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C Glossary ABANDONED MINE Excavations, either caved or sealed, that are deserted and in which further mining is not intended and open workings that are not ventilated and inspected regularly. (AGI dictionary) ACID-BASE ACCOUNTING Procedures for quantifying the potential for acid generation and acid neutralization in a geologic solid based on laboratory test to help predict the impacts of mining on local water quality. ACID MINE DRAINAGE Acidic drainage from bituminous coal mines contain- ing a high concentration of acidic sulfates, esp. ferrous sulfate. (AGI Dictionary) ACTIVE MINE The area, on and beneath land, used or disturbed in activity related to the extraction, removal, or recovery of coal from its natural deposits. (AGI Dictionary) ADSORPTION Adherence of gas molecules, or of ions or molecules in solu- tion, to the surface of solids with which they are in contact, as methane to coal or water to silica gel. ADVECTION The horizontal movement of a mass of air which causes changes in temperature or in other physical properties of air. (Webster Unabridged) ALKALINITY The extent to which a material exhibits the property of yield- ing hydroxyl ions in a water solution. (AGI Dictionary) 217
218 MANAGING COAL COMBUSTION RESIDUES IN MINES ANTHRACITE A hard, black lustrous coal containing a high percentage of fixed carbon and a low percentage of volatile matter. Commonly referred to as hard coal, it is mined in the United States, mainly in eastern Pennsylvania, al- though in small quantities in other states. (AGI Dictionary) AQUITARD Low-permeability bed, in a stratigraphic sequence, of sufficient permeability to allow movement of contaminants, and to be relevant to regional groundwater flow, but of insufficient permeability for the economic production of water. ARSENIC A metallic, steel-gray, brittle element. Symbol, As. Found native in realgar and orpiment, and combined with heavy metals. Used in bronzing, pyrotechny, insecticides, and poisons, and as a doping agent in transistors. Gal- lium arsenide is used as a laser material to convert electricity directly into coher- ent light. Arsenic and its compounds are poisonous. (AGI Dictionary) ASH The inorganic residue after burning, esp. of coal. Ignition generally alters both the weight and the composition of the inorganic matter. (AGI Dictionary) ATTENUATION A reduction in the amplitude or energy of a signal, such as might be produced by passage through a filter. (AGI Dictionary) ATTERBERG LIMITS In a sediment, the water-content boundaries between the semiliquid and plastic states (known as the liquid limit) and between the plastic and semisolid states (known as the plastic limit). (AGI Dictionary) BAGHOUSES See fabric filters BACKFILL Material excavated from a site and reused for filling, for example the use of stones or coarse gravel for filling draining trenches. (AGI Dictionary) BENTHIC Of or relating to or happening on the bottom under a body of water. BIOACCUMULATION The process by which the concentrations of some toxic chemicals gradually increase in living tissue, such as in plants, fish, or people as they breathe contaminated air or consume contaminated food or water. BITUMINOUS COAL A general term descriptive of coal other than anthracite and low-volatile coal on the one hand and lignite on the other. (AGI Dictionary) BOILER SLAG A molten ash collected at the base of slag tap and cyclone furnaces that is quenched with water and shatters into black, angular particles having a smooth, glassy appearance. (ACAA, 2003 glossary of terms)
APPENDIX C 219 BORROW MATERIAL Soil or sediment removed from a site for use in construction, such as sandy sediment dredged and pumped to restore an eroded beach, or clay taken to build a levee or dike. (AGI Dictionary) BOTTOM ASH Agglomerated ash particles formed in pulverized coal fur- naces that are too large to be carried in the flue gases and impinge on the furnace walls or fall through open grates to an ash hopper at the bottom of the furnace. Bottom ash is typically gray to black in color, is quite angular, and has a porous surface structure. (ACAA, 2003 glossary of terms) BULK CHEMICAL CONTENT The major mineral component of a fly ash is mullite, a mineral containing alumina silica oxide. The major mineral compo- nents of fluidized bed combustion (FBC) CCRs are anhydrite, calcite, lime (all calcium oxides), and hematite, an iron oxide (CIBO, 1997). Silicon dioxide com- prises 17-52 percent by weight of fly ash and FBC CCRs. Other components in fly ashes and FBC CCRs are aluminum dioxide (7-24 percent), iron oxide (5-14 percent), and magnesium oxide (2-7 percent). FBC CCRs are typically higher in calcium oxide and sulfur trioxide than pulverized coal CCRs due to the co- combustion of limestone for SO2 control in FCBs. CADMIUM A soft, bluish-white metal, similar in many respects to zinc, cop- per, and lead ores. Almost all cadmium is obtained as a by-product in the treat- ment of these ores. Symbol, Cd. Used in electroplating, in solder, for batteries, as a barrier to control atomic fission, and in TV tubes. Cadmium and solutions of its compounds are toxic. (AGI Dictionary) CAPILLARY FRINGE Zone of partially saturated material just above the water table. The depth of the fringe depends upon the size and distribution of the pore spaces within the geologic framework. CAPPING The overburden or rock deposit overlying a body of capped mineral or ore. (AGI Dictionary) CEMENTITIOUS Fly ash has the properties of, or acts like, a cement when mixed with water. (American Geological Institute, 1997) CENOSPHERES A portion of fly ash that floats on the surface of ash ponds and can be harvested. They are lightweight (0.368 to 0.449 grams per cubic centimeter), inert, hollow, essentially thin-walled glass spheres (10 to 350 mi- crons in diameter) comprised largely of silica and alumina and filled with air and/ or gases and are formed from the ash when it is in a molten state. Cenospheres are also now being extracted from dry fly ash by companies using proprietary pro- cesses and subsequently marketed under registered trade names. (ACAA, 2005b).
