Chemical Composition of Ilmenite Around The World
Under the current technical and economic conditions, the titanium resources with mining and utilization value are mainly ilmenite and rutile, of which about 85% to 90% are ilmenite. Ilmenite is a hexagonal crystal system with a metallic luster, good electrical conductivity, and a specific magnetization coefficient of 3.16×10-7 m3/kg. It is a weak magnetic mineral. Its molecular formula is FeTiO3 (also expressed as FeO·TiO2), and the theoretical content (mass fraction) of TiO2 is 52.63%. The iron and titanium content in ilmenite of different origin are different. The chemical composition of ilmenite around the world is shown in the table below.
Ilmenite is divided into rock ore and placer ore. The TiO2 grade of titanium concentrate selected from rock ore is generally 42% to 48%, while the TiO2 grade of titanium concentrate selected from placer ore can exceed 50%. According to data released by the United States Geological Survey (USGS), the world's ilmenite reserves are about 600 million tons (in terms of TiO2), and the basic reserves are about 1.2 billion tons.
China's ilmenite reserves are about 200 million tons, ranking first in the world, of which primary ore accounts for about 97%, mainly vanadium-titanium magnetite, mainly distributed in Panxi Region, Chengde, Hebei, Xingning, Guangdong, etc.; Placer ore is mainly distributed in Hainan, Yunnan, Guangdong, Guangxi, etc., with scattered ore sites, small scale, low grade characteristics.
Ilmenite is currently the most important titanium ore resource. At present, ilmenite is mainly used as the raw material for titanium dioxide by direct sulfuric acid method, but this process will produce a large amount of ferrous sulfate salt, causing great environmental pressure and wasting a lot of iron resources. In order to make full use of the iron in ilmenite, many smelters use ilmenite as raw material for electric furnace smelting to obtain pig iron and high titanium slag, which can be used as raw materials for the production of titanium dioxide by sulfuric acid or chlorination.
