To strengthen its production capabilities and optimize resource efficiency, Nyrstar has implemented a significant technical enhancement at its Hobart site in Tasmania. A newly installed membrane filter press now supports the solid-liquid separation stage within the established Roast-Leach-Electrowinning (RLE) zinc production process — a critical step that directly affects yield, process stability, and occupational safety.
Solid-liquid separation in the RLE process
The RLE process is a standard hydrometallurgical method in zinc production. Following roasting, the zinc concentrate undergoes leaching with sulfuric acid, producing a slurry that contains both dissolved zinc and solid residues. Efficient separation of these components is essential: inadequate filtration can reduce metal recovery, compromise product quality, and introduce operational inefficiencies further downstream.
Recognizing these challenges, Nyrstar sought to improve the consistency and efficiency of this process step, particularly in light of planned capacity increases at the Hobart facility. A robust and high-performing filtration system was required—one that could reliably manage larger throughputs while maintaining low residual moisture and high filtrate clarity.