Australia - Brazil - Canada - India - Kenya - Madagascar - Mozambique - Senegal - Sierra Leone - South Africa -  Sri Lanka - Vietnam

Heavy mineral sands are an important source of zirconium, titanium, and rare-earth elements. They are placer deposits formed usually in beach environments by concentration due to the specific gravity of the mineral grains. It is also likely that some concentrations of heavy minerals exist within streambeds, but most are of a low grade and are relatively small.

Zirconium

Zirconium has a concentration of about 130 mg/kg within the Earth's crust. It is not found in nature as a native metal, reflecting its intrinsic instability with respect to water. The principal commercial source of zirconium is zircon (ZrSiO4), a silicate mineral.

Zircon (ZrSiO4)

Specific gravity 4.6 - 4.7

Hardness (Mohs hardness scale): 7.5

A lustrous crystal of zircon perched on a tan matrix of calcite from the Gilgit District of Pakistan

World production trend of zirconium mineral concentrates

Zircon is mainly consumed as an opacifier and used in the decorative ceramics industry. It is also the principal precursor, not only to metallic zirconium, although this application is small, but also to all compounds of zirconium including zirconium dioxide (ZrO2), one of the most refractory materials known. Other applications include use in refractories and foundry casting and a growing array of specialty applications as zirconia and zirconium chemicals, including in nuclear fuel rods, catalytic fuel converters and in water and air purification systems.

Titanium

Titanium occurs within a number of mineral deposits, principally as the minerals rutile (TiO₂) and ilmenite (FeTiO₃)_, which are widely distributed in the Earth's crust.

Rutile (TiO₂)

Specific gravity 4.23 increasing with Nb -Ta content

Hardness 6.0 - 6.5

Ilmenite (FeTiO₃)
Specific gravity 4.70 – 4.79

Hardness 5 - 6

Ilmenite is the primary ore of titanium, a metal needed to make a variety of high-performance alloys.  Most of the ilmenite mined worldwide is used to manufacture titanium dioxide, TiO₂, an important pigment, whiting, and polishing abrasive. Leucoxene is a fine, granular alteration product of titanium minerals. Leucoxene is formed through extensive weathering of ilmenite which removes iron and increases the titanium content of the mineral grains. Although it is not a recognized mineral species, the name leucoxene has been applied to products with a Ti0₂ titanium content ranging from 70% to 93%.

Titanium minerals or titaniferous (TiO₂-containing) feedstocks are principally driven by demand for titanium dioxide (TiO₂) pigment which is used in applications such as paint, plastics, paper and inks amongst others. In 2015 the TiO₂ pigment market accounted for 83% of titanium mineral demand, while other end-uses include titanium metal, abrasive, welding rods and metallurgical fluxes.

There has been a changing landscape for titanium minerals supply over the last five years, with a significant rise in production of ilmenite in China to feed its domestic sulphate route TiO₂pigment manufacture. Elsewhere new sources of supply have some on stream which have shifted traditional trade patterns.

The five largest titanium minerals suppliers control nearly half of global feedstock production and include Cristal, Iluka, Rio Tinto, TiZir, and Tronox. Since a shortfall in supply in 2011 and subsequent price spike, producers have since faced mounting inventories. From 2013, major producers including Rio Tinto and Iluka, and others have curtailed production, but the overall supply deficit has been outweighed by a substantial supply surplus of ilmenite which has dampened prices.

Looking out to 2025, there are expansion plans from existing producers as well as new projects are in the pipeline, although some will face headwinds in the current economic climate. Chinese producers are actively investigating overseas resources to supplement supply and it is likely that exports to China will rise again in the medium term.

There have also been a significant number of mergers and acquisitions in the TiO₂ pigment industry, as well as capacity expansions in China, and latterly rationalisation in the form of plant closures, which are reshaping the industry. The paint industry remains the most important market for TiO₂ pigment, accounting for 55% of consumption in 2015. Meanwhile, the paper industry remains important but consumption has shifted into specific sectors such as coated folding boxboard and décor paper for decorative laminates.

The titanium minerals industry is evolving to supply TiO₂ pigment production, will which will shift further towards using more chloride route production over the next ten years. The underlying growth rates for TiO₂ pigment and titanium metal will ensure continued demand for titanium minerals.

Rare Earths

Monazite(Ce, La, Nd, ThPO₄) 
Specific gravity 4.6 – 5.7 (4.98 – 5.43 for monazite-Ce)

Hardness 5.0 - 5.5

Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in placer deposits. India, Madagascar, and South Africa have large deposits of monazite sands. The deposits in India are particularly rich in monazite.

Garnet

Garnet (Mg3Al2(SiO4)3, Mn2+3Al2(SiO4)3)

Specific gravity 3.1 – 4.3

Hardness 6.5 - 7.5

Garnet sand is a good abrasive, and a common replacement for silica sand in sandblasting. Alluvial garnet grains which are rounder are more suitable for such blasting treatments.

References

Rozendaal, A, Philander, C., Heyn, R; The coastal heavy mineral sand deposits of Africa 

Tyler, R.M. and Minnitt†, R.C.A., A review of sub-Saharan heavy mineral sand deposits: implications for new projects in southern Africa