Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
Issue link: https://emj.epubxp.com/i/861266
82 E&MJ; • AUGUST 2017 www.e-mj.com OPERATING STRATEGIES Canada's new Bethune mine — former- ly known as the Legacy Project — is the fi rst greenfi eld potash mine built in Sas- katchewan in nearly 40 years, and its owner K+S Potash boasts that it's the world's most modern potash operation of its type. Opened in May after a fi ve-year construction phase, the mine shipped its fi rst product in June and K+S intends to produce 600,000 metric tons (mt) to 700,000 mt of potash there this year. Annual production capacity of 2 million mt is expected to be reached soon there- after. This will be followed by the gradual expansion of production capacity to 2.86 million mt per year (mt/y) in 2023. In a third expansion phase, the mine could reach a maximum output of 4 million mt/y of potassium chloride in about 10 years. Effi cient rail service is vital to the mine's success and the railcars built for K+S by Canadian company National Steel Car are unique: they hold the same ca- pacity as a standard car (105 mt), but are slightly shorter to accommodate more cars per train. A single opening at the top of the cars allows them to be loaded while in motion. K+S initially ordered more than 500 of these rail cars, with the option to enlarge the fl eet later based on increasing production volumes. Freight trains leav- ing the mine via a purpose-built Canadian Pacifi c (CP) rail spur will be approximate- ly 3 kilometers (km) in total length, each consisting of 177 cars, and on the jour- ney to a West Coast export terminal pass through a tunnel near the mine, where the tracks intersect a two-lane road. An innovative structural support design for that railway tunnel marks the fi rst Cana- dian installation of AIL Mining's patented Super•Cor Round MSE-reinforced bevels. The AIL Group of Companies, headquar- tered in eastern Canada, has been provid- ing innovative, cost-effective solutions in corrugated structural plate, MSE retaining walls, modular steel bridges, and corrugat- ed pipe to mining and other indus- trial sectors since 1965. This innovation, said AIL, al- lowed construction of the tunnel's 14.5-meter (m)-long bevels with- out the need for internal bracing during the backfi ll process. This saved time and money compared with the traditional false-work brace method. AIL's design con- nects heavy-duty welded wire soil reinforcement mats to a series of connection anchor strips that are integrated with the exterior sides. AIL's scope on this project included the structural design of the Super•Cor tunnel and the cast-in-place concrete collars on the bevelled ends. These collars helped stiff- en the ends of the tunnel and facilitate grading of the embankment slopes to the tunnel opening. The project didn't proceed without a hiccup, though — a mid-construction tunnel design change required swift ac- tion by the company. Typically AIL man- ufactures all Canadian Super•Cor at its Ayr, Ontario, plant. Part way through construction it was decided to lengthen the tunnel by 28.2 m to accommodate a revised site layout. To lessen the impact on the construction schedule, manufac- turing of the extension components was shifted to AIL's sister company Big R Bridge. The new Super•Cor components were rushed from Big R's Texas plant to Saskatchewan without severely impacting the schedule. The AIL Group's consistent manufacturing quality control program ensured easy fi t-up between the Canadian and U.S. produced plates. AIL also offered technical assistance for constructing a pre-shaped pipe bed- ding and on injecting a cementitious, fl owable fi ll under the tunnel invert once the plate assembly was complete. Using fl owable material allowed for a faster and safer fi ll of any potential voids and saved days of hand tamping gravel below the invert. AIL said one of its engineers was re- tained by the contactor, Kelly Panteluk Railway Tunnel Design at Potash Mine Saves Time and Money The Bethune operation's rail spur intersects a two-lane road near the mine, requiring underpass construction. On track to produce at an annual rate of almost 3 million mt/y by 2023, K&S; Potash's Bethune mine needs effi cient rail service to ship its product from Saskatchewan to terminals on Canada's West Coast.