ANDRITZ has been offering innovative separation solutions for more than 150 years. We are the technology provider for reliable dewatering solutions that help you achieve the highest efficiency levels in zero-liquid discharge. Our extensive portfolio includes pusher centrifuges, decanter centrifuges, and filter presses that are ideally suited for ZLD processes and can be perfectly matched to your individual needs. What’s more, we also offer thermal drying systems, pumps, and other utilities, together with a complete range of in-house screening, ancillary, and automation technologies.
ZLD has become a popular way to increase the environmental sustainability of industrial plants in a wide variety of different sectors – from the production of chemicals, oil and gas, to the generation of energy - particularly in regions with a short supply of fresh water. ZLD not only reduces the ecological footprint of a plant by eliminating wastewater discharge, but also increases water reuse and allows for the recovery of valuable by-products. In this way, it helps companies to meet stringent wastewater disposal regulations as well as water reuse guidelines, and also improves their public image.
Zero-liquid discharge (ZLD) is an effective method to eliminate wastewater discharge, recycle water, and recover valuable solids and chemicals.
Looking back on 150 years of experience in solid/ liquid separation and at least 60 years in the handling of saturated brines, ANDRITZ provides an unrivaled portfolio of state-of-the-art separation technologies for ZLD applications. Since 1990, we have installed a large number of equipment as part of ZLD systems, supporting customers from almost all branches of industry.
In a ZLD system, corrosion is a big issue: Operating temperatures are typically above 80 °C and can reach up to 135 °C. In addition, chloride concentration is often high. In order to tackle these challenges, we use selected and well-proven high-grade alloys such as duplex and super-duplex stainless steels or even more specialized materials, avoiding corrosion and ensuring smooth operation.
When it comes to the solid/liquid separation stage in ZLD, crystal sizes and throughputs vary a lot from process to process. Hence, the equipment to be used must be selected carefully. The specialists from ANDRITZ assess your process requirements down to the last detail and recommend the best solution for your specific ZLD application.
The extensive ANDRITZ portfolio for ZLD includes pusher centrifuges, decanter centrifuges, and filter presses. All particle sizes typically found in ZLD processes can be covered with these three technologies. While continuous filtering centrifuges such as pusher centrifuges are typically the most economic and efficient choice for crystals with a median diameter of over 100 µm and containing only few fines, decanter centrifuges generally achieve the best result when median particles are in the range of 20 to 100 µm. For particle sizes smaller than 20 µm, filter presses are the best solution.
FRANÇOIS FEVRIER
Business Development Director Chemicals, ANDRITZ Separation
