Access
The access to Pucarrajo Unit is following the asphalt road
Panamericana Norte, road to Huaraz city and road to Antamina
mine. The route Lima – Paramonga – Conococha – Pucarrajo has a
longitud of 425 Km. Is made in 9 hours and only the last 9 Km.
Are road surfacing.
Property
Nowadays, the Pucarrajo Unit is integrated for 11 miner
concessions, which the company has in grant quality, named
Lucero, Maria del Pilar, Maria del Pilar numero Tres, Maria del
Rosario, Maria del Rosario numero Tres, Maria del Rosario numero
cinco, Maria del Rosario numero 6, Nuevo Peru, Santa Juana
cuatro, Santa Juana numero tres, and Excepcion Santa Juana
numero 5; besides the two miner concessions, mine Tuco and Graal,
which the company is entitle.
Additionally,
the company has a
registered entitle of the concession of benefit Don Froylan,
that authorize the plant operation to 500 Ton/day of capacity.
Geology
The geological frame Pucarrajo is located in a sedimentary basin
folded in anticline and syncline something symmetric, Andean
orientation NW-SE, with formation from inferior to superior
cretaceous that outcrops in the region. From de ancients to the
new ones this formations are: Chimu, Santa, Carhuaz, Ferrst,
Pariahuanca, Chulec and Pariatambo, all intruded by Ishpag stock
of granodiorite-diorite composition that in contact with
sedimentary formation provoke the hydrothermal metamorphism
which aureole is 2.0 x 1.7 forming chalcosilicated, development
of rocks like marble, hornfels, and quartzite; the intrusive
placed taking ply and regional faults inverse like Huari Jirca,
and San Marcos. The primary minerals from de ore are constituted
by marmatite, galena (lead ore) and in less amounts
chalcopyrite, joined for pyrrhotite, pyrites and magnetite.
Pucarrajo mine is a polimetalic layer of Zn, Pb,, Ag, skarn
type, originated by metasomatic replacement located in
limestone sequences from Chulec formation of Albiano inferior,
in which has formed irregular bodies, stratum and veins at
deposition temperature from mesothermal to epithermal. The
continuity horizontal and vertical is sometimes truncated to
show up meters ahead or in depth. Have dimensions that may vary
from a few meters to 40 – 60 from the horizontal and from a few
meters to 240 mt in the vertical.
Exploration and Development Program
The mineral resources and the ore reserves from Pucarrajo Unit,
requires an appropriate exploration program, framed inside the
geological characteristics of the layer, which has been
designed to explore the bodies and stratum mineralized through
galleries, cross heading and diamantine perforation.
Reserves and Natural Resources
See our
page of Reserves & Resources. Click Here (only in Spanish)
Mine
The Pucarrajo Unit has nowadays as principal production zones,
the areas denominated: Sabrina, Pucarrajo, Carmencita and Tania,
the most important are Sabrina and Tania.
The exploitation method used is the provisional storage because
so the mineral as the boxes are reported as competent. It has
visited active stopings and observe that the boxes and minerals
are competent. This method, has the disadvantage of using a
lot of workmanship, the productivity is from middle to low and
the great part of the mineral remains in the stopings during a
long time, but has the advantage that the investment in
equipment is lower and the mineral load is made from the hoppers
in a easy way. Besides the descript method allows a high
recovery and low dilution. The selected method is the adequate
because permits control the dilution in spite of the boxes are
irregular and have fractured zones, where is necessary use
sustain.
The perforation is made using perforators Jack Leg and Stoper.
The blast is made with Anfo and dynamite and for the loading is
used Scooptrams of 3.5 yd3. The transport to the surface is made
with trucks of 15 mt3.
The main ventilation is forced and the energy used come from the
red as well from the Hydroelectric Central Pacarenca Plant
See FlowSheet
The processing is realized in the treatment plant Don Froylan,
the most relevant characteristics are:
Feed hopper with 150 Ton capacity
with a plate feeder of 36” x 10”, a primary jaw crusher of 10”
x 36” and a secondary cone crusher SH of 3” diameter with their
respective shaking screen that works in closed circuit. To get a
¾ product that is stored in a 500 Ton capacity hopper.
The milling circuit consists of a bar mill of 5” x 12”, that
operates on a open circuit and for the re-milling a 6” x 6” ball
mill that operates in closed circuit with a 5” x 4” pump and
cyclones of 12”, to circulate and feed to flotation process.
The flotation will be composed by 2 circuit, the Pb circuit that
is constituted for 2 Rougher cells of 100 ft3. the foams pass
by the cleaning cells of 18 ft3 in 3 stages, being the foams
from the last stage the Pb concentrate. The tailings from the
cleaning cells are sent to a bench of cells Scavager of 18 ft3
and the foams return to the Rougher stage. The tailings with the
tailings from the Rougher flotation pass to a conditioned tanks
of Zinc.
The Zinc circuit comprehend a unitary cell follow of four cells
Rougher of 100ft3. The foams from this cells pass through
cleaning cells in four stages. The foams from the fourth stage
constitute the Zn concentrate. The tailings from the cleaning
stage pass to a bench of cells Scavenger, formed by four cells
of 18 ft3, the foams return to the Rougher cells. The tailings
with the tailings from Rougher flotation conform the final
tailings that is sent to the tailings field.
The Zn and Pb concentrates are thickened and filtrated and
dispatch in bulk in trucks endowed with adequate security
elements.
The tailings are disposed in a near tailings field, that use the
method of central line with use of cyclone. The settling water
are conducted to a storage well, from here the water is
recirculated totally to the concentrate plant. The present
tailings deposit has an storage capacity enough to December
2007. Nowadays the company is in the process of contract the
enginery services and environmental impact studies for a new
tailings deposit that is going to have a capacity of 1.8
millions Tons, the new deposit allowed store tailings for 6
years more, the construction of this deposit is foreseed to
begin in 2006, after have complete the requirements that the
Energy and Mine Ministry asks for this kind of structures.
