See:Pachuca tank
a. York. Hessle boulder clay. Arkell
b. See:red clay
a. A low-rank coal which is brown or brownish-black, but rarely black. It
commonly retains the structures of the original wood. It is high in
moisture, low in heat value, and checks badly upon drying. AGI
b. A light-brown to seal-brown substance intermediate between peat and
bituminous coal; usually regarded as a variety of lignite, other varieties
being darker or black. It may be distinguished from peat by three rough
criteria: (1) many tissues and fibers can be recognized in peat, but only
a few fibers or none in brown coal; (2) water can be squeezed out of fresh
peat by manual pressure, but not from brown coal; and (3) peat can be cut,
but brown coal cannot. Actually, there is no sharp distinction between
peat and coal. Some have attempted to assign it a higher rank by defining
lignite as containing at least 20% water, brown coal between 10% and 20%
water, and bituminous coal less than 10% water. Hess
c. A type of low-rank coal intermediate between bituminous coal and peat,
and comparatively high in water content. In English-speaking countries,
the terms "brown coal" and "lignite" are synonymous; in Germany and other
parts of Europe, brown coal is restricted to megascopically compact
structural varieties, and lignite is restricted to individual pieces of
wood enclosed in brown coal. It may be subdivided into low-grade brown
coal, consisting of visible vegetable remains, and high-grade brown coal,
a compact, homogeneous, and tough rock. Syn:braunkohle
Tomkeieff
d. Coal of the lowest rank, soft and friable, and having a high inherent
moisture content. BS, 4
e. Unconsolidated lignitic coal having less than 8,300 Btu (8.76 MJ),
(moist, mineral-matter-free).
See:dopplerite
See:clarkeite
A misnomer; the mineral bearing this name is limonite, a hydrous mixture
of minerals, whereas true hematite is an anhydrous oxide mineral.
Syn:limonite; brown iron ore. CF:red hematite
An annular turret-type furnace for calcining sulfide ores. Fay
a. Its approximate formula is 2Fe2 O3 .3H2 O ,
equivalent to about 59.8% iron. Probably a mixture of hydrous oxides.
See also:bog ore
b. See:limonite; brown hematite.
See:limonite
Brown matter is found in varying amounts in the attrital matter of all
splint and semisplint coals; it is occasionally present in the attritus of
bright coals. It consists of cell-wall degradation matter and the contents
of cells, which in thin sections are brown and semitranslucent. The term
has no exact equivalent in the Stopes-Heerlen nomenclature. Constituents
with a reflectance between that of vitrinite and fusinite may correspond
in part to brown matter. Some brown matter is identical with semifusinite
and massive micrinite. IHCP
See:phlogopite
See:celite
A mineral, Ca2 (Al,Fe)2 O5 ; a constituent of
Portland cement. Syn:celite
A mechanically raked, roasting, straight-line-type furnace with a series
of longitudinal combustion flues placed under the hearth. Fay
See:limonite
A long, horizontal, double-hearth furnace for the treatment of lead ores.
Fay
a. See:pillar-and-breast
b. Coal mining by long rooms opened on the upper side of the gangway. The
breasts are usually 5 to 12 yd (4.6 to 11.0 m) wide and are separated by
pillars (solid walls of coal broken by crossheadings for ventilation) 5 to
12 yd thick. The pillars are robbed by mining from them until the roof
comes down and prevents further working.
Syn:block system of stoping and filling
Tenn. Dark brown to black phosphorite resulting from the weathering of
phosphatic limestone. See also:phosphorite
Any light-colored crystalline carbonate mineral that is colored brown by
the presence of iron; e.g., ankerite, dolomite, magnesite, or siderite.
AGI
A brown or reddish-brown sandstone with grains generally coated with iron
oxide; specif. a dark, reddish-brown, ferruginous quartz sandstone of
Triassic age.
A cylindrical tank or vat, tall in proportion to its diameter, with the
bottom ending in a 60 degrees cone. Within the tank is a hollow column
extending from the bottom to within about 8 in (20.32 cm) from the top.
The apparatus works on the airlift principle, the aerated pulp in the tube
flowing upward and discharging at the top, while more pulp flows in at the
bottom to take its place. Syn:Brown agitator; Pachuca tank.
Liddell