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Titanium dioxide is the most common titanium-containing product on the world market, with increasing demand. The global consumption of TiO2 is 7–7.5 million tons annually. Titanium dioxide is mainly obtained from ilmenite and rutile concentrates. China, USA, Germany, UK, Mexico, and Saudi Arabia are the largest TiO2 producers. Alongside with the natural sources of titanium, there are man-made sources. These sources include titanium-containing slag obtained as a result of pyrometallurgical processing of ores and concentrates containing titanium dioxide. These slags, in addition to titanium dioxide, contain silicon in the form of dioxide, silicates or aluminosilicates, whose chemical processing is difficult due to a high melting point thereof (higher than 2000°C) and to their chemical stability in mineral acids (sulfuric, nitric, hydrochloric ones). Processing of such raw materials is carried out by classical chlorine-based and sulfuric-acid-based methods. The fluorides in industry are used in the production of aluminum, zirconium, uranium, beryllium, niobium, etc., which indicates the possibility of using fluoride methods for titanium slag processing. The paper is devoted to the consideration of a method for producing titanium dioxide based on the use of ammonium hydrodifluoride NH4HF2 that exhibits a high reactivity with respect to a number of chemically resistant oxides (the oxides of silicon, titanium, aluminum, etc.). The fluoroammonium method for processing titanium slag using NH4HF2 involves slag decomposition in NH4HF2 melt followed by the sublimation of silicon admixture. The purification from iron, aluminum and other impurities is performed using a solution of NH4HF2. The further precipitation of titanium followed by the precipitate treatment with the use of AlCl3 and ZnCl2 solutions with the subsequent calcination makes it possible to obtain a rutile modification of titanium dioxide.