The Aggregates & Recycling Information Network

Glossary: F

  • Fabrication

    The preparation in a workshop of the steel members of a building framework for later erection on site.

  • Face

    An exposed surface of pay mineral, usually near vertical.

  • Face Left And Right

    The positions of a theodolite when, viewed from the eyepiece, the vertical circle is to the left and right of the telescope respectively.

  • Factor Of Safety

    The ratio, allowed for in design and manufacture, between the breaking load on a member or structure and the safe permissible load on it.

  • Fail Safe

    Design in which control or structural failure leads to automatic operation of protective devices and the cutting-off of the power supply.

  • Farad

    The capacitance of a capacitor between the plates of which there appears a difference of potential of one volt when it is charged by a quantity of electricity equal to one coulomb.

    Symbol: F

  • Faraday’s Law

    Faraday’s law of electromagnetic induction states: ‘The magnitude of the electromotive force induced in a circuit is proportional to the rate of change of magnetic flux linking the circuit.’

  • Fault

    A plane of fracture in a rock body, along which there has been displacement.

    See also: normal fault and reverse fault

  • Fault Breccia

    The shattered rock material along a fault plane.

  • Fault Plane

    Any surface along which relative movement between adjacent rock masses has taken place.

  • Feed box
    Feed Box

    A box, usually mounted on the feed end of a screen, used to reduce the velocity of the feed and to distribute it across the full width of the screen.

  • Feldspar

    A family of rock-forming minerals consisting of aluminous silicates of barium, calcium, potassium and sodium. They occur as constituents of igneous rocks.

  • Field Book

    The book used by a surveyor to record his field measurements.

  • Field Regulator

    A variable resistance for varying the current in the field winding of an electric machine.

  • Filler

    A finely divided mineral powder added to road tar, bitumen or the like, or to a mixture containing the same, in order to effect some desired change in the properties of the binding material.

  • Fine Aggregate

    Graded material which, in the case of concrete aggregate, is smaller than 4mm, and for road-making material is below 2mm.

  • Fine-adjustment Screw

    A fine-adjustment screw fitted on both the horizontal and vertical circles of a theodolite for the purpose of moving the line of sight through small angles.

    Also: tangent screw

  • Fines
    1. Particles finer than 63µm.
    2. Sometimes used synonymously with ‘fine aggregate’.
  • Finger Car

    A concrete block transporter which moves the blocks in an automated sequence from the press to the curing point.

  • Fishing Tool

    A tool used to recover broken bits or other drilling equipment from a borehole.

  • Fishtail Bit

    A bit used for rotary drilling through soft ground.

  • Fixed Assets

    Relatively long-term resources of a company, acquired not for disposal but to assist in the earning of profit, eg land, buildings, plant and machinery.

  • Fixed Costs

    Costs which are not affected by variations in output but may change over a period of time, eg rates.

  • Flagstone
    1. Sedimentary rock easily separated into flat slabs.
    2. A paving stone made from (1).
  • Flake Deck

    A deck fitted to a screen for the purpose of removing excess flaky material from a product, usually achieved by the fitting of elongated slots narrower than the nominal size.

  • Flakiness Index

    An index of particle shape determined by means of a test described in BS EN 933 Part3. This European test replaces the former flakiness test BS 812 Part 105 and produces different values.

  • Flameproof

    Term applied to the enclosures of electric machines. These are such that gas or dust cannot get inside the machine and sparking within the casing of the machine cannot affect inflammable concentrations of vapour or dust which surround the machine.

  • Flash Point

    The lowest temperature at which a heated liquid gives off sufficient vapour to flash on the application of a small flame.

  • Flexible Cable

    A cable designed to be movable while in use.

  • Flexible Coupling

    A coupling used to connect two shafts in which rigid alignment is not possible. Typically the drive is transmitted between flanges on the shafts through a flexible disc or bushes.

  • Flexible Pavement

    Any pavement in which high-strength concrete is not used as a construction layer.

  • Flint

    Cryptocrystalline silica originating as nodules or layers in chalk.

  • Float

    In a network, the spare time available for a non-critical activity. The time available for an activity or path in addition to its duration, BS 2300l.

  • Flocculation

    Coalescence of minute particles into floccules to accelerate settlement as part of dewatering or thickening of a pulp. Chemicals are used to promote adhesion.

  • Floor
    1. The stratum immediately below a seam of coal or stratified mineral deposit.
    2. The base of an excavation.
  • Flotation

    A mineral processing operation which involves conditioning the surfaces of mineral grains in water so that certain minerals can be collected into air bubbles and carried to the surface to effect separation. Uses include the cleaning of fine coal and the removal of contaminants from flint glass sand.

    Also: froth flotation 

  • Flotation Reagent

    A chemical required to obtain suitable conditions for the successful operation of a flotation process.

    See also: collectors, frothers, reagents and regulators

  • Flow Diagram

    A diagram or model which shows the location of specific activities carried out and the routes followed by workers, materials and equipment in their execution.

  • Flow Divider Valves

    Hydraulic valves used to give priority to the flow requirements of a particular service. When these requirements are met, the remainder of the flow is diverted to another service or returned to the reservoir.

  • Flowsheet

    A diagrammatic representation of the flow of material through a processing plant, showing the sequence of operations and their interrelationship.

  • Fluid Coupling

    A device used to gradually apply a high-inertia load to an electric motor or diesel engine.

  • Flume

    A concrete, steel or wooden trough used to convey pulp or water.

  • Fluvial

    Relating to a river; a deposit produced by the action of a river.

