No 19, Sept. 2007
VLT® keeps mining processes dry
under extreme conditions in Andes Mountains
By Felipe Martell Magnani ,
Sales Engineer, Danfoss Chile
Los Bronces is an open pit mine with a
current capacity of processing 58,000
tons of mineral daily. Last year it
produced 250,000 tons of fine copper
concentrates. Los Bronces Mine is the
largest unit of the División Minera Sur
Andes Ltda.
Most of the production starts in Los
Bronces, located 70 km to the northeast of
Santiago, at the head of the San Francisco
marsh in the Andes mountain range at
3,500 meters above sea level, where up to
15 meters of snow fall during the winter
season. Due to these extreme conditions,
it has been a major challenge to overcome the difficulties of its access and its
severe conditions both for workers and
machines.
Mineral extracted from the mine is ground
up and then descends about 3,000 meters, transported as pulp, through a 56-km
buried pipeline, all the way to the Las
Tórtolas flotation plant in Colina.
Copper concentrates are produced in Las
Tórtolas and El Soldado, located at the
coastal mountain range, at 130 km to
the north of Santiago, then sent to the
Chagres Foundry, 93 km to the north of
Santiago, and eventually reach the end
market.
Keeping the mining process
dry with Danfoss
Water extraction is extremely important
to the mining process, due to the process
of extraction and the type of land. As the
elevation continues to drop, the land is
continually “undermined” in order to continue extracting the mineral, which means
there is major water accumulation. This is
a problem, because the mineral must be
extracted as dry as possible.
Also, this is not pure water, but contains
VLT®
keeps mining processes dry under extreme conditions in Andes Mountains
large amounts of sediment with high acidity content. Special robust pumps called
Flygt pumps Model BS2400 are used to
diminish these issues.
The interior is made of stainless steel to
prevent wear with the extracted acid
waters.
This type of pump is the most appropriate for use where major elevation height
or large pumping capacity is needed. It is
essential to rely on proper current peak
control during its startup, so each one is
controlled by a VLT® Softstarter.
large temperature variations. The distance
between the pump and each board
ranges between 60 and 100 meters, and
they are kept in special rafts so that they
cannot be submerged more than 3 to 4
meters.
Danfoss has shown excellent performance
in these extreme conditions of the Andes
Mountains.
Currently in Los Bronces Mine 13 of these
special pumps of
90 kW each are
installed, controlled by Danfoss Soft
Starters MCD 3090,
with a protection
grade IP21. To protect
against the inclement
weather; equipment
is installed in cabinets
with protection grade
IP55. It is subject to
extreme weather and
inMotion - The VLT® newsletter