Mineral Sands contain suites of minerals with high specific gravity known as Heavy Minerals (HM). Heavy mineral sands having more than specific gravity of 2.9 are placer deposits usually concentrated at beach environments by surf and longshore currents and at river sand bars by river wave action due to the specific gravity of the mineral grains. Heavy mineral deposits contain valuable heavy minerals.
The above image shows the process of HM concentrated at beach environment
Image showing HM concentrated at beach environment
Image showing HM concentrated at the fluvial environment (image taken from Everlast exploration site).
Titanium Feedstock (Ilmenite, rutile, Leucoxene) [Scientific name: Titanium Dioxide – TiO2]
TiO2 is easily the most significant white pigment in the world, with a very high refractive index, it has excellent reflectivity and brightness, it is insoluble in acids, solvents or air pollutants, has a high resistance to UV degradation. White Pigment is used, amongst other things, in paints and varnishes, print inks, plastics, rubber, linoleum, white paper, glass, enamel, and ceramics. Approx. 94 % of the titanium mineral extracted worldwide is used for the production of white pigments. TiO2 can also be part of the production of titanium used in modern aerospace components or as an aid in the stabilization of the electric arc used in welding rods.
Rutile is Titanium Dioxide in its natural form and Ilmenite, Leucoxene can be upgraded to form synthetic rutile through chemical processes.
Image showing Rutile Sand
Image showing Titanium feedstock under microscopic analysis
Zircon [Scientific name: Zirconium Silicate ZrSi04]
Approximately 53 % of the worldwide share of zircon is in finely ground form used in the ceramics industry. Zircon, once heated and baked, is an extremely hard, transparent substance. Typical areas of application are therefore glazes, sanitary ceramics, wall and floor tiles, china, earthenware, special porcelains, glazed tiles and industrial tiles. A small part of the zircon mined worldwide is used for the extraction of the metal zirconium.
Image showing Zircon Sand
Image showing Zircon under microscopic analysis
Other Mineral Sands
Garnet and Magnetite are in great abundance in Bangladesh. Garnet found in Bangladesh is mostly Almandine type. Garnet’s common uses are for abrasive materials such as sandpaper and sandblasting. Magnetite is also very common and can be mixed with Ilmenite to form Titanomagnetite to provide a feedstock for the production of steel.