  • Fluvioglacial

    May be applied to sediment transported and deposited by melt water from a glacier or ice sheet.

  • Flux

    A substance added to a solid to increase its fusibility. In soldering and welding it is added to the molten metal to dissolve oxide films which prevent adhesion.

  • Flux Oil

    A substantially non-volatile diluent used for reducing the viscosity of bitumen.

  • Fly-rock

    Material which is projected outside the declared danger zone by a quarry blast. Fly-rock may be caused by poor blast design or unexpected zones of weakness in the rock.

  • Flywheel

    Large-diameter wheel keyed to the end of the shaft of machines such as jaw crushers and the function of which is to restrict fluctuations of speed by absorbing and releasing quantities of kinetic energy for small speed variations.

  • Fold

    A bend in bedded rocks.

  • Follower
    1. In surveying, the man who holds the rear end of the tape or chain and is responsible for lining-up the leader at each tape or chain length.
    2. The driven wheel of a pair of wheels engaging with each other.
  • Foot Screws

    The three screws used for leveling a survey instrument.

  • Foot Valve

    A non-return valve attached to the lower end of a pump suction pipe. Also known as a clack valve.

  • Footwall

    The rock immediately underlying a mineral deposit.

  • FOPS Cab

    A driver’s cab providing protection from falling objects (falling object protection structure).

  • Force

    That influence which causes, or tends to cause, a change in the shape or size or the state of motion of a body.

    Unit: Newton

  • Force Ratio

    The ratio of load to effort.

    Also: mechanical advantage

  • Form Factor

    The ratio rms value/mean value of an alternating quantity such as a current or a voltage.

  • Formwork

    Temporary boarding or sheeting erected to contain freshly placed and compacted concrete until it has gained sufficient strength to be self-supporting. The appearance of the finished concrete depends on the face texture and stiffness of the formwork.

  • Foundation Bolt

    A bolt with its threaded end projecting above the foundation and secured so as to hold down a steel structure against wind loads or machinery against its vibration.

    Also: anchor bolt and holding-down bolt

  • Four-bearing Screen

    A mechanically vibrated screen in which the circular motion is generated by eccentrics incorporated in the vibrator shaft acting through two outboard bearings on the base-frame and two inboard bearings on the side-plates.

  • Four-stroke Cycle

    An internal combustion engine cycle completed in four piston strokes. On the first downward stroke induction takes place, followed by compression during the subsequent upward stroke; after combustion the power stroke and on the next upward stroke the exhaust gases are expelled.

  • FPC

    abbr. factory production control

    A European term for Quality Assurance.

  • Fractional Exposure

    The measure of the combined effect when the daily exposure is to a number of different sound-intensity levels each for its own period of time. It is the actual energy dosage received during each period expressed as a fraction of that corresponding to 90dB(A) for 8h and is used in determining whether the daily exposure is acceptable.

  • Fracturing

    Breaking of rock with or without movement of the broken pieces.

  • Fragmentation

    A term associated with rock quarrying to describe the degree of breakage by blasting evident in a rock pile.

  • Freestone

    Building stone workable in any direction.

  • Frequency

    The number of cycles which take place in one second.

    Symbol: f

    Unit: hertz (Hz)

  • Fretting
    1. A form of wear encountered when surfaces are subject to continuous relative movement of small amplitude, eg in bearings supporting shafts which oscillate through a small angle, in ball or roller races of machines subject to vibration while stationary etc.
    2. The condition of early stages of wear of a road surface as evidenced in the loss of small-size aggregate from the bound surface.
  • Friction

    The resistance to motion when it is attempted to slide one surface over another with which it is in contact.

  • Friction Course

    An asphalt mix designed to produce a high voids content and good texture to give improved drainage and skid resistance characteristics, together with reduced noise under traffic.

  • Friction Loss

    The power absorbed in the sliding contacts of an electric machine.

  • Frost Heave

    The formation of ice lenses in the lower layers of a road which may cause surface heaving.

  • Frost Shattering

    A natural process which occurs when water penetrates a road surface and expands as it freezes.

  • Froth Flotation

    A mineral processing operation which involves conditioning the surfaces of mineral grains in water so that certain minerals can be collected into air bubbles and carried to the surface to effect separation. Uses include the cleaning of fine coal and the removal of contaminants from flint glass sand. 

    Also: flotation

  • Frothers

    A type of flotation reagent which, when dissolved in water, imparts to it the ability to form a stable froth.

  • Frustum
    1. The remainder of a cone or pyramid whose upper part has been cut off by a plane parallel to its base.
    2. The part of a cone or pyramid intercepted between two planes.
  • Fuel

    A substance which, when burned, produces heat energy. An ingredient in an explosive which reacts with an oxidizer to form gaseous products of detonation.

  • Fuel Injection

    A method of operating an internal combustion engine by injecting liquid fuel directly into the induction pipe or cylinder during the suction-stroke.

  • Full-wave Rectification

    [img_assist|nid=11954|title=|desc=|link=none|align=right|width=180|height=229]The use of a bridge or double-diode rectifier to obtain a rectified current which flows during both halfcycles of the alternating voltage.

  • Fumes

    Cloud of airborne particles, generally visible, less than 1µm in size, of low volatility and formed by condensation of vapours or by chemical reaction. Noxious or poisonous fumes liberated from a blast may be due to low-fume-quality explosives or inefficient detonation.

  • Fuse

    An overcurrent protection device which prevents excessive currents from flowing in a circuit by the melting of a fuse element.

    See also: safety fuse

  • Fusing Factor

    The ratio, greater than unity, of the minimum fusing current to the current rating.