South KoreaOver fifty pyrophyllite deposits are known in the
southern part of South korea, with commercial production
concentrated in Haenam rea of Chollanam-do Province. The tongnae
and wondonf reas of Kyongsangnam-do Province. The pyrophyllite
deposits were mainly formed through hydrothermal alteration of the
late Cretaceous Bulgugsa Granite Series, a sequence of intermediate
and acidic effusive rocks, particularly andesite and rhyolitic
lavas and tuffs,and of granodiorite, granite porphyry. Deposits are
generally small and irregularly shaped. Typically a siliceous zone
at the top is underlain successively by zones of alunite and
quartz, pyrophyllite and kaolin, and sulfide minerals. Three main
mineralogical types are recognized: pyrophyllite with minor quartz,
kaolin, and alunite; kaolin-pyrophyllite and some diaspore; and
pyrophyllite-sericite with quartz.
The Wando pyrophyllite mine in kusok- ni on Nohwa-do island, off
the coast of the Haenam district, is probably the largest mine,
with an output of 120,000 tons/year (Benbow 1988). Flow structures
in the underlying rhyolite facilitated the passage of hydrothermal
solutions which altered the host rock. Lenticular pyrophyllite
bodies, unevenly distributed in the felsite, consist of a mixture
of alunite, kaolin, and quartz, in places containing diaspore and
disseminated pyrite. Similar mines in the district include
ockmaesan. Hwangsan, and Sungsan. Mineralogically similar to the
Wando mine, the latter deposit consists of a flat-lying orebody
formed by the hydrothermal alteration of quartz porphyry and
tuff.
Corea Del Sur
Ms de cincuenta depsitos pirofilita se conocen en la parte sur
de Corea del Sur, con la produccin comercial se concentr en Haenam
rea de Chollanam-do Provincia.Los Tongnae y reas wondonf de
Kyongsangnam-do Provincia. Los depsitos pirofilita se formaron
principalmente a travs de la alteracin hidrotermal de finales del
Cretcico Bulgugsa Serie de granito, una secuencia de rocas
intermedios y acidie efusivas, en particular andesita y lavas y
tobas riolticas y de granodiorita, prfido granito.Depsitos son
generalmente pequeos y de forma irregular.Normalmente una zona
silcea en la parte superior es sustentada sucesivamente por zonas
de alunita y cuarzo, pirofilita y caoln, y minerales de
sulfuro.Tres principales tipos mineralgicos se reconocen:
pirofilita con menores de cuarzo, caoln, y alunita;caoln-pirofilita
y algunos diaspore;y pirofilita-sericita con cuarzo
La mina pirofilita Wando en kusok- ni en Nohwa-do isla, frente a
la costa de la Distrito Haenam, es probablemente la mayor mina, con
una produccin de 120.000 toneladas / ao (Benbow 1988). Estructuras
de flujo en la riolita subyacente facilita el paso de soluciones
hidrotermales que alteraron la roca husped. Pirofilita cuerpos
lenticulares, desigualmente distribuidas en el felsita, consistir
en una mezcla de alunita, caoln, cuarzo y, en lugares que contienen
dispora y pirita diseminada. Minas similares en el distrito incluir
ockmaesan. Hwangsan, y Sungsan. Mineralgicamente similar al Wando
el mo, este ltimo depsito consiste en un yacimiento-mentira plana
formada por la hidrotermal alteracin de prfido de cuarzo y toba
Another major producer is the Chunbulsan mine in the Tongnae
district, which has an anual output of about 7,000 tons/year. The
ore is associated with muscovite, sericite, and kaolinite and was
formed by hydrothermal alteration of andesite. Producers with rates
ranging from 1,000 to 4,000 tons/year include the Milyang mine in
an altered Cretaceous tuff and andesite, the Ungyong mine in an
altered brecciated andesite, and the imgi mine in altered
trachyte-andesite.
Unfortunately, some deposits contain pyrite and up to 4%
potassium and sodium due to incomplete alteration. The best quality
material is the Green variety with an SiO2 content of over 70%
Al2O3 of 24% and Fe2O3 of less tan 0.5% (Anon 1972; Cornish. 1983;
Sang 1983)
USA
Us pyrophyllite production is concentrated in North Carolina.
