Appendix:Dictionary of Mining, Mineral, and Related Terms/T/3
- A mixture of aventurine quartz and quartz porphyry that may be of various colors and has been cut as ornamental or curio stones, in Russia.
- a. A sealed bid for ore to be sold.
b. The numbered check that the miner puts on his loaded car to inform the weighmaster to whom the coal belongs. See also: tag; tally.
- A small cavity in a rock; a vug.
- An extensive marshy or barren tract of land that is alternately covered and uncovered by the tide, and consisting of unconsolidated sediment (mostly mud and sand). It may form the top surface of a deltaic deposit. See also: sabkha. Syn: tidal marsh; tide flat.
- See: tidal flat.
- See: tidal flat.
- Technically lands overflowed during floodtide, but the term, by reason of the so-called Tidelands cases, has been used to describe that portion of the continental shelf between the shore and the claimed boundaries of the States--3 miles or 9 miles (4.8 km or 14.4 km) at sea.
- a. A beam, post, rod, or angle to hold two pieces together; a tension member in a construction.
b. One of the transverse supports to which railroad rails are fastened to keep them to line, gauge, and grade. c. Linear or angular measurements or a combination of the two made for the purpose of locating other points from points of known position. Ties may be made to connect physical objects with the survey line, or to locate the instrument point with reference to physical objects so that it can be reestablished if lost. To tie in is to close a survey on itself or on another survey, or to locate a point by means of ties.
- a. A beam serving the purpose similar to a fend-off beam, but fixed at the opposite side of the shaft or inclined road.
b. The wire ropes or stayrods that are sometimes used on the side of the tower opposite the hoisting engine, in place of or to reinforce the engine braces.
- a. A bar used as a tie rod.
b. A rod between two railway switch rails to hold them to gauge.
- A retaining wall tied into the adjoining ground by means of a deadman (wood block) or other suitable anchorage.
- a. A line at constant temperature that connects any two phases that are in equilibrium at the temperature of the tie line. Syn: conode.
b. A line measured on the ground to connect some object to a survey; e.g., a line joining opposite corners of a four-sided figure, thereby enabling its area to be checked by triangulation.
- An isometric mineral, HgSe ; has sphalerite structure; dark gray to black.
- A metal plate used under rails where they rest on ties. The rail is spiked to the tie through holes in the plate.
- a. A point to which a tie is made; esp. a point of closure of a survey either on itself or on another survey.
b. An image point identified on oblique aerial photographs in the overlap area between two or more adjacent strips of photography. They tie individual sets of photographs into a single flight unit and adjacent flights into a common network.
- When track is not adequately drained and water enters the ballast and roadbed, tie pumping occurs. Under the action of the rolling stock, pressure on the tie discharges water to the surface, washing the ballast from beneath and around the tie.
- A round or square iron rod passing through or over a furnace and connected with a buckstay to assist in binding the furnace together.
- Sp. Any rock or mineral; tierra blanca (Mex.), a calcareous tufa; tierra de batan, fuller's earth; tierra de fluor (Venez.), a bed of reddish clayey earth; tierra de porcelana, china clay; tierra pesada, heavy spar.
- A Spanish term for white ground or white earth, and applied to white calcareous deposits such as tufa, caliche, and chalky limestone.
- a. Sparry calcite in Wisconsin and southwestern Missouri zinc fields.
b. Sparry barite in southeastern Missouri.
- A hydrocarbon present in certain diamonds causing phosphorescence.
- A device, as a fork, for supporting a continuous series of well-boring rods or tubes while raising or lowering them in the hole.
- Alternative spelling of tiger's-eye.
- a. A usually yellow-brown chatoyant stone that is much used for ornament and is a silicified crocidolite in which the fibers penetrating the quartz are changed to oxide of iron. Also spelled tigereye. CF: hawk's-eye. See also: occidental cat's-eye; oriental cat's-eye.
b. Crocidolite asbestos replaced by quartz to yield a yellow-brown chatoyant stone used for ornament. c. Ceramic glaze resembling tiger's-eye.
- a. Soil or rock formations lacking veins of weakness. Syn: tight formation.
b. Blasts or blastholes around which rock cannot break away freely. c. Inadequate clearance or the barest minimum of clearance between working parts. d. Unbroken, crack-free, and solid rock in which a naked hole will stand without caving. e. A borehole made impermeable to water by cementation or casing. f. An impermeable rock formation. g. An underground opening having limited space in which to work. h. Lacking in porosity; impervious.
- In sandstone quarrying, a term used to describe the rock if it is massive, showing no open-bed seams. CF: thin-bedded; thick-bedded.
- A clay that is dense or approaches vitrification after firing.
- See: tight; tight rock.
- a. A borehole the diameter of which is too small for adequate clearance between the drill-stem equipment and/or inserted casing.
b. A borehole the wall rocks of which are impermeable to water or have been made tight by cementation or insertion of casing. c. A borehole-drilling operation, access to which and information about which are not released except to authorized persons.
- Lagging placed touching each other. See also: tight sheathing.
- a. Rock formation in which the joints, cracks, or crevices are sealed and impermeable to water.
b. Rock composed of tightly cemented grains of very fine, even-sized crystals. c. Rock that does not chip easily under the impact of cable tools. d. A tough, resilient rock. e. Can. Without evidence of shearing or mineralization. Syn: tight formation.
- A quarrymen's term, equivalent to blind seam, or incipient joint.
- The most complete sheathing using wood timbering. Used where water or fine wet soils must be retained. The frame is designed for this use and is generally stronger than that required for other types of sheathing. A specially edged plank, generally tongue-and-grooved, eliminates the crevices existing in close sheathing. CF: close sheathing; skeleton sheathing. See also: tight lagging.
- An explosive shot that has been set off to loosen coal in a seam that has not been previously cut or sheared.
- A monoclinic mineral, CaMg(AsO (sub 4) )F ; isomorphous with isokite; violet-gray; at Laangban, Sweden, and Kajlidongri, Central India.
- Copper obtained by roasting and refining the metal bottoms that collect under the regulus in smelting certain impure ores; usually cast in flat, rectangular plates, hence its name. See also: bottoms.
- A machine for making tubular or arch-shaped tiles from clay, operating by forcing the raw material through a die, in a continuous stream, which is cut into suitable lengths by wires.
- An earthy variety of cuprite, brick red because of admixed iron oxides.
- a. A kiln or oven for baking tiles.
b. A maker or layer of tiles.
- A device that permits laying tile directly behind a ditcher. Also called tile box.
- A tilery or tile field.
- Beds of calcareous sandstone or ironstone, near Hastings, England.
- Dominantly unsorted and unstratified drift, generally unconsolidated, deposited directly by and underneath a glacier without subsequent reworking by meltwater, and consisting of a heterogeneous mixture of clay, silt, sand, gravel, and boulders ranging widely in size and shape. See also: boulder clay; moraine. Syn: glacial till; ice-laid drift.
- A flexible wire rope composed of six small ropes, usually of seven wire strands each laid about a hemp core.
- A monoclinic mineral, Ca (sub 5) (Si (sub 2) O (sub 7) )(CO (sub 3) ) (sub 2) ; forms white grains in rock at Crestmore, CA.
