Titanium

Titanium

Titanium (Ti) is a metallic element estimated to form about 0.5% of the rocks of the Canadian SHIELD. Titanium minerals of commercial importance include the dioxides rutile and anatase, which are polymorphs of TiO₂ and ilmenite (FeO.TiO₂), a mineral that contains 52.7% TiO₂. When titanium is heated, it ignites and burns in air and is the only element that will burn in nitrogen. About 90% of titanium mineral production is used to make titanium dioxide pigments, 60% of which are used in the paint industry. In Canada, all facets of the industry are carried out in Québec. QIT-Fer et Titane Inc mines 3 million t per year of ilmenite at Havre St-Pierre, of which over 1 million t is smelted in electric furnaces at Tracy.

The smelted product, Sorelslag, contains 80% titanium dioxide; 900 000 t are produced annually, most of which are exported, mainly to the US and Europe. The balance is sold mostly to Kronos, a subsidiary of NL Chemicals, a producer of titanium pigments with a plant at Varennes, Québec. Most titanium pigments are obtained through the sulphate process, in which finely crushed and concentrated ilmenite (minimum 44% TiO₂) or titanium slag (75-80% TiO₂) is dissolved by sulphuric acid to yield titanyl sulphate (TiOSO₄) and hydrated ferrous sulphate. TiOSO₄ is clarified, filtered and dried to yield TiO₂, while hydrated ferrous sulphate is discarded. Another process involves reacting rutile with gaseous chlorine. The product (TiCl₄) is then reacted with oxygen to yield TiO₂. Most new plants use the chlorine process. Titanium metal and its alloys are light and have very high tensile strength, even at high temperatures. Titanium metal is not produced in Canada.