Diffusion dialysis using spiral membrane modules:
An economic and sustainable alternative for the recovery of free acid or dissolved metals.
Strong performance
Extremely high acid recovery rates during a continuous process for metal purge lead to minimised purge and waste water amounts. In anodising plants purge treatment with spiral membrane modules achieves acid recovery up to 95% with less than 5% of aluminium recycling.
Environmental benefits
Extremely high acid recovery. Signifi cant reduction of waste water > 30 % compared to competing processes.
Simple operation
Diffusion dialysis is a conti-nuous and stationary process without reversing valves. Due to the design a flexible configura-tion of the system is possible. Up grade to a fully automatic process for bath stabilisation can be done with minor efforts. scale up by simple parallel connection of modules. Quick and easy module change.
Low investment And operAting cost
The patented design of the spi ral membrane module leads to competitive prices for our customers. In addition this design enables a simple and low cost process realisation.
Operating costs:
Due to the continuous and stationary process flow, only a minimal amount of water is required. The regenerated acid can be reused in the bath. Substitution of exhausted modules requires only a fraction of the costs compared to the membrane modules used today for bath care.

《Product working principle demonstration》

Diffusion dialysis basics
Diffusion dialysis is a membrane separation process, all known membrane separation processes have been successfully implemented industrially with the conversion from a flat geometry into a hollow fiber / tube geometry. Examples are reverse osmosis, ultra-filtration, gas separation and haemodialysis. The process is based on two counter-current flo-wing fluids which are separated by a semipermeable membrane. In general mass transfer takes place from concen-trated to diluted fluids reaching an equilibrium. By using a membrane with selected properties, cer-tain components are retained by the membrane and desired components can diffuse into the diluted so-lution.

《Demonstration of diffusion dialysis》

《Quality assurance agreement》

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