- A consolidated or indurated sedimentary rock formed by lithification of glacial till, esp. pre-Pleistocene till (such as the Late Carboniferous tillites in South Africa and India).
- a. The angle at the perspective center of an aerial photograph between the plumb line and the perpendicular from the interior perspective center to the plane of the photograph.
b. The lack of parallelism (or the angle) between the plane of the photograph from a downward-pointing aerial camera and the horizontal plane (normal to the plumb line) of the ground. c. In aerial photography, the angle between the lens axis and a vertical through the exposure station (rear nodal point of lens). It is seldom more than 3 degrees and can generally be kept to 1 degrees . This is regarded as satisfactory for vertical photographs. d. To hammer or forge with a tilt hammer; as, to tilt steel to render it more ductile.
- A hammer for shingling or forging iron, arranged as a lever of the first or third order, and tilted or tripped by means of a cam or cog gearing and allowed to fall upon the billet, bloom, or bar.
- A bulldozer whose blade can be pivoted on a horizontal center pin to cut low on either side.
- Open-hearth furnace swung about its major axis when pouring out the melted product.
- A crest gate for dam spillways designed so that water pressure acting upon it will do so only at a definite level. It closes automatically when the water level falls to normal.
- An arrangement of idler rollers on a conveyor in which the top set is mounted on vertical arms which pivot on spindles set low down on the frame of the roller stool. This permits the entire carrier frame to lean forward slightly in the direction of belt travel. In the event of the belt not running true, the tilting idlers guide it back to its correct course again.
- A surveying instrument with sighting telescope so mounted that it can be raised or lowered through a limited arc without impairing accuracy of reading, though axis of rotation is not precisely horizontal. The bubble tube is usually mounted alongside the telescope and is viewed from the eyepiece and through an optical sighting arrangement, which either brings opposite halves of the bubble image into coincidence or the end of the bubble to a reference line.
- A concrete mixer with a rotating drum, which is tilted to discharge its contents.
- beams, etc., used to support mine workings.
b. To set or place timbers in a mine. c. Applied to rough blocks of natural rock as it comes from a quarry before being shaped into sharpening stones.
- See: timberman.
- a. An appliance for withdrawing timber supports from wastes, e.g., a sylvester.
b. A miner engaged in timber drawing. c. See: timber puller.
- See: drawing timber.
- Stope in which square-set timbering and its variations are employed. As a rule, the ground is broken by overhand methods, the face being advanced by successive small excavations, each one timbered before the next is begun.
- One who cuts, frames, and/or puts in place any of the timbers used in a shaft, slope, mine, or tunnel. Also one who draws props, posts, etc. Syn: timberman.
- See: timberman.
- a. The operation of setting timber supports in mine workings or shafts to support the roof or the face of a tunnel during excavation and lining. The term "support" would cover the setting of timber, steel, concrete, or masonry supports. See also: setting; timber set; face timbering; pin timbering.
b. Timber work taken collectively in a mine. c. Protecting against falls of roof formation of a mine, by means of horizontal timbers or caps extending across the passageway just under the roof, the ends of such timbers resting upon the vertical timbers or posts. d. Timber to support the roof or the face of a tunnel during excavation and lining.
- An electrically driven machine to raise and hold timbers in place while supporting posts are set after being cut to length by the machine's power-driven saw.
- A tunnel support consisting of a roof beam, or arch, and two posts.
- A jack to raise and hold crossbars against the roof while props are being set.
- a. In bituminous coal mining, a head timberman is a foreman who supervises workers installing timbers in a mine to support the roof and walls of haulageways, passageways, and the shaft. Also called timber boss; timber foreman.
b. A miner skilled in notching, erecting, and securing timbers set in mine workings. The craft of the timberman is gradually becoming extinct with the advent of power tools and steel as a support. c. See: roof bolter; timberer.
- In mining, a laborer who assists a timberman in erecting supports for the roof of a mine, using posts, headers, cap pieces, and wedges.
- Broken timber forming roof of ore deposit being extracted by caving methods such as top slicing. It separates the downward gravitating overburden and rock strata from the ore.
- a. A laborer who delivers timber to the working place in a pitching or inclined coal seam.
b. See: pack builder.
- A method to assist timber preservation; e.g., creosoting. See also: timber preservation.
- Any treatment of mine timber for the purpose of extending the useful life of the timber. Various preservatives are used, such as creosote, zinc chloride, sodium fluoride, and other chemicals. See also: brush treatment; guniting; open-tank method; pressure process; Bethell's process; timber pickling; seasoning timber.
- a. A piece of equipment used in removing the supports or timbers in a mine. A timber puller should be constructed so that the operator will be under safe roof while drawing the timber. A sylvester is an example of this type of equipment. Also called timber drawer.
b. See: timber robber.
- The right to cut timber on the public domain for commercial use.
- In anthracite and bituminous coal mining, a laborer who pulls out and recovers timbers and props in working places from which all coal has been mined. Also called prop drawer; timber puller.
- A timber frame to support the roof, sides, and sometimes the floor of mine roadways or shafts. For a mine roadway, the simplest timber set consists of a crossbar, cap, or collar supported on two upright posts or arms with round or board lagging. Such a set will resist roof pressure and moderate side pressure and is erected at intervals of from 2 to 6 ft (0.6 to 1.8 m). The timbers are about 5 to 10 in (12.7 to 25.4 cm) in diameter. In South Wales, such a timber set is known as double timber. See also: timbering; bar timbering; two-piece set; three-piece set; four-piece set.
- A strong carriage of low height for transporting timber from the surface stockyard to underground workings. It consists of a timber or steel base, mounted on wheels, with U-shaped arms in which the timber is lashed with chains. See also: bogie.
- Any truck or car used for hauling timbers inside a mine. In conveyor work, it is applied to the small truck mounted on wheels that is designed to run in the panline of a shaker conveyor for the purpose of carrying timber and other materials to the face.
- The coordination and analysis of the data provided by time study and motion study.
- In seismic exploration, the time required for the seismic impulse to travel from the charge in the shothole to the surface of the Earth. Syn: uphole time.
- An indication on a seismic record showing the instant of detonation of a shot or charge. CF: time signal. Syn: shot moment; shot instant; time mark.
- Correlation of rocks in one area with those of another area on basis of time equivalence or contemporaneity of origin.
- Relay that does not operate until a predetermined time has elapsed. The time ratings are usually adjustable, but some time-delay relays have the time rating built into them.
- A graphical expression of the functional relation between the velocity function and the times observed in the seismic method of geophysical exploration. It permits time increments to be converted to corresponding depths. Syn: time-depth curve.
- See: time-depth chart.
- In refraction seismic computations, a graph, usually with arrival times of distinctive seismic signals plotted as ordinates and with distances along the surface of the Earth plotted as abscissas. In earthquake studies, the times of arrival of seismic waves at recording stations may be known, but the time of initiation of the waves may be unknown. As data are accumulated from different recording stations, a time-distance graph may be constructed. If it is possible to extrapolate this graph to the origin on the time and distance coordinates, it becomes a travel-time curve.
- In refraction seismic computations, a plot of the arrival times of refracted events against the shot-point-to-detector distance. The reciprocal slopes of the plotted segments are the refraction velocities for the refracting bed.
