Ilmenite: An Important Mineral For Titanium Dioxide Production

It is a weakly magnetic mineral that contains iron, titanium, and oxygen. Its chemical formula is FeTiO3 and it crystallizes in the trigonal system. Its usually contains around 50-65% titanium dioxide and ranges between 35-49% iron(II) oxide. Trace amounts of other elements like magnesium, manganese, chromium are also sometimes present in the mineral. Ilmenite has a black to steel-gray color and its hardness on the Mohs scale ranges between 5-6.5. It has a submetallic to dull luster and leaves a brown streak.

Occurrence and Deposits

It is one of the most abundant titaniferous minerals found on Earth. It occurs in igneous and metamorphic rocks as well as in some sedimentary deposits formed by erosional processes. Some of the major occurrences of ilmenite deposits include Australia, South Africa, Canada, Norway, India, Ukraine, Russia and the United States. Australia has some of the largest deposits in the world located in Western Australia. Its deposits often form placers and heavy mineral sands near ancient or contemporary coastlines. Alluvial deposits concentrated by ocean currents and wave actions have also produced many ilmenite accumulations over geologic time.

Uses and Application

It is primarily used for the production of titanium dioxide which possesses valuable properties like brightness, high refractive index and stability under light exposure. Around 95% of the mined element is processed to obtain titanium dioxide, which is used extensively as a white pigment in paints, paper, plastics, textiles, ceramics, floor coverings etc. Titanium dioxide has superior opacity and hiding power compared to other white pigments like zinc oxide and lead carbonate. It is also used as a reinforcing agent in laminates, abrasives and welding rods. Ilmenite can be transformed into titanium tetrachloride or titanium sponge - important intermediates needed for the manufacturing of titanium metal. Due to its magnetite content, it also finds applications as an important source of iron.

Mining and Processing

Ilmenite deposits are mined through conventional open-pit mining methods. Overburden and waste rock are first removed to expose the ore bodies. Heavy mining equipment like excavators and haul trucks are used to extract and transport the run-of-mine ore rocks. The mined element is crushed and ground to liberate individual mineral grains before being concentrated through gravity or magnetic separation techniques. This results in an upgraded ilmenite concentrate ranging between 55-65% TiO2. The concentrate is then subjected to various pyrometallurgical processes to convert it into usable materials. The sulfate process and chloride processes are commonly used for transforming the concentrate into synthetic rutile, titanium slag or titanium tetrachloride respectively. These intermediates serve as feedstock for various titanium products worldwide.

Market Dynamics and Industry Trends

The global market was valued at around USD 2.5 billion in 2020 and has been growing steadily. China, India and Japan are the leading consumers of ilmenite due to large-scale paint, plastic and paper manufacturing industries prevalent in these countries. China alone accounts for more than 40% of the total global demand. Rising population and economic growth in Asia Pacific are projected to elevate its consumption in the coming decade. Tightening environmental regulations regarding the use of lead and other toxic pigments will also boost demand for titanium dioxide pigments produced from it. New mining projects coupled with advancement of mining and processing methods are helping to augment global ilmenite supplies.