Gpi Tanks XL has successfully delivered two large-scale duplex reaction tanks to Nyrstar’s facility in Budel, the Netherlands, Europe’s largest zinc producer. The project addressed a critical operational challenge when two of the facility’s three SIHAL tanks required decommissioning due to leakage, threatening production continuity.
Critical Operational Requirements
Large reaction tanks, known as SIHAL tanks, perform essential functions in Nyrstar’s production process for extracting zinc from raw materials. When two of the three existing tanks were taken out of service due to leakage issues, the continuity of production came under serious pressure, with the risk that failure of the remaining operational tank would halt the entire production process.
Murat Sozer, senior project engineer at Nyrstar, who remained involved throughout the project, explained the urgency: “It became critical when two of the three tanks were out of service. If the third tank had also failed, the entire production process would have come to a standstill. To prevent this, we submitted a request to Gpi Tanks XL for two new reaction vessels.”
Supplier Selection Process
Nyrstar approached several potential suppliers to address the requirement. Gpi Tanks XL’s previous supply of tanks to the facility provided familiarity with the company’s capabilities, whilst the risk posed by potential failure of the remaining operational tank made short lead times crucial to the selection decision.
Sozer elaborated on the supplier choice: “Gpi was already familiar to us, as they had supplied tanks before. With the risk of the last tank failing, short lead times were crucial. Gpi could deliver quickly, and we knew what to expect from them, so the choice was easily made.”
Technical Specifications and Process Requirements
The production process at Nyrstar involves leaching and purifying zinc from insoluble compounds, conducted in specialized reaction tanks operating under high temperatures with highly concentrated sulphuric acid. Gpi Tanks XL was commissioned to design and deliver two 1,089 cubic metre tanks capable of withstanding these extreme operating conditions.
Material selection proved essential to meeting the demanding process requirements. Sozer explained the selection process: “We researched which materials were most suitable for our process medium at 98°C and high concentrations of sulphuric acid. Duplex turned out to be the best choice, and Gpi was able to realise this.”
The tanks, measuring 12 metres in height and 11 metres in diameter, were constructed from duplex stainless steel 2205, providing superior resistance to corrosion and stress corrosion cracking in acidic environments. The vessels were insulated with mineral wool and finished with bolted stainless steel plates. Additional equipment included heat exchangers, steam and condensate circuits, valves, and fittings necessary for process integration.
Engineering Collaboration and Design Phase
Sozer reflected positively on the design phase, noting careful definition of requirements during initial stages: “In the initial phase, we carefully defined what we needed. During the process, there was smooth cooperation between the engineering teams of Nyrstar and Gpi. Both parties took responsibility in the right areas, which made the collaboration efficient and trouble-free.”
The collaborative approach enabled effective allocation of responsibilities between client and supplier engineering teams, ensuring technical requirements were addressed systematically whilst maintaining project efficiency.
On-Site Construction Execution
Following completion of engineering activities, the tanks were constructed directly on-site at Nyrstar’s Budel facility. This approach addressed the substantial dimensions of the vessels, which would have presented significant challenges for transportation and installation if fabricated remotely.
Sozer expressed enthusiasm regarding the construction phase: “The assembly went very well. The Gpi team on-site was professional, worked with precision, and paid close attention to detail. Agreements were met as promised.”
The on-site construction methodology required careful coordination of fabrication activities within an operating industrial facility, maintaining safety standards whilst progressing work efficiently to minimize the period during which production operated with limited reaction capacity.
Material Performance in Demanding Applications
Duplex stainless steel 2205 combines the beneficial properties of austenitic and ferritic stainless steel grades, providing approximately twice the strength of austenitic grades whilst offering excellent resistance to stress corrosion cracking, pitting, and crevice corrosion. These characteristics make duplex materials particularly suitable for applications involving hot concentrated acids.
At 98°C with high sulphuric acid concentrations, material selection must address both general corrosion resistance and resistance to localized corrosion mechanisms that could compromise vessel integrity. Duplex 2205’s performance in acidic environments, combined with its mechanical properties, provides the durability necessary for long-term operation in zinc extraction processes.
Project Delivery and Operational Impact
The successful delivery of the two reaction vessels restored Nyrstar’s production capacity to full operational capability, eliminating the critical vulnerability created when two of three tanks were out of service. The new vessels provide modern equipment designed specifically for current process requirements, potentially offering improved performance compared to the replaced units.
Gpi Tanks XL’s ability to deliver within the required timeframe whilst meeting stringent technical specifications demonstrated the company’s capabilities in executing complex projects for demanding industrial applications. The project exemplifies the importance of established supplier relationships and rapid response capabilities when addressing critical operational requirements in continuous process industries.
The successful collaboration between Nyrstar and Gpi Tanks XL, characterised by effective engineering coordination and professional on-site execution, resulted in delivery of essential production infrastructure enabling continued operation of Europe’s largest zinc production facility.
For more information visit www.gpi-tanksxl.com
