MSE Filterpressen GmbH, a German specialist in solid-liquid separation technology, has successfully delivered a state-of-the-art membrane filter press system to Nyrstar’s Hobart zinc smelter in Tasmania. The installation is tailored to the smelter’s Roast-Leach-Electrowinning (RLE) zinc production process and is designed to improve zinc recovery, process stability, and operational safety. The project demonstrates MSE’s international engineering expertise and the high performance of modern filtration technology in large-scale metallurgy.
Crucial Filtration in the Zinc RLE Process
Picture Hobart Site
Zinc ingots produced at Nyrstar’s Hobart smelter. The facility is one of the world’s largest zinc producers, with about 280,000 tonnes per year capacity . Efficient solid-liquid separation is critical in the hydrometallurgical process to maximize metal recovery and maintain environmental compliance.
In zinc smelting via the RLE process, effective solid-liquid separation is a mission-critical step. After roasting zinc concentrates and leaching the calcine in acid, the zinc-rich solution must be separated from solid residues. Any inefficiency in this step can lead to zinc losses in the residue and downstream process disruptions. At Nyrstar’s Hobart plant – one of the world’s largest primary zinc smelters by output – filtration performance directly impacts zinc yield and throughput . Recognizing this, Nyrstar partnered with MSE Filterpressen to upgrade its filtration system. The goal was to install a more efficient filter press that could handle the smelter’s high volumes while delivering drier filter cakes and clearer filtrate, thereby enhancing overall zinc recovery and process stability.
Tailored Membrane Filter Press Solution
MSE Filterpressen supplied a fully automatic membrane filter press custom-built for Hobart’s requirements. Unlike conventional filter presses, a membrane filter press uses flexible membranes that can be inflated to squeeze the filter cake after the initial filtration. This membrane squeezing capability allows it to achieve much lower residual moisture in the cake compared to standard filtration methods . The unit delivered to Hobart incorporates high-quality PVDF membranes (polyvinylidene fluoride), a material known for its excellent chemical resistance and durability in acidic environments. This choice ensures the press can withstand the aggressive sulfuric acid solutions in the zinc leaching process, extending service life and reliability.
Picture MSE filter press
A fully automated MSE membrane filter press (CellTRON series) similar to the one installed at Hobart. The system’s membrane plates inflate to compress the filter cake, achieving drier solids and improved metal recovery. Full automation and a robust design enable fast cycles and safe, continuous operation.
The filter press is engineered for high throughput, aligning with Hobart’s large production scale. Weighing roughly 40 tons, the massive press features a heavy-duty duplex steel cladded frame and a series of membrane filter plates that form multiple chambers for batch filtration. The entire system is fully automated – from feed pumping and pressure control to plate opening, cake discharge, and cloth washing – minimizing the need for manual intervention. This level of automation not only improves safety (by keeping operators away from hazardous materials) but also ensures consistent cycle times and optimizes efficiency. In fact, modern membrane presses can cut filtration cycle times by more than 50% on average, significantly boosting productivity . MSE’s design for the Hobart press includes safety interlocks and sensors to monitor the squeezing process, given that squeezing pressures can reach up to 15 bar or more. These precautions protect the equipment and personnel during operation of such a powerful system.
Operational Benefits and Performance Gains
Since commissioning the new membrane filter press, Nyrstar Hobart has reported notable improvements in its operations. Zinc yield from the leaching circuits has increased, as the advanced press recovers more dissolved zinc from the slurry and leaves behind a drier, more depleted filter cake. The residual moisture in the filter cake has been significantly lowered, which means that less valuable zinc-bearing solution is trapped in the waste solids. By producing a drier cake, the press also reduces the weight and volume of material that must be handled as waste, directly contributing to more efficient downstream handling and lower transport or disposal costs.
Another major benefit is the enhanced process stability. The new filter press operates with reliable, repeatable cycle times and has ample capacity, preventing the filtration step from becoming a bottleneck. The consistent performance helps maintain steady input to the electrowinning stage, thereby smoothing the overall production flow. According to plant engineers, the filtration upgrade has reduced unplanned downtime and maintenance needs, as the robust system is less prone to clogs or mechanical issues. The filter cloths and membranes were selected to fit Hobart’s slurry characteristics, leading to longer cloth life and sustained filtration rates.
Safety and workplace conditions have improved as well. The fully enclosed and automated cake discharge means operators no longer need to manually scrape out filter cakes or be exposed to acid slurry. The dry, solid filter cakes that drop from the press are easier and safer to transport. This reduces the risk of spills or contact with hazardous materials, aligning with the smelter’s high HSE (Health, Safety & Environment) standards. Moreover, the clearer filtrate (liquid output) from the press improves the downstream solution purification process, which in turn can enhance the quality of zinc produced and reduce the load on effluent treatment facilities. Overall, the advanced filtration system contributes to the plant’s sustainability goals by recovering more metal, reducing waste moisture, and operating energy-efficiently for a lower environmental footprint.
Logistics and Global Engineering Execution
Delivering a 40-ton industrial machine from Germany to Tasmania was a significant logistical undertaking. MSE Filterpressen managed the 16,500 km transport of the filter press system on schedule, exemplifying the company’s global project capabilities. The press was shipped in large modules via sea freight and then transported to the Hobart smelter site, where MSE’s engineers oversaw assembly and commissioning. Despite the distance and complexity, the installation was completed smoothly, thanks to thorough planning and the modular design of the equipment.
MSE’s successful execution of this project underscores its ability to serve mining and metallurgical operations worldwide. Founded in 1978, the company has grown to deliver over 3,000 filtration systems across more than 30 countries . This global experience was evident in the Hobart project – from customizing the design to local requirements, to coordinating with international freight and adhering to local installation standards. For Nyrstar, having a partner with such international expertise meant confidence that the new equipment would integrate well into the existing plant and perform as promised.
A New Benchmark for Filtration in Zinc Smelting
The membrane filter press installation at Nyrstar Hobart represents a significant advancement in the plant’s operational efficiency and metallurgical performance. By leveraging cutting-edge German engineering in filtration, the Hobart smelter has achieved higher zinc recovery, improved safety, and greater process stability – all critical factors for competitiveness in a challenging global zinc market. This case also highlights the importance of modern solid-liquid separation technology in making mining and smelting processes more sustainable. High-performance filtration equipment, like the MSE membrane press, enables producers to extract maximum value from raw materials while minimizing waste and environmental impact.
Learn More
For more insights into advanced filtration solutions, visit MSE Filterpressen GmbH or subscribe to our Techletter for the latest innovations in filtration technology.