L’Office Chérifien des Phosphates (OCP), one of the world’s leading exporters of phosphates, phosphoric acid and phosphate fertilisers, began constructing a phosphate pipeline in 2010, designed to deliver several grades of phosphate slurry to Jorf Lasfar’s terminal – a deep water commercial port located on the Atlantic coast of Morocco. The project, near Khouribga 200 km northwest of Marrakech, consists of a 187 km 36 in transportation pipeline, plus 37 km of 18 in and 20 in feeder lines, running to Jorf Lasfar’s terminal as well as Doui Pump Station, MEA Head Station, and Halasaa Pump Station, representing an investment of $433 million. Volvo rotating pipelayers are being used to perform the tie-ins (fusing two sections of pipe together), which are completed every 500 m, as well as lowering the entire pipeline into the trench. The pipelayers’ long booms make them the perfect candidate to accurately align the pieces so that they can be bolted together.
The pipeline project was contracted to Turkish company, Tekfen Construction and Installation Co. On site Tekfen is using Volvo PL4608 pipe layers and Volvo EC210B excavators. The first job of the Volvo EC210B excavators was to hold and supply hydraulic flow to the pipe facing machines in preparation for welding. As phosphates are both corrosive and abrasive in nature, Tekfen have sub-contracted UPS-APTec, a joint venture between United Pipeline Systems and Allied Pipeline Technologies, two specialised pipeline contractors, to install a high density polyethylene (HDPE) pipe liner system to avoid what could otherwise result in costly damage to the steel pipe, shortening its life span. The liner installation process begins once the length of pipe is buried in the ground. Sections of the high-density, polyethylene (HDPE) pipe are joined by heat fusion to create a continuous length of liner.
Volvo excavators are used to raise the pipe from the ground into the trench and another one is used to handle and hold the special tool, which is needed to clamp and stretch the HDPE pipe to an exact length where it’s cut and the liner is effectively sucked back inside the host pipe. Finally, a polyethylene stub end is fused to the edge of each section and the flanges can then be bolted together. On completion an air test can be conducted to confirm a leak free, sealed system. The PL4608’s 360 degree upper structure swing enables the machine to re-position its boom, necessary to facilitate the tie-in process – something which is not possible with a traditional side boom pipe layer.
The completion of this project will reduce OCP’s transportation costs considerably from the mine in Khouribga to the port off Morocco’s Atlantic coast. It will also reduce energy costs and the environmental impact associated with previous transportation handled by the region’s railway line. The feeder pipelines from each wash plant pump station will deliver sequential batches of slurry to segregated tanks at MEA’s Head Station. From there, successive phosphate loads will be pumped through the main pipeline into storage tanks at the port’s terminal. One slurry grade will be supplied to local acid plants but all of the grades will be supplied for export purposes. The facilities are currently designed to handle a total of 38 Mt/y with the possibility to increase it to 44 Mt/y in the future.