Surfactant-assisted synthesis of pure calcium carbonate nanoparticles from Sri Lankan dolomite

Abstract

Sri Lanka is rich in extensive deposits of dolomitic
marbles with large quantities, which have not yet been exploited
on an industrial-scale to produce value-added products such as
precipitated calcium carbonate (PCC) nanoparticles. PCC is
used extensively and is imported by Sri Lankan industries for
application as a filler and extender. Hence, this work attempts
to examine Sri Lankan impure dolomitic marbles as a source
for the synthesis of pure PCC nanoparticles, so as to fulfill the
current industrial demand and to add value to the cheap and
mundane marbles. As reported in this paper, the calcium (Ca)
components of the marbles can be extracted from impurities
by preparing solutions of saturated calcium hydroxide, calcium
citrate, Ca2+
-ethylenediaminetetraacetic acid complexes and
calcium sucrate, separately from dolomite. PCC nanoparticles
are then synthesized by adding sodium carbonate to each
calcium extract. The results shows that the best extract to
synthesize PCC nanoparticles with high yield and purity is
calcium sucrate. Here, calcium sucrate has been used for
surfactant assisted hydrothermal synthesis of PCC nanoparticles
with particle sizes ranging from 38.9 − 51.6 nm, which is a
novel effort. This method could be applied to manufacture PCC
nanoparticles on an industrial-scale.