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.

 
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> Process for scrubbing ammonia from acid gases comprising ammonia and hydrogen sulfide

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