remaining (Resources/Reserves):
