ACCESS
The
access from Lima is made by asphalt road of 526 Km, plus 8 Km. of
road surfacing, in 8 hours of total time.
PROPERTY
Nowadays, the Contonga project is integrated for 15 miner
concessions, which the company is registered
titrate of the next 11
concessions that sum a total of 948.22 Ha.
Which were transferred by Sociedad Minera
Gran Bretaņa liquidator, from now on (“SMGB”), in favor of the
company: Contonga Nē 1, Contonga Nē2, Contonga Nē3, Contonga Nē4,
Contonga Nē5, Contonga Nē6, Delicias, La Florida, La Inmaculada,
Prosperidad and Prosperidad Numero Dos.
Additionally,
the company acquires from third party and own solicitude, the
titration of the following four (04) miner concessions: Flor de
Contonga Uno, Contonga trece, Contonga 15 and Contonga 16, that sum
a total of 601.77 Ha.
By
last to nowadays is in transaction before General Direction of
Mining of Energy and Mine Ministry the concession of benefit to
operate the concentrate plant of Contonga, with a capacity of 600
ton/day.
GEOLOGY
In
Contonga area outcrop sedimentary rocks, intrusive and volcanic. The
sedimentary rocks are represented by clastic formations from Goyar
group, over lie to this limestones, limolites, shale from Chulec
formation, limestone from Pariatambo formation, lodolites limestone
and greywacke from Jumasha formation, topping out the stratigraphic
sequence, outcrop limestone and marl from Celendin formation.
The
intrusive rocks cuts the sedimentary sequences, outcrops like
“stocks” in the Contonga sector ( Stock Contonga ) and at south of
this you can distinguish the Stock Taully. The composition of
intrusives is represented by quartz and feldspar, whom takes
characteristics of porphyry; besides inside intrusive has been
recognized porphyry monzonite and some dikes felsitic of dacite.
The
alteration – mineralization is related to intrusives which cuts the
sedimentary sequences and principally on the contacts with limestone
Jumasha and the Contonga Stock have produced Skarn and massive
replacement of sulphides in carbonate, surrounding the intrusive and
like mantle controlled by faultage along the stratums. Besides it
can distinguish a circular structure around Stock Contonga, that
shows zones brecciated cemented with sulphides.
The
mineralization in Skarn presents gross grains of sphalerite (
marmatita ), galena (lead ore), pyrite, chalcopyrite and
occasionally tetrahedrite (ore of silver and cooper). The first ones
increases in depth, also observed pyrrhotite. Bismuthinite has been
reported by SMGB, enterprise who exploited Contonga in the past.
Structures mantle kind, place it following the course of stratums
Jumasha and Pariatambo. The mentioned structures named “A”
(Pariatambo Formation), structures “B” and “C” (Jumasha Formation).
In the present knowledge, the most important of them is the “B”,
presents interesting values of Ag, Pb, Cu and Zn.
PROJECT
ANTECEDENTS
Historically Contonga is a project that has been explored
systematically since their beginnings until today as is described
lines below.
SMGB
operated a concentrate plant with a capacity of 400 ton/day since
1984 to 1990, have produced like 420,000 ton. With head laws of 5%
Zn, 1.94% Pb, 0.35% Cu and 3.25 Oz/TM Ag. Miner working and
exploration works has been realized as much in Contonga Stock like
in the structure “B”. From 1985 to 1990, SMGB made an miner
operation, have extracted 420,000 ton. Of mineral, proceeding from 4
levels of exploitation; from lower to higher N 240, N 300, N 360, N
415 (approximately 7 Km. of underground mine work).
After
a 10 years shut down, in 1999, CEDIMIN in a Joint Venture with Anglo
American restarting complete studies of exploration in all the mine
area and surroundings, the results to Anglo Americana were not the
expected because the reduce volume of the resources that adjust it
more to a middle mining, withdraw at the end of 2000.
When
Anglo America withdraw, CEDIMIN take control until end of 2001. BHL
del Peru S.A.C signs a buy option of Contonga rights, this is
practiced by the company on December 2003.
EXPLORATION AND DEVELOPMENT PROGRAM
During the SMGB administration has developed more than 7 Km. Of
underground mine working which had to add 11 diamantine perforation
drills with a total of 3,800 mt.
In
year 2000, CEDIMIN and Anglo American developed a profuse program of
exploration that comprised superficial maps, geochemistry,
geophysics, and diamantine perforation of 5 drills, totalizing
1,900 mt.
In
year 2001, CEDIMIN realized diamantine perforation of 15 drills,
totalizing 2,900mt., perforated since level 240, principally to
explore the compartment in depth of contact from Contonga Stock,
until a maximum of 280 mt below the mentioned level, also a few
drills were directed to explore in depth the structre “B”.
