AEL Mining Services, a South Africa-based supplier of commercial explosives, initiating systems and blasting services, recently reported the Rukodzi mine, part of Zimbabwe Platinum Mines' Ngezi Mining Division, converted its perimeter blasting practice from AEL's PE Barrel to polypipes, after using the former system in its bord (room) and pillar blasting operations since 2003.
PE Barrel is a water gel explosive packaged in special plastic tubes that can be clipped together for use in holes where a decoupled charge is needed. Applications include smooth blasting of perimeter holes in shaft sinking, development or tunneling.
"PE Barrel, a specialist blasting technique product manufactured at low volumes, is supplied at a premium compared to other standard explosives. Due to the drop in platinum prices in 2008 driven by the global commodity crisis, Ngezi Mining Division's quest for best practices in all its mining activities was accelerated," said Gift Zhou, Ngezi Mining Division's best practice manager.
Late in 2008, a team from AEL Mining Services initiated a project to find a more cost-effective alternative to PE Barrel, and subsequently recommended an innovative approach which was trialed during the mining of tunnels for the Gautrain Rapid Rail project in Johannesburg, South Africa. This innovation involved a trial with emulsion charged into polypipes as an alternative to PE Barrel.
"The results recorded were outstanding and encouraged full scale trials in Rukodzi mine, resulting in the total conversion to polypipes, which was concluded in June 2010," said Zhou.
Although the conversion resulted in a 3% increase in powder factor, the net effect of the conversion was a 3% saving in explosives cost per metric ton blasted.
AEL said its relationship with Zimplats Ngezi Mining Division dates back to 2001 when Ngezi issued an explosives tender to provide Prime, Load, Tie and Shoot (PLTS) blasting services for the open-pit mine. AEL was initially awarded a three year PLTS contract. Over the years following the initial contract, more 70,000 tons of emulsion has been used to blast ore and overburden totaling approximately 60 million bcm using a fleet of four AEL Mobile Manufacturing Units.
AEL's UBS technology in conjunction with Tunnelmaster shock tube system was accepted as the blasting system for Ngezi Mining Division's bord and pillar mining after extensive trials at the start of underground mining in 2003.
In another offshoot from AEL's involvement in the Gautrain project, the company said it recently completed the first phase of the Goldfields South Deep shaft sinking project using its QuickShot electronic detonator system to sink 110 m of the 9.4-m-diameter shaft. This followed a contract awarded to AEL by Murray and Roberts in April 2010.
"Having seen the outstanding results from the Gautrain Project blast, QuickShot electronic detonators were the natural choice to deepen the Goldfields' South Deep Gold mine, some 3,000 meters," said Mark Mocombe, vice president of Goldfields South Deep.
"AEL's QuickShot electronic detonator system, developed by our sister company, DetNet, debuted with the Gautrain project and achieved maximum advance rates, as well as adherence to environmental restrictions. Blasting was performed without incurring damage to sensitive structures on surface with Peak Particle Velocity levels well under the target maximum of 10 mm/s," said Carlos Goncalves, product manager, AEL Electronics.
With existing foundations at the South Deep shaft project very close to the perimeter blast ring—a 234-hole by 1.2-m deep round—care had to be taken to not inflict damage on the winder and compressors.
"Given that this was new to us and the crew members, we had no idea how complex the drill and blast design could be. AEL demonstrated leadership in underground blasting and we are satisfied with the work done so far. The shaft is starting to take shape nicely," said Morcombe.
The second phase of the project requires a further 143 m of sinking and has not yet been awarded.
Meanwhile, the Dutch company NX Burst Europe BV announced the introduction of NXbursT, which it claims is a safer alternative to traditional explosives used for specialized and secondary blasting applications in the mining and demolition sectors. The technology is based on a non-detonating chemical compound enclosed in a cartridge, which reacts quickly when ignited to produce high volumes of harmless gas, mainly consisting of nitrogen, carbon dioxide and steam.
When the cartridge is sealed in a drill hole, the gas generated by the ignition of the propellant enters into the micro-fractures created from the percussive drilling process and into the natural fractures and planes of the rock to produce a shearing often known as splitting. There are no expensive initiation systems required or special tools needed. It is said to be fast, simple and, most importantly safe.
Given its unique characteristics, the non-explosive product is suitable for use in breaking rock and concrete in sensitive locations or in built-up areas. Examples of use include: secondary boulder breaking; dimension stone quarrying; and pass and boxhole excavations.
Inmet Chooses PITRAM Software Solution
Perth, Australia-based software and solutions provider Micromine said it has been retained by Cayeli Bakir Isletmeleri, a subsidiary of Inmet Mining, to supply and install its mine production control solution, PITRAM, at the Cayeli mine in Turkey. Micromine said PITRAM will increase operational efficiencies at Cayeli by capturing data in real-time and improving the site's reporting capabilities. The first stage of implementation is expected to be complete by late December 2010.
PITRAM, said Micromine, is capable of managing and coordinating all functions within a mine site, including mine development, production, equipment and maintenance. PITRAM tracks and reconciles the delivery and quality of the ore and provides production and activity reports in real time, allowing key personnel to view and monitor the location and status of all equipment and personnel.
The implementation of PITRAM at Cayeli, an underground copper and zinc mine located on the Black Sea coast of northeastern Turkey, was due to begin in early November. The PITRAM Voice System will be operational by the end of December 2010. Two additional modules—Grade Control and Shift Planner—will be introduced throughout 2011.
"After considering various mining solutions, PITRAM was selected due to its proven record of introducing operational improvements and increased efficiencies within underground mine sites. I have used PITRAM at three other operations and am confident that the solution will deliver positive results at Cayeli," said Cayeli Mine Manager Phil Jay.
"PITRAM users can visualize and manage all mine site operations as they occur. Micromine's Shift Planner Module will allow Cayeli to implement a production plan within a real-time environment, and use short-interval control methods to manage daily activities," said Micromine UK Manager James Hogg.
"Cayeli's material movements will be closely tracked using the Grade Control Module which enables real-time management of stockpiles. The reports available from Grade Control provide valuable Key Performance Indicators which can be used to assess the outcomes from production related Business Process Improvement initiatives.
"Through PITRAM, Cayeli will be able to identify areas of constraint and where greater efficiencies could occur. Most importantly, management will have increased control over its operation," Hogg said.