Major economic minerals require for production of metals:

Major economic minerals require for production of metals:

Earth crust consists of rocks, and all the rocks have minerals. An ore is a rock containing metalliferous minerals of economic value, are mined for profitable extraction of metals. Ore is formed by concentration of low-abundance elements. 99% of the Earth’s crust is made up of oxygen, silica, aluminum, iron, calcium, sodium, potassium, magnesium and titanium. These are called major elements.

Many other elements are useful in modern society. Concentration of these elements in average crust is very small (all together they’re only 1%). Geologic processes are must to concentrate these elements hundreds to thousands of times to make ore. Most ore minerals belong to these four non-silicate mineral groups: (i) Native Elements (none); (ii) Sulfides (S); (iii) Oxides (O2); (iv) Hydroxides (OH). Examples are given below:

(i) Native Elements:

• Metals - metallic bonds, metallic luster

• Semimetals - have some, but not all, properties of metals: arsenic, antimony and bismuth

• Non-metals - covalent bonding, lack metallic properties

Principal Native Metals

• Gold (Au)

• Silver (Ag)

• Copper (Cu)

• Platinum (Pt, rarest and most valuable)

Native Non-metals

• Sulfur (S)

• Graphite (C) – Low pressure polymorph of Carbon

• Diamond (C) – High pressure polymorph of Carbon >30kbar, – Formed deep in the Earth’s mantle >90km, – Brought to the surface by violent, explosive igneous eruptions of magmas called kimberlites

(ii) Common Sulfide Minerals (reduced, formed in low oxygen environments)

• Pyrite (FeS2) Grows in cubes.

• Chalcopyrite (CuFeS2) is the most important ore mineral of Copper.

• Sphalerite (ZnS) is the most important ore mineral of zinc.

• Galena (PbS) is the most important ore mineral of Pb (lead).

(iii) Common Oxide Minerals (oxidized, formed in hi oxygen environments)

• Magnetite (Fe3O4)

• Hematite (Fe2O3)

• Zincite (ZnO)

• Franklinite (ZnFe2O4)

• Pyrolusite (MnO2)

• Chromite (FeCr2O4)

• Cassiterite (SnO2)

Hematite (Fe2O3) and Magnetite (Fe3O4) are Fe (iron) ores

Hematite and Magnetite occur together with red chert in BIFs

(iv) Common Hydroxide Minerals

• Goethite FeO(OH)

• Al hydroxides - gibbsite Al(OH)3, boehmite AlO(OH), diaspore AlO(OH),

Together these make up bauxite (actually a rock name, multiple minerals), the most important Aluminum ore.