Effects of square-wave excited alternating magnetic fields on calcium carbonate crystallization and their application...

Elucidating how electromagnetic fields influence calcium carbonate crystallization is crucial for advancing electromagnetic scale inhibition technology. This study systematically investigates the effect of alternating magnetic fields (AMFs) generated by a wound electromagnetic processor under square wave voltage excitation on CaCO₃ crystallization through theoretical derivation, experimental exploration, and scale inhibition application. By establishing a mathematical model of magnetic flux density inside the processor and solving the current response of the excitation system under square wave voltage excitation, the magnetic flux density waveform was obtained. Based on this, three-dimensional trajectories of Ca²⁺ and CO₃²⁻ under Lorentz force were calculated, showing that Lorentz force increases ion collision frequency, enhances radial enrichment, and increases ion kinetic energy. Combined with classical nucleation theory (CNT), these effects synergistically promote CaCO₃ nucleation and growth in bulk solution. Magnetic treatment experiments using conductivity and pH as crystallization indicators confirmed that AMFs effectively promote CaCO₃ crystallization, with 1 kHz and 300 Gs showing the most significant effect within the experimental range. To validate the practical effectiveness of these parameters, electromagnetic scale inhibition experiments were further conducted, revealing through fouling resistance, XRD (X-ray Diffraction), and SEM (Scanning Electron Microscopy) analysis that magnetic treatment significantly reduces crystallization fouling on heat transfer surfaces. This study provides theoretical basis and experimental reference for optimizing electromagnetic scale inhibition parameters.