The deposits are part of a belt of late Precambriam
volcano-sedimentary rocks in the Piedmont Plateau, stretching from
Petersburg, Virginia, through North and South Carolina to
Milledgeville, Georgia, a distance of 400 miles. In North Carolina
this is known as the Caroline Slate Belt, an rea characterized by
high-alumina minerals such as kaolinite, sericite, andalusite
topaz, diaspore, and pyrophyllite.
Otro productor importante es la mina Chunbulsan en el distrito
Tongnae, que tiene una produccin anual de alrededor de 7.000
toneladas / ao.El mineral se asocia con la moscovita, sericita, y
caolinita y se form por la alteracin hidrotermal de andesita.Los
productores con tasas que van de 1.000 a 4.000 toneladas / ao
incluyen la mina Milyang en un alterado Toba Cretcico y andesita,
la mina Ungyong en una andesita brecciated alterada, y la mina imgi
en alterado traquita-andesita
Desafortunadamente, algunos depsitos contienen pirita y hasta 4%
de potasio y el sodio debido a la alteracin incompleta.El material
de mejor calidad es la variedad verde con un SiO2 contenido de ms
del 70% de Al2O3 Fe2O3 24% y menos de bronceado 0,5% (Anon 1972;
Cornish. 1983;Sang 1983)
EE.UU.
Nosotros produccin pirofilita se concentra en Carolina del
Norte.Los depsitos son parte de una cinturn de finales Precambriam
rocas volcano-sedimentarias en la meseta de Piedmont, que se
extiende desde Petersburg, Virginia, a travs del Norte y Carolina
del Sur a Milledgeville, Georgia, una distancia de 400 millas.En
Carolina del Norte esto se conoce como la Caroline Slate Belt, una
zona caracterizada por los minerales de alta almina como caolinita,
sericita, andalucita topacio, dispora, y pirofilita.
The major commercial concentration of pyrophyllite is in the rea
extending from Wadesville, Montgomery County through Moore County
northeastward to northern Granville County Irregular lenticular
bodies of pyrophyllite replace medium- to fine- grained tuffs and
volcanic breccia which were sheared and mashed during movement.
Genesis by metasomatic replacement is shown by various stages of
alteration, alignment of the bodies with the strike and dip of
cleavage in the country rock, pseudomorphs after original rock
structures, and the introduction and removal of elements. As with
some shows of gold and copper in the rea, it is thought that the
source of the mineralizing solution was an igneous magma at depth,
and that the pyrophyllite was formed under conditions of
intermediate temperature and pressure. According to Stuckey (1967)
the sequence of events was.
(1) Metamorphism of host rocks(2) Silicification of these rocks
by metasomatism and formation of pyrite(3) Development of
chloritoid(4) Development of sericite replacing previously
silicified rocks(5) Development of pyrophyllite replacing
previously silicified and mineralized tuffs and breccias closely
associated with or immediately following the formation of
sericite.
La concentracin comercial importante de pirofilita es en el rea
que se extiende desde Wadesville, Condado de Montgomery a travs del
condado de Moore hacia el noreste hasta el norteGranville Condado
irregulares cuerpos lenticulares de pirofilita sustituir a medio y
fino tobas de grano y brechas volcnicas que fueron esquilada y pur
durante el movimiento. Gnesis por el reemplazo metasomtico se
muestra por diversas etapas de alteracin, alineacin de los cuerpos
con la huelga y la inmersin de la escisin en el country rock,
pseudomorfos despus de estructuras de piedra originales, y la
introduccin y extraccin de elementos.Al igual que con algunos
programas de oro y cobre en el rea, se cree que el fuente de la
solucin de mineralizacin era un magma gneo en profundidad, y que
lapirofilita se form en condiciones de Temperatura y presin
intermedia. Segn Stuckey (1967) la secuencia de eventos fue
1) El metamorfismo de rocas anfitrionas(2) silicificacin de
estas rocas por metasomatism y la formacin de pirita(3) Desarrollo
de cloritoide(4) Desarrollo de sericita reemplazar rocas
previamente silicificados(5) Desarrollo de pirofilita reemplazar
tobas previamente silicificados y mineralizadas y brechas
estrechamente asociados con o inmediatamente despus de la formacin
deSericita
The largest producer is R.T. Vanderbilts Standard Mineral Co,
with an annual output of some 50,000 tons from its operations in
Moore County. Most is sold to the ceramics industry, with some
going to the filler market. Also in Moore County, Glendon
Pyrophyllite produces around 20,000 tons/year for use as fillers,
mainly in joint cement and related products. A small percentage
goes into refractories. In general, the pyrophyllite occurs in
pod-like masses together with local concentrations of kaolinite and
sericite. Chloritoid and pyrite are abundant in rocks adjacent to
the ores, but andalusite and diaspore are rare or absent. North of
Glendon, high-alumina deposits tend to be present close to the
transition from apilli breccia and conglomeratic mudstone to an
overlying fine-bedded tuffaceous argillite and lapillite. The
alteration to high-alumina minerals cuts across the bedding.
