Rare Earth Magnets and Limescale: Analysis of Magnetic Water Treatment Using a Dynamic Scale Rig

Treatment of limescale build-up in process-and municipal pipes by magnetic water treatment has been a topic of research for decades. However, there is no realistic mechanistic hypothesis as to why such treatments would be effective. Therefore, a test regime was established to explore scale inhibition by means of magnetic forces in a robust and reproducible manner. In this study, two magnetic devices were developed using Neodymium-based rare earth magnets for the application of static magnetic fields. One device, based on a Halbach array, is designed to test high-intensity (965 mT) magnetic fields. The other is based on a Halbach trap arrangement, designed to test high magnetic field gradients (490 mT, 82.5 T/m). The precipitation reactions of calcium carbonate, calcium sulfate, and calcium phosphate were monitored in real-time to determine the effectiveness of these devices for inhibiting scale. No magnetic treatment effects were observed.

Automated summary

There is no mechanistic hypothesis as to why magnetic water treatment is effective in inhibiting limescale build-up in process-and municipal pipes. Two magnetic devices were developed and tested, but no effects of magnetic treatment on scale inhibition were observed.