Spotlight Feature Articles MINE SAFETY - Page 8

MINE SAFETY The longwall system for JSW’s Budryk mine The new face set will operate in the Cz-2 face of the 405/1 seam at a depth of 1,290 m at the Budryk mine. Commissioning will begin with the extraction of seams 405/1 and 405/2, which have totally 68.5 Mt of hard coking coal resources. Extraction is expected to commence later this year, or early in 2020. The longwall system to be used in the Cz-2 face consists of 118 Becker Warkop powered roof supports, each 1.75 m wide. The company also took special care to ensure the safety of workers directly at the coal face, designing, among other things, a walkway for the crew to move through in front of and behind the powered roof support shield’s legs. In accordance with the requirements of the mine, the safety of the workers to service the shearer has also been ensured by equipping 24 of the 118 powered roof supports with specially designed telescopic face heading protecting shields. This will protect the workers from falling rocks while in place at the shearer. Becker’s powered roof supports come with the latest longwall automation systems and can be operated either locally, remotely, or semi- automated, according to the customer’s requirements. In seams with a longitudinal inclination of over 12°, the support collaborates with conveyor stabilisation, roof shield correction, and main gat face-end protective devices. shaped steel guides and, according to the company, offers superior safety and other operational benefits to underground mining companies. It uses steel guides instead of conventional timber guides to eliminate uncertainties inherent with wood and provide an enhanced degree of safety, repeatability and reliability, the company said. “The Cage Guardian Safety Brake is strictly mechanical – no hydraulics, pneumatics or electricity – for fail-safe operation, even on wet or contaminated guides,” FLSmidth said. “Actuation and operation is performed by redundant mechanical systems, only requiring a slack-rope or rope break event to bring the cage to a safe stop.” It also comes with average deceleration rates of 0.9 g to 2 g (9 to 20 m/s/s) meaning the Cage Guardian Safety Brake has a lower jerk rate and Cages and shafts FLSmidth says it is delivering on a promise to provide solutions for a sustainable tomorrow with its Cage Guardian™ Safety Brake for steel guides. Designed for underground mining operations, the Cage Guardian Safety Brake is used on conveyances running on tubular or top-hat- International Mining | OCTOBER 2019 FLSmidth’s Cage Guardian Safety Brake uses steel guides instead of conventional timber guides to eliminate uncertainties inherent with wood and provide an enhanced degree of safety, repeatability and reliability provides smoother deceleration than other such brakes on the market, according to FLSmidth. The safety brake system also allows for easy retrieval of the cage after an event, with, unlike conventional safety dogs for wood guides, the brake inflicting minimal damage to any cage or guide components, resulting in faster redeployment of the cage. Henry Laarakker, a Product Manager at FLSmidth, said as wood guides become increasingly less desirable from both environmental and economic perspectives, the use of steel guides is becoming ever more attractive. “The Cage Guardian opens up a new world of opportunities for the safe transport of personnel underground,” he said. “It also allows for a fully-engineered safety solution, inspiring a high degree of confidence without reliance on the variability of nature inherent with wood guides.” Still within the underground mining safety space, Winder Controls Australia, a subsidiary of the SIEMAG TECBERG group, recently launched a gravity feed system for safe personnel recovery in the event of a power loss or control system malfunction. This system involves the use of a standalone control system and generator to ensure the gravity feed system is isolated from any malfunctions/power loss with the winder. The company explained: “This arrangement ensures that personnel recovery operations are conducted in a safe and controlled manner without exposing trapped or recovery personnel to any additional risks.” It relies on the drum, brake callipers and piping to the callipers being fully functional, with all other components and systems assumed inoperable. The gravity feed system allows the conveyance to be lowered at a controlled speed of 0.7-1 m/s to enable personnel to be safely evacuated at an underground level. Single rope drum winders are the primary application for this system, but the company says it can be employed on other hoisting systems where the conveyances are not balanced. A similar system has also been developed for a standard friction winder with a pony drive system capable of bi-directional travel to enable personnel to be evacuated at surface or any underground level. This is conducted at a speed of 0.25-0.5 m/s. “Without a system in place for personnel recovery, mines are forced to use primitive or unsafe recovery methods,” the company said. These methods often involve acquiring equipment off-site, which exposes personnel to more potential risks. The company worked with regulators and miners to develop this fit-for-purpose system, which is SIL-2 compliant. Winders Controls