Hafnium Mining

Hafnium is a metal found in both land and water of the earth's crust. Hafnium is very much identical to zirconium and found in all of its composites.

Ore:

The principal ore of hafnium is zircon. Zircon consists about 1% to 4% of hafnium with it. Zircon is occurs in the ores of titanium such as ilmenite and rutile. It can also be found on alluvial deposits and beaches which are now the largest contributors of zircon for commercial production of hafnium.

Mining:

The zircon is a byproduct of ilmenite and rutile which are mined by open pit mining. The initial process of open pit mining is checking the surface, ore's quality, distribution and the surrounding area for environmental hazards. After confirming the needed requirements from the checked factors, the mine or quarry is established. The mines are dug as steps of walls with benches and in-pit ramps for locomotion.

The miners, machineries, goods truck and wastes are transported in the ramps. The mines are often round for a deeper excavation. Miners handle drilling and blasting for the extraction of ore in the mines. The ores collected are transported by trucks to the nearby processing plant. The processing plants are usually built near the mines. The collected ilmenite and rutile ores are mostly heavier and larger in size. The open pit mining is much profitable than other mining techniques as it is less expensive, less dangerous and an easy shut-down.

The zircons on the alluvial deposits and beach sands are mined by dry mining methods using the excavators and scrappers. The scrappers remove the surface dirt from the deposits and also collect the zircon ores. The excavators on the other hand dug out zircon ores which are heaped in at a certain area. Then the collected zircon ores are transported to the nearby processing plants by trucks or bulldozers.

Dredge mining is employed in the areas where the zircon ore deposits are below the water table. In dredge mining, the zircon ores are excavated from water bodies by continuous bucket railing from the surface. The bucket stocks up zircon sands inside the water body and moves to the initial processing plant where zircon is separated leaving the tailings which are moved back inside the water and filled by the same railing buckets.

Processing and extraction:

The zircon composing ores from open pit mining are milled and crushed. The zircon is separated by magnetic separation method. In magnetic separation method the metallic ores and non metallic ores are separated based on their magnetic property in which zircon is collected as metallic ore separating itself from the non metallic impurities like quartz, clay and dirt.

HfCl4 + 2 Mg (1100 ?C) ? 2 MgCl2 + Hf

The zircon sands from the alluvial deposits and beaches are directly employed mechanical separation for isolating zircon from tailings of quartz and clay. The mechanical separation method separates the components based on the weight and density.The zircon from the wet deposits is separated by wet spiral separators. In wet spiral separators the separation is done by weight and speed of the sliding materials.

In wet spiral separators the separation is done by weight and speed of the sliding materials.Hafnium producing nations are Australia, South Africa, China, Brazil, Malawi and India.

Definition:

Hafnium is a chemical component with the symbol Hf and atomic number 72. A shiny, silvery gray, tetravalent conversion metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its survival was predicted by Dmitri Mendeleev in 1869. Hafnium was the second-to-last element of those with stable isotopes to be discovered. It was found by Dirk Coster and Georg von Hevesy in 1923 in Copenhagen, Denmark, and named Hafnia after the Latin name for "Copenhagen".

Properties:

Hafnium is a shiny, silvery, ductile metal that is corrosion-resistant and chemically similar to zirconium. The physical properties of hafnium metal sample are noticeably affected by zirconium impurities, as these two elements are among the most difficult ones to separate because of their chemical similarity. A prominent physical difference between them is their density.

Application:

Hafnium is predictable to make up about 5.8 ppm of the Earth's upper crust by weight. It does not survive as a free element in nature, but is found combined in solid solution for zirconium in natural zirconium compounds such as zircon, ZrSiO4, which usually has a about 1 - 4 % of the Zr replaced by Hf.