- In the reflection seismic methods applied to dipping reflectors, the travel time curves may not be straight lines; i.e., the apparent velocity observed varies with the spread from shot point to detectors. The time gradient is the reciprocal of the apparent velocity. In seismic prospecting, also the rate of change of travel time with depth.
- a. In refraction seismic interpretation, where arrival times are plotted against shot-detector distances, if some of the paths from shot point to detector include a low-speed bed, the corresponding arrival times will be abnormally long, and the departure from normal travel time is called a time lag. Also, in seismic prospecting, time delays in arrivals due to phase shifts in filtering, to shot-hole fatigue, etc.
b. A delay in the arrival time of seismic energy from the time expected. Time lags may be produced by an abnormal low-velocity layer, phase shifts in filtering, or other factors.
- In a method of interpretation of refraction seismic records where the arrival times are plotted against shot-detector distances, if some of the paths from shot point to detector include a high-speed segment, the corresponding travel times will not fall on a smooth curve. The departure in this case from the curve is called a time lead, and it is proportional to the horizontal extent of the high-speed segment. Used in salt-dome exploration.
- a. See: time break.
b. Mark corresponding to a particular time (e.g., hour, minute, and second time marks) on a seismic recording.
- Lines on a seismogram that mark increments of time.
- See: time-stratigraphic unit.
- See: geologic time scale.
- In geophysics, a signal used to indicate the time of explosion in a shothole and successive intervals of time on the recording. CF: time break.
- A body of rock established to serve as the material reference for all rocks formed during the same span of time. Each of its boundaries is synchronous. Chronostratigraphic units in order of decreasing rank are eonothem, erathem, system, series, stage. Syn: chronostratic unit; chronolithologic unit; time-rock unit; chronolith.
- A detailed investigation in which the average time taken to do each operation of a complete cycle is recorded. See also: method study; motion study.
- In seismograph continuous profiling, a coincident travel path for seismic energy initiated at opposite ends of the path. The use of such coincident travel paths on adjacent reflection layouts facilitates correlation from one layout to the next as the shot point or recording position is changed.
- See: diachronous.
- The interval of geologic time represented by or involved in producing a stratigraphic unit, an unconformity, the range of a fossil, or any geologic feature or event.
- The time elapsing between two successive exposures of an aircraft camera when taking vertical photographs. See also: photogrammetry.
- One of a series of marks or lines placed on seismic records at precisely determined intervals of time (usually at intervals of 0.01 or 0.005 s) for the purpose of measuring the arrival time of recorded events.
- a. A tetragonal mineral, Sn : rare; soft; malleable: bluish white.
b. The metal extracted from cassiterite; used as a coating to protect iron and copper, such as a foil, and in solder, bronze, and other alloys. Commercially, tin is available in three grades: Grade A must assay 99.75%; grade B must assay 99.7%; and grade C, or common tin, must assay 99% tin. c. To coat with tin, such as to tin iron; tinplate. d. Metallic element that has a highly crystalline structure. Symbol, Sn. Found chiefly in cassiterite, SnO (sub 2) . Used in alloys such as soft solder, type metal, fusible metal, pewter, bronze, and bell metal and as a crystalline tin-niobium alloy. e. See: zinn.
- a. Corn. To mark a limit, as on a tract of waste land, within which one claims or reserves the right to mine unworked tin ore.
b. Land so reserved.
- The name given, since early itmes, to crude borax obtained from salt lakes in Kashmir, India, and Xizang (formerly Tibet), China. Also spelled tinkal. Syn: borax.
- A trigonal mineral, Na (sub 2) B (sub 4) O (sub 5) (OH) (sub 4) .3H (sub 2) O . Syn: mojavite; octahedral borax.
- A Davy lamp placed inside a tin can or cylinder having a glass in front, airholes near the bottom, and an open top.
- An impure variety of jamesonite.
- A pan used by prospectors for washing gold-bearing materials and extracting the gold. See also: pan.
- The extraction of tin-bearing ore from placers by means of dredges.
- The actual excavating tooth or point of a grab bucket, scraper loader, dragline, or excavator bucket.
- a. Corn. A thin flat mass of tinstone between beds of rock.
b. A flat mass of tin ore.
- A color designation. A faint trace of a hue that modifies another hue, as a blue with a tinge of green, i.e., blue tinged with green or, stated differently, very slightly greenish-blue.
- Corn. Tin-bearing alluvium, stream works.
- A head covering made of reinforced sheet aluminum or plastic-impregnated fabric and shaped somewhat like a sun helmet; worn for protection and/or to reduce the severity of head injuries from falling objects. Also called hard hat. Syn: safety hat.
- See: tincal.
- Derb. Laminated carbonaceous shale.
- Virtually all the industrial supply of tin comes from cassiterite, SnO (sub 2) , though a little has been won from the sulfides stannite, cylindrite, and franckeite. Bulk of cassiterite comes from alluvial workings. Main market is in tin plating, tin foil, solders, bearing metals, bronze and other alloys, and such salts as opacifiers and dye mordants.
- See: tin plate.
- A tinsmith.
- An alloy of equal parts of tin and lead; used by electrotypers for coating copper shells before backing.
- See: cassiterite.
- Sheet iron or steel, cleaned by pickling in acid and then passed through bath of molten tin to produce coating. Three grades are charcoal plate, coke plate, and crystallized. Tin is also deposited by electroplating. Syn: tinned sheet iron.
- See: stannite.
- See: salt of tin.
- See: cassiterite. Also called tinstone.
- See: cassiterite.
- See: cassiterite.
- See: smaltite.
- A place or an establishment where tin is manufactured or mined.
- a. The point at which loaded mine cars are dumped on the surface. Also called tipple.
b. A piece of tool material secured to a cutter tooth or blade.
- a. Originally the place where the mine cars were tipped and emptied of their coal, and still used in that sense, but more generally applied to the surface structures of a mine, including the preparation plant and loading tracks.
b. The dump; a cradle dump. c. Aust. The tracks, trestles, screens, etc., at the entrance to a colliery where coal is screened and loaded. CF: dump.
- a. An angle iron having T-shaped cross section.
b. T-rails used in a mine, as distinguished from wooden rails.
- See: titanium; titanite.
- See: titanian augite. Found in basaltic rocks.
- A titaniferous variety of hornblende.
- a. See: titanium dioxide.
b. TiO (sub 2) . Also called titanium oxide; titanic dioxide; titanic oxide. A common constituent of iron ores. Used as a pigment, and it replaces zinc oxide in manufacturing white rubber and as a filler for paper; can be used alone as a refractory and as an electrical insulator. Its crystals show marked piezoelectric effects and have a greater brilliance and a higher refractive index than diamond. c. The minerals tetragonal rutile, anatase, octahedrite, and orthorhombic brookite. d. Commonly refers to synthetic white titanium dioxide that is produced mainly from ilmenite, FeTiO (sub 3) , that contains 50% to 54% TiO (sub 2).
- See: titanaugite.
- A white pulverulent titanium oxide, TiO (sub 2) , found native as brookite, octahedrite, and rutile, and a common constituent of iron ores. Also called titanic oxide.
- See: titanium dioxide.
- See: ilmenite. Also called titaniferous iron ore.
- See: titanium dioxide.
- See: rutile.