220 MANAGING COAL COMBUSTION RESIDUES IN MINES COAL BED The smallest distinctive division of a stratified series of coal, marked by a more or less well-defined surface or plane from its neighbors above and below; also known as a layer or stratum. COAL COMBUSTION RESIDUES Solid residues generated by coal-burn- ing electric utilities in the production of electricity. COAL RESERVES Measured tonnages of coal that have been calculated to occur in a coal seam within a particular property. COAL SEAM A bed or stratum of coal. COAL SPOILS Refer to spoil. CO-FIRED MATERIALS Non-coal materials fired at the same time as coal in the same boiler. COGENERATION FACILITIES A steam generation facility that that uses the steam for an industrial process (e.g., heating, cooling, manufacturing) as well as for electricity generation. COKE Bituminous coal from which the volatile constituents have been driven off by heat, so that the fixed carbon and the ash are fused together. Commonly artificial, but natural coke is also known; e.g., where a dike has intersected a bituminous coal bed and has converted the bordering coal to natural coke. (AGI Dictionary) COLUMN LEACHING METHODS Simulation of in situ leaching through the use of a long narrow column in which ore sample and solution are in contact for measuring the effects of typical variables encountered in actual in situ leach mining. (AGI Dictionary) COMBUSTION The action or operation of burning; the continuous combina- tion of a substance with certain elements, such as oxygen or chlorine; e.g., ac- companied by the generation of light and heat. (AGI Dictionary) CULM In anthracite terminology, it is the waste accumulation of coal, bone, and rock from old dry breakers. In bituminous coal preparation, culm corre- sponds to slurry or slime, depending upon the size distribution of the suspended solids. (AGI Dictionary) CYCLONE The conical shaped apparatus used in dust collecting operations and fine grinding applications. In principle, the cyclone varies the speed of air,
APPENDIX C 221 which determines whether a given particle will drop through force of specific gravity or be carried through friction of the air. (AGI Dictionary) DESORPTION The reverse process of adsorption whereby adsorbed matter is removed from the adsorbent. The term is also used as the reverse process of absorption. (AGI Dictionary) DESULPHURIZE To free from sulfur; to remove the sulfur from an ore or mineral by some suitable process, as by roasting. (AGI Dictionary) DILUTION The contamination of ore with barren wall rock in stoping. The assay of the ore after mining is frequently 10% lower than when sampled in place. (AGI Dictionary) DIOXINS Toxic, human-made chemical by-products (dibenzo-p-dioxins), re- leased into the atmosphere from incineration and during industrial processes that use chlorine. Dioxin tends to accumulate in the fatty tissue of fish. They can have immediate and long-term health effects, including skin disease, cancer, and re- productive failure. ELECTROSTATIC PRECIPITATOR (ESP) The most common particulate control technology used by coal-fired utilities. An ESP generates a high-intensity electrical field that causes ash particles to acquire an electrical charge and mi- grate to an oppositely charged collection surface. For typical coal-fired utilities, this process results in a collection efficiency of greater than 99 percent. EVAPOTRANSPIRATION Loss of water from the soil both by evaporation and by transpiration from the plants growing thereon. (Webster's dictionary online) FABRIC FILTERS Also known as baghouses, capture ash as the exit gas passes through a series of porous filter bags. Baghouses have an efficiency of greater than 99 percent. FUGITIVE DUST The particulate matter not emitted from a duct or stack that becomes airborne due to the forces of wind or surface coal mining and reclama- tion operations or both. During surface coal mining and reclamation operations it may include emissions from haul roads; wind erosion of exposed surfaces, stor- age piles, and spoil piles; reclamation operations; and other activities in which material is either removed, stored, transported, or redistributed. (AGI Dictionary)