In
year 2004, the company developed an additional program of
diamantine perforation, from level 240 (11 drills with 1,156.40 mt).
Until
march 2005, the company has drilled 3 depth drill holes, below level
240.
Is
important to say that the exploitation program since 2005 to 2009
also includes the execution of about 4,000 mt of diamantine
perforations like annual average. This explorations allowed that the
indicated and inferred resources increase. Is not possible to say
which would be this increment because the RC of resources by
diamantine perforations is not reported.
MINERAL RESERVES AND
RESOURCES
See our page
of Reserves & Resources. Click Here (only in Spanish)
MINE
The
exploitation method selected of cut and filling ascending, is the
indicated for this kind of layer, so that must culminate the
proposal ramp so that the preparation labour
In
the perforation will be used Jack Leg perforators for the
sub-vertical drilling in zones with less than 3 mt of power and
breasting in zones with more than 3 mt of power. For the blasting
will use dynamite and detonator as indicator and Anfo like main
explosive. The mineral cleaning or deads .in the excavation and its
transportation to the ore pass and the waste pass will be made by
scoops through the access windows to the excavation.
The
proposal method is apparent to guarantee the daily production of 600
TM/day, in opinion of the expert, it must be prepare and have
operational at least 7 excavations; 6 will guarantee the daily
production and the last one fits to cover the contingency of
paralyse the operation of any excavation for stability problems or
lack of equipment etc.
The presence of water filtrations in some excavations will make
that the boxes median competent and incompetent originate an
insecure condition, must use in this cases support with casing
squares and/or split set or cement bolts with net and eventually
shotCrete that will make slower the excavation production.
PLANT
See FlowSheet
The
principal characteristics of the process will be:
Gross
hopper with 350 Ton capacity of 9” of light, a plate feeder, a
stationary screen, a primary jaw crusher of 15” x 24” and a
secondary cone crusher of 3” diameter with their respective shaking
screen that works in closed circuit. To get a ž product that is
stored in a 400 Ton capacity hopper.
The
milling circuit consists of a ball mill of 8” x 8”, that operates on
a open circuit and for the re-milling a 5” x 8” mill that operates
in closed circuit with a 5” x 4” pump and cyclones of 10”, the
produced fines are feed to flotation.
The
flotation will be composed by 2 circuit, the lead-cooper circuit
that is constituted for 2 unitary cells of 6” x 6” and 12 cells of
36” x 36”, the concentrates from the conditioner and the first 3
cells (cleaning), are conducted to a thickener of 20” diameter x 10”
height and the obtained concentrate represents 80 to 85 % recovery
of Pb-Ag mineral, the tailing from this circuit constitutes the head
of Zinc circuit.
The
Zinc circuit will be composed by a 8´x 9´ conditioner that works as
a unitary cell, the concentrate is conducted to a thickener of 30” x
10” and obtain the Zinc concentrate, the tailing from the
conditioner goes to 12 cells bank of 43” x 43” and the concentrate
process continues with cleaning cells, the concentrate is sent to
the thickener previously mentioned, the tailing is conducted to a
tailings field.
The
Pb and Zn concentrates will be filter and dispatch in bulk.
The
new tailings deposit will be the Tucush small valley, the field will
be lined with geo membrane, it will be used the central line method
with gross separation which will be pumped like hydraulic fill to
the mine, the settling waters are conducted to 2 treatment wells to
be recirculated to the concentrating plant. The capacity of the
tailings deposit is 1.3 millions Tons, and an approximate life of 5
years to 600 Tons/day production.
It
considers that from 600 Tons/day that will be treated as tailings,
the 87.1%, means 522 Tons or 177 cubic meters approximately , which
returns to the mine as hydraulic fill, the 45% remains in the
tailings 97.3 cubic meters/day.
The
energy consumption will be of 1300Kw, which can obtain in the future
from the red connected to the Interconnected National System.
In
plant it has a water reservoir from the Contonga Lagoon with 700
cubic meters.
The
concentrating plant has an standard flow sheet and in expert
opinions is well conception. The metallurgic balance that reports is
made in basis to tests made in TECSUP.
The
average recovery reported in the inform Planning 2005 are as
follows: to Zn 92.36%, to Pb 90.54%, to Ag 85.98%, and to Cu 42.02%.
in the Company Business Plan has used the next recoveries: to Zn
91.1%, to Pb 91.03%, to Ag 82.09% and to Cu 55.76%
With
respect to the laws in the concentrates, the average obtained from
the metallurgic tests in TECSUP, reported in Planning 2005 are: in
Zn concentrate the law is 58.27%, in Pb concentrate the law is
58.0%, and Ag is 76.01 OzAg/Ton and in the Cu concentrate the law
are Cu 27.05% and 19 OzAg/Ton. The recoveries has been ratified in
the pilot test made recently.
