SOUTH AFRICAN SUPPLIERS
Dymot Engineering Company ’ s pre-sink single drum winder systems for United Mining Services are fitted with two SIBRE Siegerland Bremsen braking systems , supplied by Magnet Service Binder RSA
Magnet Service Binder RSA . The braking system consists of one USB5 high speed thruster operated disc brake and an SHI dual path hydraulically operated calliper disc brake on each side of the winder drum .
“ The brakes include all safety proximity switches as well as a sophisticated air gap measuring transmitter on each of the hydraulic calliper brakes ,” Snyman said . This measures the exact distance that the brake covers during opening and closing and is transmitted back to the PLC in a 4-20 mA signal for monitoring .
The control system and control desk are built into a 6 m container with an ergonomic layout , according to Snyman , who explained that the
winder can be operated at either low or high speeds via the VFD and joystick . The motor can also be held at 0 Hz at full torque , ensuring no runback when the brakes are released .
A PLC and “ watchdog ” are included for system monitoring , while a remote input / output panel with Ethernet communication protocol is fitted to the winder . All safety devices are taken back to the PLC through the network , according to Snyman .
“ The HMI displays all system operation modes and monitoring of the winder , and also all alarms / trips occurring during operation ,” he said . “ These alarms / trips must be acknowledged and resolved before the system resumes operation .” Trend graphs from the HMI can also be downloaded for review and interrogation after each shift .
Temperature transmitters are fitted to the plummer block bearings , and a pressure transmitter is fitted to the power pack . These are also monitored for safe operation of the winder .
“ This project has been a major achievement for Dymot and confirmation of our capabilities as a leading manufacturer of winch systems ,” Snyman said . “ We are involved with the majority of mining projects and have products in more than 50 countries .”
South African record
South Africa-based BME continues to lead the way in the domestic mining sector ’ s electronic detonator blasting efforts .
Its latest record blast occurred at the end of 2020 at a manganese mine in the Northern Cape .
This saw BME , an Omnia Group company , use its AXXIS™ electronic initiation system to plan and execute a blast of 4,647 detonators . Just a few months earlier , the company had broken a previous record at the same mine by initiating
3,780 detonators in a single blast .
“ The latest achievement involved a remarkable 535 t of emulsion explosive in over 2,300 blast holes requiring a total of more than 37,000 m of drilling ,” Kobus Boonzaaier , BME Area Manager in the Northern Cape , said . “ The resulting blast was able to move almost 2.3 Mt of rock within a matter of seconds .”
Boonzaaier highlighted that the advantage of these large blasts is they allow mines to blast less often , meaning less disruption and a more streamlined operation . The size of the blast was not the only factor to consider , however , as a quality blast must also optimise key outcomes like fragmentation , according to BME .
Such blasts are only likely to increase in regularity after the recent launch of BME ’ s AXXIS Titanium™ electronic blast detonation system .
Designed to seamlessly integrate with BME ’ s software systems and hand-held digital tools , AXXIS Titanium is billed as improving safety levels through enhanced communication with the detonator during manufacturing to avoid defects . Performance is raised through the increased blast duration per detonator , more units per blasting box and precise firing accuracy , the company added .
The system can now manage 1,000 detonators per blasting box , doubling the capability of the previous generation , and up to 20 blasting boxes can be linked and synchronised through hard wiring , enabling the possibility of initiating up to 20,000 electronic detonators in a single blast . The commercialisation of AXXIS Titanium follows extensive laboratory and field testing in South Africa , leading to the recent award of an Inspection Authority certificate by the Department of Mineral Resources and Energy . Uptake has already begun in BME ’ s southern African market , and the system will soon be rolled out across BME ’ s extensive Africa footprint , the company said .
IM
JANUARY 2022 | International Mining 25