Effect of the magnetic field on the growth rate of aragonite and the precipitation of CaCO3

Synergetic effects of temperature and magnetic field on the aragonite and calcite growth

“…The magnetic effects on the calcite growth were first investigated using a commercial MWTD with an intensity of 1800 Gauss (Tai et al, 2008a). The growth rates of calcite were reduced almost completely under low pH and supersaturation after the solution had been magnetized for 2 h. In contrast, the growth rates seemed to increase marginally at high pH and supersaturation in the transient period, but they were eventually reduced by an order after a long magnetization time of 20 h (Chang and Tai, 2010). From this, it seems that the magnetic field needs time to develop its effect on the reduction of calcite growth rate.…”

“…Then, two pieces of permanent magnets of different intensity were fixed on the suspended bed where the calcite crystals grew (Tai et al, 2008b). The calcite growth rate was lower than that without magnetization, and the magnet of higher intensity yielded a lower growth rate for the magnetization time below 1 h. The magnetic effects on the aragonite growth were further investigated using the MWTD and a permanent magnet of lower intensity (Chang and Tai, 2010). The magnetic effects on the aragonite growth were opposite those of calcite growth.…”

“…Recently, Tai et al (2008a,b) and Chang and Tai (2010) investigated the effect of a magnetic field on the growth rate of CaCO 3 polymorphs, calcite and aragonite, using the constant-composition method, which was able to control the solution variables at a steady state during an experimental run. In addition, each variable was able to be varied by keeping the others constant to see its interaction with the magnetic field.…”

Magnetic device simulation modelling and optimisation for scale control

“…Additionally, Lorentz-force action on electrically charged particles, ions, molecules and surfaces occurs when water is conducted through the magnetic field [16]. Much experimental research under well-controlled laboratory conditions [3,4,17,18] and field tests in real longterm conditions [19] were needed to determine the operational requirements that are essential for efficient scale control (Table I). An alternating magnetic field, orthogonal to the waterflow direction is more efficient.…”

“…Therefore, fouling is a frequent technological problem that requires proper scale-prevention treatment. The environmental and economic concerns that arise with traditional chemical treatments are strong motivation for the development of safer and cleaner physical methods, such as the application of permanent magnets [3][4][5][6], electromagnetic coils [7][8][9][10], electrodes [11], ultrasound [12] and catalytic metals [13]. Several operational parameters, e.g.…”