- Magnetite containing titanium.
- A monoclinic mineral, CaTiOSiO (sub 4) ; Ca is replaced by Sr, Ba, Na, Mn, Th, or rare earths; Ti is replaced by Al, Fe, Mg, Nb, Ta, V, or Cr; up to 1/5 of O (sub 2-) may be replaced by (OH,F) (super -) ; weakly radioactive: forms wedge-shaped crystals; a common accessory in felsic plutonic rocks, in gneisses, schists, and marbles; a source of titanium. Formerly called sphene.
- A silvery-gray or iron-gray, metallic element. Symbol, Ti. Found in nature only in combined form; occurs chiefly in ilmenite (FeTiO (sub 3) ), and in rutile and titanite. Used as an alloying agent with aluminum, molybdenum, manganese, iron, and other metals. Used in aircraft and missiles and has potential for use in desalination plants.
- A compound produced by fusing titanium dioxide with carbon or calcium carbide. Has a melting point in the range of 3,140 to 3,160 degrees C. This very hard, refractory material is used for wear-resistant applications and where good thermal shock resistance is needed, as in bearings, nozzles, and special refractories under either neutral or reducing conditions.
- a. Also called titanium oxide, titanic dioxide, titanic oxide, titania, rutile, anatase, or brookite. Colorless, white, pale yellow or yellowish-red, reddish-brown, brown, blue or bluish, violet, and black; tetragonal and orthorhombic; TiO (sub 2) ; molecular weight, 79.90; sp gr, 3.82 to 5.13 depending on crystal system and crystal form; Mohs hardness, 5.5 to 6.5; melting point, 1,825 to 1,850 degrees C; boiling point, 2,500 to 3,000 degrees C; insoluble in water and in most acids; and soluble in hot concentrated sulfuric acid and in alkalies. Titanium dioxide occurs as the minerals rutile (tetragonal); anatase or octahedrite (tetragonal); and brookite (orthorhombic). Titanium dioxide is a common constituent of iron ores.
b. Titanium dioxide as rutile: colorless, pale yellow, reddish-brown, red, bluish, violet, and black; tetragonal; adamantine to submetallic luster; refractive indexes, 2.616 and 2.903; sp gr, 4.26 and ranges from 4.18 to 5.13; Mohs hardness, 6.0 to 6.5; and the same melting points, boiling points and solubility characteristics as above. Titanium dioxide possesses the gredatest hiding power of all the white pigments. Used in glassware and in ceramics, in enamel frits, in welding rods, and single crystals are used as high-temperature transducers. Syn: titania; octahedrite.
- Any of three grades of titanium-dioxide-based pigments used in the production of paints, paper, and many other products requiring a white pigment with a high hiding power and chemical stability. Rutile and anatase grades are more or less pure titanium dioxide, but owing to a difference in crystal structure, they differ slightly in hiding power and chalking quality. Titanium dioxide of pigment quality is manufactured principally by treating finely ground ilmenite or titanium slag with concentrated sulfuric acid. Also used in ceramics and fiberglass, and in making titanium gems.
- TiN; a special refractory material (melting point, 2,930 degrees C). It can readily be produced from TiC1 (sub 4) and NH (sub 3) .
- a. TiO (sub 2) ; used as an opacifier, particularly in vitreous enamels, and as a constituent of some ceramic colors. Titania and titanate electroceramics, for use in the radio frequency field, are based on this oxide and its compounds. Titania occurs in three crystalline forms: anatase, brookite, and rutile.
b. See: titanium dioxide.
- Ti (sub 5) Si (sub 3) ; sp gr, 4.2. This special ceramic has good resistance to high temperature oxidation, but not to thermal shock.
- The metal product from reducing titanium tetrachloride with magnesium in the Kroll process. It is called sponge because of its spongelike appearance. Sodium-reduced metal also is referred to as sponge.
- See: titanomagnetite.
- A titaniferous andradite approaching schorlomite in composition; garnet group.
- a. A titaniferous variety of magnetite with titanium in crystal solution. Syn: titanmagnetite.
b. A term for mixtures of magnetite, ilmenite, and ulvoespinel. CF: mogensenite.
- A process of concentrating iron ore that comprises the steps of (1) effecting a dry, thermal, partial reduction of the iron in the ore to the metallic state to a degree of reduction of between 50% and 80%, (2) subjecting the reduced product to a magnetic separation, and (3) recovering the magnetic concentrate.
- Eng. A portion of ore set aside for the payment of rental or royalty on mineral lands.
- The right to enter, develop, and work a coal or mineral deposit. See also: claim; lease.
- See: Threshold Limit Value.
- See: toadstone.
- Eng. Shelly pink limestone in the Corbula Beds of the Purbeck Beds at Durlston Bay. So called because it is full of the small gastropods Pachychilus manselli that resemble eyes when seen in transverse section. CF: rabbit-eye.
- A reddish or brownish variety of cassiterite in botryoidal or reniform shapes with internal concentric or fibrous structure.
- a. Applied earlier to various stones or stonelike objects likened in color or shape to toads (batrachites, bufonites, crapodius). Syn: toadrock; fiery dragon.
b. Eng. A kind of traprock. c. An old Derbyshire name for amygdaloidal basalt lava in the Carboniferous Limestone. d. A fossilized object, such as a fish tooth or palatal bone, once thought to have formed within a toad and frequently worn as a charm or an antidote for poison. Syn: toadrock.
- A term used in the Southwest United States for a favorable host rock for uranium, characterized by light yellow or gray color and by brown limonite stains.
- An orthorhombic mineral, Ca (sub 9) Si (sub 12) O (sub 30) (OH) (sub 6) .4H (sub 2) O ; the principal cementing compound in Portland cement.
- A mixture of columbite and samarskite.
- A monoclinic mineral, (Na,Ca) (sub 0.5) (Mn,Mg) (sub 6) O (sub 12) .4H (sub 2) O ; forms black spongy banded and reniform aggregates composed of minute lathlike crystals; in Hokkaido, Japan.
- a. The base of the coal, ore, or overburden face in a quarry or opencast mine.
b. The front end of a frog, opposite the heel, in a car track. c. The lowest part of a slope or cliff; the downslope end of an alluvial fan.
- A raised edging around the perimeter of a work platform in drilling to prevent hand-tools from being accidentally kicked or knocked off the platform.
- In underground blasting, the cut obtained by the use of single cut holes inclined downward.
- A blasting hole, usually drilled horizontally or at a slight inclination into the base of a bank, bench, or slope of a quarry or open pit mine.
- A quarry term for the wedging-in of the end of a granite sheet under an overhanging joint, probably in consequence of the faulting of the sheets along the joint. It is also applied to the overlapping of lenticular sheets.
- The distance from the inner end of the hole to the adjacent free face measured at right angles to the direction of the hole; or that portion of the hole that is filled with powder; or that part of the seam to be broken lying between the powder and a free face.
- See: toernebohmite.
- The drilling of large-diameter blasting holes in quarries and opencast pits. They are put down vertically from top to bottom of the quarry face. Deck loading is often adopted, with half to two-thirds of the total charge at the bottom and the remainder in one or more deck charges as required.
