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mast

a. A drill derrick or tripod mounted on a drill unit, which can be raised
to its operating position by mechanical means. Long
b. A single pole, used as a drill derrick, supported in an upright or
operating position by guys. Long
c. A tower or vertical beam carrying one or more load lines at its top.
Nichols, 1

master alloy

An alloy, rich in one or more desired addition elements, that can be added
to a melt to raise the percentage of a desired constituent. ASM, 1

master hauler

S. Wales. The person in charge of haulers in a coal mine and who controls
the horse haulage traffic and the allocation of trams. Nelson

master joint

A persistent joint plane of greater-than-average extent. AGI

master lode

The main productive lode of a district. CF:mother lode

master pin

The only pin in an integrated crawler track that will open the track when
driven out. Nichols, 1

mastershifter

N. of Eng. Official responsible for the working of a seam during the third
(night) shift of the day. Trist

master station

A position in the ventilation circuit of a mine specially chosen for the
regular and accurate estimation of the total quantity of air circulating.
Spalding

mat

a. An accumulation of broken mine timbers, rock, earth, etc., coincident
with the caving system of mining. As the ore is extracted, the mat
gradually settles and forms the roof of the working levels, slopes, etc.
b. Lusterless or dull surface in a metal, produced by a method of
finishing. Standard, 2

match

The part of a detonator that is most easily ignited. Mason

materials flowsheet

A flowsheet principally concerned with solid materials.
See also:operational capacities

materials handling

The art and science involving movement, packaging, and storage of
substances in any form.

materials lock

An air lock through which materials are passed into or out of a pneumatic
caisson or a shaft being driven under air pressure. See also:manlock
Hammond

Mathewson's device

An apparatus for separating matte and slag at lead-silver blast furnaces
where matte is of secondary importance. Fay

matildite

A hexagonal mineral, AgBiS2 ; forms prismatic crystals; sp gr, 6.9
. Syn:schapbachite; plenargyrite.

matlockite

A tetragonal mineral, 2[PbFCl] ; basal cleavage; an alteration of galena
or lead-bearing slags.

mat pack

Small pack of timber consisting of a number of timbers laid side by side
to form a solid mass 2 to 2-1/2 ft square by 4 to 6 in thick (approx. 0.7
m square by 10 to 15 cm thick). Holes are drilled edgeways through the
mat, and wires are threaded through to hold it together. Mats are
transported underground and built up to form very effective supports.
Spalding

matraite

A trigonal mineral, ZnS ; trimorphous with sphalerite and wurtzite.

matrix

a. The nonvaluable minerals in an ore; the gangue.
b. The rock material in which a fossil, crystal, or mineral is embedded.
Syn:groundmass
c. A local term for the phosphate-bearing gravel in the land-pebble
deposits of Florida. AGI
d. The metal in which the diamonds inset in the crown of a bit are
embedded. Long
e. The material that forms a cushion or binder in the construction of
pavement.
f. The finer-grained material between the larger particles of a rock or
the material surrounding a fossil or mineral. BS, 11
g. The principal phase or aggregate in which another constituent is
embedded. ASM, 1
h. In electroforming, a form used as a cathode. ASM, 1

matrix metal

The continuous phase of a polyphase alloy or mechanical mixture; the
physically continuous metallic constituent in which separate particles of
another constituent are embedded. ASTM

matrosite

A microscopical constituent of torbanite; opaque, black mass forming its
groundmass. CF:gelosite; humosite; retinosite. Tomkeieff