222 MANAGING COAL COMBUSTION RESIDUES IN MINES GOB A pile of loose waste, coal, and other minerals extracted from a mine that are not marketable. Gob may be left piled in underground workings or at the surface of the mine. GRADING The relative proportions of the variously sized particles in a batch, or the process of screening and mixing to produce a batch with particle sizes correctly proportioned. (AGI Dictionary) GRATE FIRING Coal is combusted while residing on a grate within the furnace. HEAT CONTENT The sum of the latent heat and sensible heat contained in a substance, above the heat contained at a selected zero condition of temperature and pressure; expressed as Btu or calories per unit of volume or weight. HYDROCARBON DEPOSITS Any organic compound, gaseous, liquid, or solid, consisting solely of carbon and hydrogen. They are divided into groups of which those of special interest to geologists are the paraffin, cycloparaffin, olefin, and aromatic groups. Crude oil is essentially a complex mixture of hydrocarbons. (AGI Dictionary) HYDRAULIC CONDUCTIVITY Refers to the capability of subsurface ma- terials (sand, rock, etc.) to allow a fluid (usually water) to flow through it. IMPOUNDMENT General term for any confined water body, usually due to artificial structures but may be natural. INDEPENDENT POWER PRODUCERS Private companies that develop, own, or operate electric power plants, often fueled by alternative energy sources such as biomass, cogeneration, small hydro, waste-to-energy, and wind facilities. INFILTRATION The flow of a fluid into a solid substance through pores or small openings; spec. the movement of water into soil or porous rock. (AGI Dictionary) INTEGRATED GASIFICATION COMBINED CYCLE (IGCC) A power generation system which produces synthesis gas (syngas), mainly of CO and H2, converted from fossil fuel, such as vacuum residue, heavy oil, petroleum coke, coal and Orimulsion by a partial oxidation process and then burned to generate electricity from syngas by combined cycle. (http://www/chiyoda-corp.com/biz/e/ hpi/igcc.shtml)
APPENDIX C 223 KINETIC TESTING METHODS Kinetic methods are designed to emulate field conditions and may involve exposing a sample to alternating wetting and drying conditions to promote oxidation reactions before the drainage waters are analyzed for pH, alkalinity, and concentrations of sulfate and dissolved metals. LEACHATE A solution obtained by leaching; e.g., water that has percolated through soil containing soluble substances and that contains certain amounts of these substances in solution. (AGI Dictionary) LEACHING RATE TEST A test designed to assess the value of antifouling compositions by measuring the rate of loss of toxic ingredients from a painted surface during immersion in seawater. (AGI Dictionary) LIGNITE Coal of low rank with a high inherent moisture and volatile matter; in this general sense, lignite may be subdivided into black lignite, brown lignite, and brown coal. (AGI Dictionary) LINER A cover of clay, concrete, synthetic film, or other material, placed over all or part of the perimeter of a conduit or reservoir, to resist erosion, minimize seepage losses, withstand pressure, and improve flow. (AGI Dictionary) LITHOLOGY The character of a rock described in terms of its structure, color, mineral composition, grain size, and arrangement of its component parts; all those visible features that in the aggregate impart mines and commonly is reliable over a distance of a few miles. (AGI Dictionary) MAXIMUM CONTAMINANT LEVEL (MCL) The highest level of a con- taminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consid- eration. MCLs are enforceable standards. (AGI Dictionary) MAXIMUM CONTAMINANT LEVEL GOAL (MCLG) The level of a con- taminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals. (AGI Dictionary) METALLOID An element--such as boron, silicon, arsenic, or tellurium-- intermediate in properties between the typical metals and nonmetals. (AGI Dic- tionary)
224 MANAGING COAL COMBUSTION RESIDUES IN MINES MINE An opening or excavation in the ground for the purpose of extracting minerals. (AGI dictionary) MINEFILL Manmade deposits of natural soils and waste material into a mine. MONOFILLS Locations of large-volume CCR disposal without blending or layering of the CCRs with mine spoil or other materials. MULLITE An orthorhombic mineral consisting of an aluminum silicate that is resistant to corrosion and heat; used as a refractory. (AGI Dictionary) OVERBURDEN Designates material of any nature, consolidated or uncon- solidated, that overlies a deposit of useful materials, ores, or coal--especially those deposits that are mined from the surface by open cuts. (AGI Dictionary) PARTINGS A lamina or very thin sedimentary layer separating thicker strata of a different type; e.g., a thin layer of shale or slate in a coal bed, or a shale break in sandstone. Strata tend to separate readily at partings. (AGI Dictionary) PERFORMANCE STANDARD A standard which sets an objective perfor- mance level that must be met, without specifying how this is to be achieved. For example, such a standard may impose emission limits that specify the amount and type of pollutant that may be discharged. PERMEABLE Pertaining to a rock or soil having a texture that permits pas- sage of liquids or gases under the pressure ordinarily found in earth materials. (AGI Dictionary) PULVERIZED COAL Finely ground coal that can be burned as it issues from a suitable nozzle. (AGI Dictionary) RECHARGE The processes by which water is absorbed and added to the zone of saturation, either directly into an aquifer or indirectly by way of another formation; also, the quantity of water so added. (AGI Dictionary) RECLAMATION Restoration of mined land to original contour, use, or con- dition. (AGI Dictionary) RESIDUE HANDLING TECHNOLOGY Residue collection systems from the boiler and its auxiliaries vary between facilities and form unit to unit. Some
