Getting the Best Bang for the Buck Safely
Technology advancements and investments in R&D provide some new tools for blasters
By Steve Fiscor, Editor-in-Chief
The mining industry is constantly pushing the limits when it comes to blasting. A bigger blast results in less downtime. If a bigger blast is poorly shot, fragmentation issues can lead to longer lasting headaches. Fortunately, advances in blasting technology are helping blasters minimize the chances of that happening.
The new tools that are available today incorporate GPS with better software. They can store and share data more effectively. Remote systems allow blasters to withdraw everyone from harm’s way. The blasting business continues to conduct research and development (R&D), and that investment is paying dividends.
Photogrammetry, Engineering
Geology and Blasting
An Austrian company, 3GSM, has developed a face profiling system that uses
technology to visually demonstrate the burden between holes. “Our core competence
is combining know-how from computer
vision, photogrammetry, engineering geology, blasting, and of course, software development,” said Markus Pötsch, customer
support and sales, 3GSM, at the International Society of Explosives Engineers
meeting, which was held during February
in Denver, Colorado, USA.
The company offers two packages, ShapeMetriX and BlastMetriX, which measure surface images and blast design. “We provide easy-to-use systems that do not require special surveying skills as with other approaches using classical photogrammetry,” Pötsch said. “We use standard hardware components and specific software for geometric measurements from photos.” 3GSM develops its own software. The company also works with Graz University of Technology and the Mining University of Leoben.
BlastMetriX3D is used for bench face surveying and planning of blast layouts based on three-dimensional images. It uses photogrammetry to provide 3-D information that is digitally enhanced by modern algorithms from computer vision. The implemented modern algorithms allow the use of an off-the-shelf digital camera equipped with zoom lens and freehand application without any external surveying. The resulting 3-D image is a digital photo combined with spatial information on the objects/surfaces it shows.
Profiles are generated by the intersection of a plane and the free surface of the bench. A minimum burden diagram plots this shortest distance from a search in any spatial direction, spherically around any location of the borehole. A minimum burden diagram daylights crucial information that pure profiles might hide.
Using the 3-D image and the data offloaded from the drill, the software determines a relationship between the borehole and burden. Green is design burden, purple is excessive burden and red is minimum burden. Knowing where the minimum burden exists, blasters can use a decoupled charge or the blasthole can be decked. The system can also be used for stope blasting underground.
Remote Firing Devices
The 1673 Remote Firing Device (RFD)
from Rothenbuhler Engineering is an intelligent and discrete two-way radio-controlled remote blast initiation system. The
radio system’s signal is digitally encoded
(addressed). The latest microprocessor and
message encoding/validation technology
has been combined to provide a safe, reliable and accurate RFD.
The Controller units are capable of commanding up to 64 remotes that can be either electric or non-electric, in 8-remote groups. With a minimum of 350 volts, the remotes can fire 75 electric caps in series, or a maximum circuit resistance of 150 ohms. Both the Controller and Remote units can run on standby (sleep) for typically 10 to 14 hours before recharging is required.
A history event log keeps a record of information such as unit state, post blast motion detect value, firing voltage level, battery level, and the date and time the event was logged. With the GPS included, each event will also have the longitude and latitude of where the unit was when the event was recorded.
Each Remote unit has a sensor that measures the seismic motion that may be expected when detonation occurs. The Controller unit reports a post-fire motion was detected, which is useful in underground operations when the successful initiation of a blast cannot be easily determined.
An automatic-disarming function ensures that the unit returns to a safe state in the event of a loss of communications, after a time-out period.
The Sequential Fire feature allows the user to space the firings of each Remote Unit so that they do not fire at the same time, 0-2 seconds between the firing of each Remote. This feature is particularly useful when firing multiple blocks where a delay is needed between each block.
Kumba Iron Ore Detonates
Record Blast
During November 2013, AEL Mining
Services (AEL) reported a new African
record for the largest number of DigiShot
Plus detonators fired simultaneously at
Kumba Iron Ore’s Kolomela mine. A total
of four, 786 detonators were fired in the
newly opened Klipbankfontein pit. Morne
Stiglingh, managing director for open pit
and massive mining at AEL, said the new
record was 2,100 detonators more than
the previous Africa record (also at
Kolomela) and a mere 332 short of the
world record of 5,118 detonators.
