The invention relates to a process to increase the amount of TiCI₄ that is retrieved from a waste stream comprising one or more titanium (halo) (alk) oxides while also reducing the quantity and/or hazard of the resulting waste. Valuable solvents/diluents and/or alkyl halides that are introduced into or formed during the process can also be retrieved. The so obtained TiCI₄, solvents/diluents and/or alkyl halides are recyclable to, for instance, the process to make Ziegler-Natta catalysts and or co-catalysts.