APPENDIX C 225 units use a collection system that results in a combined residual either in a dry or wet form. The type of materials that may be combined prior to leaving a plant is a function of individual plant collection logistics and or any requirements to facilitate final disposal. Because residues are constantly being produced during the combustion process and must be removed regularly, facilities usually have a storage system such as a silo for dry materials or a surface impoundment (pond) for wet materials. (AGI Dictionary) REVEGETATION The process of restoring or replacing the botanical species upon an area disturbed by mineral operations. Revegetation is a customary re- quirement for reclamation of a mineral operation. (AGI Dictionary) SATURATED ZONE A subsurface zone in which all the interstices are filled with water under pressure grater than that of the atmosphere. (AGI dictionary) SCRUBBER Device for separating environmentally noxious chemical sub- stances from waste gas streams. (AGI Dictionary) SHALE One of the impurities associated with coal seams; the term should not be used as a general term for washery rejects. (AGI Dictionary) SHORT TON The U.S. ton is the short ton which is equal to 2000 pounds; the British ton is the long ton which is equal to 2240 pounds. Both tons are actually defined in the same way. 1 ton is equal to 20 hundredweight. However, the definition of the hundredweight differs between countries. In the United States there are 100 pounds in the hundredweight, and in Britain there are 112 pounds in the hundredweight. This causes the actual weight of the ton to differ between countries. To distinguish between the two tons, the smaller U.S. ton is called short, while the larger British ton is called long. SLAG Material from the iron blast furnace, resulting from the fusion of flux- stone with coke ash and the siliceous and aluminous impurities remaining after separation of iron from the ore. (AGI dictionary) SLURRY Fine particles concentrated in a portion of the circulating water (usu- ally by settling) and waterborne to treatment plant of any kind. (AGI Dictionary) SPOIL MATERIAL Overburden, nonore, or other waste material removed in mining, quarrying, dredging, or excavating. (Global InfoMine) STRATA Plural of stratum, a bed or layer of rock.
226 MANAGING COAL COMBUSTION RESIDUES IN MINES SUBSIDENCE The settling of waste piles or other areas at mine sites which causes the surface of the land to sink. SUBBITUMINOUS COAL Coal of rank intermediate between lignite and bituminous. (AGI Dictionary) SURFACE MINING Mining at or near the surface. This type of mining is generally done where the overburden can be removed without too much expense. (AGI Dictionary) SUSPENSION FIRING (PULVERIZED COAL FIRING) Coal is crushed to a fine powder prior to entering the boiler's furnace and subsequently com- busted in suspension with the combustion air. TRACE METAL CONTENT The trace metals contained in CCRs are de- rived from the naturally occurring minerals present in the source coal. Trace metal content of coal varies across the coal types. (AGI Dictionary) UNDERGROUND MINE (DEEP MINE) Usually located several hundred feet below the earth's surface, an underground mine's coal is reached through vertical or inclined shafts, or, if the deposit is located in a mountain, through level or nearly level tunnels. The coal is removed mechanically and transferred to the surface. UNSATURATED ZONE An area underground between the ground surface and the water table where the pore spaces are not filled with water, also known as the zone of aeration. VALENCE The degree of combining power of an element or a radical. (AGI Dictionary) VENTURI A contraction in a tube or duct to accelerate the flow and lower the static pressure. It is used for metering and other purposes. (AGI Dictionary) WATER TABLE The surface between the zone of saturation and the zone of aeration; that surface of a body of unconfined groundwater at which the pressure is equal to that of the atmosphere. (AGI Dictionary)