Dewatering solutions for open pits and slimes dams generally comprise a choice between undertaking civil construction for pump stations and selecting a mobile pontoon or skid mounted pumping solution. Experience indicates that the land based pump station does not always have the same flexibility that pontoon or skid mounted pump sets would offer. Howard Jones, Weir Minerals Africa’s Product Manager – Dewatering Africa and Middle East says that this is apparent in the fact that pontoons are installed at the source, making pumping more efficient as the pumps face consistent suction conditions. In addition, pontoon or skid mounted pumping solutions can be readily migrated to wherever they are required. This eliminates the costly and time consuming alternative of developing a new pump station for each location.“It is important to select the most appropriate solution based on accurate information gathered during an on-site inspection. Factors such as topography, volume of water, quality of water, the total distance to be pumped, the difference in elevation from the start of pumping to the discharge point, the preferred piping material, the availability of electricity, and the specific mining methodology are critical to the resolution of the dewatering issues,” Jones points out.Weir Minerals Africa is one of three Weir Minerals global design centres that focus on pontoon and structural design specifically, with modifications implemented for local conditions. The selection of the pumping unit could include any of the well-established Weir Minerals brands such as Warman® and Multiflo® and could vary from pure dewatering or dirty water pumps to submersible dirty water pumps, as well as heavy duty slurry submersible and other end suction products.Multiflo® pontoons are constructed with integral access walkways which could either be fixed to the bank or floating. The walkway holds the cable and piping from the docking station to the shore and provides ready access to the pumps for inspection or regular maintenance. Light masts, as well as LED strip lighting, form part of the offering and are supplied according to client’s requirements. The pipes comprise Linatex® rubber hoses which are also locally manufactured by Weir Minerals Africa and offer the customer extended wear life because of the specialised rubber compounds used in their manufacture.Weir Minerals uses a variety of construction materials including complete steel pontoon barges to linear low density polyethylene flotation devices with steel frames for lighter applications, where mobility from one pond to another is required. These designs can handle most Weir Minerals pump offerings, with a load bearing capacity from 500 kg to 10 t, including the structure. The steel hulled heavy duty pontoons can easily have a total mass of 30 t. All designs comply with the South African Marine Safety Association’s requirements pertaining to HSE regulations. The majority of the pumps are manufactured locally at Weir Minerals Africa’s facilities, allowing for ready accessibility to spare parts and components through the company’s extensive sales and service centre network. Supervision of the installation and commissioning of the pumping solution is undertaken by Weir Minerals Africa to ensure that the exact specifications are met.