Why Choose Triodetic?

Canada: Leading Potash Producer

Canada is the world’s largest producer of potash, contributing 32% of global consumption with a production of 13.3 million tpy. Potash mining in Canada began in Saskatchewan in the 1940s, and by the 1950s, high-grade potash layers were discovered. These layers, formed millions of years ago by an evaporated inland sea, make up over 50% of the world’s potash reserves. The high-quality potash averages 28% potassium oxide (K2O), compared to Europe’s 19% K2O.

Potash Mining and Corrosion Challenges

In Saskatchewan, potash is mined using conventional methods. Large rotary machines cut tunnels into the ore body, leaving salt pillars as supports. The crushed ore undergoes a flotation process, creating a highly corrosive mixture that can damage piping, containment vessels, and machinery. Engineers and maintenance personnel continuously work to protect facilities from corrosion.

Corrosion Protection Strategies

Metal corrosion is a significant issue, causing material deterioration through chemical and electrochemical reactions. In potash facilities, both the process systems and ambient air can cause corrosion. Using stainless steel and specialized coatings can help resist this damage, though coatings can be compromised, leading to progressive corrosion and structural failures.

Case Study 1: Dome Replacement at a Saskatchewan Potash Mine

In 2013, a timber dome collapsed at a Saskatchewan potash mine due to severe corrosion of its metal connections and steel rod bracing. The collapse not only highlighted the critical need for durable materials but also significantly impacted production, as this mine operates with a capacity of 1.5 million tpy of potash. The loss of the thickener tank was a major setback.

Triodetic was tasked with an urgent and complex mission: to replace the collapsed timber dome with a structure that would resist the harsh, corrosive environment. After meticulous planning, stainless steel 316L was chosen for all components of the new dome structure, including connections, cladding, and fasteners, ensuring maximum resistance to corrosion.

The new dome is an engineering marvel, with a diameter of 73 m (239 ft) and a height of 24 m (60 ft), supported by 96 equidistant perimeter points. The assembly process was groundbreaking, allowing the potash production to continue uninterrupted beneath the construction site. This was achieved without the need for scaffolding, using a suspended net to catch any accidental drops of tools or materials.

Inside the dome, custom-designed stairs provide access to its apex, highlighting the attention to detail and functionality. The entire structure is insulated with spray-on insulation, enhancing its resilience against the harsh climate. This project not only restored production efficiency but also set a new standard for geodesic dome design, showcasing the economic and structural advantages of this innovative approach.

Case Study 2: Agrium Mine Expansion

The Agrium mine, now known as Nutrien, near Saskatoon, underwent an extensive expansion that called for a sophisticated and durable solution for covering a critical flotation tank. The project demanded a dome that could withstand the aggressive environment while providing robust support for the ongoing operations.

The resulting dome, with a diameter of 45 m (146 ft) and a height of 19 m (63 ft), is a testament to advanced engineering and material science. Made from stainless steel 316L, the structure includes several large dormers around its perimeter. These openings, measuring 4 m (14 ft) wide and 14 m (45 ft) high, accommodate a bridge truss frame that supports the central rotating mechanism and pipe conduits.

Despite the complexity added by these dormer openings, which interrupted the geometric pattern of the triangular elements, the structure’s integrity was maintained through special tubular reinforcements. This attention to detail ensured the dome’s stability and durability during and after assembly.

The dome is covered with pre-curved corrugated stainless steel decking, followed by a 90 mm (3.5 in.) layer of spray-on insulation topped with a UV-resistant membrane. This three-layer insulation system, consisting of Premicote 429 primer, Bayseal 3.0 closed-cell polyurethane, and Rhino Eco Coat exterior membrane, ensures that the facility remains protected against extreme winter temperatures, maintaining operational efficiency throughout the year.

Conclusion

As the global population grows, so does the demand for food and potash. Potash demand is expected to increase by 3-4% annually, driving investments in mining expansions and new operations. To minimize corrosion and control maintenance costs, it is essential to design long-lasting production systems. Utilizing stainless steel and durable coatings will enhance the longevity and efficiency of mining operations.