Ivanplats is an Ivanhoe Mines company which trades on the TSX and is also developing copper projects in the DRC.
The early engineering of the three separate winders was necessary to facilitate the design of the headframe structure by Murray & Roberts Cementation.
The largest Koepe winders previously supplied by FLSmidth are the two 6.5 m diameter units at Impala 16 Shaft and their successful implementation forms the basis of the design and engineering undertaken for the Ivanplats Platreef project winders.
“Experience is critical in projects of this nature and the ability to adapt to changing conditions is one which differentiates FLSmidth. Each of the two 6 m diameter Koepe winder installations with drums, brake systems and drives needs to be accommodated within the constraints of the headframe dimensions. The solution we provided involved installing the two Koepe winders at 90° degree angles to each other, with the auxiliary winder being installed in a lower level,” Mark Sheward, sales manager mine shaft systems for FLSmidth, explains.
During the early engineering phase, FLSmidth made use of Finite Element Analysis (FEA) to establish and verify the stress loading in the final design. Other supplied data included dimensions, loads, required tolerances, stiffness requirements and the position and length of the anchor bolts, as well as the mass and dimensions of the major components to be lifted into the headframe.
Both the production and service winders are four rope friction winders. The production winder will hoist two 40 t skips while the service winder will be equipped with a man/material cage and counterweight. The rock or production winder is being designed for a rope speed of 18 m/sec while the man/material winder will operate at 10 m/sec.
The auxiliary winder, with a rope speed of 6 m/sec, will be a 2.4 m diameter, 1.2 m wide single drum unit and could initially be ground-mounted and used for shaft equipping before being relocated to the head frame on completion of shaft sinking.
The shaft depth is approximately 1 050 m and braking will be effected on all three winders by a 4-channel closed loop hydraulic system incorporating disc brakes.
New small winder design
The auxiliary winder forms part of the new small winder design which FLSmidth has been developing over the past year. This on-going development work allows design optimisation and a reduction in the weight of the actual winder, as well as the simplification of the clutch design.
“Best practice benchmarking was used and this allowed for the formulation of a parametric model which can be either up- or downscaled to accommodate specific application requirements. This has dramatically reduced the engineering time required and ultimately translates into the facilitation of faster responsiveness to customer requests for design/engineering on small single drum and double drum winders (with clutch) of up to 3.66 m in diameter,” says Sheward.
FLSmidth also secured the contract for the design and engineering of the conveyances for the Ivanplats winders. This contract comprises the detailed design of the two 40 t skips for the production winder and a 40 t double deck cage and cage counterweight for the man/material hoist. The skips will incorporate hydraulic dump mechanisms.