Abstract: The invention provides a process for preparing a crystalline vanadyl sulphate/vanadous sulphate material, the process including the steps of providing a mixture of vanadium pentoxide (V2O5) and vanadium trioxide (V2O3); adding to the mixture a predetermined volume of a sulphuric acid solution to produce a powder slurry; and heating the slurry at a temperature and for a time sufficient to form a crystalline vanadyl sulphate/vanadous sulphate material. The invention extends to a process for preparing an electrolyte from such a crystalline vanadyl/vanadous sulphate material, including the steps of dissolving the crystalline material in boiling water and adding a stabilising agent, typically phosphoric acid, to stabilise the electrolyte.

Abstract: A method of recovering titanium dioxide from a titanium oxide bearing raw material, such as e.g. steel slags rich in TiO2 includes the steps of grinding the titanium dioxide raw material, reacting the particulate raw feed material with sulphuric acid under specified conditions, digesting and filtering the resultant cake material containing titanyl sulphate, hydrolysing the titanyl sulphate and, after washing the hydrolysate, calcining the hydrolysate to produce titanium dioxide.

Abstract: A method of recovering titanium dioxide from a raw material additionally containing aluminium includes the steps of grinding the titanium dioxide raw material, reacting the particulate raw feed material with sulphuric acid under specified conditions, digesting and filtering the resultant cake material containing titanyl sulphate, if present, treating the solution to remove calcium and/or iron, precipitating out the aluminium as aluminium ammonium sulphate, hydrolysing the remaining titanyl sulphate solution and, after washing the hydrolysate, calcining the hydrolysate to produce titanium dioxide.

Abstract: A process for producing a vanadyl sulphate solution (VOSO4) comprises forming a suspension of vanadium trioxide (V2O3) in a sulphuric acid solution and contacting the V2O3 suspension with a strong oxidising agent under controlled conditions to produce the VOSO4 solution. A preferred oxidising agent is hydrogen peroxide, which is added very slowly to the V2O3 suspension due to the violent nature of the reaction.

Abstract: A process for preparing a reconstituted vanadyl sulphate/vanadous sulphate solution for use as an electrolyte in a vanadium redox battery is disclosed. The process includes preparing a starting material including a vanadyl sulphate/vanadous sulphate solution, evaporating the starting material by applying heat to form vanadyl sulphate/vanadous sulphate crystals, and re-dissolving the vanadyl sulphate/vanadous sulphate crystals with a volume of de-ionized water to form a reconstituted vanadyl sulphate/vanadous sulphate solution having substantially the same chemical composition at the starting material. A process for preparing a vanadyl sulphate/vanadous sulphate starting material from a vanadium bearing ore material, particularly a titaniferous magnetite ore material is also disclosed.