Dissolution Kinetics Of CaCO3 In Common Laboratory Solvents

Abstract

ABsrp~cr: The dissolution of calcium carbonate with both organic and aqueous solvents was examined quantitatively and kinefically. Neither ethanol and nor acetone at 25°C dissolved appreciable aragonite or calcite, even after nearly ten days. Bleach (sodium hypochlorite) was a much less effective solvent than deionized water, producing little or no net calcium in solutions in contact with calcium carbonate. Although exposure to sodium hydroxide solutions also yielded relatively small concentrations of calcium in the fluid, characterization of the exposed carbonate grains by X-ray powder diffraction and by light microscopy revealed extensive replacement of the CaCO3 by Ca(OH)2, calcium hydroxide (portlandite). A solution of Aleonox@, a commercial laboratory anionic detergent, was about half again as potent as deionized water, and hydrogen peroxide proved to be many times more corrosive of calcium carbonate than deionized water.These results are consistent with published and anecdotal observations of the effects of laboratory preparation protocols on calcium carbonate. Our quantitative data permit the researcher to assess the potential for a treatment procedure using any of these solutions to compromise the integrity of a sample of calcium carbonate.

Microstructural and Mechanical Characteristics of Alkali-Activated Binders Composed of Milled Fly Ash and Granulated Blast Furnace Slag with µ-Limestone Addition

“…It was found that there was a reaction between the activating solution and the addition of limestone, this addition mineral being one more ingredient for the effective activation of the binary compounds (slag and fly ash). This analysis coincides with the studies of Nicholas E. Pingitore et al [ 104 ] on the dissolution of calcium carbonate in a sodium hydroxide (NaOH).…”

“…Nicholas E. Pingitore et al [ 104 ] analyzed CaCO 3 (aragonite and calcite mineralogic phases) activation in a Na(OH) solution using fine (62 to 125 μm in size) and coarse (250 to 500 μm in size) lime particles. They found CaCO 3 in any mineralogical phase dissolved in calcium hydroxide-Ca(OH) 2 .…”

The method of cleaning and modification of the material for bone xenografts in bi-phase media containing high pressure CO2

“…Отсутствие карбоната кальция в костном экстракте, полученном из растворов пероксиугольной кислоты под высоким давлением СО 2 , можно объяснить следующим образом. Известно, что карбонат кальция слабо растворим в воде, но лучше растворяется в присутствии перекиси водорода благодаря более низким значениям рН и более высоким значениям диэлектрической проницаемости [14]. Поэтому в отсутствие перекиси водорода можно ожидать более выраженного роста диспергированных кристаллических частиц карбоната кальция по мере растворения исходного гидроксилапатита кости в процессе экспозиции.…”