Abstract
D.Phil. (Chemistry)
The formation ofcalcium carbonate scale is a major problem in industry as well as in households.
The scale that forms acts as an insulator, decreasing the effectiveness ofheat exchangers, be it a
water cooling systems or a water heating system This raises the energy costs ofthat company
and the costs of cleaning are expensive. Physical water treatment has been used for at least 50
years in the treatment ofwater with scale forming potential to reduce the formation ofthis scale.
In thisthesis, tests were made on a magnetic and constantelectric field antiscaling device on the
effect they have, ifany, on CaC03 scale formation. An attempt will be made to give a mechanism
for any effect found. It is hoped that a contribution is made by this research in clearing up the
misconceptions that abound in this controversial field ofphysical water treatment.
Water with a high calcium bicarbonate content was exposed to the antiscaling devices and then
calcium carbonate was forced to precipitate out ofsolution. This precipitation was followed by
meauring the pH and the crystal structure ofthe precipitated calcium carbonate was studied.
The most important results were that by exposing the calcium bicarbonate solution to an
antiscalingdevice, the start ofprecipitation ofthe calcium carbonate was significantly delayed and
the crystal structure of the calcium carbonate that formed was predominantly aragonite as
opposed to calcite that usually formed.