Environmental Engineering Reference
In-Depth Information
1986) for mercury recovery. Posnansky (in Petersen, 1970)
describes a site near Machu Picchu where amalgamation
was used, before the arrival of the Europeans, to recover
gold from crushed quartz vein material. Kaufmann Doig
(1978) also describes the use of mercury for gilding precon-
tact copper artifacts with gold.
The Inca (1300-1533
CE
), as did the Romans, recognized
the health hazards of mercury and that exposure to mercury
and cinnabar during mining and retorting would cause the
ancient miners “to shake and lose their senses”; therefore,
the use of mercury by the Inca declined (Garcilaso de la
Vega, in Larco Hoyle, 2001). As in the Old World, whether or
not the ancient Andean metallurgists retorted cinnabar for
mercury is controversial; however, retorts have been found
near the mercury mines at Huancavelica (Kendall Brown,
Ph.D., professor, Brigham Young University, written com-
munication, May 9, 2003). Mercury was recovered from
drainages and, according to Petersen (1970), from retort-
ing cinnabar near Huancavelica. And, only 15 km from
Huancavelica is Atalla, an archaeological site interpreted as
an ancient cinnabar pigment production center (Burger and
Matos, 2002). Isotopic data on mercury in lake sediments,
combined with
14
C geochronology, indicate that mercury
mining at Huancavelica began around 1400
BCE
. and that
mercury production peaked at approximately 500
BCE
and
at 1450
CE
, corresponding to the heights of Chavin and
Inka rule, respectively, in the region (Cooke et al., 2009).
In describing the early history of the amalgamation pro-
cess, Craddock (2000) indicated that if mercury had been
used, then trace amounts of mercury would be present in
the chemical analyses of the gold foils. The implication is
that the quantity of mercury used in the amalgamation
process would have been reduced by fi ring the gold, which
would have volatilized most, but not all, of the mercury.
Therefore, using SEM-EDX (scanning electron micro-
scope combined with energy dispersive x-ray spectroscopy),
Ramage and Craddock (2000) analyzed gold samples from
Sardis and found mainly gold and silver. They concluded
that since mercury was not detected, no mercury had been
used to amalgamate the gold.
However, using induced coupled plasma (ICP) analysis,
8 ppm mercury was found in gold after the gold-mercury
amalgam (
Powdered cinnabar was used to decorate gold masks
during the Formative Period in Peru (1000-400
BCE
) (De
Lavalle, 1992; Shimada and Griffi n, 2005); as a mural pig-
ment (Muelle and Wells, 1939; Bonavia, 1985; Brooks et al.,
2006); for painting warriors' bodies and as a cosmetic for
the elite Inca women (Brown, 2001); and for funeral prep-
arations (Maravelaki-Kalaitzaki and Kallithrakas-Kontos,
2003; John Verano, Ph.D., anthropologist, Dumbarton
Oaks, Washington, DC, oral communication, December 12,
2005). Wooden funerary fi gures painted with cinnabar were
recovered from Huaca Tacaynamo and Huaca El Dragón,
both of which are Chimu (800-1450
CE
) ceremonial sites in
northern Peru (Jackson, 2004). Mollusk shells, some with
cinnabar found in the interior of the shell, suggests that the
shells were used as ancient palettes (Petersen, 1970).
A variety of “reds” were readily available in ancient Peru.
Sources for “red” included plant-derived achiote, Spondylus
(a mollusk), insect-derived cochineal, feathers, plant pig-
ments, and mineral-derived cinnabar, goethite, hematite,
and jasper. However, ancient Peruvians selectively used
powdered cinnabar for funeral preparations (Shimada
and Griffi n, 2005; John Verano, Ph.D., anthropologist,
Dumbarton Oaks, Washington, DC, oral communication,
January 25, 2006). Therefore, in ancient Peru and else-
where in the New World, as in the Old World, the question
persists as to whether or not cinnabar was used because of
its blood-red life symbolism or because of its toxicity and
preservative qualities.
In 1566, the mercury mines of Huancavelica were redis-
covered by the Spaniards. In 1571, mercury once again
became an important industrial metal in mining when
Pedro Fernandez de Velasco used mercury for silver amal-
gamation at Porco and Potosí, Bolivia (Arana, 1901). Until
that time, mercury had been transported from Spain for
use in the New World, and Spanish shipwrecks, which still
contain mercury, are known in Samaná Bay, Dominican
Republic, and Cartagena Bay, Colombia (Petersen, 1979). In
the late 1500s, mercury from Huancavelica was also used in
the “patio process” for silver processing in Chile, Bolivia,
and Mexico. Salt, mercury, and vitriol (mixed copper and
iron sulfates) were mixed with crushed silver ore that con-
tained argentite (Ag
2
S), cerargyrite (AgCl), or pyragyrite
(Ag
3
SbS
3
), also known as the “dry ores,” in a large open area,
or patio, and at Potosí, Bolivia, the cold climate required
that the patios be heated from below to speed silver pro-
duction, which also increased mercury losses (Craddock,
1995). Mercury's role was well established in mineral pro-
cessing in Spanish Colonial Peru and adding mercury, “el
azogado,” was an essential step in silver recovery (Del Busto
Duthurburu, 1996).
300,000 ppm mercury) was burned (refogado),
to volatilize the mercury, in the modern gold shops in
Madre de Dios, Perú. From 12.3 to 13.9 ppm mercury was
found in worked gold artifacts from Huaca la Ventana, a
Middle Sicán (900-1200
CE
) site at Lambayeque, Perú, and
low levels of mercury were found in precontact worked
gold samples from Colombia and Ecuador. Similarly low
levels of mercury in the ICP analyses of modern refogado
gold and precontact worked gold are consistent with a com-
parable, ancient small-scale mining technology that would
have used mercury to amalgamate the fi ne-grained placer
and vein gold, and then, as now, burning the amalgam to
volatilize the mercury, beautify, and recover the gold for
craft production (Brooks et al., 2009).
Conclusion
Since ancient times, mercury has been used for a variety
of industrial applications and one of those, its use for arti-
sanal gold mining continues today in many parts of the
