A new method for the study of calcium carbonate growth on steel surfaces

The growth of calcium carbonate crystals on a steel surface, known as scaling, has been investigated. A heat exchanger cell was built for this purpose, and the crystals formed on the surface were examined in a scanning electron microscope. Two surface active polymers with a diphosphate end group, differing in hydrophobic/hydrophilic ratio, were synthesized. The effect on crystal formation of addition of these polymers was studied. Both polymers decreased the amount of calcium carbonate deposition on the surface. When the experiment started at low pH the polymers promoted the formation of very symmetrical spheres of calcium carbonate, ranging from 1 to 10 μm in size. When the experiment was started at neutral pH only amorphous calcium carbonate was obtained on the steel surface.