- a. Made to gauge, or a size as specified, esp. as applied to the outside set diameter of bits and reaming shells and the inside diameter of a borehole.
b. To determine, by measurement or other test, the capacity, quantity, or dimension.
- Application of crushing force so that the distance moved diminishes without change of input strength, between gape and set. Thus greatest speed of movement of the approaching faces is applied with weakest thrust and vice versa.
- A joint having a central hinge like an elbow, and operated by applying the power at the junction of motion, as from horizontal to vertical, and giving enormous mechanical advantage; a mechanism common in many forms of presses and in stone crushers.
- A mechanism utilized to apply heavy pressure from a small applied force, such as in a jaw breaker, and other machinery.
- An old French unit of length used in early geodetic surveys and equal to 6 French ft, 6.396 U.S. ft, or 1.949 m.
- A specified allowance (either plus or minus) of the given dimensions of a finished product to take care of inaccuracies in workmanship of parts to be fitted together. The amount allowed as tolerance is generally small as compared with the standard dimension of the part; e.g., the tolerance allowed in the set diameters of a diamond bit is + or -0.02 mm.
- In control of a measured value in a process, limited drift from optimum or norm (e.g., pH 7.6 + or - 0.2).
- Ches. Royalty on rock salt, or other mineral.
- A proposed arrangement by which uranium owned privately could be enriched in uranium-235 content in U.S. Government facilities upon the payment of a service charge.
- Situation in which the owner of ore or concentrate contracts the refining of the metal to another party for a fee, but the refined metal remains under the original ownership for final sale or disposition.
- a. An inclined trough in which gold-bearing earth or gravel is crudely washed; usually called long tom because it is longer than the rocker.
b. Cumb. A parting of black shale in a coal seam.
- An electrolytic process for refining lead in which the electrolyte is a solution of a double acetate of lead and potassium or sodium. The anodes are cast from crude argentiferous lead, and the cathodes are in the form of large disks of copper or aluminum bronze and are about half immersed in the electrolyte.
- A short rod used as a lever or handle for turning a jackscrew or a spanner by being inserted loosely in the hole provided for that purpose.
- A division of radiography dealing with the photography of a particular plane in an object while leaving out undesired detail in other planes. Although this technique was developed for medical radiography, it is recommended for certain purposes in work with metals where it is essential that the location of faults be exactly known.
- Commercial brand of wire screen cloth with long rectangular meshes.
- a. That attribute of a color that determines its position in a scale from light to dark. Thus white, and also light gray, are light tones, and dark gray is the dark tone of the same color sensation; pink is a light tone of red, and maroon a dark tone. A light tone is usually known as a tint, a dark tone as a shade. See also: intensity.
b. A monochromatic frequency of vibration, such as in a violin string or vibrations of bodies of finite size and shape.
- A hard, replaceable, serrated metal insert in pipe tongs, which comes in contact with and grips the outside of a pipe, casing, or drill rod. Also called tong key.
- One of the various tools or wrench devices that can be made to fit and grasp drill rods, casing, or drivepipe.
- a. A branch or offshoot of a larger intrusive body. See also: epiphysis. Syn: apophysis.
b. A minor lithostratigraphic unit of limited geographic extent, being a subdivision of a formation or member, and disappearing laterally (usually by facies change) in one direction; a member that extends outward beyond the main body of a formation. CF: lentil. c. A lava flow that is an offshoot from a larger flow; it may be as much as several kilometers in length.
- In welding, a split joint formed by inserting a wedge-shaped piece into a corresponding split piece and welding the two together.
- An adjustable plate that controls the quantity of feed entrapped by the rolls of a double-roll press.
- A test by which crystals and crystalline gemstones can be distinguished from glass that feels warmer in comparison when held to the tongue because of its lower thermal conductivity.
- A blasting explosive consisting of a mixture of guncotton with a nitrate and sometimes a nitro compound.
- A unit of measurement often used for the work done in transport. The number of ton-kilometers is the weight in tons of material transported multiplied by the number of kilometers driven.
- A system that permits calculating how hard an earth-moving tire should work and how much work it is doing. The Ton MPH for any tire is determined by multiplying the mean load and average speed. The resulting figure provides an index to the work a tire is doing. The system enables the operator to determine which type of tires to use to get top performance without overheating.
- Cubic feet of ore per ton in deposit.
- In anthracite coal mining, a person who is paid at a certain rate per ton of coal mined.
- The extraction of 200 Btu/min (211 kJ/min), 12,000 Btu/h (12.7 MJ/h), or 288,000 Btu/d (3.1 GJ/d). The last is also called a ton-day of refrigeration. A ton of refrigeration is equal to 3.5168 kW of heat removal.
- An apparatus for measuring damping values.
- A compact argillaceous rock containing the clay mineral kaolinite in a variety of forms together with occasional detrital and carbonaceous material; commonly occurring as a thin band in a Carboniferous coal seam (or locally in the roof of a seam); often used as an aid in correlating European strata of Westphalian age.
- See: powder box.
- A lazy miner, specif. one who rests on a tool box while another miner does the work.
- The driller's helper on a cable tool rig. Syn: cable-tool dresser; toolie.
- An implement for grasping and withdrawing drilling tools when broken, detached, or lost in a borehole. A fishing tool. Also called tool grab.
- In stonework industry, one who grinds the cutting tools for stoneworking planers and lathes to a keen edge of the desired shape.
- One who hardens and tempers tools, dies, and fixtures.
- A worker who sharpens churn-drill bits; a dresser. See also: tooldresser.
- A worker skilled in the making of jigs, fixtures, gauges, etc.
- A person who carries powder, drills, and tools to the various levels of a mine and brings dulled tools and drills to the surface.
- a. The head driller or drill foreman.
b. The general supervisor of operations on a drilling rig. More commonly used in petroleum drilling.
- Industrial diamond used for wire-drawing dies, indentor points, shaped-diamond tools, glaziers, and dressers. Toolstones approach gem diamonds in perfection, although not in color. The finer grades may be identical with diamonds sold as low-grade gems. The lower grade toolstones are also sometimes used as drill diamonds. CF: drill diamond.
- a. Steel projections on a tool, such as a saw or excavation bucket, designed to provide a cutting or increased digging action.
b. A projection on the circumference of a wheel (gear), designed to engage corresponding projections on another wheel (cog), and thereby transmit force.
- a. The inner part of a two-piece tooth on a digging bucket.
b. Occasionally, the socket in which a tooth fits.
- A brake used to hold a shaft by means of a tooth or teeth engaging with fixed sockets. Not used for slowing or stopping.
- See: roller bit.
- A drivepipe or casing shoe with a serrated or toothed cutting edge.
- Odontolite; fossil tooth material.
- A mine-safety expression used to describe those mines or areas of mines that are too wet to propagate explosions even though they are not rock dusted. Too wet is when water exudes from a ball of dust when it is squeezed in the hands.
- a. The surface around a mine shaft; the outside.
b. A mine roof; the upper part of a coalbed separated from the rest by a seam or parting. c. The apex of a vein. d. See: cap; blue cap; overburden.
- The words top and apex as applied to mineral veins were not a part of the miner's terminology prior to the adoption of the U.S. Mining Law of 1872, but were words used by legislators to convey the intent of the formulators of that law. CF: apex.
