Effects of Desilication Conditions on the Formation of Wollastonite during the Autoclave Leaching of Silica–Titanium Concentrates

Abstract

The dissolution of quartz during the hydrometallurgical desilication of silica–titanium concentrates from Pizhemskoe field (Komi Republic) was studied. The concentrate desilication occurs in the CaO–SiO₂–Na₂O–H₂O system due to the binding of silica into calcium silicate hydrate, in particular, into CaO·SiO₂·nH₂O. The main factors (temperature, duration, CaO : SiO₂ ratio, NaOH content) governing the extent of concentrate desilication and crystallization of wollastonite from calcium silicate hydrates resulting from the reaction were determined.