Tag: extraction of metal from concentrated ore

Dressing of ore can be carried out by first handpicking followed by crushing and grinding and then pulverization.

Formula of Limonite is $F _eO(OH)\cdot nH _2O$. It is an oxide ore.

Smelting is the process where heat is applied to ore to extract the base metal, using a reducing agent. So, it is used to carry out reduction of metal oxides to metal by heating with coke.

Cinnabar ($HgS$), when heated with a current of $O _2$ gets reduced to $Hg$ without the need of any additional reducing agent. The process involved is known as self reduction

Oxides of highly reactive metals cannot be reduced by $CO$. Hence $CaO$ and $Al _2O _3$ are not reduced by $CO$ and both $ZnO $ and $Fe _2O _3$ are reduced by $CO$

The alkali halides crystallize in the NaCl structure also known as rock-salt structure (rock salt is the mineral form of sodium chloride); exceptions being CsCl, CsBr, and CsI, which crystallize in the CsCl structure. In the NaCl structure (face-centered cubic lattice), each cation is surrounding by six anions, and vice versa (coordination number of 6). In the CsCl structure, each cation is surrounded by eight anions and vice versa (coordination number of 8).

These are the methods for extraction of metals from oxide ores:
Carbon reduction, involving reduction with CO or C
Self reduction
Thermite reduction, which employs Al
Electrolytic reduction.

The advantage(s) of using carbon to reduced a number of oxides and other compounds are
 (i) easy availability of coke.
 (ii) low cost of carbon.
 (iii) exothermic nature of reaction which requires less energy to keep the furnace hot.

During extraction of metals from oxide ores, the reduction of metal ore to crude metal can be carried out by using several methods such as pyrometallurgy, hydrometallurgy and electrometallurgy. Various reducing agents such as carbon, hydrogen, aluminum or other metals can be used. CO also reduces metal ores to crude metals.