- A triclinic mineral, Al (sub 2) (F,OH) (sub 2) SiO (sub 4) ; pseudo-orthorhombic; colorless to pale blue, pale yellow to pinkish-beige ("sherry" topaz); defines hardness 8 on the Mohs scale; in cavities in granites, granite pegmatites, and rhyolites, and in surrounding metamorphic rocks; may be of gem quality. CF: false topaz; Scotch topaz; Spanish topaz.
- See: topazite.
- A hypabyssal rock composed almost entirely of quartz and topaz (Johannsen, 1920). Syn: topazfels; topazoseme; topaz rock.
- A yellow variety of andradite resembling topaz.
- See: topazite.
- See: gold topaz.
- See: topazite.
- Eng. Often applied to the highest bed in a quarry. In Dorset and Somerset, the upper division of the Inferior Oolite.
- The method by which the bench is removed from above, as with a dragline. See also: benching.
- Fireclay brick for use in lining the top section of a blast furnace.
- A worker at the top of a shaft to superintend the operation of lowering and raising of a cage. At most mines, duties include removing loaded cars from the cage and placing empty cars on the cage. See also: cager.
- That part of a mine roof that has to be taken down to give headroom on roadways.
- Standard grade of diamonds.
- a. A machine cut made in the upper limit of the workable section of a coal seam. See also: overcut.
b. A horizontal cut or groove made in coal at or near the top of the working face. See also: middle cut; bottom cut.
- A cutting machine designed esp. for cutting through the seam at a high level above the footwall.
- A frame set at or just below ground level as a preliminary to the main timbering in an excavation. See also: setting.
- A gate road at the upper end of an inclined longwall conveyor face; usually a tailgate. See also: bottom gate.
- A method of driving used for adits, tunnels, and drifts. The upper part or top heading is driven to the full length, before the enlargement of the rest of the section is carried out.
- An earlier system of working coal between two levels in an inclined coal seam. The top holes are driven to the full rise, and the face-line is usually stepped. Only the coal is worked, and no ripping is done in the top holes. The coal gravitates into trams in the lower level. See also: stepped longwall.
- See: lander.
- See: tufa. Etymol: Latin. Pl: tophi.
- See: top shot.
- See: lander.
- A lease granted by a landowner during existence of a recorded mineral lease that is to become effective if and when the existing lease expires or is terminated.
- In mining, a worker who is employed at surface jobs around the mine plant.
- An imaginary line on the ground, all points of which are at the same elevation above (or below) a specified datum surface.
- See: terrain correction.
- A map showing the topographic features of a land surface, commonly by means of contour lines. It is generally on a sufficiently large scale to show in detail selected man-made and natural features, including relief, and such physical and cultural features as vegetation, roads, and drainage. CF: planimetric map.
- See: profile.
- Map upon which is shown a portion of land having elevations indicated by a series of separate lines, each of which passes through a specified elevation; the sinuosity and spacing or crowding together of the contour lines, as they are called, indicate slope and relief of the terrain.
- a. The relationship between two parts of a landscape or two kinds of topography that are out of adjustment with one another, due to an interruption in the ordinary course of the erosion cycle of a region; e.g., a lack of harmony between the topographic forms of the upper and lower parts of a valley, due to rejuvenation.
b. A land surface exhibiting topographic unconformity.
- a. The general configuration of a land surface or any part of the Earth's surface, including its relief and the position of its natural and manmade features. CF: relief. Syn: lay of the land.
b. The natural or physical surface features of a region, considered collectively as to form; the features revealed by the contour lines of a map. In nongeologic usage, the term includes manmade features (such as are shown on a topographic map). c. The art or practice of accurately and graphically delineating in detail, as on a map or chart or by a model, selected natural and manmade surface features of a region. Also, the description, study, or representation of such features. Etymol: Greek topos, place, + graphein, to write.
- A recrystallization in which the crystallographic orientation of the parent crystal determines that of the product crystal, e.g., goethite to hematite with a -> c/3, b -> 2 a, and c#M# -> a T3/3. CF: epitaxy; syntaxy.
- a. The contents of a loaded mine car above water level.
b. Fine material forming a surface layer or dressing for a road or grade. c. A finishing layer of fine concrete, usually 2 in (5.1 cm) thick, laid over the base concrete of a ground floor or over the structural components of a solid or hollow suspended floor or roof.
- Eng. The first regular layers of flints in the Brandon flint mines.
- Roof ripping.
- Scot. The rod connecting the uppermost pump rod to the bellcrank (lever) on a bellcrank drive.
- An explosion or puff of gas at a furnace top. Syn: top kick.
- a. On the surface as opposed to underground.
b. Above the drill rig in the derrick or tripod. c. The inlet end of the hydraulic cylinder of a hyraulic-feed mechanism on a diamond drill.
- A horizontal block of ore extracted by top slicing. The dimensions vary in different mines.
- A method of stoping in which the ore is extracted by excavating a series of horizontal (sometimes inclined) timbered slices alongside each other, beginning at the top of the orebody and working progressively downward; the slices are caved by blasting out the timbers, bringing the capping or overburden down upon the bottom of the slices that have been previously covered with a floor or mat of timber to separate the caved material from the solid ore beneath. Succeedingly lower slices are mined in a similar manner up to the overlying mat or gob, which consists of an accumulation of broken timbers and lagging from the upper slices and of caved capping. See also: block caving.
- See: top slicing and cover caving.
- A mining method that entails working the orebody from the top down in successive horizontal slices that may follow one another sequentially or simultaneously. The whole thickness of the slice is worked. The ore may be broken by overhand or underhand stoping in each unit. The overburden or cover is caved after mining a unit. Syn: mining ore from top down; top slicing and caving; transverse slicing with caving.
- A method of working an orebody from the top down in successive slices. Instead of taking the full height of the slices, only the lower part is taken and the upper part is caved. After removing this portion of the ore, the cover is caved. A timber mat is used in most cases to separate the broken cover from the ore and for safety. Also known as caving system subdrifting and caving; subslicing; slicing under ore with back cave; sublevel caving; sublevel slicing.
- See: roof testing.
- See: hanging wall.
- Water introduced with the raw coal feed to assist the transport of material through the washbox. Also called transport water. CF: flush water.
- A high, isolated crag, pinnacle, or rocky peak; or a pile of rocks, much jointed and usually granitic, exposed to intense weathering, and often assuming peculiar or fantastic shapes, e.g., the granite rocks standing as prominent masses on the moors of Devon and Cornwall, England.
- See: torbanite.
- a. A variety of algal or boghead coal from Torbane Hill, Scotland. It is layered, compact, brownish-black to black in color, very tough, and difficult to break. On distillation, torbanite gives a high yield of oil. Also called bathvillite. See also: bitumenite; boghead cannel; boghead coal; boghedite; kerosine shale. Syn: Torbane Hill mineral.
b. A dark-brown variety of cannel coal. c. An oil shale mined in South Africa.
- A tetragonal mineral, Cu(UO (sub 2) ) (sub 2) (PO (sub 4) ) (sub 2) .12H (sub 2) O ; autunite group; strongly radioactive; green; in tabular or foliated crystals, associated with other uranium minerals; commonly in parallel growth with autunite; a secondary mineral resulting from alteration of uraninite. Also called chalcolite, copper uranite, cuprouranite. Syn: uranmica; uranphyllite. CF: metatorbernite.
