VIETNAM, HA LONG BAY
Drilling for coal in Vietnam
Within the Vietnamese mountains overlooking Ha Long Bay's karst formations lie the country's largest coal reserve.
Coal mining in
Ha Long Bay
Coal production is a vital part of
the Vietnamese economy, and
the country’s largest field has
turned to modern drilling technology to optimize productivity
and efficiency. Atlas Copco is working with many of the region’s
companies, providing them drill
rigs of various sizes to meet their
specific excavation needs.
A world wonder
With its thousands of limestone karst
formations that begin in the surrounding mountains and continue to the sea
where they stand out as lush, domeshaped islands, Ha Long Bay is recognized as one of the wonders of the
world. In those mountains that overlook
the bay lies Vietnam’s largest coal
reserve.
The coal region in Vietnam is centered in Cam Pha in Quang Ninh province, one of the two towns of Ha
Long Bay. Geographically the region
is 130 kilometers long, varying from
10 to 30 kilometers wide, or approximately 1,300 square kilometers. Reserves here total 2.5 billion tonnes of
sustainable supply. Last year the region’s 70 or more enterprises produced
43 million tonnes, representing 90 percent of the coal burned in Vietnam and
100 percent of the country’s exported
coal.
Diverse needs
Atlas Copco supplies the mines of the
region with rigs matched to the size of
their various pits. With a complete product line offering a full range of equipment, and with a staff of technicians
there onsite, Atlas Copco meets the specific needs of each of its customers.
The majority of drilling in the area
is performed by its DML and DM45
blasthole drill rigs. A variety of surface crawlers, including ROC F7, ROC
F6 and ROC L7 CR COPROD drill
rigs, work in smaller operations. The
following is a look at three mines and
the drilling operations that make them
successful.
Dong Bac
Coal Exploration Enterprise-Dong Bac
Corporation produces 140,000 tonnes
of coal per year running two rigs. The
mine has operated drills from several
manufacturers but found its greatest
success with the Atlas Copco ROC L7
COPROD drill rig because of its availability. Mr. Vu Van Tan, Chief Operator
at Dong Bac, says, “The Atlas Copco
drill rigs have similar penetration rates
with our other rig, but it’s the uptime
of the COPROD L7CR that makes it the
mine’s most productive rig.”
At this mine the ROC L7CR drills
a 165-millimeter (6 ½ inch) hole to
depths of approximately 8 meters (26
feet). The 6-meter (20-foot) deep coal
seam rests at an angle from the surface,
which results in drilling to depths that
end at varying degrees along the coal
seam. Mr. Tan likes the size and mobility of the ROC L7 and thinks it’s the
best rig for this size operation.
Blasthole Drilling in Open Pit Mining141
Drilling for coal in Vietnam
Ptam Trung Kien, Technical Manager for Nui Beo Coal Company in front of their DM45.
Nui Beo
Nui Beo Coal Company is a much larger operation working adjacent to the
Dong Bac mine. In 2009 the mine produced 5.1 million tonnes of coal using
four blasthole drills. Two of those are
Atlas Copco diesel-powered rigs.The
others are Russian-made electric models. The mobility and faster penetration of Atlas Copco DM45 and DML
blasthole rigs significantly out-drill the
competitor’s models.
The two Atlas Copco rigs drill 8,500
meters per month, whereas the other two
rigs drill only 3,000 meters per month.
The mine’s three shifts produce 22 million tonnes of waste annually from a
pit 4 kilometers long by 1.1 kilometers
in width. The projected life extends to
the year 2015, with a new property
already planned and scheduled for
development.
Pham Trung Kien, the electro-mechanical department technical Engineer,
oversees the drill fleet for the mine. Of
all these drills, Kien likes the DML the
most. With its Cat engine, he thinks it
offers more power than the DM45, but
both are more productive and efficient
142
than other drills they have operated.
Although he has had no major problems
with his Atlas Copco drills, he likes the
fact that Atlas Copco and Caterpillar
have support people in the area to assist
if he should need them.
The DML and DM45 blasthole rigs
in the area use 230-millimeter (9-inch)
Secoroc tricone bits and 7-meter (23foot) rods. At Nui Beo, operations are
currently 100 meters (328 feet) below
sea level on 20-meter (60-foot) benches.
Drilling is done at an angle of 10 to 20
degrees at an incline of 5 to 10 percent.
Tay Nam Da Mai
In comparison, Tay Nam Da Mai Joint
Stock Corporation also operates the
DML, currently drilling at bench
elevations 40 meters (130 feet) above
sea level. The coal seam is about 40
meters below sea level. Benches are 16
meters (52 feet) in depth on a 6 by 5
meter pattern (16 by 20 feet), which is
common in this the area.
Measuring 1.8 kilometers long by
1.5 kilometers wide, this mine produces
1 tonne of coal for every 9 to 10 tonnes
of waste. It yielded one million tonnes
Tay Nam Da Mai prefers the DML drill rig.
of coal last year and will produce 1.5
million tonnes this year. Here the DML
drills 5,000 to 6,000 meters per month
in the mine’s harder rock and 8,000 to
9,000 meters per month in the softer
formations, with another 15 years of
life at the current production rate.
Mr. Hoa, Deputy Manager Electro
Mechanical department says, “I like
the durability of the Atlas Copco rigs
and their ability to drill more meters.”
Because the competitive rigs have less
availability and drilling performance
is less, “It takes the (competitive rig) a
year to drill the same meters the DML
will drill in three months.”
Because of the variations in pit size
and desired production, the Quang
Ninh province is well served by Atlas
Copco’s product line, with the DML as
a leader in the class.
Acknowledgements
This article first appeared in Atlas Copco
Mining & Construction No. 3, 2010.
Story and pictures by Scott Ellenbecker.
Blasthole Drilling in Open Pit Mining