The Versatile Mineral Ilmenite and its Wide Applications

Introduction

Ilmenite is a naturally occurring iron-titanium oxide mineral which is black in color. Chemically, it is an iron(II) titanium oxide with the chemical formula FeTiO3. It crystallizes in the trigonal-hexagonal system and its crystal structure is rutile-type. This makes up about 1% of the Earth's crust and is one of the most abundantiron-bearing minerals.

Formation and Occurrence

This forms via igneous and metamorphic processes. During the cooling of basaltic magma, this separates out as accessory mineral along with pyroxene, olivine and magnetite. It is commonly found in basic and ultrabasic igneous rocks like basalt, gabbro and kimberlite. Metamorphic develops as a result of alteration of pre-existing iron-titanium minerals like titanomagnetite or titaniferous magnetite under high temperature and pressure conditions.

The major countries with significant ilmenite reserves include Australia, South Africa, Canada, India, Ukraine and Norway. Australia has some of the largest deposits in the world located in Western Australia. In India, this deposits occur mainly in coastal beach sands of Kerala, Tamil Nadu and Orissa states. Other important sources are in Kenya, Mozambique, South America and Western Greenland.

Uses of Ilmenite

Titanium dioxide pigment

The primary use of this is in the production of titanium dioxide pigment which imparts whiteness and opacity to paints, plastics, paper and other materials. Around 95% of the mined material goes into manufacturing titanium dioxide either via the chloride process or the sulfate process. Titanium dioxide pigment has become integral to modern life being used across multiple industries.

Welding rods

This finds application as a feedstock in manufacturing of welding rods. During production of welding electrodes, this is reduced to metallic titanium which acts as an alloying element in steel-based welding rods. The titanium improves ductility, strength and corrosion resistance properties of the welding wires.

Titanium metal and welding alloys

Fine grained material concentrate can also be directly utilized to extract pure titanium sponge through various pyrometallurgical or hydrometallurgical processes. The titanium sponge serves as the raw material for further reprocessing into high-strength titanium alloys and components. Common titanium alloys containing ilmenite-derived titanium find widespread applications across aerospace and medical industries.

Ceramic glazes and colors

This finds some niche usage in manufacturing ceramic glazes and colors due to its opacity and coloration properties. Very finely ground material is added to ceramic slips, engobes or glazes to impart different colored effects during firing. The iron content determines the ultimate color which can range from black, brown to reddish-gray tones.

Production Trends and Challenges

According to the US Geological Survey, world production in 2020 was around 5.8 million tonnes with Australia, China and India being the top three producers. The titanium dioxide pigment sector is the major demand driver for mining worldwide. However, over the years,availability of high-grade resources has declined while reserves have become more dispersed, remote and harder to access. Environmental regulations around mining and processing have also become more stringent. Rising production costs along with fluctuating titanium dioxide market prices pose certain economic challenges for mining companies. Technological innovations and efficient resource utilization hold the key to sustainable long term supply of this important mineral to key global industries in future.

In summary, ilmenite is a valuable iron-titanium oxide mineral that serves as raw material for various titanium based products consumed extensively across modern civilization. While titanium dioxide pigment remains the dominant end-use, other applications like welding alloys and titanium metal extraction add to it's strategic significance. Though challenges persist, continual improvements are helping establish responsible and resilient supply chains for industries globally.