- An oil-burning, wick-fed, miners' lamp of tin or copper, with a long spout.
- A monoclinic mineral, (Na,Mg,Fe) (sub 7) Si (sub 4) O (sub 11) (OH,F) approx.; an amphibole intermediate between richterite and glaucophane; dark blue; at Itorendrika, Madagascar, and near Tine, Wadai, Africa.
- See: coal ball.
- See: dopplerite.
- a. A wooden axle, studded with iron spikes, for puddling auriferous clay as it spins or turns in a trough. See also: puddler.
b. A device somewhat similar to a log washer.
- The Tornado crusher is based on the principle of central impeller shoes spinning to hurl particles of gravel against breaker plates at tremendous speed. The impact literally "explodes" the rock, causing it to cleave across the grain as well as with the grain, producing the most desirable cubical product.
- A monoclinic mineral, (Ce,La) (sub 2) Al(SiO (sub 4) ) (sub 2) (OH) ; weakly radioactive; green to olive; in contact zones at Bastnaes, Sweden. Also spelled toernebohmite.
- An encased explosive charge that is slid, lowered, or dropped into a borehole and exploded to clear the hole of obstructions or to open connections with passage ways to an oil or water supply. Also called a bullet.
- The effectiveness of a force that tends to rotate a body; the product of the force and the perpendicular distance from its line of action to its axis.
- Square or vertically fluted bar run on one type of auger drill to rotate, raise, and lower the auger. See also: torque rod.
- A hydraulic coupling that utilizes slippage to multiply torque.
- A device for measuring the actual torque transmitted to the drilling head and/or to the drill-rod string.
- A bar having the function of resisting or absorbing twisting strains. Syn: torque bar.
- Tank thickener in which bottom rakes rise when overloaded with settled material.
- The pressure exerted per square centimeter by a column of mercury 1 mm high at a temperature of 0 degrees C where the acceleration of gravity is 980.665 cm/s (super 2) .
- Beds of quicksand encountered below the chalk marl in the Anzin Coalfield, in France.
- A monoclinic mineral, (Mg,Mn) (sub 9) Zn (sub 4) (SO (sub 4) ) (sub 2) (OH) (sub 22) .8H (sub 2) O ; related to mooreite and lawsonbauerite; at Sterling Hill, NJ.
- If a twisting couple is applied at a given section of a straight member, that section rotates about some point in its plane. This point, which does not move when the member twists, is the torsional center of that section. It is sometimes defined as though identical with the flexural center, but the two points do not always coincide. Syn: center of twist; center of torsion; center of shear. CF: flexural center; elastic center; elastic axis.
- A shear test in which a relatively thin test specimen of solid circular or annular cross section, usually confined between rings, is subjected to an axial load and to shear in torsion. In-place torsion shear tests may be performed by pressing a dentated solid circular or annular plate against the soil and measuring its resistance to rotation under a given axial load.
- See: Ree's torsion anemometer.
- A geophysical prospecting instrument that is used to determine distortions in the gravitational field. It consists of a pair of masses suspended by a sensitive torsion fiber and so supported that they are displaced both horizontally and vertically from each other. A measurement is made of the rotation of the suspended system about the fiber; the rotation is caused by slight differences in the gravitational attraction on the two masses. Syn: Eoetvoes torsion balance.
- A break in the drill core caused by an accumulation of chips at the bit face. When drilling is stopped to rechuck, these chips grip the core, and the core is twisted and broken. CF: torsion fracture.
- A spiraled crack in a drill core caused by torque in a blocked bit or core barrel. CF: torsion break.
- A seismograph with which the horizontal component of the earthquake can be defined making use of the torsion of a vertical suspension thread on which a stationary mass is fastened offcenter.
- Sometimes applied by miners to structures such as pots, bells, kettles, and other rock masses that tend to fall easily from the roof of a coal mine. See also: pot bottom; camel back.
- See: turbulent flow.
- The operation of raising the grade or purity of a concentrate by violent stirring, followed by packing, in a kieve or open dolly tub. Chimming is a similar process on a smaller scale. See: tozing.
- Acidity to phenolphthalein. Total acidity of mine water indicates the complete capacity of water to produce chemical change by acid reaction. It is the total amount of acid held in solution or the sum of the quantities of both the ionized and the un-ionized portions of actual acid and the potential quantity of acid that can be formed from mineral salts held in solution. Total acidity is customarily reported in equivalent parts per million (ppm) by weight of calcium carbonate. The indicated total acidity of mine water found by currently accepted methods of analysis generally is greater than the actual total acidity.
- Residue of the mineral matter obtained by incinerating coal under standard conditions.
- A drilling term describing the total amount of any load or pressure, expressed in kilograms, pounds, or tons, that is applied to a bit when it is in use.
- A blasting term describing the total time between application of current and the detonation.
- The sum of the free and combined carbon (including carbon in solution) in a ferrous alloy.
- The difference between the total heat content of the air-steam mixture entering a conditioner per hour and the total heat of the mixture leaving per hour.
- The sum of the sensible and latent heat components that must be removed from a space to maintain desired conditions.
- a. The total load or pressure that must be applied to a bit for its optimum rate of penetration in a specific rock.
b. The maximum load that can be applied to a bit without causing damage to the bit. CF: critical pressure.
- See: slip. CF: dip slip.
- The total of the static head (the suction discharge heads), the friction head, together with any discharge head that must be overcome by a pump is termed the total dynamic head.
- The total energy at any section in a moving fluid consists of the sum of the internal static, velocity, and potential energies at that section.
- See: hardness.
- All waters contain two forms of hardness, i.e., temporary (or carbonate) hardness, and permanent (noncarbonate) hardness. The combination of the two is referred to as total hardness. See also: hard water.
- The sum of the elevation head, pressure head, and velocity head of a liquid. For ground water, the velocity-head component is generally negligible.
- a. The total heat of atmospheric air is the heat contained in the same amount of dry air (known as sensible heat) plus the latent heat of the contained water vapor plus the sensible heat of the water vapor above the wet-bulb temperature. This is called the sigma function or sigma heat. True total heat or enthalpy is the sigma heat plus the heat of the water below the wet-bulb temperature. The latter is a very small quantity, and in mining work sigma heat is always used. Sigma heat is usually measured above 0 degrees F (-18 degrees C), so that it is the heat that would be given up if all moisture were condensed out and removed and the air cooled to 0 degrees F. Some engineers use 32 degrees F (0 degrees C) as the basic temperature so care should be taken to verify the base used. If absolute total heat is specified, it is measured above absolute zero (-459 degrees F or -273 degrees C).
b. The sum of sensible heat and latent heat in a substance or fluid above a base point, usually 32 degrees F or 0 degrees F.
- In an air lift, the distance water is elevated during pumping. Total lift equals drop plus static head plus elevation. Also called lift.
- The vector resultant of the intensity of the horizontal and vertical components of the Earth's magnetic field at a specified point.
- a. Free moisture plus moisture in air-dried coal, both being expressed as percentages of the sample as received.
b. The moisture in the coal or coke as samples.
- The sum of the weights of material correctly included in the products of a sizing or density separation, expressed as a percentage of the weight of the feed to the separator (and equal to 100 minus the "total of misplaced material").
