A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

F

Face       The end of a drift, crosscut or stope in which work is progressing. Or The exposed area of a coal bed from which coal is being extracted.

Face cleat       The principal cleavage plane or joint at right angles to the stratification of the coal seam.

Face conveyor       Any conveyor used parallel to a working face which delivers coal into another conveyor or into a car.

Factor of safety       The ratio of the ultimate breaking strength of the material to the force exerted against it. If a rope will break under a load of 6000 lbs., and it is carrying a load of 2000 lbs., its factor of safety is 6000 divided by 2000 which equals 3.

Fahrenheit       A system of temperature measurement.

Fall       A mass of roof rock or coal which has fallen in any part of a mine.

Fall of Earth       Cave in.

False set       Temporary timbering in a mine.

Fan signal       Automation device designed to give alarm if the main fan slows down or stops.

Fan, auxiliary       A small, portable fan used to supplement the ventilation of an individual working place.

Fan, booster       A large fan installed in the main air current, and thus in tandem with the main fan.

Fault       A break in the Earth's crust caused by tectonic forces which have moved the rock on one side with respect to the other; faults may extend for many kilometres, or be only a few centimetres in length; similarly, the movement or displacement along the fault may vary widely.

Fault zone       A fault, instead of being a single clean fracture, may be a zone hundreds or thousands of feet wide. The fault zone consists of numerous interlacing small faults or a confused zone of gouge, breccia, or mylonite.

Feeder       A machine that feeds coal onto a conveyor belt evenly.

Feldspar       A crystalline mineral consisting of aluminum silicates and other elements that is an essential ingredient for the ceramics industry, and also is used in the glass and paint industries. A group of rock-forming minerals. Includes: microcline, orthoclase, plagioclase and anorthoclase.

Felsic       Term used to describe light-colored rocks containing feldspar, fledspathoids and silica.

Ferrous       Containing iron.

Fill       Any material that is put back in place of the extracted ore to provide ground support.

Fine gold       Fineness is the proportion of pure gold or silver in jewelry or bullion expressed in parts per thousand. Thus, 925 fine gold indicates 925 parts out of 1,000, or 92.5%, is pure gold. A fine ounce is a troy ounce of 99.5% gold and 0.5% silver.

Fineness       Gold content expressed in parts per thousand