MINING HOISTS ventilation shaft – to serve a dual function .
“ This is a unique project in many respects , as the shaft will be hoisting ore at the same time as allowing upcast air to reach surface ,” Graham Chamberlain , New Business Director at Murray & Roberts Cementation , says . “ We were able to bring our well experienced experts into the planning process to develop a safe and effective solution .”
The project has followed the sinking of the vent shaft by Murray & Roberts Cementation , which had required very accurate drilling , using raiseboring equipment guided by directional drilling technology . The 5.1-m diameter shaft meets horizontal development at a depth of 950 m below surface .
“ During this process , Ivanhoe looked at bringing forward some of their ore generation activities , and this required adding hoisting capacity ,” Chamberlain explains . “ The timeline for their main shaft meant that it would not be able to contribute to this capacity , so a team was established to consider how to retrofit the vent shaft into an early hoisting shaft .”
As an integral part of that multidisciplinary team , Murray & Roberts Cementation conducted a feasibility study on the options , allowing for the selection of the most suitable methodology . The company also carried out the necessary designs , including winders and headgear as well as hoisting and tipping arrangements . In September 2023 , the project was awarded to Murray & Roberts Cementation to implement , and is scheduled to take about two years .
“ This project stands out in terms of innovation , adaptability , teamwork and design ,” Chamberlain says . “ With our many decades in the sector , we were able to draw on hundreds of years of experience in mining – and leverage this in our design team .”
Among the range of technical challenges is the need to work within the vent shaft while it is performing its function of channelling an upcast current of air to surface . Any blockage of the air current in the shaft would affect the development operation of the mine , so this is critical to avoid .
“ There needs to be periods during which we can reduce the ventilation , but we will have to ensure that air flow is always adequate ,” Chamberlain says . Another vent shaft is planned to add ventilation capacity for the future .
Chamberlain points out that it will be necessary to deal with the slight deviations in the shaft ; while accurately drilled , vent shafts are not designed to the same tolerances as hoist
Murray & Roberts Cementation is in the process of repurposing the Platreef 3 Shaft – a ventilation shaft – to serve a dual function to also hoist ore
shafts . An important aspect of the design was the steelwork required to accommodate those deviations .
“ The work will be conducted by a relatively small team of our highly skilled people ,” he says . “ This will include the installation of a compact headgear using refurbished winders from our strategic stockholding .”
The infrastructure will employ technology that will allow man-less operation to enhance safety , using automated processes in loading and measuring functions , for instance . The project will require specialised subcontractors on much of the equipment employed , but the more day-today consumables are procured locally to support local businesses .
“ In the absence of a supplier , we would then develop their capability through our procurement system and enterprise development commitment ,” Chamberlain says . “ In this way , we foster small businesses and help to nurture them until they are self-sustaining .”
OLKO-Maschinentechnik innovative hoisting tech for nuclear waste disposal
OLKO-Maschinentechnik GmbH has been awarded a contract to supply materials handling equipment for a nuclear waste repository in Germany . This important project involves a variety of advanced technologies to ensure that radioactive waste is transported efficiently and safely . Together with Thyssen Schachtbau , OLKO ’ s parent company , a comprehensive solution will be offered from a single source .
At the centre of the project is an 8-rope Koepe winder specially designed for the demanding conditions in a nuclear repository . This hoist is used to transport radioactive waste packages ,
special materials , personnel and inspection trips and can be used in both manual and automatic mode . The technical design without deflection sheaves ensures a high level of operational safety and efficiency . The motor power is 2.2 MW , the travel distance is 970 metres at a speed of 12 m / s . The maximum payload is 25 tonnes . The machine is equipped with the COBRA01 multi-channel constant retardation braking system .
A single drum winder is used to relieve the main rope travelling system . This hoist is designed for maintenance tasks in the shaft and contributes to the flexibility of the overall system . The winder achieves a maximum speed of 4 m / s . As the safety aspect is a major issue , OLKO also relies on the COBRA01 brake for this single drum machine .
In addition , a semi-mobile auxiliary system is used , which enables people to be rescued in case of an emergency . This system is stored in the winder house building when not in use and can be quickly moved into position in the event of an emergency . The system has a rope length of 1,050 metres , is designed for a payload of 1.85 tonnes and achieves a maximum speed of 0.5 m / s .
A key component in the scope of supply is the rope changing equipment , which consists of eight winches and a total of 35 winding drums . This equipment enables efficient unwinding and rewinding of the ropes , which is essential for maintenance and safe operation .
The patented 8-rope clamping and lifting device ( CLD ) is another innovative solution from OLKO . This device is used for inspection and maintenance work as well as for rope laying and changing operations . It is installed in the head gear below the 8-rope Koepe winder and enables the ropes in the shaft to be raised or lowered safely . The maximum load that can be lifted is 194 t . Lifting and lowering the loads is used by electrically driven spindles instead of complex hydraulics . In order to ensure safe operation before its actual use , a prototype of the CLD was installed at the work shop of OLKO , testing a wide variety of applications .
With this project , OLKO Maschinentechnik says it is setting new standards in hoisting technology for nuclear waste disposal . The close cooperation with Thyssen Schachtbau provides customers with a comprehensive and reliable solution . The innovative technologies and customised systems guarantee maximum safety and efficiency in the handling of radioactive waste . IM
AUGUST 2024 | International Mining 91