Stiglingh explained the aim of the blast was to minimize blast stoppages in the newly established pit and to showcase AEL’s capability of delivering superior products and services. According to Stiglingh, a total of nine blast blocks and a presplit were fired in various positions in the Klipbankfontein pit. A crew of 10 AEL members worked for 14 days in temperatures above 30°C to make this possible. The success of the blast has enabled the mine to change their methodology by having the confidence to fire fewer and larger blasts to minimize mining interruptions. Subsequently, a second blast containing 4,787 detonators was fired further improving the Africa record by one detonator.
Tagging Systems for
Initiators
In addition to showing its prowess at detonating large blasts, AEL is constantly working on ways to improve safety and security.
As an example, in a joint venture with its
technical partner DetNet, the company
launched the CE4 Tagger, the next generation of tagging devices, which aims to revolutionize blasting in the mining through
ease-of-use, simplicity, visibility, productivity and robustness.
Tagging systems test the integrity of the detonator, the harness and the connectors. The CE4 Tagger enhances this function by allowing testing of poor connections, which can be replaced at the site. “This enables the blaster to ensure electrical functionality of the system and to minimize misfires and possible lost blasts while remaining on the shot,” said Gys Landman, CEO of DetNet. “The DetNet CE4 Tagger, which is GPS enabled, is an inherently safe device for testing and tagging of electronic detonators and will, through its design and usability, enhance productivity and accuracy of a blast.
“The unit features a bigger, higher quality LCD screen, which is easier to read especially in harsher climates and has a scratch-resistant glass screen. The tagger has also been designed for water resistance where the previous generation taggers were only splashproof,” said Landman.
A new feature of the tagger is that it is compatible with two- and four-wire (with inter-changeable head) systems, reducing the amount of components needed for the electronic blasting system and also making it a more cost-effective option.
DetNet and AEL offer product-specific training prior to use and ensure that users also comply with all local regulations when using this device.
Initiation R&D
The R&D teams at AEL are working on a
number of new concepts, which are showing promise, explained Cheryl Kelly, group
technical manager initiating systems.
“The launch of a new booster is imminent
as we are busy building the first prototype
pilot plant at our Pinelands site,” Kelly
said. “This booster will offer improved
hot-hole resistance as well as less dependence on a long supply chain of raw materials. This will be a game-changer for initiation systems.”
Kelly and her group have been working to optimize the pyrotechnic compositions and in particular the binder and oxidizer selection and concentration, which has significantly improved the timing and the reliability of the compositions.
The full range of delay powders for shock tube initiation has now been developed to cover both the underground and surface application. The development of a new surface connector (Rhino) offers more robustness and flexibility.
AEL invests 3% of its annual revenue into R&D to vigorously explore cutting-edge research while offering field and plant support on all new and existing developed technologies. The R&D team ensures that AEL maintains a firm grasp on the anticipated changes and developments in the world of explosives.
Over Pressure Monitor
Instantel’s Micromate vibration and overpressure monitor is a four-channel unit
designed to monitor and transmit event
data with one triaxial geophone and one air
overpressure microphone. Easy-to-use with
a touch-screen interface including intuitive menus, color display, and an associated
keypad, the Micromate offers a rugged
design featuring a high-impact case. This
advanced monitoring technology with a
real-time operating system has a USB
interface, expansive memory, and a variety
of plug and play peripherals that provide
versatility across multiple applications.
Blasters can now download events using
a memory stick rather than a PC. The
touch-screen monitor has large, high-resolution color graphics. An improved menu
structure allows blaster to quick navigate
through the system. The unit is equipped
with remote access.
Optimizing Underground
Blast Planning
CAE Mining announced the launch of Aegis,
an underground drill and blast planning system. This new product, according to the
company, provides a unique combination of
features giving blast planners the tools to
optimize the entire mine-to-mill process,
resulting in significant cost savings.
Aegis, the latest addition to CAE Mining’s Underground Planning Solution portfolio, is described as combining the power of intelligent, automatic blasthole placement and charging with the simplicity of an intuitive interface. “Aegis provides tools to improve drill and blast operations by helping to make smart design decisions based on past experience,” said Ian Lipchak, solutions manager at CAE Mining.
