Study of One Sort of Romanian Diatomite as Precursor in the Synthesis of Some Metallic Silicates

The behaviour of one sort of Romanian diatomite as precursor in the synthesis of calcium and magnesium silicates was studied. The calcination of this diatomite, 3 h at 10000C in air, does not produce major modifications in structure and composition. In the same conditions, the thermal reaction between diatomite and calcium carbonate leads to a mixture of calcium silicates (CaSiO3, Ca2SiO4, Ca3SiO5) whereas the reaction product with magnesium oxide is orthomagnesium silicate (Mg2SiO4 - forsterite). This sort of Romanian diatomite can play the same role as other silica sources in the synthesis of alkaline-earth silicates.