Metal Hydroxide Sludge Drying

Large quantities of metal hydroxide sludge are generated during the treatment of galvanic and metal-processing wastewater. Its disposal is complex, as it often still contains high water content. Metal hydroxide sludge drying with HARTER heat pump technology significantly reduces this volume – cleanly, energy-efficiently, and reliably. The process operates exhaust-free and independently of environmental influences, reducing disposal costs while increasing process reliability.

Learn how HARTER develops custom-tailored systems in: How Heat Pump Dryer Solutions are Created.
A technical overview is provided in: Energy-Saving Drying with Heat Pumps.

After filtration or chamber filter pressing, metal hydroxide sludge often still contains 50 – 70% water. This moisture content is too high for transport, landfill, or recycling. HARTER heat pump drying gently and reproducibly removes residual water from the sludge – at low temperatures between 30 °C and 75 °C.

The system operates in a closed air circuit:

• The air is dehumidified, heated, and recirculated over the material.
• Moisture condenses, energy is recovered.

This creates a constant process without exhaust air, which does not burden the environment with odors or pollutants.

Your Benefits:

• significant volume and weight reduction,
• up to 70% energy savings compared to hot air systems,
• exhaust-free, clean drying,
• constant residual moisture levels through precise control,
• low-maintenance, durable technology.

How this technology can increase capacities is shown in Expanding Capacities with Heat Pump Dryers.

HARTER drying is suitable for various industrial sectors with sludge and residue accumulation:

• Electroplating and Surface Technology
• Metal Processing, Grinding, and Polishing Processes
• Chemical Industry and Pigment Production
• Recycling and Waste Treatment Plants

The systems have a modular design and can be flexibly integrated into existing dewatering lines – directly after the chamber filter press or centrifuge. The drying process takes place in closed stainless steel chambers, ensuring no contact with the environment. Temperature, air volume, and humidity are continuously monitored and documented.

Before each series design, HARTER tests your original sludge in its in-house technical center. There, the optimal parameters for air guidance, temperature, and drying time are determined. The result is a robust process with clearly defined residual moisture values – ideal for subsequent disposal or further processing.

We dry with dry air and deliver it to the right places: A perfect interplay of air preparation and air guidance provides you with the best possible drying result.

Dewatering with HARTER systems makes an important contribution to environmental protection and cost reduction. Due to heat recovery in the closed circuit, energy consumption remains extremely low. Since no exhaust air is generated, the need for exhaust air purification or filter systems is also eliminated.

Sustainable advantages:

• Reduction of CO₂ emissions through energy savings
• lower disposal and transport costs
• no odor or dust pollution
• stable process conditions for consistent quality
• eligible technology due to high efficiency

HARTER values durability and easy maintenance. All systems are made of high-quality materials and designed for continuous operation.
Many customers combine drying with heat recovery or photovoltaics to further reduce their ecological footprint.

Further information on related applications can be found under Industries.