A database containing information on rock type properties, explosives, drill rigs, slot raises, and report templates allows Aegis to rapidly and automatically generate hole layouts and charging plans.
Aegis allows users to adjust individual rings and holes and then output the final drilling, charging and blasting layouts in a printable format or directly to compatible drill rigs using electronic data transfer. This product also contains configurable reporting templates for statistics such as explosives quantities and drilling and explosives costs.
The Aegis package consists of two modules: Aegis Designer, for underground drill and blast design; and Aegis Analyzer, which provides analysis and forecasting tools, adding to the forecasting features of Aegis Designer by providing blast recovery, dilution and value estimates. It also provides advanced blast modeling and cavity prediction algorithms. According to CAE Mining, Analyzer provides an unobtrusive, content-rich interface that integrates seamlessly with Aegis Designer, allowing planners to instantaneously see the consequences of design decisions.
Laser-based Rock Face
Profiling System
A new face profiling system from Laser
Technology Inc. combines reflectorless
laser-based measurements with the company’s Face Profiler software to calculate
bench heights, minimum and optimum
burdens, drill hole angles and offsets, hole
depths, and more. The system includes a
BAP data collector with Face Profiler software and a TruPulse 200X laser rangefinder. LTI’s point-and-shoot handheld lasers
have the ability to measure directly to any
type of surface and the Face Profiler software is easy and intuitive enough that anyone can do it. The system provides precise
data to help improve blasting safety, pinpoint blasthole locations and angle and
optimize fragmentation.
Maxam Provides an
Alternative for the Americas
With a large presence at both the ISEE
2014 and Expomin 2014, Maxam presented its full range of mining products
and services to the Americas earlier this
year. Founded in Spain by Alfred Nobel in
1872, Maxam is the world’s third largest
blasting products and services provider.
Rioflex is a bulk explosive, which the company characterizes as a very versatile product, adaptable to extreme conditions (from the -40º experienced in Siberia to +40º of the Caribbean), low smoke generation, and high energy potential given its reduced water composition, as well as its high performance even in environments where water is present and its easy use in the loading of boreholes.
In addition to Rioflex, Maxam also manufactures ANFO and provides on-site services to its customers in both underground and open-pit mining operations with its bulk mobile sensitizing units.
Seismic Analysis Software
AnalysisNET from GeoSonics/Vibra-Tech is
the company’s most comprehensive and
advanced software for its SSU 3000 seismographs. It combines seismic analysis
and event manager software into a single
package that employs the .NET framework.
The system allows easier access to data
files, provides multiple report combinations and gives blasters the ability to manage data. Other features include: auto
hide/docking of multiple screens, direct
email of results from the program, direct
link to GeoSonics online tools, FFT Analysis, and multiple U.S. and international
compliance standard formats. The software
is compatible with Windows 7 operating
systems and provides the latest innovations
from GeoSonics.
Doctorate in Explosives
Engineering
The Missouri University of Science and
Technology has been approved by the
Coordinating Board of Higher Education to
offer the U.S.’s first doctorate in explosives
engineering, said university officials.
Missouri S&T, they noted, was also the
nation’s first to offer undergraduate and
post-graduate minors in explosives engineering in 2005, a postgraduate certificate
in 2006, and a master’s degree in 2010.
The new doctorate will help accommodate critical shortfalls in the government and the industry, according to university officials. In the mining industry alone, they noted, more than 5,000 engineers will retire in the next decade.
Explosives engineers work in mining, construction and demolition industries, among others. Some 6 billion to 7 billion lb of explosives are used annually in the U.S., 85% in providing raw materials for various uses and 12% for new construction.
More than 150 students have graduated from Missouri S&T with explosives credentials, including 18 with master’s degrees, said university representatives said. The program’s 16 courses are available on campus and via distance learning, they added.
The Missouri S&T explosives engineering program is directed by Dr. Paul Worsey, professor of mining engineering, and is a part of the mining and nuclear engineering department. The 72-hour doctorate curriculum requires a dissertation and explosives engineering core courses and electives. Field work and research will primarily be conducted at the university’s experimental mine facility in Rolla.
Information about the explosives engineering program at Missouri S&T can be found online at explosives.mst.edu