Parameters determining the deposition of calcium carbonate into a glass capillary

Abstract

The deposition in situ of calcium carbonate inside glass capillaries was studied as a function of the temperature, the flow rate of the solutions, the concentration ratio of calcium and carbonate ions, the capillary radii, and the solution volumes which flowed through the capillary. Calcium carbonate was precipitated just before the inlet to the capillary from sodium carbonate and calcium chloride solutions. Two series of experiments were conducted in two separate laboratories, and despite the difference in relative depositions, some common features of the deposition process were found. Thus, maximum deposition occurred around 65 ° C. There were optimum flow rates, 0.60-0.80 ml/s, of the solutions for maximum deposition to occur. The deposition was very sensitive to the concentration ratio of calcium and carbonate ions. For example, the deposition at a ratio 5:1 (calcium to carbonate ion concentration) was more than twice that for an equimolar 1:1 ratio of the ions. The results indicate that the depositio...