Process for upgrading a titaniferous material containing silica

Abstract

An industrially realistic process for upgrading of titaniferous materials is disclosed. The process comprises the following steps: (i) a pretreatment which has the effect of rendering silica amenable to leaching under the particular conditions of a subsequent leach, and (ii) an aqueous leach in the presence of an acid, the conditions of which are chosen such that silica which enters solution is not hydrolysed or precipitated as a silicate. The pretreatment step (i) may comprise alkaline leaching, roasting or smelting. The leaching step (ii) may be conducted at low solids densities.

1 . An industrially realistic process for upgrading of titaniferous materials, which process comprises the following steps: 
 (i) a pretreatment which has the effect of rendering silica amenable to leaching under the particular conditions of a subsequent leach, and    (ii) an aqueous leach in the presence of an acid, the conditions of which are chosen such that silica which enters solution is not hydrolysed or precipitated as a silicate.    
     
     
         2 . The process defined in  claim 1  wherein the is pretreatment step (i) comprises alkaline leaching the titaniferous material which has the effect of converting silica to amorphous or crystalline silicates.  
     
     
         3 . The process defined in  claim 1  or  claim 2  wherein the pretreatment step (i) comprises roasting the titaniferous material, with or without an additive, which has the effect in roasting of converting contained silica to silicates or transferring silica into a glassy phase.  
     
     
         4 . The process defined in  claim 2  or  claim 3  wherein the pretreatment step (i) comprises smelting the titaniferous material to make a titaniferous slag.  
     
     
         5 . The process defined in any one of the preceding claims wherein the acid of the leach step (ii) comprises any one of hydrochloric acid, sulphuric acid, an organic acid, and sulphurous acid.  
     
     
         6 . The process defined in any one of the preceding claims which comprises conducting the leached step (ii) at low solids densities.