Any of various instruments used for measuring angles of slope, elevation,
or inclination (esp. the dip of a geologic stratum or the slope of an
embankment); e.g., a simple hand-held device consisting of a tube with a
cross hair, a graduated vertical arc, and an attached spirit level so
mounted that the inclination of the line of sight can be read on the
circular scale by centering the level bubble at the instant of
observation. A clinometer is usually combined with a compass (e.g., the
Brunton compass). Syn:inclinometer; plain clinometer.
CF:drift indicator
An exceptionally accurate instrument for borehole surveying, designed
particularly for use with the freezing and cementation methods of shaft
sinking; capable of giving the slope of a borehole to within 1 min of arc.
Hammond
A monoclinic mineral, (Na,K,Ca)2 Al3 (Al,Si)2 Si (sub
13) O36 .12H2 O; of the zeolite group.
A group name for monoclinic pyroxenes. Abbrev. cpx. Syn:monopyroxene
CF:orthopyroxene
A discredited name for phosphosiderite, a dimorph of strengite.
A monoclinic mineral, sodium potassium iron sulfate; possibly dimorphous
with ungemachite.
An epidote having the composition of zoisite, Ca2 Al3 (SiO
4 )3 (OH) ; monoclinic; crystals striated. Dana, 4
a. A monoclinic mineral, Ca(Mg,Al)3 (Al3 Si)O10 (OH)
2 ; mica group. Syn:seyberite; xanthophyllite.
b. A group name for the brittle micas.
A red, fossiliferous sedimentary iron ore; e.g., the Clinton Formation
(Middle Silurian) or correlative rocks of the east-central United States,
containing lenticular or oolitic grains of hematite. It supplies the
ironworks at Birmingham, AL. See also:fossil ore; flaxseed ore.
AGI
Connector between an underground tub, car, truck, or tram, and endless
rope haulage. A clip pulley has a broad rim into which studs are set, to
grip links of a haulage chain. See also:haulage clip; automatic clip;
coupling; clam. Pryor, 3
The clip method of making wire rope attachments is widely used.
Drop-forged clips of either the U-bolt or the double-saddle type are
recommended. When clips of the correct size are properly applied, the
method uses about 80% of the rope strength.
a. Eng. Deposits interstratified with coal; Yorkshire and Midland
Counties. Nelson
b. A hard earthy clay on the roof of a working place in a coal seam; often
a fireclay. CTD
c. A miner's term applied to a soft, weak, or loosely consolidated shale
(or to a hard, earthy clay), esp. one found in close association with coal
or immediately overlying a coal seam. It is so called because it falls
away in lumps when worked. An artificially formed aggregate of soil
particles. AGI
d. A clod of dirt, of greater or less diameter, thin at the edges and
increasing in thickness to the middle. See also:kettle bottom
e. An artificially formed aggregate of soil particles.
a. Mid. A short piece of timber about 3 in by 6 in by 24 in (7.6 cm by
15.2 cm by 61.0 cm) fixed between the roof and a prop. Fay
b. A flat wedge over a post. See also:lid
c. To obstruct, hinder, or choke up; e.g., the stoppage of flow through a
pipe by an accumulation of foreign matter, or the filling up of the
grooves in a file when operating on a soft metal. Crispin
d. Eng. Rock filling a fault. Arkell
Applied to dredges in which the buckets are each connected to the one in
front without any intermediate link. Fay
a. A water circuit designed so that the only water added is that necessary
to replace the loss of water on the products. BS, 5
b. A system in which coal passes from comminution to a sorting device that
returns oversize for further treatment and releases undersize from the
closed circuit.
A size-reduction process in which the ground material is removed either by
screening or by a classifier, the oversize being returned to the grinding
unit. Typical examples are a dry pan with screens, dry milling in an
air-swept ball mill, and wet milling in a ball mill with a classifier.
See also:circulating load
Retention and retreatment of ore in part of flow a line until it satisfies
criteria for release. Used in comminution to reduce overgrinding by
passing intermediate particles repeatedly through grinding systems,
classifying the product and returning oversize. Used in concentration
(e.g., rougher-scavenger-cleaner flotation) to retain a selected fraction
of ore in circuit for retreatment (a middling), until it is either
upgraded to rank as concentrate or sufficiently denuded of value to be
rejected as tailing. Pryor, 1
System in which television cameras relay pictures of conditions at
important points in a plant, thereby aiding workers to watch inaccessible
places and exercise extended control.
A contour line that forms a closed loop and does not intersect the edge of
the map area on which it is drawn; e.g., a depression contour indicating a
closed depression, or a normal contour indicating a hilltop. AGI
A fault in which the two walls are in contact. CF:open fault
AGI
A mine support frame used esp. in inclined shafts where protection from
rock pressure is needed on all sides. This completely closed set is
provided at the bottom with a sill. The joint is usually effected by
tenons, so that when the pressure is exerted in a downward direction the
timbers interlock. Stoces