In the Republic of Moldova are valuable mineral deposits - alumosilicate,silicates and
carbonates, etc., which are used in the national economy as a raw material for construction (lime,
cement, mixtures for finishing - parget for the walls). However, less they are used as filter
material. The problem, first of all, consists in the necessity in they nprepapation according to
certain technologies, which requires additional expenses. A disadvantage of these materials is
the fact that they have not a mechanical strength sufficient for use in adsorption columns. But
they are widespread across in the country [1,2], as well a through their relatively low cost, they
can stimulate research in the search for solutions to improve the physicochemical properties and
enlarging of their applications. The purposem of this work was to obtain a granular diatomite
adsorbent having adsorptive properties and mechanical strength enough to be used for
purification of the wastewaters of industrial enterprises. As raw materials were used Ghidirim
diatomite, calcium carbonate and sodium silicate. As added to obtain the required density for
granulation of mineral mixture the water was used. In order to form a porous structure of the
sorbents, and to strengthening they grains,, the samples were calcined at 850 ° C. Structural
particularities of adsorbents were studied using the installation Autosorb with nitrogen as
adsorbate. Structural and sorptional characteristics of the obtained samples are shown in the
table.
Table 1. Sorbţionale structural characteristics of the adsorbent samples

References:
[1] Maftuleac, A.; Rusu, V.; Bolotin, O.; Petuhov, O. The mineral composition and
physicochemical properties of certain samples (natural and modified) of the Ghidirim
diatomite. In: Bull. Inst. Geol. Seismol. Acad. Sci. of Moldova, 2009, Nr. 2, 49-56 (In
Romanian).
[2] Rusu, V.; Vrînceanu, A.; Polevoi, I. Composition of mineral phases of the Ghidirim
diatomite. In: Chem. J. of Moldova, 2007, V. 2, Nr. 1, 63-66.