IM 2019 August 19 | Page 12

MINE HOISTS Winding down Paul Moore looks at news in hoisting and winding projects, from a series of major potash installations to synthetic fibre mine ropes entering the market he largest and most complex mine hoist projects seem to be dominated by potash currently, from Canada to Belarus to the UK. At Sirius Minerals’ Woodsmith polyhalite mining project in the UK, Thyssen Schachtbau company OLKO-Maschinentechnik GmbH is supplying two Blair multi-rope machines (BMR) with the electrical equipment coming from Siemens. One hoist will work as a so-called production winder for material hoisting, one as a service winder for personal transport, with a hoisting capacity of 35 t payload. The polyhalite is hosted from approximately 1,450 m below sea level to the surface at a hoisting speed of 18 m per second (m/s). The delivery includes a medium-voltage synchronous motor with an output of 9.3 MW and a torque of 1,550 kilonewton metres (kNm) for each machine which are powered directly from a medium-voltage Sinamics SM150 (PWM) frequency converter. Both winders are fitted with a COBRA01 multi-channel brake system which is a joint development between OLKO and Siemens. The latest news at Woodsmith is that service shaft works are on target to complete the construction of the foreshafts by year end to enable commencement of excavation of the main shaft using the Herrenknecht shaft boring roadheader (SBR). The company's first SBR recently passed its Factory Acceptance Test and is due to commence arrival at the Woodsmith mine site in August 2019. The SBR will then be erected on-site. Assembly of the SBR and installation into the foreshaft is scheduled to be completed in December 2019. The excavation of the 35 m diameter service shaft foreshaft to 45 m was completed in the first quarter of 2019, T 10 International Mining | AUGUST 2019 enabling commencement of the excavation of the inner-main shaft, which will be excavated to a total depth of approximately 120 m. The main shaft has now been excavated to approximately 85 m below ground level, using conventional excavation techniques.  The service shaft temporary winder building foundations have been completed. Erection of the temporary and permanent winder buildings, which will house the service shaft hoists, and installation of the temporary and permanent winders is in progress and on schedule. Production shaft works are on target to complete the construction of the foreshaft and excavation of the main shaft to 120 m by year end. The 32 m diameter production shaft foreshaft, which will be excavated to a depth of 45 m from surface, had been excavated to approximately 9 m below ground level by end Q2 2019. The production shaft differs from the service shaft in that it already has diaphragm walls installed to a depth of 120 m in the inner- The control station for the SIEMAG TECBERG six-rope Koepe double-drum winder at the new Mosaic Esterhazy K3 potash mine main shaft.  Once the larger diameter foreshaft has been excavated to a depth of 45 m and the floor installed, the inner-main shafts will be excavated to a depth of 120 m using conventional methods inside the existing diaphragm walls. This is expected to be completed in December 2019. The Herrenknecht SBR for the production shaft is due to commence arriving on-site in October 2019. The SBR for the production shaft is currently erected in Germany and will be undertaking various cutting optimisation tests prior to being dismantled and shipped to the Woodsmith mine. In Canada, using a six-rope Koepe double- drum winder by SIEMAG TECBERG, on 18 December 2018 the first load of potash ore from the new Mosaic Esterhazy K3-Mine in Canada was brought to the surface and sent for further processing. This is a major step in this project, which was started seven years ago. In 2011 SIEMAG TECBERG received an order from Mosaic for the delivery of a one-rope-drum Blair winding machine for the service shaft and The main production headframe under construction at Slavkaliy potash mine in Belarus