Sthrike faulting probably controlled the hydrothermal fluids; the
quartz veins may represent fault planes that acted as channelways.
It is suggested that these deposits were formed under slightly
different conditions from the others in North Carolina, perhaps at
a lower temperatura (shallower and/or further from the heat source)
and by less acid solutions (lack of silicification)(Schmidt,
1985)
To the north Piedmont Minerals Co. Operates the 10,000 tons/year
Hillsborough Mine in Granville County. This exploits an andalusite-
pyrophyllite-quartz orebody. Selective mining, crushing screening
and blending provides a series of grades all containing a mixture
of the three minerals. The alumina content ranges from 30 to 50%.
Three main grades are sold to the refractories industry, and other
grades go into the whiteware and electrical porcelain
industries.
Pyrophyllite is produced by Standard Industrial Minerals from a
new mine in the White Mountains, near Laws, California.El mayor
productor es estndar Mineral Co de RT Vanderbilt, con una produccin
anual de unas 50.000 toneladas de sus operaciones en el condado de
Moore.La mayor parte se vende a la cermica la industria, con un
poco de ir al mercado de relleno.Tambin en el condado de Moore,
Glendon Pirofilita produce alrededor de 20.000 toneladas / ao para
su uso como material de relleno, sobre todo en el cemento conjunta
y productos relacionados.Un pequeo porcentaje va en materiales
refractarios.En general, la pirofilita se produce en las masas-pod
como junto con concentraciones locales de caolinita y
sericita.Cloritoide y pirita son abundantes en las rocas adyacentes
a los minerales, pero andalucita y dispora son raras o ausentes.,
Depsitos de alta almina Norte de Glendon tienden a estar presentes
cerca de la transicin de la brecha apilli y conglomertica lutolita
a un suprayacente fino camas argilita tobceo y lapillite.La
alteracin a los minerales de alta almina corta a travs de la ropa
de cama.Sthrike fallamiento probablemente controlado los fluidos
hidrotermales;las vetas de cuarzo pueden representar planos de
falla que actuaron como ranuras y.Se sugiere que estos depsitos se
formaron bajo ligeramente diferente condiciones de los otros en
Carolina del Norte, tal vez en una Temperatura ms baja (Superficial
y / o ms lejos de la fuente de calor) y por soluciones de cido
menos (falta de silicificacin) (Schmidt, 1985)
Al norte de Piamonte Minerales Co. opera el 10.000 toneladas /
ao de Minas de Hillsborough en el condado de Granville.Esto explota
un yacimiento de cuarzo pirofilita andalusite-.Selectivo minera,
molienda y mezcla de deteccin ofrece una serie de grados todos
contienen una mezcla de los tres minerales.El contenido de almina
vara de 30 a 50%.Tres principal grados se venden a la industria de
los materiales refractarios y otros grados van a la loza, y las
industrias de porcelana elctricos.Pirofilita es producido por
Minerales Industriales estndar de una nueva mina en el blanco
Montaas, cerca de Leyes, California
CANADA
A mine near Foxtrap, 12 miles southwest of St. Johns,
Newfoundland, operated by Newfoundland Minerals Ltd. Accounts for
Canadas entire output of about 35,000 tons/year of pyrophyllite.
