Hydrochloric Acidic Processing of Titanite Ore to Produce a Synthetic Analogue of Korobitsynite

Abstract

The modal composition of (apatite)-nepheline-titanite ore and its geological setting within apatite deposits of the Khibiny Massif allow selective mining of titanite ore and its hydrochloric acidic processing. The reaction of titanite with concentrated hydrochloric acid produces hydrated titanosilicate precipitate (TSP) which, in turn, can be a precursor in titanosilicate synthesis. It is particularly noteworthy that a synthetic analogue of korobitsynite, Na5(Ti3Nb)[Si4O12]2O2(OH)2·7H2O, was synthesized by means of TSP alteration by alkaline hydrothermal solution at 200 °C within three days. The titanosilicate obtained this way has comparatively weak cation-exchange properties regarding Cs+ and Sr2+ cations and considerable photocatalytic activity occurring under visible light, which allows the use of a synthetic korobitsynite analogue (SKR) for production of self-cleaning, sterilizing, and anti-fouling building materials.

Crystal chemistry of ivanyukite-group minerals, A3–xH1+x[Ti4O4(SiO4)3](H2O)n (A = Na, K, Cu), (n = 6–9, x = 0–2): crystal structures, ion-exchange, chemical evolution

“…All the mineral species that served as prototypes of synthetic materials were first discovered in the Khibiny or Lovozero alkaline massifs of Kola Peninsula, Russia. Less well known and less studied in chemistry are minerals of the lovozerite group (tisinalite), hilairite group (pyatenkoite-(Y)), and labuntsovite group that also have pronounced ion-exchange and photocatalytic properties (Chukanov and Pekov, 2005; Gerasimova et al , 2019).…”