Effect of electric field and Mg²⁺ doping on calcium carbonate scaling shown in experiments and first principle calculations

The effect of an applied electric field and Mg2+ doping on the formation of calcium carbonate scale in circulating cooling water was investigated by using a home-made experimental device, which can simulate the formation of scale in a local power plant. The results show that high-voltage electrostatic fields and magnesium ions can inhibit scale growth in circulating cooling water. When the magnesium ion concentration is 4 mmol/L, the scale inhibition effect is the best under the action of the electric field (6 kV), and its scale inhibition rate can reach 44.56%. Meanwhile, some phenomena are explained and confirmed by the results of first principle calculations. The calculated shear modulus of aragonite is greater than that of calcite. This might explain why aragonite adheres more easily to the heat exchange surface. This is in good agreement with experimental results. Calcite has better anti-scaling properties than aragonite. The crystal structure after physical water treatment is blunt, and the untreated crystal structure is sharp.