This deposit, like those in North Carolina is contained in a belt
of late Precambrian rocks here termed the Avalon Zone. The Avalon
Peninsula consists of an elongated northerly trending dome. The
core of the dome consisting largely of pyroclastic and minor
sedimentary rocks of the harbour Main Group, is intruded by the
shallow-level granitoid Holyrood Pluton and is overlain on both
flanks by clastic sedimentary rocks. Felsic rocks within I or 2
kilometers of the Harbour Main volcanic- Holyrood Pluton contact
contain fracture zones. Near to the pluton these fracture zones
have been altered though hydrothermal leaching to a fine- grained
assemblage of quartz, muscovite (sericite), and pyrophyllite ough
the depletion of SiO2,alkalies, calcium, magnesiun and iron
(papezink et al, 1976;Papezik and hume 1984 Taylor et al 1979)
Commercial extraction which has been continuous for more tan 20
year, occurs in the Oval Pit some 3 kilometers southeast of
Foxtrap. The deposit contains both low-and high-grade lenses,
containing from 12% to 18% Al2O3, and so selective mining using a
17% Al2O3 cut-off grade is employed. The entire output is consumed
by American Olean Tile Co, the mine owners parent Company, at its
floor-tile plant near philadelphia (Papezik and hume 1984)
CANAD
Una mina cerca Foxtrap, a 12 millas al suroeste de San Juan de
Terranova, operado por Terra nova Minerals Ltd. Cuentas para Caadas
produccin total de alrededor de 35.000 toneladas / ao de
pirofilita.Este depsito, como los de Carolina del Norte se
encuentra en un cinturn de rocas precmbricas finales aqu denomina
Zona de Avalon.La pennsula de Avalon consta de una cpula de
tendencia norte alargada.El ncleo de la cpula que consiste gran
parte de las rocas sedimentarias piroclsticos y menores del grupo
principal puerto, es invadido por el granitoide nivel superficial
Holyrood Pluton y est cubierta en ambos flancos por rocas
sedimentarias clsticas.Rocas flsicas en I o 2 kilmetros del puerto
principal contacto Volcnica Holyrood Pluton contiene zonas de
fractura.Cerca del plutn stos zonas de fractura se han alterado
aunque lixiviacin hidrotermal a un grano fino ensamblaje de cuarzo,
muscovita (sericita), y pirofilita ough el agotamiento de SiO2,
lcalis, calcio, hierro y magnsico (papezink et al, 1976; Papezik y
hume 1984 Taylor et al 1979)
Extraccin comercial que ha sido continuo durante ms moreno 20
aos, se produce en el Oval Pit unos 3 kilmetros al sureste de
Foxtrap.El depsito contiene tanto bajo y lentes de alta calidad,
que contiene de 12% a 18% de Al2O3, y la minera de manera selectiva
utilizando un Se emplea ley de corte 17% Al2O3.Toda la produccin se
consume por American Co Azulejos Olean, la Compaa propietarios de
las minas de los padres, en su planta baja de tejas cerca
philadelphia (Papezik y Hume 1984)
AustraliaAustralian pyrophyllite production comes from a mine
near Pambula. 12 miles northwest of Eden. A port on the southeast
coast of New South Wales. The mine is operated by Commercial
Minerals Ltd. The deposit lies in the central part of the ancient
Eden Rifi Zone which contains the Upper Devonian Boyd Volcanic
Complex of agglomerate, basalt, intrusive and extrusive rhyolite,
and intercalated sedimentary rocks
Within this complex a north-striking sequence of flowbanded
rhyolite and volcanic breccias and pyroclastics that dips 40
eastwards contains a pyrohyllite-bearing belt. The latter strikes
northwest, dips vertically, and was formed through the hydrothermal
alteration of the host rock by ascending acidic lavas. A zonal
sequence of alteration has been formed with a central core of
almost pure pyrophyllite, and local zones enriched in diaspore and
cookeite (a high-lithium chlorite). This is surrounded by
imperfectly segregated zones of chalcedonic and sericitic
pyrophyllite, which grade into unaltered rock (Nichol, 1983). The
alteration process involved the selective mobilization of alkalies,
which migrated laterally forming a zone rich in sericite; alumina
and silica-rich residues reacted with components of the solution to
form pure pyrophyllite. Host rock and structure controlled the
formation of the orebodies, which tend to be lenticular (Cornish,
1981 and 1983)
Proved reserves are put at 10 million tons, with inferred
reserves of 30 to 50 million tons. Exploitation in three quarries
the Bottom, Middle, and Top-is by standard open- pit methods.
Various grades are produced. Chalce-donic pyrophyllite ( typically
14% Al2O3,