- The sum of the weights of the misplaced material in the products of a sizing or density separation, expressed as a percentage of the weight of the feed. When three products are made in a single separator, the total of misplaced material will be the sum of the weight of material wrongly placed in each of the three products, expressed as a percentage of the feed to the separator.
- See: porosity.
- a. The total ventilating pressure in a mine, usually measured in the fan drift.
b. The algebraic sum of static pressure and velocity pressure at any particular point. c. The pressure in a soil mass due to overlying material and any superimposed loads. d. The pressure on any horizontal plane in a mass of soil as calculated from the weight of the material above the plane, or the soil together with any applied loads.
- In gemology and optical mineralogy, total reflection occurs in a transparent solid where a light ray strikes the surface of a medium of lower refractive index at any angle greater than its critical angle as defined sin r = 1/n, where r is the critical angle and n is the refractive index of the solid (or n (sub 2) /n (sub 1) , where n (sub 1) represents the lower refractive index if other than 1 for air). CF: critical angle; reflection; law of refraction.
- An instrument for measuring the critical angle in a transparent solid.
- The total resistance (R) or friction of a ventilation system is calculated from the total ventilating pressure (P) and the total quantity of air at the fan (Q). Thus: R= P/Q (super 2) .
- The total force per unit area acting within a mass of soil. It is the sum of the neutral and effective stresses.
- Tonnage of ore or product shipped plus tonnage of ore, waste, and tailings dumped.
- Value of ore or product shipped plus value of the ore, waste, and tailings dumped.
- The sum of the natural ventilating power plus the effective (or air) horsepower of all fans in series. When the circuit is divided and fans are in parallel, the total ventilating power of each split is worked out separately, the natural and fan powers being added; finally the power of each circuit is summed to give the total ventilating horsepower.
- The pressure required to overcome the static and potential energy head losses and to provide the velocity head to move a quantity of air through a network. See also: ventilating pressure; mine total head; fan total head; water gage.
- A test to determine the deviation of a well from the vertical, employing an instrument known as a Totco.
- A black, flinty stone, such as a silicified shale or slate, or a variety of quartz allied to chert or jasper, whose smoothed surface was formerly used to test the purity or fineness of alloys of gold and silver by comparing the streak left on the stone when rubbed by the metal with that made by an alloy of predetermined composition. Syn: Lydian stone; basanite.
- The exact state or quality of texture and consistency of refined copper. See also: tough cake.
- Refined or commercial copper. See also: cake copper; tough.
- a. A property of a material that denotes, nominally, an intermediate value between softness and brittleness. Tensile tests show a tough material to have a fairly high tensile strength accompanied by moderate values of elongation and reduction of area.
b. The amount of work required to deform a body to its rupture point.
- The ratio between the index of plasticity and the flow index of a soil.
- Resistance to crumbling, to abrasion, or to coarse particles being dislodged from the brick structure.
- a. A term used in electrolytic copper refining to designate copper that has set, from the molten condition, with a level surface. See also: underpoled copper; overpoled copper.
b. A term applied to copper in which the oxygen content has been correctly adjusted at 0.03% to 0.06% by poling. Distinguished from overpoled and underpoled copper.
- Copper containing from 0.02% to 0.05% oxygen, obtained by refining copper in a reverberatory furnace.
- Soft tenacious clay floor of coal seams.
- A quarryman's term for the third easiest direction of rock fracture after the rift and the grain. Syn: hard way. Also called head.
- A work-shift. Sometimes incorrectly spelled tower.
- a. Any member of the trigonal mineral group, XY (sub 3) Z (sub 6) (BO (sub 3) ) (sub 3) Si (sub 6) O (sub 18) (OH,F) (sub 4) where X is Na partially replaced by Ca, K, Mg, or a vacancy, Y is Mg, Fe (super 2+) , Li, or Al, and Z is Al and Fe (super 3+) ; forms prisms of three, six, or nine sides; commonly vertically striated; varicolored; an accessory in granite pegmatites, felsic igneous rocks, and metamorphic rocks. Transparent and flawless crystals may be cut for gems.
b. The mineral group buergerite, dravite, elbaite, ferridravite, liddicoatite, schorl, and uvite.
- Introduction of, or replacement by, tourmaline.
- A channel-type, steel-arch support consisting of three elements or sections set close to the face of a tunnel. These elements overlap and yield by sliding one upon the other under the constraint of bolted clamps. The center or crown element is usually foreset to give temporary protection until the complete arch is erected. See also: Usspurwies arch; steel arch; steel support.
- An endless chain supported by trolleys from an overhead track or running in a track at (above, flush with, or under) the floor with means for towing trucks, dollies, or cars.
- See: grader.
- a. See: tour.
b. A misnomer for derrick and an incorrect spelling of tour.
- A swing-jib or other type of crane mounted on top of a tower, the base of which may sometimes move on rails. These cranes are esp. effective on congested sites. See also: monotower crane; swing-jib crane.
- In anthracite coal mining, one who operates a hoist to raise loaded mine cars from the surface of a mine to the top of the breaker, where the coal is dumped, crushed, and prepared for market.
- A cableway excavator designed specif. for levee work, but which is used extensively in the stripping of overburden, spoil, or waste in surface mining. The unit is basically an excavator with towers either fixed or movable. With the headtower located on the spoil pile and the tail tower on the unexcavated wall, it is possible to dig pits of almost unlimited width.
- A front-end loader whose bucket is lifted along tracks on a more or less vertical tower.
- A device utilizing a rotating field of magnetic force to induce a vigorous rotary movement in a small magnetized bar totally enclosed in a polythene or glass tube, and placed in the liquid to be stirred.
- The unit of survey of the U.S. Public Land Survey system, representing a piece of land that is bounded on the east and west by meridians approx. 6 miles (9.6 km) apart (exactly 6 miles at its south border) and on the north and south by parallels 6 miles apart, and that is normally subdivided into 36 sections. Townships are located with reference to the initial point of a principal meridian and base line, and are normally numbered consecutively north and south from a base line (e.g., township 14 north indicates a township in the 14th tier north of a base line). The term township is used in conjunction with the appropriate range to indicate the coordinates of a particular township in reference to the initial point (e.g., township 3 south, range 4 west indicates the particular township that is the 3rd township south of the base line and the 4th township west of the principal meridian controlling the surveys in that area). Abbrev. (when citing specific location): T.
- One of the imaginary boundary lines running east and west at 6-mile (9.6-km) intervals and marking the relative north and south locations of townships in a U.S. public land survey. CF: range line.
- Dusts poisonous to body organs, tissue, etc. They include ores of beryllium, arsenic, lead, uranium, radium, thorium, chromium, vanadium, mercury, cadmium, antimony, selenium, manganese, tungsten, nickel, and silver (principally the oxides and carbonates).
- In geochemical exploration, a collective term for the abnormal colors and morphological features of a plant caused by a poisonous element in the nutrient solution.
- Water that is discharged from active or abandoned mines or other areas affected by mineral exploration or surface mining and reclamation operations that contains a substance that through chemical action or physical effects is likely to kill, injure, or impair biota commonly present in the area(s) to which it might be exposed.
- See: tossing.